JPH10187568A - Method for macro state determination, check point setting and re-execution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a macro state without transmitting any control message to all network channels and to enable application to a system having passing of message. SOLUTION: Respective processors (PE) (PEA-PEC) mutually exchange ordinary messages. A determination process defines the state of system at a certain time point as the macro state. The determination process 1, PE and ordinary messages are respectively weighted and controlled so as to be fixed values when all the weight is added. Under the weight control, the absence of ordinary message on a network is detected and the macro state is determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a global state determination, checkpoint setting, and re-execution method in a multiprocessor system that performs inter-processor processing by asynchronous message communication.

[0002]

2. Description of the Related Art First, the following calculation model is considered. First, it is assumed that a finite number of processors (hereinafter abbreviated as PEs) are connected by a network channel. Thus, a multiprocessor system is configured. Each PE communicates with each other by asynchronous message communication.
There is no clock to control the whole system, and each PE and network channel operate individually according to each clock. There is a special process for determining the global state (called the decision process). The decision process can communicate with all PEs. Here, the global state is "a set of states of all PEs and states of all network channels". The state of a certain network channel is “a set of messages on the network channel”. To determine the global state,
"To find a consistent state in a certain situation." It is not to “find the state at a certain moment”. Since there is no clock to control the whole system, each P
This is because there is no time common to E and the network channel.

This global state will be described in more detail with reference to FIGS. FIG. 2 shows a conceptual diagram of the multiprocessor system. As shown, three PEs are connected by four network channels. PEA and PEC, and P
EB and PEC are connected by a bidirectional channel.
There is no channel between EA and PEB. A network channel is a logical communication path established on a communication line.

FIG. 3 shows an example of message transmission / reception and PE state change on such a system.
In (a), PEA sends message M0 to PEC. After transmission, the state of PEA is A0. In (b), as a result of receiving M0, the PEC changes its own PE state from C0 to C1, and furthermore, the message M1 is changed to PEB.
Sent to On the other hand, the state of PEA changed from A0 to A1 as a result of processing in the own PE. In (c), PEB
As a result of receiving M1, the state of its own PE has changed from B0 to B1. When the process of obtaining the global state is started after observing the state of (a), for example, any of the following five may be obtained.

(1) @PEA: A0, PEB: B0, P
EC: C0, CHAC: M0 (2) {PEA: A0, PEB: B0, PEC: C1,
CHCB: M1 (3) {PEA: A1, PEB: B0, PEC: C1,
(4) {PEA: A0, PEB: B1, PEC: C1} (5) {PEA: A1, PEB: B1, PEC: C1}

[0006] PEA :, PEB :, PEC: indicate the state of PEA, the state of PEB, and the state of PEC, respectively.
CHAC: means "message sent by PEA to PEC but not yet arrived at PEC". This is the state of the network channel from PEA to PEC
It is. Similarly, CHCB: is the state of the network channel from PEC to PEB. (1) in (a),
(3) corresponds to (b), and (5) corresponds to (c).
(2) and (4) differ from (3) and (5) only in the state of PEA. The PEAs in (2) and (4) indicate before the state change, and the PEAs in (3) and (5) indicate after the state change. Since the state change of PEA from A0 to A1 is independent of the others, both (2) and (4) are correct.

On the other hand, the following two are not correct. (6) @PEA: A0, PEB: B0, PEC: C1,
CHAC: M0, CHCB: M1 (7) {PEA: A0, PEB: B0, PEC: C0} (6) The CHAC indicates that the message M0 still exists on the network channel, ,
CHCB indicates the state after M0 has been received. (7) is incorrect in the opposite respect to (6). PEB
Shows the state before receiving M0, but M0 does not exist in the CHAC.

[0008] It is now commonplace to build a system on parallel computers or "computers connected by a network". When a program is developed in such a system, it is necessary to examine the state of the PE and the message on the network at some timing (that is, determine the global state). This corresponds to suspending the execution of the program under development and examining the contents of registers and memories when developing a program in a system on a single PE. Thus, the determination of the global state is an indispensable function for a system on a group of computers connected by a parallel computer or a network.

[0009] In the following description of the prior art, a normal message and a control message are used in the following meaning. Normal message: Message for normal processing,
PEs transmit and receive from each other. Control message: message for determining the global state,
The decision process and the PEs communicate with each other.

The following document describes a method for determining the global state by sending a control message that acts to "remove normal messages from a network channel" to all network channels. Chandy, K.
M. and Lamport, L., “Distributed Snapshots: Deter
mining Global States of Distributed Systems, ”ACM
Transactions on Computer Systems, Vol.3, No.1, pp.
63-75, 1985.

[0011]

However, the above-mentioned conventional global state determination method has the following problems to be solved. In the above example, control messages are sent to all network channels in order to expel normal messages from the network channels. Therefore, it is necessary to transmit a number of control messages in proportion to the number of network channels not only between the decision process and the PEs, but also between the PEs. In addition, since it is assumed that messages are received in the order in which they are transmitted, the system cannot be applied to a system in which messages are overtaken. If there is a possibility that the control message will overtake the normal message, even if a certain control message is received, it cannot be said that all the normal messages transmitted before the control message have been received.

[0012]

The present invention employs the following structure to solve the above problems. <Structure 1> In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. It operates under the control of its own clock. There is a determination process for performing a process of determining the global state of the system, and this determination process has a weight for canceling the sum of the weight of the normal message transmitted from each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value.
A message transmitted and received between the decision process and each processor to determine the global state is called a control message, and the decision process has a global state buffer for storing the determined global state. Each processor stores a message switch that indicates which control message corresponds to the corresponding state, a state buffer that stores its own state, a receive buffer that stores received normal messages, and stores a normal message that is pending transmission. The message switch is initialized to notRecorded, indicating that nothing is stored in the buffer. The decision process clears the global state buffer, transmits a record control message instructing to suspend the transmission of the normal message to all processors with a predetermined weight, and transmits its own weight by the weight. Reduce. Processor is a record
When a control message is received, its status is stored in a status buffer, and its own weight and the sum of the weights attached to the record control message are returned.
The control message is sent to the decision process, the message switch is set to "recorded" indicating that the transmission of the normal message is suspended, and the reception buffer and the transmission buffer are cleared. After that, when the message switch is recorded, the processor, upon receiving the normal message, stores a copy of the normal message in a reception buffer, and each time,
Return the weight attached to the normal message (retu
rn) The control message is transmitted to the decision process, and the normal message to be transmitted is suspended from transmission and stored in the transmission buffer. Upon receiving a return control message from the processor, the decision process adds the weight attached to the return control message to its own weight, and when the result becomes a constant value obtained by adding all the above weights, , Send a request control message for a stored data request to all processors. When each processor receives the request control message, it sends the contents of its own status buffer and the contents of the reception buffer to the decision process in the form of an answer control message, and sends a message switch indicating that the stored data transmission has been completed. (Ready). The decision process is based on the answer (an
swer) When receiving the control message, the answer (an
swer) The contents of the status buffer carried by the control message and the contents of the reception buffer are stored in the global state buffer, and when an answer (answer) control message is received from all processors, a restart (res
tart) The control message is weighted and sent to all processors, and its weight is reduced by the weight. When each processor receives a restart control message, it adds the weight attached to the restart control message to its own weight, and sends the normal message if it is stored in the transmission buffer. And
If the message switch is ready, the message switch is set to notRecorded and the operation is resumed (started).
rted) send a control message to the decision process. The decision process is started from all processors (sta
rted) When the control message is received, the process is completed and the contents of the global state buffer are determined.

<Description> Asynchronous message communication refers to a communication method in which each processor transmits and receives messages without synchronizing with each other, and the number of processors is arbitrary. The network channel is a logical communication path on a line provided between processors. The global state refers to the consistent state of the system at any time. Normal messages are messages transmitted and received between processors. A decision process, a processor,
Each normal message transmitted by each processor is assigned a numerical weight. The processor that has transmitted the normal message decreases its own weight, and the processor that has received the normal message increases its own weight. The sum of all these weights, including that of the decision process, will always be constant. This weighting is used because if the decision process receives a constant value from each processor when the weight becomes constant, it can be confirmed that the message is no longer present on the network channel regardless of whether the message has passed or not. is there.

The cancellation means that the sum of the weights of the processor and the normal message transmitted by each processor is
This includes the case where the sign of the weight of the decision process is opposite to the sign and the absolute value is equal, and the case where the sum with the weight of the decision process becomes a constant value other than zero. The global state buffer collects and stores the state of each processor and the state of messages transmitted and received. The message switch is normally not Recorded, and during the process of determining the global state, it is recorded and ready.
And finally changed again not record (notRecord
Return to ed).

After receiving a record control message, the processor does not send the normal message to other processors. Once, there is usually no message present on the network channel to determine the global state. The transmission buffer is provided for holding a normal message to be transmitted in this case. The receiving buffer is for storing a copy of the received normal message so that the status of the network channel can be returned when a request is received from the decision process. The weights of the record control messages are provided so that it can be confirmed that all record control messages have arrived at their respective destination processors.

When the processor receives the record control message, it stores its state in the state buffer in order to inform the decision process later of its current state as its state in the global state. is there. Therefore, the internal processing for the subsequently received normal message may be executed. However, all the received normal messages are in the state of the network channel,
It is stored in the reception buffer, and later notified to the decision process. The reason for not notifying the decision process of the contents of the transmit buffer is that it occurs after the desired global state. The processor informs the decision process of the weight of the received normal message so that the cancellation can confirm that the normal message is no longer present on the network channel. When the decision process receives a return control message from the processor, it adds the weight attached to it to its own weight. When the added result becomes a constant value when all the weights are added, it can be confirmed that there is no normal message on the network channel. As a result, if a state notification is received from each processor, a consistent global state is obtained.

The restart control message is a message indicating to each processor that operation is restarted.
After receiving the control message, each processor resumes normal operation. Putting the ready state before transitioning from the recorded state to the notRecorded state is because the processor that has not reported its state to the decision process has already finished reporting to the decision process. This is to prevent a new normal message from being transmitted from the processor that has resumed the operation of the above, thereby causing inconsistency in the state. Each processor is restarted
The message switch is ready (read
Wait in the state of y). In this state, transmission of the normal message is still suspended and stored in the transmission buffer. Therefore, when the operation is resumed, they are sent to empty the buffer, and the message switch is set to not record (n
otRecorded).

In the twelfth paragraph, the expression "if the message switch is ready" means that each processor restarts the termination of the global state determination processing (r
estart) before receiving the control message, in which case, as shown in Configuration 6, the restart (resta
rt) This is because the message switch may already be set to notRecorded when the control message is received.

<Structure 2> In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. Operate under the control of their own clocks. There is a determination process for performing a process of determining the global state of the system, and this determination process has a weight for canceling the sum of the weight of the normal message transmitted from each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value. A message transmitted and received between the decision process and each processor to determine the global state is called a control message, and the decision process has a global state buffer for storing the determined global state. Each processor:
It has a message switch that indicates which control message it is in, and a transmission buffer that stores normal messages that are pending transmission. The message switch is initially set to notRecorded, indicating that nothing is stored in the buffer, and the decision process clears the global state buffer and records (instructing to suspend normal message transmission). record) A control message is transmitted with a predetermined weight to all processors, and its own weight is reduced by the weight. When the processor receives the record control message,
Return the sum of the weight of the self and the weight attached to the record control message and the state of the self (retur
n) Send to the decision process in a control message, set the message switch to recorded, indicating a state where normal message transmission is suspended, and clear the transmission buffer. Thereafter, when the processor whose message switch has been recorded receives the normal message, the processor sends a copy of the normal message and the weight attached thereto to the return control message each time and sends it to the decision process. The transmission of the normal message to be transmitted is suspended and stored in the transmission buffer. Upon receiving a return control message from the processor, the decision process stores a copy of the state or normal message of each processor carried by the return control message in a global state buffer, and returns the return control message. Is added to its own weight, and if the result becomes a constant value when all the weights are added, the procedure (procee
d) Send control messages to all processors. When each processor receives the proceed control message, it sends a proceed control message to the decision process and sets the message switch to ready. When the decision process receives a proceeded control message from all processors, a restart (res
tart) Control messages are weighted and sent to all processors, and their weight is reduced by the weight. When each processor receives the restart control message, it adds the weight attached to the restart control message to its own weight, and if the message switch is ready, the not record (not).
Recorded), and sends a started control message indicating that the operation has been resumed to the decision process, and if a normal message is stored in the transmission buffer, transmits them. The determination process completes the processing when a started control message is received from all processors, and determines the contents of the global state buffer.

<Explanation> The difference from the configuration 1 is that the status of the processor is immediately notified to the decision process side in response to a record control message, and thereafter, a copy of the normal message received by the processor is sent to the decision process each time. The point is to be notified to the side. That is, the record (reco
rd) After receiving the control message, the processor will voluntarily notify the decision process of the global state,
It is not necessary to send a set of normal message copies according to the request from the decision process side as in the configuration 1. The processor normally sends a copy of the message to the decision process upon receipt, so there is no need to store a copy of the received communication message. The state of the processor does not need to be stored because it is sent when a record control message is received from the decision process. Therefore, although the transmission buffer is provided on the processor side, the status buffer and the reception buffer are not required. Unlike the request control message of Configuration 1, the proceed control message does not request data for global state determination from each PE, but
From the recorded state to ready
The point used for the purpose of making a state is common.

That is, even if the decision process grasps the state,
As soon as a restart status message is sent, a new normal message sent from the processor on which the message arrives arrives on a processor whose status is not yet known (recorded). The decision process is notified. Since the decision process has already determined the global state, the notification may be ignored. However, when subsequently trying to find the next global state, the weight of the ignored normal message hinders the calculation of the sum of the weights in the subsequent decision process. That is, it is meaningful to provide this (ready) state when repeatedly trying to obtain the global state.

<Structure 3> In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. Operate under the control of their own clocks. There is a determination process for performing a process of determining the global state of the system, and this determination process has a weight for canceling the sum of the weight of the normal message transmitted from each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value. A message transmitted and received between the decision process and each processor to determine the global state is called a control message, and the decision process has a global state buffer for storing the determined global state. Each processor:
A message switch for indicating which control message is in a corresponding state, and a transmission buffer for storing a normal message pending transmission, the message switch not indicating that no message is stored in the buffer Initialized to (notRecorded). The decision process clears the global state buffer, transmits a record control message instructing to suspend the transmission of the normal message to all processors with a predetermined weight, and transmits its own weight by the weight. Reduce. When the processor receives the record control message, it sends the sum of its own weight and the weight attached to the record control message to a return control message to the decision process, and sends a message switch to the normal message. Set to "recorded", which indicates a state where transmission is suspended, and clear the transmission buffer. After that, the message switch is
When the processor that has become corded receives the normal message, it sends the weight attached to the normal message to the decision process with the return control message added thereto each time. Store in transmission buffer. The decision process, upon receiving a return control message from the processor, adds the weight attached to the return control message to its own weight, and the result is a constant value obtained by adding all the weights. If so, send a request control message to all processors. When each processor receives the request control message, it sends its state and the contents of the transmission buffer to the decision process in an answer control message, and sets the message switch to ready. Upon receiving an answer (answer) control message, the decision process stores the state of the processor carried by the answer (answer) control message and the contents of the transmission buffer in a global state buffer, and receives an answer (answer) from all processors. When a control message is received, a restart control message for instructing restart of operation is weighted and sent to all processors, and its own weight is reduced by the weight. When each processor receives the restart control message, it adds the weight attached to the restart control message to its own weight, and the message switch reads the ready (read) message.
If it is y), it is set to not Recorded (notRecorded), indicating that operation has been resumed (starte
d) Send control messages to the decision process and send regular messages if they are stored in the send buffer. The determination process is characterized in that when a started control message is received from all processors, the process is completed and the contents of the global state buffer are determined.

<Explanation> In the configuration 3, the request (reques
t) The state of each processor when receiving the control message is the state of each processor in the global state. Until that time, each processor holds a normal message to be transmitted to the network in a transmission buffer and notifies the decision process collectively. Therefore, before that, only information about the weights is gathered in the decision process and it is usually monitored whether the message is present in the network. Therefore, in the case of this configuration, traffic accompanying frequent status reports and the like is reduced. Although the number of return control messages that the processor sends to the decision process does not change, each return control message carries only a weight, so the data traffic due to the return control message is very small.

<Structure 4> In a multiprocessor system in which interprocessor processing is performed by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. Operate under the control of their own clocks. There is a determination process for performing a process of determining the global state of the system, and this determination process has a weight for canceling the sum of the weight of the normal message transmitted from each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value. A message transmitted and received between the decision process and each processor to determine the global state is called a control message, and the decision process has a global state buffer for storing the determined global state and a reception counter for counting the number of received messages. . Each processor has a message switch for indicating which control message corresponds to the state, a transmission buffer for storing a normal message pending transmission, and a transmission counter for counting the number of message transmissions. Not Recorded (notRecorded)
Initially set to The decision process clears the global state buffer and the reception counter, sends a record control message indicating that the transmission of the normal message is suspended to all processors with a predetermined weight,
The self weight is reduced by the weight. The processor is
When a record control message is received, the sum of its own weight and the weight attached to the record control message is added to a return control message and sent to a decision process, and the message switch sends a normal message. Set to "recorded" to indicate the status to hold, and clear the transmission buffer and transmission counter. Thereafter, when the processor whose message switch has been recorded receives the normal message, the processor sends the weight attached to the normal message to the decision process in a return control message each time, and transmits the normal message. The transmission is suspended and stored in the transmission buffer, and a copy of the normal message is sent to the decision process in a report control message, and the transmission counter is incremented.
Upon receiving a report control message from the processor, the decision process stores a copy of the normal message carried by the report control message in a global state buffer, increments a reception counter, and returns control. When you receive a message,
If the weight added to the return control message is added to its own weight, and the result becomes a constant value when all the weights are added, the request control message is changed to all the weights. Send to processor. When each processor receives the request control message, it sends the contents of the transmission counter and its state to the decision process in an answer control message, and sets the message switch to ready. The decision process is based on the answer from the processor (answe
r) When a control message is received, the answer (answe)
r) The state of the processor carried by the control message is stored in the global state buffer, the reception counter is reduced by the number of transmission counters carried by the answer control message, and the answer control message is sent from all processors. Is received, and when the value of the reception counter is cleared, the restart control message instructing the restart of operation is weighted and sent to all processors, and the weight of the self-restart control message is transmitted to all processors. Reduce weight.
When each processor receives the restart control message, the weight added to the restart control message is added to its own weight. And sends a started control message indicating that the operation has been resumed to the decision process and, if normal messages are stored in the transmission buffer, transmits them. The decision process is
The process is completed when a started control message is received from all processors, and the contents of the global state buffer are determined.

<Explanation> Each processor has a transmission buffer in order to suspend transmission of a normal message on a network channel. Like the previous configuration,
The decision process, the processor, and the weighting of the normal message are performed so that the decision process side can confirm that the normal message on the network channel has disappeared.

The reason for sending the contents of the transmission buffer to the decision process is to make it the state of the network channel. In the configuration 4, the contents of the transmission buffer are spontaneously transmitted to the decision process without waiting for a request from the decision process. The reason why the reception counter is provided on the decision process side and the transmission counter is provided on the processor side is to confirm that all report control messages transmitted from the processor to the decision process have arrived at the decision process. This is because if the answer control message overtakes the report control message, an inconsistent global state will be determined.

When the weighted result becomes zero, it is recognized that there is no longer a normal message on the network channel. The processor requests
When receiving the control message, it reports its status to the decision process. That is, the state of the processor at the time of receiving the request control message becomes the state of the processor in the global state, and the set of normal messages transmitted up to that point becomes the state of the network channel. The restart control message, similar to configurations 1 to 3, serves to indicate to each processor that the operation should be restarted.

<Structure 5> In a multiprocessor system in which interprocessor processing is performed by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. Operate under the control of their own clocks. There is a determination process for performing a process of determining the global state of the system, and this determination process has a weight for canceling the sum of the weight of the normal message transmitted from each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value. A message transmitted and received between the decision process and each processor to determine the global state is called a control message, and the decision process has a global state buffer for storing the determined global state. Each processor:
A message switch for indicating which control message is in a corresponding state, and a transmission buffer for storing a normal message pending transmission, the message switch not indicating that no message is stored in the buffer Initialized to (notRecorded). The decision process clears the global state buffer, transmits a record control message instructing to suspend the transmission of the normal message to all processors with a predetermined weight, and transmits its own weight by the weight. Reduce. When the processor receives the record control message, it sends the sum of its own weight and the weight attached to the record control message to a return control message to the decision process, and sends a message switch to the normal message. Set to "recorded", which indicates a state where transmission is suspended, and clear the transmission buffer. After that, the message switch is
When the processor that has become corded receives the normal message, it sends the weight attached to the normal message to the decision process with the return control message added thereto each time. Store it in the transmit buffer and send a copy of the normal message to the decision process in a report control message. Upon receiving a report control message from the processor, the decision process stores a copy of the normal message carried by the report control message in a global state buffer and returns (re)
turn) control message, the return (re
turn) The weight attached to the control message is added to its own weight, and when the result becomes a constant value when all the weights are added, a request control message is sent to all processors. . Each processor:
Upon receiving a request control message,
Sends its state to the decision process with an answer control message and sets the message switch to ready. When the decision process receives an answer (answer) control message from a processor, it stores the received processor state in the global state buffer together with the answer (answer) control message, and receives an answer (answer) control message from all processors. Then, restart (resta
rt) The control message is weighted and sent to all processors, and its weight is reduced by the weight. When each processor receives the restart control message, it adds the weight attached to the restart control message to its own weight.
set to corded) and send a started control message to the decision process to indicate that it has resumed operation, and send them if the transmit buffer contains normal messages. The determination process is characterized in that when a started control message is received from all processors, the process is completed and the contents of the global state buffer are determined.

<Explanation> This configuration is adopted in the case of the configuration 4 where it is guaranteed that the answer control message does not overtake the report control message. Since the reception counter and the transmission counter become unnecessary, the configuration is simplified.

<Structure 6> In the structure 1, 2, 3, 4 or 5, when a processor whose message switch is ready receives a normal message from another processor, the processor switches its own message switch to a notre. It is characterized in that it is codeted (notRecorded) and normal operation is resumed.

<Explanation> If each processor detects that the decision process has transmitted a restart control message by any means, the respective processors operate normally even if they do not receive the restart control message. May be resumed. Each processor resumes normal message transmission upon receiving a restart control message from the decision process. Thus, the arrival of the normal message from the other processor is evidence that one of the processors has received a restart control message from the decision process and has resumed normal operation. Therefore, the operation is restarted without waiting for the arrival of a restart control message from the decision process. In this way, it is possible to indirectly know that the global state determination processing has been completed.

<Structure 7> In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. Operate under the control of their own clocks. There is a determination process for determining the global state of the system, and the determination process has a weight for canceling the sum of the weight of the normal message transmitted by each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value. A message transmitted and received between the decision process and each processor to determine the global state is called a control message. The decision process includes a global state buffer for storing the determined global state, and an old state buffer for counting the weight of the old generation. It has a generation weight counter. The decision process clears the global state buffer, sets its own weight in the old generation weight counter, sets its own weight to the above-mentioned constant value, advances the generation by one, and notifies the request to notify the state. The control message is transmitted to all processors with a predetermined weight, and the weight of the processor is reduced by the weight. Each processor sends a request (reque
st) When a control message is received, the request (r
equest) comparing the weight generation of the control message with the generation of its own weight, and if the generation of the weight of the request control message is newer, return its state and its own weight to the return control message. To the decision process, set the weight of the request control message to its own weight, and if both are the same, add the weight of the request control message to its own weight; Compare the normal message weight generation with its own weight generation.If both are the same, add the normal message weight to its own weight.If the own weight generation is newer, copy the normal message and the normal message copy. Return message weight and return
Send to the decision process with the control message, usually if the message generation is newer, send its status and weight in the return control message to the decision process,
Set the weight of the normal message to its own weight. When the decision process receives the return control message, the weight attached to the return control message is added to the old generation weight counter, and the state of each processor added to the return control message and the normal message Store the copy in the global state buffer. When the value of the old generation weight counter reaches the above-mentioned constant value, the contents of the global state buffer at that time are determined to be the global state.

<Explanation> The initial value of the weight of the decision process is
It may be zero or a preset constant value. The decision process is based on advanced generations of weighted requests (reques
t) After transmitting the control message, the weight of the new generation is subsequently used for transmitting the normal message and the like. The process group having the weight of the previous generation and the normal message group constitute a global state, and these are collected by a return control message. Completion of the collection can be confirmed by the value of the old generation weight counter becoming a constant value, for example, zero.

<Configuration 8> In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. Operate under the control of their own clocks. There is a determination process for determining the global state of the system, and the determination process has a weight for canceling the sum of the weight of the normal message transmitted by each processor to another processor and the weight of the processor. , The system is controlled so that when all these weights are added, the weight becomes a constant value. A message transmitted and received between the decision process and each processor to determine the global state is called a control message. The decision process includes a global state buffer for storing the determined global state, and an old state buffer for counting the weight of the old generation. It has a generation weight counter. The decision process clears the global state buffer, sets its own weight in the old generation weight counter, sets its own weight to the above-mentioned constant value, advances the generation by one, and instructs to save the state. The control message is transmitted to all processors with a predetermined weight, and the weight of the processor is reduced by the weight. Each processor has a state buffer for storing its own state, and upon receiving a record control message, compares the generation of the weight of the record control message with the generation of its own weight, If the generation of the weight of the record control message is new, store its state in the state buffer,
The weight of the record control message is set to its own weight, and the weight of the record control message is set to its own weight. When a normal message is received in addition to the weight, the generation of the weight of the normal message is compared with the generation of its own weight. If both are the same, the weight of the normal message is added to its own weight, and the generation of its own weight is added. Is newer, a copy of the normal message is stored in the status buffer, the weight of the normal message is appended to the return control message, and sent to the decision process.
It stores its state in the state buffer, sends its weight to the decision process in a return control message, and sets the weight of the normal message to its weight. When the decision process receives the return control message, it adds the weight attached to the return control message to the old generation weight counter. When the value of the old generation weight counter reaches the above-mentioned fixed value, the decision process sends a request control message to all processors, and when each processor receives the request control message, it stores it in the status buffer. The state of the self and the copy of the normal message
swer) The control message is sent to the decision process, and the status buffer is cleared. The decision process is based on the answer (answ
er) Store the state of each processor added to the control message and a copy of the normal message in the global state buffer. When an answer (answer) control message is received from all processors, the contents of the global state buffer at that time are read. It is characterized in that it is determined to be in a global state.

<Explanation> The difference from the configuration 7 is that, in the configuration 8, when the weight of the previous generation is returned to the determination process, the state of the processor and a copy of the normal message are stored in the processor and the determination process is performed. The point is to send at once according to the request.

<Structure 9> The structure 7 or 8 is characterized in that three or more kinds of symbols whose order is relatively clear are used as the generation to be added to each weight.

<Explanation> The fact that the order is relatively clear means that, when the two are compared, it is possible to judge the old and new without any other information according to a predetermined criterion. Therefore, 3
Combinations of more than one symbol are suitable. The contents are arbitrary.

<Structure 10> A finite number of processor groups (hereinafter referred to as PE groups) are connected to each other via a network. The PE groups communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. , Each PE and network channel operate independently according to their clocks, each PE can send messages to other PEs, record their status and received messages, and set checkpoints. There is a special process (called a control process) for issuing an instruction, the control process and all the PEs can perform message communication with each other, and a message transmitted and received between the PEs for normal processing is called a normal message. Messages sent and received by the control process and the PEs to set checkpoints Is called a control message, the control process, the PE and the message have a weight, the sum of all the weights takes a predetermined constant value, the weight has a generation, and all the weights are initialized to the same generation. Each PE has a state buffer, and the control process performs a checkpoint control message (hereinafter, ch.
eckpoint) to all PEs, wait until a checkpoint recognition (ackCheckpoint) control message (hereinafter ackCheckpoint) is received from all PEs, set their own weight in the old generation weight counter, and Set the weight to a certain fixed value, advance the generation of one's own weight by one, and send a record control message (hereinafter referred to as record) to all PEs. Is reduced by that amount, PE is ch
When the eckpoint is received, the status buffer is cleared and ackC
When heckpoint is returned to the control process and record is received, "the generation of the weight held by the record" is compared with "the generation of its own weight". In the status buffer, send its own weight to the control process with a return control message (hereinafter referred to as "return"), reset its own weight with the weight of record,
If the two generations are equal, the weight of record is added to its own weight, and upon receiving the normal message, the PE compares "the generation of the weight that the normal message has" with "the generation of its own weight", If the “own weight generation” is new, the normal message weight is sent to the control process by return, the contents of the normal message are recorded in the status buffer, the normal message is processed, and the “normal message weight generation” is new. If so, send your weight to the control process with return, record your state in the state buffer, reset your weight with the weight of the normal message, process the normal message, and if the two generations are equal, Adds the weight of the normal message to its own weight, processes the normal message, and when the control process receives the return, it returns the weight carried by the return to the old generation weight counter. As a result, when the value of the old generation weight counter reaches a certain fixed value, it is confirmed that the setting of the checkpoint has been completed, and a set of the contents of the state buffer of each PE at the time of confirming the completion. A checkpoint setting method.

<Explanation> The sum of the weights of the control process, the PE, and the message is a predetermined constant value, which is set in advance to an arbitrary value.

<Configuration 11> A finite number of processor groups (hereinafter, referred to as PE groups) are connected to each other via a network. The PE groups communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. , Each PE and network channel operate independently according to their respective clocks, and each PE can send messages to other PEs, record their status and received messages, set checkpoints and There is a special process (called a control process) that issues a re-execution instruction. The control process and all the PEs can perform message communication with each other. Called a message, the control process and PEs send each other to set a checkpoint and re-execute. The message to be transmitted is called a control message, the control process, the PE and the message have a weight, the sum of all the weights takes a predetermined constant value, the weight has a generation, and all the weights are initialized to the same generation, The control process has an old-generation weight counter, each PE has a status flag and a status buffer, and the status flag takes only one of the value C indicating that a checkpoint is being set and the value R indicating that the process is being re-executed. In order to perform checkpoint setting, a checkpoint control message (hereinafter referred to as checkpoint) is transmitted to all PEs, and checkpoint recognition (ackCheckpo) is performed from all PEs.
int) Wait until a control message (hereinafter referred to as ackCheckpoint) is received, set its own weight in the old generation weight counter, set its own weight to a certain fixed value, advance its own weight by one generation, Sends a record control message (hereinafter referred to as record) to all PEs, assigns a weight to the record, reduces its own weight by that amount, and when the PE receives the checkpoint, sets the status flag to C Returns an ackCheckpoint to the control process,
When a record is received, the "generation of the weight held by record" is compared with the "generation of its own weight". If the "generation of the weight of record" is new, the status buffer is cleared and the status of one's own is cleared. Record in buffer and return own weight
Send it to the control process with a control message (hereinafter referred to as return), reset its own weight with the weight of record, and if the two generations are equal, add the weight of record to its own weight,
Upon receiving the return, the control process adds the weight carried by the return to the old generation weight counter, and when the value of the old generation weight counter reaches a certain fixed value, the checkpoint setting is completed. It is confirmed that the control process is ready for re-execution (roll
back) sends a control message (hereinafter referred to as “rollback”) to all PEs, waits until a re-execution readiness (ackRollback) control message (hereinafter referred to as “ackRollback”) is received from all PEs, and stores the old generation weight counter in the old generation weight counter. Set the weights, set their own weights to a certain fixed value, advance their own weights by one, send a re-execute control message (hereinafter called execute) to all PEs, and Weights, and reduces its own weight by that amount. When the PE receives the rollback, it sets the status flag to R, sends ackRollback to the control process, and receives the reexecute. The generation and the generation of their own weight are compared.
If the "generation of the weight of execute" is new, reset your own state with the contents of the state buffer and return your own weight.
To the control process, reset its own weight with the reexecute weight, and if the two generations are equal, execute
When the control process receives the return, the control process adds the weight carried by the return to the old generation weight counter, and as a result, the value of the old generation weight counter becomes a certain fixed value. Then, the start of the re-execution can be confirmed to be completed, and the PE receives the normal message,
Compare the "generation of the weight that the normal message has" with the "generation of its own weight". If the "own weight generation" is new and the status flag is C, return the weight of the normal message.
To send to the control process, record the contents of the normal message in the status buffer, process the normal message, and if the "own weight generation" is new and the status flag is R, send the weight of the normal message to the control process by return Normal message is discarded without processing. If "normal message weight generation" is new and status flag is C, clear status buffer, record own status in status buffer, and control own weight by return. Sends to the process, resets its own weight with the weight of the normal message, processes the normal message, and if the "generation of normal message weight" is new and the status flag is R, sets its own status with the contents of the status buffer Reset, send your weight to the control process with return, reset your weight with the weight of the normal message, process the normal message, If generations are equal, adding the weight of normal messages to their weight, usually checkpointing and redo wherein processing the message.

<Explanation> The state flag only needs to be able to distinguish between the checkpoint setting and the re-execution.

<Structure 12> A finite number of processors (hereinafter referred to as PEs) are connected to each other via a network. The PEs communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. , Each PE and network channel operate independently according to their clocks, each PE can send messages to other PEs, record their status and received messages, and set checkpoints. There is a special process (called a control process) for issuing an instruction, the control process and all the PEs can perform message communication with each other, and a message transmitted and received between the PEs for normal processing is called a normal message. Messages sent and received by the control process and the PEs to set checkpoints Is called a control message, the control process, the PE and the message have a weight, the sum of all the weights takes a predetermined constant value, the weight has a generation, and all the weights are initialized to the same generation. It has an old generation weight counter, each PE has a status buffer and a message buffer, the message buffer is cleared by initialization processing, and the control process sets its own weight in the old generation weight counter to perform checkpoint setting And
Set its own weight to a certain fixed value, advance its own weight by one generation, and send a record control message (hereinafter referred to as record) to all PEs.
Cord is weighted, my weight is reduced by that much,
When the PE receives record, it clears the status buffer,
Record your state in the state buffer and retu your weight
rn Control message (hereinafter referred to as "return") is sent to the control process, and its own weight is reset by the weight of record. If normal messages are stored in the message buffer, the message weight is applied to those messages. Is added to its own weight and then processed, the message buffer is cleared, and when the PE receives the normal message, the PE compares the "generation of the weight that the normal message has" with the "generation of its own weight" And "the generation of their own weight"
Is new, send the weight of the normal message to the control process by return, record the contents of the normal message in the status buffer, process the normal message, and if the "generation of the weight of the normal message" is new, send the normal message The message is stored in the message buffer, and if the two generations are equal, the weight of the normal message is added to its own weight, and the normal message is processed.
The weight carried by return is added to the old generation weight counter, and as a result, when the value of the old generation weight counter reaches a certain fixed value, it is confirmed that the checkpoint setting is completed, and the completion is confirmed. A checkpoint setting method, wherein a set of contents of the status buffer of each PE at a time constitutes a checkpoint.

<Configuration 13> A finite number of processor groups (hereinafter referred to as PE groups) are connected to each other via a network. The PE groups communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. , Each PE and network channel operate independently according to their respective clocks, and each PE can send messages to other PEs, record their status and received messages, set checkpoints and There is a special process (called a control process) that issues a re-execution instruction. The control process and all the PEs can perform message communication with each other. Called a message, the control process and PEs send each other to set a checkpoint and re-execute. The message to be transmitted is called a control message, the control process, the PE and the message have a weight, the sum of all the weights takes a predetermined constant value, the weight has a generation, and all the weights are initialized to the same generation, The control process has an old generation weight counter, each PE has a status flag, a status buffer, and a message buffer, and the status flag takes only one of the values C indicating that a checkpoint is being set and R indicating re-execution, The message buffer is cleared by initialization processing, and the control process sets its own weight in the old generation weight counter, sets its own weight to a certain fixed value, and sets its own weight to perform checkpoint setting. One generation, send a record control message (hereafter, record) to all PEs, assign a weight to the record, When the PE receives record, the PE sets the status flag to C, clears the status buffer, records its own status in the status buffer, and sets its own weight in the return control message (hereinafter referred to as a return control message). ) To the control process, reset its own weight with the weight of record, and if normal messages are stored in the message buffer, add the weight of the message to those weights for those messages After processing, clears the message buffer, and upon receiving the return, the control process adds the weight carried by the return to the old generation weight counter,
As a result, when the value of the old generation weight counter reaches a certain fixed value, it is confirmed that the setting of the checkpoint is completed, and the control process stores the old generation weight counter in the old generation weight counter in order to execute again. , Set its own weight to a constant value, advance its own weight by one generation, and execute (reexecute) control message
ute) is sent to all PEs, execute is weighted, its own weight is reduced by that amount, and PE
When execute is received, the state flag is set to R, the state is reset by the contents of the state buffer, the own weight is sent to the control process by return, and the own weight is reexecuted.
If the normal message is stored in the message buffer, the message weight is added to its own weight and then processed, and the message buffer is cleared. When the control process receives the return, the control process adds the weight carried by the return to the old-generation weight counter, and when the value of the old-generation weight counter reaches a certain fixed value, the start of re-execution is completed. When the PE receives the normal message, the PE compares the "generation of the weight of the normal message" with the "generation of its own weight", and the "generation of its own weight" is newly set and the status flag is set. If it is C, return the weight of the normal message to the control process by return, record the content of the normal message in the status buffer, process the normal message, and If generation "is new status flag R, it sends the weight of normal messages to the control process in return, normally the message discarded without treatment,
If the "normal message weight generation" is new, the normal message is stored in the message buffer, and if the two generations are equal, the normal message weight is added to its own weight, and the normal message is processed. Checkpointing and re-run method. <Description> The values of the status flags are the same as in the configuration 11.

<Configuration 14> A finite number of processor groups (hereinafter, referred to as PE groups) are connected to each other via a network. The PE groups communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. , Each PE and network channel operate independently according to their respective clocks, each PE can send messages to other PEs, record their status and received messages, set checkpoints and There is a special process (referred to as a control process) that issues a re-execution instruction. The control process and all PEs can perform message communication with each other. Called a message, the control process and PEs send each other to set a checkpoint and re-execute. The message to be transmitted is called a control message, the control process, the PE and the message have a weight, the sum of all the weights takes a predetermined constant value, the weight has a generation, and all the weights are initialized to the same generation, The control process has an old generation weight counter, and the control process sets its own weight in the old generation weight counter, sets its own weight to a constant value, and sets the generation of its own weight in order to perform checkpoint setting. Next, record (reco
rd) Control messages (hereinafter referred to as record) are sent to all PEs.
, The record is weighted, its own weight is reduced by that amount, and when the PE receives the record, the PE compares "the generation of the weight that the record has" with "the generation of its own weight", If the "record weight generation" is new, clear the state buffer, record your state in the state buffer,
Sends its own weight to the control process with a return control message (hereinafter referred to as "return"), resets its own weight with the weight of record, and if the two generations are equal, adds the weight of record to its own weight and controls When the process receives the return, the process adds the weight carried by the return to the old generation weight counter, and when the old generation weight counter reaches a certain fixed value, the checkpoint setting is completed. Is confirmed, the control process sets its own weight in the old generation weight counter, sets its own weight to a certain fixed value, performs two generations of its own weight, and performs Execute (reexecute) control message (hereinafter referred to as “reexecute”) is sent to all PEs, and reex
The ecute is weighted, and its own weight is reduced by that amount. When the PE receives the reexecute, the PE compares "the generation of the weight that reexecute has" with "the generation of its own weight", and "the weight of the reexecute If the "generation" is new, reset its own state with the contents of the state buffer, send its own weight to the control process by return, and reexecut its own weight.
reset by the weight of e, and if the two generations are equal, re
Adding the weight of execute to your own weight, the control process
When return is received, the weight carried by return is added to the old generation weight counter, and when the value of the old generation weight counter reaches a certain fixed value, it can be confirmed that re-start has been completed. When the PE receives the normal message, the PE compares the “generation of the weight that the normal message has” with the “generation of its own weight”, and “the generation of its own weight”
Is one generation newer, usually returns the weight of the message
To the control process, record the contents of the normal message in the status buffer, process the normal message, and if the "generation of its own weight" is new by two generations, send the weight of the normal message to the control process by return, The normal message is discarded without processing, and if the "generation of the weight of the normal message" is newer by one generation, the status buffer is cleared, the own status is recorded in the status buffer, and the own weight is set.
Send to the control process with return, reset its own weight with the weight of the normal message, process the normal message, and if the "generation of the weight of the normal message" is two generations newer,
Resets its state with the contents of the state buffer, sends its weight to the control process with return, resets its weight with the weight of the normal message, processes the normal message, if the two generations are equal A checkpoint setting and re-execution method, wherein the normal message is processed by adding the weight of the normal message to its own weight. <Description> The values of the status flags are the same as in the configuration 11.

<Structure 15> In structures 10 and 12,
It is assumed that three types of generations of A, B, and C are provided as the generations of the weights, and the processing of advancing the generations of the weights is processing of setting B for A, setting C for B, and setting A for C. The old and new generations of weights, B is newer in A and B, C in B and C
The checkpoint setting method is characterized in that it is determined that is newer, and that C and A are newer.

<Structure 16> In structures 11 and 13,
It is assumed that three types of generations of A, B, and C are provided as the generations of the weights, and the processing of advancing the generations of the weights is processing of setting B for A, setting C for B, and setting A for C. The old and new generations of weights, B is newer in A and B, C in B and C
Is newer, and between C and A, A is newer.

<Structure 17> In Structure 14, five generations of A, B, C, D, and E are provided as weight generations.
The processing to advance the weight generation by one is changed to B if A,
If B, then C, C, then D, D, then E, E, then A D, C, E, D, A, E, B
In the processing of A and B, B is one generation newer in A and B, C is one generation new in B and C, D is one generation new in C and D, E for D and E
Is one generation new, A is one generation new in E and A, C is two generations new in A and C, D is two generations new in B and D, E is C and E Is two generations new,
A checkpoint setting and re-execution method characterized in that A is two generations newer for D and A, and B is two generations newer for E and B.

<Structure 18> A finite number of processors (hereinafter, referred to as PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous message communication, and overtake messages on the communication channel. This can happen, there is no guarantee that messages will arrive in the order in which they were sent, there is no clock governing the entire system, each PE and network channel will operate independently according to their own clock, and each PE will send to every other PE. There are special processes (called control processes) that can send messages, record their status and received messages, and issue checkpointing and re-execution instructions. PEs can communicate with each other, and PEs send messages to each other for normal processing. A message to be transmitted is called a normal message, a message transmitted and received by a control process and a group of PEs for setting and re-executing a checkpoint is called a control message. The control process, the PE, and the message have a weight. Takes a constant value, the weight has a generation, all weights are initialized to the same generation, the control process has an old generation weight counter, each PE has a status flag and a status record, an ID register, The record is composed of an ID field and a status field. The status flag takes a value of either C or R. The status field is cleared at the stage of allocation, and the control process sets the checkpoint. Checkpoint ID (checkpointID
) And a checkpoint control message (ch
eckpoint) to all PEs and checkpoint
Has checkpointID as an argument, and ac
Wait until a kCheckpoint control message (hereinafter referred to as ackCheckpoint) is received, set your own weight in the old generation weight counter, set your own weight to a certain value, advance your weight by one generation, and record control message ( Below re
cord is abbreviated to all PEs, record is weighted, own weight is reduced by that much, PE is chec
When a kpoint is received, the status flag is set to C and checkp
Record the checkpoint ID carried by oint in the ID register, allocate a new status record, and checkpoint in the ID field
Record ID, send ackCheckpoint back to control process, r
When the ecord is received, the "generation of the weight that record has" and the "generation of its own weight" are compared, and if the "generation of the weight of record" is new, the self is added to the status field of the status record indicated by the ID register. And send its weight to the control process with a return control message (hereinafter referred to as "return"), reset its own weight with the weight of record,
If the two generations are equal, the weight of record is added to its own weight, and the control process receives a return and returns
The weight carried by rn is added to the old generation weight counter.As a result, if the value of the old generation weight counter becomes a constant value, it is confirmed that the setting of the checkpoint is completed. The set of status fields of the PEs constitute a checkpoint, and the control process determines a checkpoint to start the re-execution, obtains a checkpoint ID indicating the check point, and executes a rollback control message (hereinafter, rollback and rollback control message). Writeback) to all PEs, and rollback has a checkpointID as an argument, and an ackRollback control message (hereinafter ackRollback
back) is received from all PEs, sets its own weight in the old generation weight counter, sets its own weight to a certain value, advances the generation of its own weight by one,
Sends an xecute control message (hereinafter referred to as reexecute) to all PEs, assigns a weight to reexecute, and reduces its own weight by that amount. When the PE receives rollback, the PE sets the status flag to R, Checkp carried by
Record the ointID in the ID register, send ackRollback to the control process, and when reexecute is received, compare the `` generation of the weight that reexecute has '' with the `` generation of your own weight '', and the `` generation of the weight of reexecute '' If it is new, reset its own state with the contents of the state field of the state record indicated by the ID register, send its own weight to the control process with return, reset its own weight with the weight of reexecute, two generations Are equal, the reexecute weight is added to its own weight, and the control process, upon receiving the return, adds the weight carried by return to the old generation weight counter,
As a result, when the value of the old generation weight counter becomes a constant value, it can be confirmed that the re-execution has been started, and that PE
Receives the normal message, compares the “generation of the weight that the normal message has” with the “generation of its own weight”, and if the “own weight generation” is new and the status flag is C, Send the weight to the control process by return, record the contents of the normal message in the status field of the status record indicated by the ID register, process the normal message, and if the "own weight generation" is new and the status flag is R, the normal The weight of the message is sent to the control process by return, the normal message is discarded without processing, and if the "generation of normal message weight" is new and the status flag is C, the status field of the status record indicated by the ID register indicates its status Record, send its weight to the control process by return, reset its weight with the weight of the normal message, and process the normal message. If the “normal message weight generation” is new and the status flag is R, reset your own status with the contents of the status field of the status record indicated by the ID register, send your weight to the control process by return, and Is re-weighted by the weight of the normal message, the normal message is processed, and if the two generations are equal,
A checkpoint setting and re-execution method characterized by processing a normal message by adding the weight of the normal message to its own weight.

<Structure 19> A finite number of processors (hereinafter, referred to as
PEs) are connected to each other by a logical communication channel, the PEs communicate with each other by asynchronous messaging, overtaking of messages may occur on the communication channel, and messages arrive in the order in which they were sent. There is no guarantee, there is no clock to control the whole system, each PE and network channel run independently according to their clock, each PE can send messages to all other PEs, their status and received messages And there is a special process (called a control process) that issues a checkpoint setting and re-execution instruction. The control process and all PEs can perform message communication with each other, and perform normal processing. P to do
Messages transmitted and received by the group E are called normal messages, messages transmitted and received by the control process and the group of PEs for setting and re-executing checkpoints are called control messages, and the control process, the PEs and the messages have weight. , The sum of all weights takes a constant value, the weights have a generation, all weights are initialized to the same generation, the control process has an old generation weight counter, each PE has a status flag and status record, an ID register , A message buffer, a status record consists of an ID field and a status field, a status flag takes a value of either C or R, the status field is cleared at the stage of allocation, and the message buffer is initialized by an initialization process. Clear and set the control process to checkpoint Checkp indicating the checkpoint to perform
Determine the ointID, set its own weight in the old generation weight counter, set its own weight to a fixed value, advance the generation of its own weight by one, send record to all PEs, record
Has a checkpointID as an argument, weights record, reduces its own weight by that amount, and when PE receives record, it sets the status flag to C, and record carries
Record the checkpoint ID in the ID register, allocate a new status record, record the checkpoint ID in the ID field, record your status in the status field, send your weight to the control process with return, and re-apply your weight with the weight of record. Set, if the message buffer normally contains messages, add their weights to their own weight, then process them, clear the message buffer, and the control process will return when the return is received. The weight is added to the old generation weight counter. As a result, when the value of the old generation weight counter becomes a constant value, it is confirmed that the setting of the checkpoint is completed, and the state of each PE at the time when the completion is confirmed The set of fields constitutes a checkpoint, and the control process sets a checkpoint to begin Determine, find checkpointID indicating the checkpoint, set own weight in old generation weight counter, set own weight to a certain value, advance one weight generation, and send reexecute to all PEs Then, reexecute has checkpointID as an argument, weights reexecute, and reduces its own weight by that amount. When PE receives reexecute, it sets the status flag to R, and the chec carried by reexecute
Resets its own state with the contents of the state field of the state record indicated by kpointID, sends its own weight to the control process by return, resets its own weight by reexecute weight, and stores the normal message in the message buffer. If so, add those weights to their own weights, process them, clear the message buffer, and when the control receives a return, add the weight carried by return to the old generation weight counter, add As a result, when the value of the old generation weight counter becomes a constant value, it is possible to confirm that the re-execution has been started, and when the PE receives the normal message, the PE reads "generation of the weight held by the normal message". Compare “own weight generation” and “own weight generation”
Is new and the status flag is C, the weight of the normal message is sent to the control process by return, the contents of the normal message are recorded in the status field of the status record indicated by the ID register, the normal message is processed, and “the weight of the own weight” is output. generation"
Is new, if the status flag is R, the weight of the normal message is sent to the control process by return, and the normal message is discarded without processing. If the "generation of the weight of the normal message" is new, the normal message is not processed. And if the two generations are equal,
A checkpoint setting and re-execution method characterized by processing a normal message by adding the weight of the normal message to its own weight.

<Structure 20> A finite number of processors (hereinafter referred to as
PEs) are connected to each other by a logical communication channel, the PEs communicate with each other by asynchronous messaging, overtaking of messages may occur on the communication channel, and messages arrive in the order in which they were sent. There is no guarantee, there is no clock to control the whole system, each PE and network channel run independently according to their clock, each PE can send messages to all other PEs, their status and received messages And there is a special process (called a control process) that issues a checkpoint setting and re-execution instruction. The control process and all PEs can perform message communication with each other, and perform normal processing. P to do
Messages transmitted and received by the group E are called normal messages, messages transmitted and received by the control process and the group of PEs for setting and re-executing checkpoints are called control messages, and the control process, the PEs and the messages have weight. , The sum of all weights takes a constant value, the weights have a generation, all weights are initialized to the same generation, the control process has an old generation weight counter, each PE has a state switch and state record, an ID register The status record has an ID field and a status field. The status switch takes one of the values C, C ', R, and R'. The initial value is C. The status field is cleared at the stage of allocation. The control process sets a checkpoint ID indicating the checkpoint to be set in order to set the checkpoint. Decide, set its own weight in the old generation weight counter, set its own weight to a certain value, advance its own weight by one generation, send record to all PEs, and record has checkpointID as an argument. , Record is weighted, its own weight is reduced by that amount, and when PE receives record, it compares "the generation of weight that record has" with "the generation of its own weight",
If the "generation of record weight" is new, set the status flag to C ', record the checkpoint ID carried by record in the ID register, allocate a new status record, checkpointID in the ID field, and write your own in the status field. Record the state, send your weight to the control process with return, reset your weight with the weight of record, and if the two generations are equal, add the weight of record to your weight, and the control process will When return is received, the weight carried by return is added to the old generation weight counter.As a result, if the value of the old generation weight counter becomes a constant value, it is confirmed that the checkpoint setting is completed. The set of status fields of each PE at the time of confirmation constitutes a checkpoint, and the control process confirms the completion of checkpoint setting. : C
ompleted) to all PEs, completed
Is weighted, its own weight is reduced by that amount, and the control process determines a checkpoint to start the re-execution and indicates the check point in order to perform the re-execution
Find the checkpointID, set its own weight in the old generation weight counter, set its own weight to a certain value, advance the generation of its own weight by one, send reexecute to all PEs, reexecute with checkpointID as an argument Have, ree
xecute is weighted, its own weight is reduced by that amount, and when PE receives reexecute, it compares "the generation of weight that reexecute has" with "the generation of its own weight", and "reexecute weight If the "generation" is new, set the status flag to R 'and checkpoint carried by reexecute
Record the ID in the ID register, reset the own state with the contents of the state field of the state record indicated by checkpointID, send your own weight to the control process with return, reset your own weight with the weight of reexecute, If the two generations are equal, the reexecute weight is added to its own weight, and the control process, upon receiving the return, adds the weight carried by return to the old generation weight counter, and as a result, the value of the old generation weight counter is added. Can be confirmed that the start of re-execution has been completed if the value of has reached a certain value. When the control process confirms the completion of the start of re-execution, the completed control message
completed) to all PEs
ed is weighted, own weight is reduced by that much, P
When E receives the completed message, the status switch is set to C if the status switch is C ', and when the status switch is R', it is set to R if the status switch is R '. Compare the "weight generation" with the "own weight generation". If the "own weight generation" is new and the state switch is C ', send the weight of the normal message to the control process by return, and return the state indicated by the ID register. Record the contents of the normal message in the status field of the record, process the normal message, and if the "own weight generation" is new and the state switch is R ', return the weight of the normal message.
And the normal message is discarded without processing. If the "normal message weight generation" is new and the "normal message status flag" is C ', the status switch is set to C', and the normal message is discarded. Checkp carried
Record ointID in the ID register, allocate a new status record, record checkpointID in the ID field, record your status in the status field, send your weight to the control process with return, and assign your weight with the weight of the normal message. Reconfigure and process normal messages, new "normal message weight generation" new "normal message status flag"
Is R ', the status switch is set to R', and the checkpoint ID carried by the normal message is recorded in the ID register.
Reset your own state with the contents of the state field of the state record indicated by eckpointID, send your own weight to the control process with return, reset your own weight with the weight of normal message, process normal message, Are equal, the weight of the normal message is added to its own weight, and the normal message is processed. When the normal message is transmitted, if the state switch is C 'or R', the value of the state switch is equal to the value of the state switch. Ch recorded by ID register
Checkpoint setting and re-execution method characterized by sending eckpointID to normal message.

<Structure 21> A finite number of processors (hereinafter, referred to as
PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous messaging, which may overtake messages on the communication channel and arrive in the order in which the messages were sent. There is no guarantee, there is no clock to control the whole system, each PE and network channel run independently according to their clock, each PE can send messages to all other PEs, their status and received messages There is a special process (called a control process) that issues a checkpoint setting and re-execution instruction. The control process and all the PEs can perform message communication with each other. It has a return destination register that indicates the return destination, and sends a return to the destination indicated by the return destination register. And, upon receipt of the return,
"Returned weight generation" and "own weight generation"
If the two generations are equal, the received return is transmitted as it is to the destination indicated by the return destination register, and if the “own weight generation” is new, the weight carried by return Checkpoint setting and re-execution method characterized by adding to the above.

<Structure 22> A finite number of processors (hereinafter referred to as
PEs) are connected to each other by a logical communication channel, the PEs communicate with each other by asynchronous messaging, overtaking of messages may occur on the communication channel, and messages arrive in the order in which they were sent. There is no guarantee, there is no clock to control the whole system, each PE and network channel run independently according to their clock, each PE can send messages to all other PEs, their status and received messages And there is a special process (called a control process) that issues a checkpoint setting and re-execution instruction. The control process and all PEs can perform message communication with each other, and perform normal processing. P to do
Messages transmitted and received by the group E are called normal messages, messages transmitted and received by the control process and the PE group for setting and re-executing checkpoints are called control messages, and the control process, the PE and the message have weight. , The sum of all weights takes a fixed value, the weight has a generation, and all weights are initialized to the same generation.The PE has a return destination register and return weight counter, a return transmission switch, and a return reception table. , The return reception table is composed of the return source PE and the reception flag, the return weight counter is initialized to zero,
The turn transmission switch takes one of the notReady, ready, and done values, and the PE that does not receive a return is done.
, The other PEs are initialized to notReady, the reception flag takes either the value of notReceived or received, and initialized to notReceived, and the PE uses the weight of a newer generation than its own generation. Having record, reexe
When receiving a cute or normal message and resetting its own weight with the weight of the received message, initialize the return weight counter, return transmission switch, return reception table, and when PE tries to transmit return, That P
If the return transmission switch of E is done, a return is sent to the destination indicated by the return transmission destination register. If the return transmission switch of the PE is ready, “the weight to be returned by return” is added to the rejection weight counter, Retu of that PE
If the sending switch is notReady and the values of the receiving flags in the return receiving table are all received, the return carrying the sum of the "weight to be returned by return" and the "weight stored in the return weight counter" is returned. Send to the PE indicated by the transmission destination register, set the return transmission switch to done, return return switch of that PE is notReady, and return
rn One or more reception flags in the reception table are notReceiv
If ed, set the return send switch to ready,
"Return weight to be returned" is added to the return weight counter, and when the PE receives the return, the return transmission switch is done and the "generation of the weight carried by return" is equal to the "own weight generation". Then, return weight counter and re
Initialize turn send switch, return receive table,
The weight carried by return is added to the return weight counter, and re
In the turn reception table, set the reception flag corresponding to the transmission source PE of the received return to received, and if the return transmission switch is done and the "own weight generation" is newer than "the weight carried by return" Then, the return is sent to the PE indicated by the return destination register as it is, and if the return transmission switch is ready, the weight carried by the return is added to the return weight counter, and the return PE in the return reception table is transmitted to the source PE of the received return. Receiv the corresponding receive flag
If the value of the reception flag is set to "received" as a result of the setting, the return carrying the weight stored in the return weight counter is sent to the PE indicated by the return destination register, and the return transmission switch is set to "done". Set to re
If the turn transmission switch is notReady, the check point is that the weight carried by return is added to the return weight counter, and the reception flag corresponding to the source PE of the received return in the return reception table is set to received. Configuration and re-run method.

<Structure 23> The PE has a return destination register, a return weight counter, a return transmission switch, and a return reception counter. The return weight counter is initialized to zero, and the return transmission switch is set to notReady, ready, or done. PE that takes the value of heel and does not receive return
Is initialized to done, the other PEs are initialized to notReady, the reception counter is initialized to "the minimum number of returns to receive", and the PE has a newer generation weight than its own weight. When a PE receives a reexecute or normal message and resets its own weight with the weight of the received message, it initializes the return weight counter, return transmission switch, and return reception counter, and the PE attempts to transmit a return. , The return transmission switch of that PE is
If done, return to destination indicated by return destination register
If the return transmission switch of the PE is ready, add the “weight to be returned by return” to the return weight counter, and set the return transmission switch of the PE to notR.
If return return counter value is zero in eady, "return
Send the return carrying the sum of the weight to be returned by "the weight stored in the return weight counter" to the PE indicated by the return destination register, set the return transmission switch to done, and return transmission of that PE The switch is notReady
If the value of the return reception counter is not zero, the return transmission switch is set to ready, and the “weight to be returned by return” is added to the return weight counter.
When a turn is received, the return send switch is set to done and "retu
If the "generation of the weight carried by rn" and the "generation of its own weight" are equal, the return weight counter and the return transmission switch, re
Initialize the turn reception counter, add the weight carried by return to the return weight counter, and set the return reception counter to -1
If the return transmission switch is done and the “own weight generation” is newer than the “return weight weight generation”, re
The return is sent to the PE indicated by the turn destination register as it is, and if the return transmission switch is ready, the weight carried by the return is added to the return weight counter, the return reception counter is decremented by 1, and the result of -1 is received. If the value of the counter becomes zero, the return carrying the weight stored in the return weight counter is sent to the PE indicated by the return destination register, the return transmission switch is set to done, and if the return transmission switch is notReady, And adding a weight carried by return to a return weight counter and decrementing a return reception counter by one.

[0054]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below using specific examples. FIG. 1 is an explanatory diagram of the global state determination method of the present invention. Hereinafter, a method of detecting “the message no longer exists on the network channel” by the weighting method and determining the global state of the system in which the message may be overtaken will be described with reference to the drawings. First, the weighting method will be described, and then a specific example will be described. still,
As in the prior art, the normal message and the control message are used in the following sense. Normal message: A message for performing normal processing.
PEs transmit and receive from each other. Control message: A message for determining the global state.
The decision process and the PEs communicate with each other. The global state is finally collected in the global state buffer 3.

As shown in FIG. 1, each of the following three has a weight. That is, the decision process 1 includes W1, PEA,
PEB and PEC have weights of W2, W3 and W4, respectively, and the message has a weight of X. The weight W1 of the decision process 1 is, for example, a negative integer, and the other weights W2 to W4 and X are, for example, positive integers. The respective weights are initialized so that “the sum of all the weights (W1 + W2 + W3 + W4 + X) becomes a constant value, for example, zero”. Each PE and the decision process 1 perform the following processing on the weight, and keep the state that the sum of all weights is, for example, zero.

When transmitting a message, weight the message and reduce its own weight. -When a message is received, the weight attached to the message is added to its own weight. As a result, "decision process 1"
Weight of, for example, zero "means that there are no messages on the network channel and all P
This means that the state where the weight of E is zero is simultaneously established. For this reason, this method "the message no longer exists on the network channel"
Can be detected. Below, "the sum of all weights is zero"
It will be described under the setting of.

<Specific Example 1> In this method, the state of the network channel is determined by the PE on the receiving side of the normal message. For this purpose, each PE is provided with a status buffer 5, a transmission buffer 6, and a reception buffer 7, respectively. The state of the network channel and the state of the PE are stored in the reception buffer 7 and the state buffer 5, respectively, on the PE side, and are reported upon receiving a request from the decision process 1.

Decision process 1 sends a record control message to all PEs. When receiving the record control message, the PE stores its own state at that time in the state buffer 5. Thereafter, a copy of the received normal message is stored. When decision process 1 detects that the message is no longer on the network channel, it sends a request control message to all PEs.
When receiving the request control message, the PE reports its own status stored in the status buffer 5 and a copy of the received message stored in the reception buffer 7 in an answer control message. This set of report contents becomes the global state.

The details of the buffer used in this specific example are as follows. The decision process has a global state buffer 3. "PE status" sent from each PE
And the "network channel state" are stored in this buffer. The contents of this buffer become "global state".

Each PE has the following switches and buffers. Message switch: A switch related to handling of a received normal message and transmission processing of the normal message. The value can be recorded, ready, or notRecorded.
The initial value is notRecorded. PE status buffer: Stores “PE status”. Receive buffer: Stores a copy of the normal message received during the global state determination process in this buffer. The content of the buffer becomes the “network channel state”. Transmission buffer: Temporarily stores ordinary messages that have not yet been transmitted in this buffer. The messages in the buffer are not weighted. This is because the state before transmitting this message is set to the desired global state. The weight of the transmission message is assigned when the transmission is actually performed after the global state determination processing.

FIG. 1B shows the state of the message switch of each PE. The decision process 1 performs the following operations after the start of the processing. 1. Clear the global state buffer. 2. Send record control message to all PEs. reco
The rd control message is weighted, and its own weight is reduced accordingly. Upon receiving the return control message, add the weight attached to your own weight. If the weighted result is not zero, do nothing. If the weighting results in zero, a request control message is sent to all PEs. r
The equest control message is not weighted. At this time, no message exists on the network channel, and the message switches of all PEs are recorded. an
When the swer control message is received, the “(source) PE status” and “(source PE)”
The state of the network channel is stored in the global state buffer.

When the answer control message is received from all PEs, the following processing is performed. At this time, no message exists on the network channel, and the message switches of all PEs are ready. 1. The contents of the global state buffer at this point are “global state”. 2. Send a restart control message to all PEs. Completion of global state determination processing: The processing is completed when started control messages are received from all PEs. At this time,
All PE message switches are notRecorded.

The PE performs the following operation. When the record control message is received, the following processing is performed. The message switch of the PE receiving the record control message must be n
otRecorded. 1. The status of the own PE is recorded in the PE status buffer. 2. Set the message switch to recorded. 3. Clear the receive and transmit buffers. 4. The sum of the weight of the own PE and the weight attached to the record control message is sent to the decision process in a return control message.

When the request control message is received, the following processing is performed. The weight of the PE receiving the request control message is zero, and the message switch is record
ed. 1. Set the message switch to ready. 2. The content of the PE status buffer (PE status) and the content of the reception buffer (network channel status) are sent to the decision process in an answer control message.

When the restart control message is received, the following processing is performed. The message switch of the PE that receives the restart control message is ready or notRecord.
ed. 1. The weight attached to the restart control message is assigned to the own PE.
Weight. 2. If the message switch is ready, set to notRecorded. 3. Send a started control message to the decision process. 4. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly.

Processing when a normal message is received differs depending on the value of the message switch. If recorded, the following processing is performed. 1. Store a copy of the message in the receive buffer. 2. Process the message as usual. However, the attached weight is sent to the decision process by a return control message. If ready, perform the following processing. 1. Process the message as usual. 2. Set the message switch to notRecorded. 3. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly. If notRecorded, process the message as usual. Normal message transmission processing also differs depending on the value of the message switch. Message switch is notRecorded
If so, weight is actually transmitted. recorded or
If it is ready, it is not transmitted and stored in the transmission buffer.

<Operation of Embodiment 1> FIGS. 4 to 8 are explanatory diagrams of the operation of Embodiment 1. FIG. In FIG. 4, first, the decision process 1 sends a record control message to all PEs to determine the global state. It is unknown when these control messages arrive. The weight W of each record control message is set to "1", and the weight of the decision process 1 is changed to "-503" by subtracting "3" for this message from "-500". PEA has a weight of 3
00, PEB have a weight of 100, and PEC has a weight of 100. Here, the PEA transmitted the normal message MA to the PEB. This normal message M
The weight W of A is 100. Therefore, the weight of PEA is 3
It has decreased from 00 to 200. PEB is PEC
Sent the normal message MB to the user. The weight W of the normal message MB is 50. Therefore, the weight of PEB has been reduced from 100 to 50. Note that since all of these processors have not yet received a record message, the message switch is notRecorded.

In FIG. 4B, a record control message arrives at PEA and PEB. At this time, they store their states A0 and B0 in the state buffer, and transmit a return control message to the decision process 1 respectively. The weight of the return control message transmitted from PEA is 201. This is because all weights of PEA and reco
This is a value obtained by adding the weight of the rd control message. Similarly, the weight of the return control message transmitted from PEB is 51. PEB weight is 50 and received record
Since the weight of the control message is 1, a value obtained by adding these values is obtained. Note that in this state, the message MA is still PE
B has not arrived. On the other hand, message MB is already PE
Arriving at C, the state of PEC has changed from C0 to C1. At this time, the PEC is 150, which is the original weight 100 plus the weight 50 of the received normal message MB.

Next, referring to FIG. 5C, when the record control message from the decision process 1 arrives at the PEC, the P
EC stores its state C1 in the state buffer and returns
Send a control message to decision process 1. In this case, the own weight has already been changed to 150, and the weight 1 of the received record control message is added thereto, and a weight of 151 is transmitted to transmit the return control message. PEB
Received the normal message MA thereafter, and the state changed from B0 to B1. At this time, a copy of MA was stored in the receiving buffer, and the weight assigned to MA was transmitted to the decision process 1 in a return control message. Therefore, the weight of the return control message is 100. As a result, as shown in (c), all processors PEA, PEA
B and PEC both have a weight of 0.

In FIG. 5D, the decision process 1 receives the return control messages from all the PEs, and the weight is reduced to zero by canceling the self control weight. Therefore, the decision process 1 has transmitted the request control message to all the PEs. The state of PEA changed from A0 to A1 due to internal processing. PEC is PE
The normal message MC to be transmitted to B is stored in the transmission buffer. The PEC then changed its state from C1 to C2. After the process of FIG. 5D, the request control message has arrived at all PEs. Then, as shown in FIG. 6E, each of the PEs receiving the request control message exchanges the content stored in the status buffer with the content stored in the reception buffer.
Sent to decision process 1 using the answer control message.
In FIG. 6 (f), the decision process 1 having received the answer control message from all the PEs stores the P in the global state buffer.
E and the state of the network channel have been stored. Thereafter, decision process 1 sends a restart control message to all PEs. Each restart control message has a weight of 300, and the decision process 1 changes its own weight from 0 to -900.

In FIG. 7 (g), a restart control message arrives at PEA and PEC. Where PEA and P
EC uses its own weight as the weight of its restart control message and sends a started control message to decision process 1 as a response. Note that each processor performs the decision process 1
After sending the answer control message to, the message switch is set to ready. When the restart control message is received from the decision process 1 in the state of FIG. 6F, the message switch is changed to notRecorded. Thus, the normal operation is resumed. Accordingly, as shown in FIG. 7 (g), the PEC transmits the transmission message MC, which has been held in the transmission buffer, to the PEB. As a result, 250 obtained by subtracting the weight 50 of the transmission message from its own weight 300 becomes a new P.
It becomes the weight of EC. Also, in FIG.
Receives the message MC from the PEC before receiving the restart control message from the decision process 1. res
After the tart control message is transmitted from the decision process 1, any processor is ready to resume operation. Therefore, even if the restart control message does not arrive from the decision process 1, the PEC is already restarted by receiving the normal message from the PEC.
Knowing that it has received the control message, PEB receives its normal message and resumes operation. Therefore,
Change the message switch from ready to notRecorded. At this time, the processor PEA changes its state from A1 to A2 due to internal processing.

In FIG. 8I, when the restart control message arrives at the PEB, the PEB sends a started control message to the decision process 1. At this stage, PE
The weight of B is the sum of the weight of the restart control message and 35
It has changed to zero. Then, in FIG. 8 (j), the decision process 1 that has received the started control messages from all the PEs ends the global state decision processing, and sets the global state to obtain the contents stored in the global state buffer. Therefore,
As a result, the state of PEA is A0 and the state of PEB is B0.
, PEC is C1, and the state of the network channel from PEA to PEB is MA.

<Effect of Specific Example 1> According to this specific example,
It is not necessary to send control messages to all network channels. Further, the present invention can be applied to a system in which a message is overtaken by a weighting process.

<Embodiment 2> FIG. 9 is an explanatory diagram of a state determining method according to Embodiment 2. In this example, the state of the network channel is determined by the PE on the receiving side of the normal message. The status of the network channel and the PE are sequentially reported by the PE to the decision process 1, and the decision process 1 stores the status in the global status buffer. Therefore, the PE has only the transmission buffer 6. The message switch changes as shown in FIG. Decision process 1 sends a record control message to all PEs. When receiving the record control message, the PE reports its own state at that time. And
Thereafter, each time a normal message is received, the contents of the message are reported. The decision process 1 stores the received report contents, and the set of report contents at the time when it is detected that the message is no longer present on the network channel becomes the global state.

The decision process 1 has a global state buffer 3. The “PE state” and the “copy of received normal message” sent from each PE are stored in this buffer. The contents of this buffer become "global state". Each PE
Has the following switches and buffers. Message switch: a switch related to handling of a received normal message and transmission processing of the normal message. The value is one of recorded, ready, and notRecorded. The initial value is notRecorded. Transmission buffer: Temporarily stores ordinary messages that are not transmitted (yet) in this buffer. The messages in the buffer are not weighted. Weights are assigned when actually transmitting.

When the process starts, the decision process operates as follows. 1. The global state buffer 3 is cleared. 2. Send record control message to all PEs. reco
The rd control message is weighted, and its own weight is reduced accordingly. When the return control message is received, the following processing is performed. 1. Add the weight attached to the message to your own weight. 2. The “state of the (source) PE” or “copy of the normal message (received by the source PE)” recorded in the message is stored in the global state buffer 3. 3. If the weighting results in zero, send a proceed control message to all PEs. The proceed control message is not weighted. Further, the contents of the global state buffer at this point are “global state”.

After receiving the proceeding control message from all the PEs, the decision process sends a restart control message to all the PEs. At this time, no message exists on the network channel, and the message switches of all PEs are ready. When the started control messages are received from all the PEs, the processing is completed. At this time, the message switches of all PEs are notRecorded.

Each PE operates as follows. When the record control message is received, the following processing is performed. In addition, reco
The message switch of the PE receiving the rd control message is always notRecorded. 1. Set the message switch to recorded. 2. Clear the transmission buffer 3. 3. The “sum of the weight of the own PE and the weight attached to the record control message” and the “state of the own PE” are sent to the decision process by a return control message.

Upon receiving the proceed control message, the following processing is performed. The weight of the PE receiving the proceed control message is zero, and the message switch is
rded. 1. Set the message switch to ready. 2. Send a proceeded control message to the decision process. Perform the following processing when the restart control message is received. The message switch of the PE receiving the restart control message is ready or notRecorded.

1. The weight attached to the restart control message is added to the weight of the own PE. 2. If the message switch is ready, set to notRecorded. 3. Send a started control message to the decision process. 4. If normal messages are stored in the transmission buffer 6, they are transmitted. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly.

The processing when a normal message is received differs depending on the value of the message switch. If recorded, the following processing is performed. 1. The "copy of the message" and the "weight attached to the message" are sent to the decision process by a return control message. 2. Process the message as usual. If ready, perform the following processing. 1. Process the message as usual. 2. Set the message switch to notRecorded. 3. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly. If notRecorded, process the message as usual. Normal message transmission processing also differs depending on the value of the message switch. Message switch is notRecorded
If so, weight is actually transmitted. recorded or
If it is ready, it is not transmitted and stored in the transmission buffer.

<Operation of Embodiment 2> FIG.
FIG. The operation of the second embodiment is the same as that of the first embodiment until the decision process 1 transmits a record control message. This has been described with reference to FIG. Next, the operation when each PE receives the record control message will be described. In this specific example, as shown in FIG. 10A, when PEA and PEB receive the record control message, each PE immediately transmits its own state to the decision process 1 using the return control message. That is, return
In the control message, PEA indicates its own state A0 and PEB
Puts its own state B0. At this time, the weight of the return control message is 201 as in the case of the specific example 1 described with reference to FIG. It is 51.

Thus, when the return control message arrives at the decision process 1, the decision process 1 stores the state of each PE in the global state buffer. In FIG. 10B, upon receiving the return control message from the PEA and PEB, the decision process 1 changes the weight from -503 to-
251. This processing is the same as the processing of the specific example 1 shown in FIG. At this timing, the PEC receives the record control message and transmits its state C1 to the decision process 1 using the return control message. The weight of the return control message at that time is 151. This description is given in FIG.
This is the same as in the case of the specific example 1 performed using. On the other hand, re
After transmitting the turn control message, the normal message MA further arrives at PEB. PEB notifies the decision process 1 of a copy of the received normal message MA using a return control message. The received normal message is processed by the PEB, and its state is changed from B0 to B1. The return control message is added with the weight 100 of the received normal message to determine
Is sending to.

As described above, in the specific example 2, similarly to the specific example 1, when a normal message is received, its weight is transmitted to the decision process 1, and a copy of the received normal message is also added. Notify sequentially. The decision process 1 stores and holds the contents in a global state buffer. Therefore, at the same time when the weight of the decision process 1 becomes 0, the content stored in the global state buffer of the decision process 1 becomes the desired global state. Thereafter, the decision process sends a proceed control message to each PE instead of the request control message sent in the case of the first embodiment. This is because there is no need to receive any more information from each PE. proceed messages are not weighted. Then, the pro corresponding to the proceed control message
When the ceeded control message arrives at the decision process from each PE, the restart operation is performed in exactly the same manner as in the first embodiment.
Transmission and reception of the control message and the started control message are performed.

<Effect of Specific Example 2> In this example as well, it is not necessary to transmit control messages to all network channels. Also, the present invention can be applied to a system in which messages are overtaken. Unlike the method of the specific example 1, the PE does not need to have the status buffer and the reception buffer. Also, P
In the specific example 1, the report of the PE status and the received message to the E determination process has the effect of being collectively notified, while in the specific example 2, these pieces of information are divided and transmitted. Therefore, there is an effect that the data amount for one report can be reduced.

<Embodiment 3> FIG. 11 is an explanatory view of the method of Embodiment 3. In this example, the state of the network channel is obtained by the PE on the transmitting side of the normal message. The state of the network channel is determined by the PE on the transmission buffer 6.
And receives a report from the decision process 1 to report. The state of the PE is a state in which the record control message is received in the specific example 1, but in this specific example, the state at the time of receiving the request message when the request from the decision process 1 is received is reported. First, the outline of the specific example 3 will be described. Decision process 1 sends a record control message to all PEs. When the PE receives the record control message, the PE stores the normal message to be transmitted thereafter in the transmission buffer 6. When decision process 1 detects that the message is no longer on the network channel,
Send a request control message to all PEs. PE is
Upon receiving the request control message, it reports its status at that time and the stored transmission message. This set of report contents becomes the “global state”.

The decision process has a global state buffer. The “PE state” and the “network channel state” sent from each PE are stored in this buffer. The contents of this buffer become "global state". Each PE has the following switches and buffers. Message switch: a switch related to handling of a received normal message and transmission processing of the normal message. The value is one of recorded, ready, and notRecorded. The initial value is notRecorded. Transmission buffer: Temporarily stores ordinary messages that are not transmitted (yet) in this buffer. The messages in the buffer are not weighted. Weights are assigned when actually transmitting. The buffer contents are "Network channel status"
Becomes

The determination process performs the following processing. 1. Clear the global state buffer. 2. Send record control message to all PEs. reco
The rd control message is weighted, and its own weight is reduced accordingly. Upon receiving the return control message, add the weight attached to your own weight. If the weighted result is not zero, do nothing. If the weighting results in zero, the request control message is sent to all P
Send to E. Request control messages are not weighted. At this time, no message exists on the network channel, and the message switches of all PEs
rded. When the answer control message is received, the "state of the (source) PE" and the "state of the network channel (of the source PE)" recorded in the message are stored in the global state buffer.

Determination of global state and processing after determination: When answer control messages are received from all PEs, the following processing is performed. At this time, the message switches of all PEs are ready. 1. The contents of the global state buffer at this point are “global state”. 2. Send a restart control message to all PEs. Completion of global state determination processing: Processing is completed when started control messages are received from all PEs. At this time,
All PE message switches are notRecorded.

The PE operates as follows. When the record control message is received, the following processing is performed. Note that the message switch of the PE receiving record must be notRecorded.
It is. 1. Set the message switch to recorded. 2. Clear the transmission buffer. 3. The sum of the weight of its own PE and the weight attached to record is re
Turn to send to decision process.

When the request control message is received, the following processing is performed. The weight of the PE receiving the request control message is zero, and the message switch
rded. 1. Set the message switch to ready. 2. The state of the own PE and the contents of the transmission buffer (state of the network channel) are sent to the decision process by an answer control message.

When the restart control message is received, the following processing is performed. The message switch of the PE that receives the restart control message is ready or notRecord.
ed. 1. The weight attached to the restart control message is assigned to the own PE.
Weight. 2. If the message switch is ready, set to notRecorded. 3. Send a started control message to the decision process. 4. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly.

Processing when a normal message is received differs depending on the value of the message switch. If recorded, process the message as usual. However, the attached weight is sent to the decision process by a return control message. If ready, perform the following processing. 1. Process the message as usual. 2. Set the message switch to notRecorded. 3. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly. If notRecorded, process the message as usual. Normal message transmission processing also differs depending on the value of the message switch. Message switch is notRecorded
If so, weight is actually transmitted. recorded or
If it is ready, it is not transmitted and stored in the transmission buffer.

<Operation of Embodiment 3> FIG. 12 is a diagram for explaining the operation of Embodiment 3. This specific example is performed in the same manner as the first specific example.
The status determination process is started by the control message and the weight is returned by the return control message. When the request control message arrives at the PE from the decision process as shown in FIG. 12, each PE sends its own state and the contents of the transmission buffer to the decision process as shown in FIG.
The subsequent operation is not different from that of the first embodiment.

<Effect of Embodiment 3> In this method, it is not necessary to transmit a control message to all network channels. Also, the present invention can be applied to a system in which messages are overtaken. In comparison with the first example, the point that only the transmission buffer needs to be provided on the PE side is advantageous for the PE.

<Example 4> This method is a method in which the state of the network channel is determined by the PE on the transmitting side of the normal message. The status of the network channel is sequentially reported by the PE. The status of the PE is reported by the PE when it receives a request from the decision process. The decision process sends a record control message to all PEs. PE is record
When the control message is received, the content of the normal message is reported each time the control message is transmitted. When the decision process detects that there is no longer a normal message on the network channel, it sends a request control message to all PEs. PE is
Immediately after receiving the request control message, it reports its status at that time. A set of the above report contents becomes a global state. By counting the number of reports, it detects that all reports have been received.

FIG. 13 is an explanatory view showing the method of the fourth embodiment. As shown, decision process 1 comprises the following counter 1
1 and buffer 3. report reception counter 11: a counter for confirming that the decision process has received all report control messages transmitted by the PE. Global state buffer 3: Stores "copy of normal message to be transmitted" and "PE state" sent from each PE in this buffer. The contents of this buffer become "global state". Each PE has the following switches and counters 12,
It has a buffer 6. Message switch: a switch related to handling of a received normal message and transmission processing of the normal message. The value can be record, ready, or notRecorded,
The initial value is notRecorded. report transmission counter 12: counts the number of report control message transmissions. Transmission buffer 6: A normal message that is not transmitted (yet) is temporarily stored in this buffer. The messages in the buffer are not weighted. Weights are assigned when actually transmitting.

The decision process performs the following processing. 1. The report reception counter 11 is cleared. 2. The global state buffer 3 is cleared. 3. Send record control message to all PEs. reco
rd is weighted and its own weight is reduced accordingly. When the report control message is received, the following processing is performed. 1. The report reception counter 11 is incremented by one. 2. The "copies of normal messages (transmitted by the source PE)" recorded in the message are stored in the global state buffer 3.
To be stored. Upon receiving the return control message, add the weight attached to your own weight. If the weighted result is not zero, do nothing. If the weighting results in zero, a request control message is sent to all PEs. r
The equest control message is not weighted. At this time, the message switches of all PEs are recorded.
When the answer control message is received, the "report transmission counter value" and "(sender) P
The following processing is performed using "state of E". 1. The report reception counter 11 is decremented by “report transmission counter value”. 2. "(Transmission source) PE status" is changed to the global status buffer 3
To be stored. In the global state determination processing, when the value of the report transmission counter becomes zero and the answer is received from all PEs, the following processing is performed. At this time, no message exists on the network channel, and the message switches of all PEs are ready. 1. The content of the global state buffer 3 at this point is "global state". 2. Send a restart control message to all PEs. The process is completed when the started control messages are received from all the PEs. At this time, the message switches of all PEs are notRecorded.

The PE performs the following processing upon receiving the record control message. The message switch of the PE that receives the record control message is always notRecorded. 1. Set the message switch to recorded. 2. The report transmission counter 12 and the transmission buffer 6 are cleared. 3. The sum of the weight of the own PE and the weight attached to the record control message is sent to the decision process in a return control message. When the request control message is received, the following processing is performed. The weight of the PE receiving the request control message is zero, and the message switch is recorded. 1. Set the message switch to ready. 2. "Report transmission counter value" and "own PE status"
Sent to decision process in answer control message. When the restart control message is received, perform the following processing. The message switch of the PE receiving the restart control message is ready or notRecorded. 1. The weight attached to the restart control message is assigned to the own PE.
Weight. 2. If the message switch is ready, set to notRecorded. 3. Send a started control message to the decision process. 4. If normal messages are stored in the transmission buffer 6, they are transmitted. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly.

The processing when a normal message is received differs depending on the value of the message switch. If recorded, process the message as usual. However, the attached weight is sent to the decision process by a return control message. If ready, perform the following processing. 1. Process the message as usual. 2. Set the message switch to notRecorded. 3. If normal messages are stored in the transmission buffer 6, they are transmitted. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly. If notRecorded, process the message as usual.

The normal message transmission process also depends on the value of the message switch. Message switch is not
If it is Recorded, it is actually weighted and transmitted. recorded
If not, the data is not transmitted and stored in the transmission buffer. Then, a copy of the message is sent to the decision process by a report control message, and the report transmission counter 12 is incremented by one. repo
No weight is assigned to the rt control message. If it is ready, it is not transmitted and stored in the transmission buffer.

There are the following difficulties in confirming that all report control messages have been received. -Since the report control message has no weight, (PE
Sends a report control message when the weight is zero, so it cannot have a weight. ) It cannot be ascertained by weighting that the decision process has received all report control messages. -The total number of report control message transmissions is undefined,
Since the number of transmissions differs depending on the case (there may be PEs that transmit many times, or there may be PEs that never transmit), it is not enough for the decision process to simply count the number of receptions. -The PE sends an answer control message after sending all report control messages. However, in systems where message overtaking can occur, the answer control message may overtake the report control message. Thus, even though the decision process receives an answer control message from all PEs, there may still be a report control message on the network channel. In this method, each PE communicates to the decision process the number of report control messages sent,
Confirm that the report has been received.

<Operation of Embodiment 4> FIG.
FIG. The PE receiving the record control message stores the normal message to be transmitted in the transmission buffer, and transmits a copy of the normal message to the decision process using the report control message. At this time, the transmission counter 12 is incremented by 1 to confirm the number of transmissions. The decision process whose weight becomes zero sends a request control message to all PEs. FIG. 14A shows the above state. As shown in (b), the decision process that has received the report control message sets the report reception counter to +
First, a copy of the normal message carried by the report control message is stored in the global state buffer 3. On the other hand, r
The PE receiving the equest control message determines its own status.
Send the value of the report transmission counter to the decision process in the answer control message. In this way, the decision process checks the value of the counter and confirms the arrival of all answer control messages.

<Effect of Embodiment 4> This method does not need to transmit a control message to all network channels, as in the previous embodiments. Also, the present invention can be applied to a system in which messages are overtaken. Since the transmission of the transmission message to the copy determination process is performed not in a lump as in the third embodiment but in a divided manner, there is an advantage that the size of one message can be small. further,
There is an advantage similar to that of the third embodiment in that the PE only needs to have the transmission buffer.

<Example 5> This example is also a method in which the state of the network channel is obtained by the PE on the transmitting side of the normal message. The status of the network channel is sequentially reported by the PE. The status of the PE is reported by the PE when it receives a request from the decision process. The method of this specific example is simplified from the method of the specific example 4 by omitting the report transmission / reception counter. For this reason, the number of report control messages cannot be collated, and is applicable only to "a system without message overtaking."

The configuration of this specific example 5 is based on the report reception counter 11 and the report transmission counter 1 in the explanatory diagram of FIG.
2 is excluded. Decision process 1 sends a record control message to all PEs. After receiving the record control message, the PE reports the content of the normal message to the decision process every time the PE attempts to transmit the normal message. When the decision process detects that there is no longer a normal message on the network channel, it sends a request control message to all PEs. When receiving the request control message, the PE reports its own state at that time. A set of the above report contents becomes a global state. "No message overtaking"
To detect that all reports have been received.

The decision process 1 has a global state buffer 3. The “PE state” and the “network channel state” sent from each PE are stored in this buffer.
The contents of this buffer become "global state". Each PE has the following switches and buffers 6. Message switch: a switch related to handling of a received normal message and transmission processing of the normal message. The value is one of recorded, ready, and notRecorded. The initial value is notRecorded. Transmission buffer: Temporarily stores ordinary messages that are not transmitted (yet) in this buffer. The messages in the buffer are not weighted. Weights are assigned when actually transmitting. The buffer contents are "Network channel status"
Becomes

The determination process performs the following processing. 1. The global state buffer 3 is cleared. 2. Send record control message to all PEs. reco
The rd control message is weighted, and its own weight is reduced accordingly. When the report control message is received, the “copy of the normal message (transmitted by the source PE)” recorded in the message is stored in the global state buffer 3. Upon receiving the return control message, add the weight attached to your own weight. If the weighted result is not zero, do nothing. If the weighted result is zero, req
Send uest control message to all PEs. Request control messages are not weighted. At this time, the message switches of all PEs are recorded. answer
When the control message is received, the “state of the (source) PE” recorded in the message is stored in the global state buffer.

When the answer control message is received from all PEs, the following processing is performed. At this time, no message exists on the network channel and all PEs
The message switch to is ready. 1. The contents of the global state buffer at this point are “global state”. 2. Send a restart control message to all PEs. The process is completed when the started control messages are received from all the PEs. At this time, the message switches of all PEs are notRecorded.

When the PE receives the record control message, it performs the following processing. The message switch of the PE that receives the record control message is always notRecorded. 1. Set the message switch to recorded. 2. Clear the transmission buffer. 3. The sum of the weight of the own PE and the weight attached to the record control message is sent to the decision process in a return control message. When the request control message is received, the following processing is performed. The weight of the PE receiving the request control message is zero, and the message switch is recorded. 1. Set the message switch to ready. 2. The "state of own PE" is sent to the decision process by answer. Perform the following processing when the restart control message is received. The message switch of the PE receiving the restart control message is ready or notRecorded. 1. The weight attached to the restart control message is assigned to the own PE.
Weight. 2. If the message switch is ready, set to notRecorded. 3. Send a started control message to the decision process. 4. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly.

Processing when a normal message is received differs depending on the value of the message switch. If recorded, process the message as usual. However, the attached weight is sent to the decision process by a return control message. If ready, perform the following processing. 1. Process the message as usual. 2. Set the message switch to notRecorded. 3. If normal messages are stored in the transmission buffer, send them. The normal message to be transmitted is weighted, and the weight of the own PE is reduced accordingly. If notRecorded, process the message as usual.

The normal message transmission process also differs depending on the value of the message switch. Message switch is not
If it is Recorded, the message is usually sent with weight. If recorded, it is not transmitted and stored in the transmission buffer. Then, a copy of the message is sent to the decision process in a report control message. The report control message is not weighted. If it is ready, it is not transmitted and stored in the transmission buffer.

The PE sends an answer control message after sending all report control messages. Therefore, the method is applicable. That is, in the "system without message overtaking", "the decision process has received the answer control message from all PEs" means that "all the report control messages have been received".

<Operation of Embodiment 5> FIG. 15 is an explanatory diagram of the operation of Embodiment 5. P that received the record control message
E stores the normal message to be transmitted in the transmission buffer and transmits a copy of the normal message to the decision process in a report control message. In the specific example 4, the transmission counter was operated at this time to count the number of transmissions.
In the specific example 5, such processing is unnecessary. The decision process whose weight becomes zero sends a request control message to all PEs. FIG. 15A shows the above state. Further, as shown in (b), the decision process that has received the report control message stores a copy of the normal message carried by the report control message in the global state buffer 3. On the other hand, the PE that has received the request control message sends its state to the decision process using an answer control message. If the answer control message does not overtake the request control message, the arrival of all answer control messages is confirmed, and the global state determination processing ends.

<Effect of Embodiment 5> This method can obtain the same effect as that of Embodiment 4 as long as the system does not overtake messages. Further, there is an effect that the procedure of the counter control and the like can be simplified as compared with the specific example 5.

<Specific Example 6> In this example as well, the global state is determined using a weighting method. As in the previous examples, the normal message is a message for performing normal processing.
Group E transmits and receives each other. The control message is a message for determining the global state.
Group E transmits and receives each other. The decision process, the PE and the message each have a weight. The weight of the decision process is a negative integer and the other two are positive integers. Each weight is initially set so that “the sum of all weights becomes a constant value, for example, zero”. Each PE and the decision process perform the following processing on the weights, and keep the state that “the sum of all weights is zero”. 1. When sending a message, weight the message and reduce your weight by that amount. 2. When a message is received, the weight attached to the message is added to its own weight. As a result, the state of "zero weight for the decision process"
If there are no messages on the network channel,
And the weight of all PEs is zero.
Therefore, this method can detect "the message no longer exists on the network channel".

In the specific example 6, the global state is determined by introducing the generation into the weight. A set of normal messages and PE states having the same generation weight constitutes a global state. Normal message with specific generation weight and PE
, And the completion of the report is detected by the weighting method.

The basic functions of each part are as follows.
The decision process advances its weight generation by one from old to new and sends a request control message of W = 500 new to all PEs. PE is an advanced generation (new generation n
When a weighted request control message is received, the current state of the request is reported to the decision process.
Return the weight of the (old generation old) with the report,
The weight of the new generation new carried by the request control message is taken as the new weight of the user. After that, when a normal message with the weight of the previous generation old is received, a copy of the message is reported, and the weight is also returned. The decision process detects, by means of the weighting scheme, that the message and PE having the weight of the previous generation no longer exist anywhere. The set of report contents from each PE at the time of this detection is in the global state.

To realize the above-described general operation, each unit has the following configuration. FIG. 16 is a diagram for explaining the method of the specific example 6. For this purpose, the decision process 1 has a global state buffer 3 and an old generation weight counter oldw.
The global status buffer 3 collects and stores the “PE status” and “copy of normal message” sent from each PE. The contents of this buffer become "global state".
The old generation weight counter oldw is a counter for detecting that a message or PE having the weight of the previous generation no longer exists.

[0120] Decision process 1 operates as follows. At the start of the process, the following process is performed. 1. The global state buffer 3 is cleared. 2. Set its own weight in the old generation weight counter oldw. 3. The generation of the weight is advanced by one, and the value is set to zero. 4. Send a request control message to all PEs. r
The equest control message is given a weight of W = 500, and its own weight is reduced accordingly. Note that the generation of the weight added to the request control message is old in the third processing.
From new to new.

When the decision process 1 receives the return control message, the following processing is performed. 1. The weight attached to the message is the old generation weight counter
Add to oldw. 2. The “state of the (source) PE” or the “copy of the normal message received by the source PE” recorded in the message is stored in the global state buffer 3. When the old generation weight counter oldw becomes zero, the content of the global state buffer 3 at that time is "global state".
It is. At this time, all messages and PEs on the network channel have the weight of the new generation. There is no message or PE with the weight of the previous generation.

Each PE operates as follows. When the request control message is received from the decision process 1, the message “own PE
The following processing is performed by comparing the “weight generation of the request control message” with the “generation of the weight of the request control message”. If the generation of the weight of the request control message is newer, the following processing is performed. 1. The “state of the own PE” and the “weight of the own PE” are sent to the decision process in a return control message. 2. “Weight of own PE” is set to “weight of request control message”. On the other hand, if the two generations are the same, the “weight of the request control message” is added to the “weight of the own PE”.

When the normal message is received, the following processing is performed by comparing the “generation of the weight of the own PE” with the “generation of the weight of the normal message”. If the weight generation of the own PE is newer, “normal message copy” and “normal message weight” are sent to the decision process in a return control message. On the other hand, if the two generations are the same, the “weight of the normal message” is added to the “weight of the own PE”. If the generation of the weight of the normal message is newer, the following processing is performed. 1. The “state of the own PE” and the “weight of the own PE” are sent to the decision process in a return control message. 2. The “weight of the own PE” is set to “the weight of the normal message”. In any case, the received normal message is processed as usual after performing the above processing. 17 to 20 show a specific example 6.
It is operation | movement explanatory drawing of FIG. Hereinafter, the operations shown in FIGS. 17 to 20 will be sequentially described.

FIG. 17 is an operation explanatory diagram (part 1) of the embodiment 6. First, as described above, the decision process 1 sends a request control message to all PEs. In this case, the new generation weight W = 500 is requeued.
Sent with the st control message. At this time, the PEA simultaneously sends the normal message MA to the PEB,
Normally sends a message MB to the PEC. At this time, PEA and PEB assign the old generation weight to the normal messages MA and MB.

At the next stage, the state shown in FIG. 18 is obtained.
That is, request control messages with new weights arrive at PEA and PEB, respectively, and PEA and PEB
Sends the new weight W = 500 as its own weight and sends the old weight W = 200 or W = 50 to the decision process 1 together with the return control message. PEA and PEB at the same time
Reports its state A0 and B0 to decision process 1.

On the other hand, message M transmitted from PEB
B arrives at PEC and the state of PEC has changed from C0 to C1. In addition, the PEC weight is between 100 and 150
Changed to This weight is the weight of the old generation. PEC
Has not yet received the request control message.
Furthermore, the message MA sent by PEA to PEB
Has not yet arrived.

FIG. 19 shows the following state. The request control message has arrived at the PEC. Here, the PEC determines its state C1 by the return control message in the decision process 1.
Reported to. At this time, the weight W = 150 of the old generation was also transmitted to the decision process 1. Further, the PEC sets the weight W = 500 of the new generation as its own weight. The message MA arrives at PEB, and the state of PEB changes from B0 to B1. PEB has the weight of the message MA and the weight of the old generation.
100 was sent to decision process 1.

FIG. 20 shows the state after that. In the decision process 1, a return control message arrives from PEB and PEC, and weights are added. That is, the weight of each old generation is added to oldw, and the sum becomes zero.
This completes the global state determination process. The determined global state is that PEA is A0, PEB is B0, PEC is C1, C2.
HAB becomes MA.

<Effect of Embodiment 6> According to this embodiment,
It is not necessary to send control messages to all network channels. Also, the present invention can be applied to a system in which messages are overtaken. Furthermore, by introducing the generation to the weight, it is determined whether or not the received normal message is a component of the global state. As a result, the global state could be determined without interrupting the message transmission / reception processing.

<Specific Example 7> Specific example 6 is based on the "state of PE".
And a "copy of normal message" in response to the request control message and immediately report to the decision process. This is a method in which the PE does not record the state by itself.
In the specific example 7, a method is provided in which the PE itself records “the state of the PE” and “copy of the normal message”, and reports the same in response to a request from the decision process. The basic functions of each part are as follows.

The decision process advances the generation of its own weight by one, and sends a record control message to all PEs. PE
Is a record with advanced (new generation) weights
Upon receiving the control message, it records its own state at that time. Then, the weight of the own (previous generation) is added to the return control message and returned to the decision process.
Let the weight of the new generation carried by the control message be its new weight. Then, when a normal message with the weight of the previous generation is received, a copy of the message is recorded and the weight is returned to the decision process. The decision process detects that the message and PE having the weight of the previous generation no longer exist by the weighting method. The set of recorded contents of each PE at the time of this detection is in the global state.
The decision process sends a request control message to each PE
Collect records of

To have the above functions, the configuration of each unit is as follows. FIG. 21 is an explanatory diagram of the method of the specific example 7. Decision process 1 has the following buffers and counters. The global state buffer 3 stores “PE” sent from each PE.
Status and a copy of a normal message are stored. The contents of this buffer become "global state". The old generation weight counter oldw is used to store a message or P with the weight of the previous generation.
This is a counter for detecting that E no longer exists. Each PE has a PE status buffer 20. Record your status and copy of normal message in this buffer.

Decision process 1 operates as follows. At the start of the process, the following process is performed. 1. Clear the global state buffer. 2. Set your own weight in the old generation weight counter. 3. The generation of the weight is advanced by one, and the value is set to zero. 4. Send record control message to all PEs. reco
The rd control message is weighted, and its own weight is reduced accordingly. The generation of the weight added to the record control message is advanced by one in process 3.

Upon receiving the return control message, the decision process 1 adds the attached weight to the old generation counter. If the weighted result is not zero, do nothing. If the weighting results in zero, a request control message is sent to all PEs. Request control messages are not weighted. When the answer control message is received, the message "(source) PE
Is stored in the global state buffer. ”And“ Copy of normal message (received by source PE) ”.

[0135] Decision process 1 is answered by all PEs.
When the control message is received, the processing is completed. The contents of the global state buffer are "global state". At this time, all messages and PEs on the network channel have the weight of the new generation. There is no message or PE with the weight of the previous generation.

The PE operates as follows. When the record control message is received, “generation of weight of own PE” and “re
The following processing is performed by comparing the “cord control message weight generation”. If the weight generation of the record control message is new, the following processing is performed. 1. The “weight of the own PE” is sent to the decision process in a return control message. 2. The “state of the own PE” is recorded in the PE state buffer. 3. “Weight of own PE” is set to “weight of record control message”. If the two generations are the same, the “weight of the record control message” is added to the “weight of the own PE”.

When the normal message is received, the “generation of the weight of the own PE” is compared with the “generation of the weight of the normal message”, and the following processing is performed. If the generation of the weight of the own PE is new, the following processing is performed. 1. The "normal message weight" is sent to the decision process in a return control message. 2. “Copy normal message” is recorded in the PE status buffer. If the two generations are the same, the “normal message weight” is added to the “own PE weight”.

If the generation of the weight of the normal message is new, the following processing is performed. 1. The “weight of the own PE” is sent to the decision process in a return control message. 2. The “state of the own PE” is recorded in the PE state buffer. 3. The “weight of the own PE” is set to “the weight of the normal message”. In any case, the received normal message is processed as usual after performing the above processing. When the request control message is received, answer "PE status" and "Copy of normal message" recorded in the PE status buffer.
A control message is sent to the decision process and the PE status buffer is cleared.

FIGS. 22 to 27 are explanatory diagrams of the operation of the seventh embodiment. Specific examples of FIGS. 22 to 27 will be described in order. First, in the state shown in FIG. 22, the decision process 1 sends a record control message having a new generation weight 500 to P
Sent to EA, PEB, PEC. At this time, PEA transmitted the normal message MA to PEB, and PEB transmitted the normal message MB to PEC. These messages MA and MB have an old generation weight W = 100 or W
= 50 is added.

In the state shown in FIG. 23, the record control message arrives at PEA and PEB. PEA and PEB return their weights to decision process 1 in a return control message. These weights are all old generation weights. PEA and PEB have their own state A0 respectively.
And B0 were recorded in the PE state buffer 20. The message MB arrives at PEC and the state of PEC changes from C0 to C1.
Has changed. Also, the weight of PEC has changed from 100 of the old generation to 150. At this time, the record control message has not yet arrived at the PEC. Further, P
The message MA sent from EA has not yet arrived at PEB.

FIG. 24 shows the following state. The record control message has arrived at the PEC. PECs use their weights
It returned to the decision process 1 with a return control message, and recorded its state C1 in the state buffer 20. PEB receives message MA, and the state changes from B0 to B1. At this time, the weight of the old generation attached to the message MA is returned to the decision process 1 by a return control message. A copy of the message MA was recorded in the PEB status buffer 20.

In the next FIG. 25, the decision process 1
Return control messages were received from PEB and PEC, and weights were added. As a result, the old generation weight counter oldw
Became zero. Therefore, a request control message was sent to each PE so as to return the contents of the status buffer. In FIG. 26, each PE receives the request control message, and returns the status of its own PE and the copy of the normal message recorded in the respective PE status buffers to the decision process 1 with the answer control message. In FIG.
Thus, the decision process 1 has received the answer control message from all PEs, and the global state decision processing has been completed.
The global state at that time is PEA = A0, PEB = B0,
PEC = C1, CHAB = MA.

<Effect of Specific Example 7> According to this specific example,
It is not necessary to send a control message to all network channels, and the present invention can be applied to a system in which message overtaking is performed. Further, there is no need to interrupt the message transmission / reception processing. Unlike the specific example 6, in this method, “P
Reporting to the decision process of "state of E" and "copy of normal message" is done at once. A large amount of data is transmitted and received intensively at a certain time. Some computer systems have a network for intensive large-capacity communication separately from that for normal message communication. The method is particularly suitable for such systems.
In some cases, it is not necessary to collect the determined global states in one place (decision process). This method is also suitable in this case.

<Embodiment 8> As can be seen from the explanations of Embodiments 6 and 7, there are at most two generations of weight in any scene. The decision process is the same generation and the previous generation. If the two generations can be distinguished, the global state can be determined by the methods described in the specific examples 6 and 7. For this purpose, 3
Create a generation. For example, weights are distinguished in a manner such as 0 → 1 → 2 → 0 → 1 →.

The processing relating to the generation of the weight is performed as follows. The processing to advance the generation of the weight by one is “set to 1 if the weight is 0”, “set to 2 if the weight is 1”, “set the weight to 2”.
Then, set to 0. " The process of comparing the generations of weights is “1 is newer when the weight is 0 and 1”, and “1
And 2 are newer ”and“ 0 is newer when the weight is 2 and 0 ”. FIG. 28 shows an example of the change of the generation in the specific example 8 as described above.

<Effect of Embodiment 8> According to this method, 3
Since only the kind of symbol is required, the generations of the specific examples 6 and 7 can be realized with a small information amount of 2 bits.

<Specific Examples 9 to 13> The specific examples 9 to 13 relate to a method of “setting a checkpoint and re-executing processing from the set checkpoint” in a multiprocessor system that performs inter-processor processing by asynchronous message communication. It is. (Calculation model) Here, the following calculation model is set. A finite number of processors (hereinafter abbreviated as PE) are connected to each other by a logical communication channel (network channel). No assumptions are made about the physical communication path. -PEs communicate with each other by asynchronous message communication. -Messages may be overtaken on the communication channel. There is no guarantee that messages will arrive in the order in which they were sent. -There is no clock that controls the entire system, and each PE and network channel operate individually according to their clocks. -Each PE can send a message to all other PEs. In addition, the user's status and the received message can be recorded in the internal memory. There is a special process (called a control process) that issues a checkpoint setting and re-execution instruction. The control process and all PEs can communicate with each other.

(Setting of Checkpoint) The checkpoint in this specific example is "a consistent set of states of all PEs and states of all communication channels".
It is not a "set of states at a certain moment". This is because there is no clock for controlling the entire system, and there is no time common to each PE and the communication channel. The state of a certain communication channel means that the transmitting PE of the channel transmits before recording its own state as a checkpoint element, and the receiving PE receives after recording its own state as a checkpoint element. It is a set of messages.

FIG. 29 is an explanatory diagram of message transmission / reception and PE state change. In (a) of the figure, PEa, PE
The states of b and PEc are A0, B0 and C0, respectively.
In (b), PEa and PEb are the respective messages Ma.
b, Mbc was sent. The states of PEa and PEb each changed due to message transmission. In (C), the state of PEb and PEc has changed after receiving the message.

FIG. 30 is a view for explaining an example of a correct check point. For example, any of the following are valid checkpoints: The following is the state shown by the dashed line in FIG. (A) PEa A0, PEb B0, PEc C0 (b) PEa A0, PEb B1, PEc C0, CHbc:
Mbc (c) PEa A1, PEb B1, PEc C0, CHab:
Mab, CHbc: Mbc (d) PEa A1, PEb B1, PEc C1, CHab:
Mab PEa, PEb, PEc are PE, CHab :, C
Hbc: indicates the state of the communication channel. CHbc: Mbc means that the message Mbc exists on the channel CHbc.

On the other hand, the following are incorrect checkpoints. FIG. 31 illustrates an example of an incorrect checkpoint. (E) PEa A0, PEb B0, PEc C1, CHbc:
Mbc (f) PEa A1, PEb B2, PEc C1, CHab:
Mab Finding the correct checkpoint as described above is the setting of the checkpoint.

(Re-execution) Returning all PE states and messages to the state of "set checkpoint" is re-execution. This means, for example, that each PE records “its own state” (of the checkpoint components) and “the state of the communication channel to itself” and gives an instruction from the control process to the recorded state. It can be realized by returning. (Setting of checkpoint) The start of the process can be instructed by the control process sending an instruction message to all PEs. The difficulty is after the process is started. (Determination of transmission before / after state recording) Consider a PE that receives an instruction message from a control process and records its state as a component of a checkpoint. When this PE receives a message from another PE, it must know whether the message is: (A) A message sent before the sender records its state. (B) A message sent after the sender records its state. (A) If it is a checkpoint component, it must be recorded. No. On the other hand, in the case of (B), since it is not a component of the checkpoint, it must not be recorded.

(Detection of Checkpoint Setting End) It must be possible to detect that all the components of the checkpoint have been recorded. If this detection is not possible, there are the following problems. -The checkpoint that has been set (should be) cannot be used. For example, the re-execution process cannot be started. -Checkpoint cannot be set again. -The control data used for the checkpoint setting process cannot be released. It can be easily detected that all the states of the PE have been recorded.
This is because the control process only needs to be notified from all the PEs. Difficult is the condition of the communication channel. It must be possible to detect that all the messages transmitted by the source PE before the status recording arrive at the destination PE and are recorded.

(Re-execution) (Determination of transmission before / after state recording) Consider a PE that has received an instruction message from the control process and returned the state of the PE to the “set checkpoint”. This PE is another PE
When a message is received from, it must know whether the message is: (A) A message sent before the sender returns its status to the checkpoint. (B) A message sent after the sender returns its status to the checkpoint. The message of (A) is processed. Do not. on the other hand,
If it is (B), it is necessary to process.

(Detection of Start of Re-execution) It must be possible to detect that the start of re-execution has been completed. Completion of the start of the re-execution means the following state. -The status of all PEs returns to "set checkpoint". -PE before returning the status to "set checkpoint"
The message sent by is no longer on the communication channel. If the completion of the rerun has not been confirmed,
Messages that should not be processed may exist on the communication channel. Therefore, if the completion of the re-execution is not detected, the following problem occurs. -Checkpoint cannot be set again. -It is not possible to release the control data used for the re-execution start processing.

(Comparative technique) In the "model in which messages are received in the order of transmission", the following literature describes a method of performing "set checkpoint and re-execute processing". Higaki, H., Shima, K., Tachikawa, T. and
Takizawa, M., “Asynchronous Recovery in Distribut
ed Systems, "Transaction Workshop on Multimedia Communication and Distributed Processing, pp.151-158, Information Processing Society of Japan, 1996.
However, this has the following problems. -Assuming that "messages are received in the order in which they are sent", it is only applicable to systems that do not overtake messages. The amount of information that each PE must have to set a checkpoint and re-execute processing is proportional to the number of PEs. For this reason, as the number of PEs increases, information to be held increases. -The number of messages needed to detect the completion of the start of the re-execution is proportional to the number of communication channels. The number of communication channels is generally proportional to the square of the number of PEs. For this reason, as the number of processes increases, an enormous number of messages are required.

(Characteristics of the following specific example) In contrast, the following specific example provides a processing method having the following characteristics. -It can also be applied to systems that pass messages. The amount of information that each PE must have in order to set a checkpoint and re-execute processing is constant regardless of the number of PEs. The completion of the start of re-execution can be detected with a number of messages proportional to the number of PEs.

(Specific Configuration) In this specific example, a method in which one PE has only one checkpoint will be described. If checkpoint B is further set while checkpoint A has already been set, previous checkpoint A is cleared. First, "set checkpoint" is performed, but after that, "set checkpoint" and "re-execute" may be performed in any order. A situation where two processes are being performed at the same time is not recognized. Certain "checkpoint setting or re-execution"
Starts after confirming that "checkpoint setting or re-execution" immediately before is completed. This check is performed by a weighting method. First, the weighting method will be described, and then five specific examples will be described. In the description, a normal message and a control message are used in the following meaning. Normal message: A message for performing normal processing. P
Group E transmits and receives each other. Control message: A message for setting and re-executing checkpoints. The control process and the PEs transmit and receive each other.

(Weighting Method) Each of the control process, the PE, and the message has a weight. Initially, each weight is set so that the sum of all weights is "a certain fixed value". Each PE and the control process perform the following processing on the weights, and maintain a state where the sum of all weights is “a certain fixed value”. When sending a message, weight the message and reduce its own weight. -When a message is received, the weight attached to the message is added to its own weight. As a result, "the weight of the control process is" a certain fixed value "" means that there is no message on the network channel and that the weight of all PEs is zero at the same time. means. For this reason, this method "the message no longer exists on the network channel"
Can be detected.

For example, the following two methods can be considered for assigning weights. (A) The sum of the weights is zero. The control process weight is set to a negative integer and the other two are set to positive integers. (B) The sum of the weights is 1. Each weight is set to 0 or more and 1 or less. FIG. 32 shows an example of the weighting method using the above (a). In the figure, in (a), PEa is a message (Me
ssage). The message is given a weight of 150. PEc receives the message and adds weight 150 to 900. PEb sent all weights 500 to the control process on return. The control process received the return and added the weight to -1600.

<Structure of Embodiment 9> Here, a basic method will be described. This is a method in which the control process sends a control message notifying the start of processing to all PEs when setting a checkpoint or starting re-execution. (Configuration) The control process, the PE, and the message have weight. Initialization of each weight is performed so that the sum of the weights is “a certain fixed value”. Weights have generations.
Initialize all weights to the same generation. The control process has an old generation weight counter. The old generation weight counter is used to detect that a message or PE having the weight of the previous generation no longer exists. Each PE has the following flags and buffers. Status flag: When a normal message of a different generation is received, the processing to be performed is determined by the value of this flag. Take either the value of C or R. Status buffer: "My status" and "copy of normal message" are recorded in this buffer. The set of contents of this buffer constitutes a checkpoint.

(Operation of Control Process) Setting of Checkpoint The setting of the checkpoint is started by the following processing, and the completion of the setting is confirmed. (Start of setting) Perform the following processing. 1. A checkpoint (checkpoint) control message (hereinafter abbreviated as checkpoint) is transmitted to all the PEs, and waits until a checkpoint recognition (ackCheckpoint) control message (hereinafter abbreviated as ackCheckpoint) is received from all the PEs. 2. Set your own weight in the old generation weight counter. 3. Set your weight to "a certain fixed value". 4. Advance one generation of your weight. 5. A record control message (hereinafter abbreviated as record) is transmitted to all PEs. Record is weighted, and your weight is reduced accordingly. The generation of the weight of the record is one ahead of the generation of the weight of the old generation weight counter.

(Confirmation of Setting Completion) Upon receiving a return control message (hereinafter abbreviated as “return”), the weight carried by return is added to the old generation weight counter. As a result, when the value of the old generation weight counter becomes “a certain fixed value”, it can be confirmed that the setting of the checkpoint is completed. A set of contents of the status buffer of each PE at the time of confirming completion constitutes a checkpoint.

(Re-execution) Re-execution is started by the following processing, and it is confirmed that the re-execution has been started. (Start of re-execution) The following processing is performed. 1. Re-execution preparation (rollback) control message (hereinafter, roll
back to all PEs, and waits until a re-execution preparation recognition (ackRollback) control message (hereinafter abbreviated as ackRollback) is received from all PEs. 2. Set your own weight in the old generation weight counter. 3. Set your weight to "a certain fixed value". 4. Advance one generation of your weight. 5. Reexecute control message (hereinafter reexec)
ute) is sent to all PEs. Reexecute is weighted and your weight is reduced accordingly. reexecut
The weight generation of e is one ahead of the weight generation of the old generation weight counter. (Confirmation of completion of re-execution) When return is received, the weight carried by return is added to the old-generation weight counter. As a result of the addition, the value of the old generation weight counter becomes "a certain fixed value"
When it becomes, it can be confirmed that the start of re-execution has been completed.

(Operation of PE) When the checkpoint is received,
Set the status flag to C and return ackCheckpoint to the control process. When record is received, "the generation of the weight that record has" and "the generation of its own weight" are compared, and the following processing is performed. If the “record weight generation” is new, the following processing is performed. 1. Clear the status buffer. 2. Record your status in the status buffer. 3. Return your weight to the control process by return. 4. Reset your weight with the weight of record. By this processing, the generation of the own weight is advanced by one. If the two generations are equal, add the weight of record to your weight. It should be noted that this is the "other P that received the record.
This is a case where the normal message (the weight generation is advanced by one) transmitted by E arrives before record.

When the rollback is received, the status flag is set to R, and ackRollback is sent to the control process. reexecut
When e is received, the "generation of the weight held by reexecute" is compared with the "generation of its own weight", and the following processing is performed. If the "reexecute weight generation" is new, perform the following processing. 1. Reset your state with the contents of the state buffer. Thus, re-execution from the state recorded in the state buffer starts. 2. Return your weight to the control process by return. 3. Reset your weight with the reexecute weight. By this processing, the generation of the own weight is advanced by one. If the two generations are equal, add the weight of reexecute to your weight. Note that this is the case where the “normal message (the weight generation is advanced by one) transmitted by another PE that has received the reexecute” has arrived before the reexecute.

When the normal message is received, the "generation of the weight of the normal message" is compared with the "generation of its own weight", and the following processing is performed. If the "own weight generation" is new and the status flag is C, the following processing is performed.
Note that this means that "other PEs that have not yet received the record
Normal message sent by (previous weight generation remains) "
Is a case where a record has been received and arrived at the PE that has begun setting a checkpoint. 1. Normally the weight of the message is sent to the control process by return. 2. Record the contents of the normal message in the status buffer. 3. Process normal messages. If “own weight generation” is new and status flag is R,
Normally the weight of the message is sent to the control process by return.
Normally, the message itself is discarded without processing. Do not process this regular message because you have already started the rerun. Note that this is a case where the “normal message transmitted by another PE that has not received the reexecute yet (the weight generation remains the same)” arrives at the PE that has received the reexecute and has begun re-execution. .

If the "normal message weight generation" is new and the status flag is C, the following processing is performed. This is the case where the “normal message (the weight generation is advanced by one) transmitted by another PE that has received the record” arrives before the record. 1. Clear the status buffer. 2. Record your status in the status buffer. 3. Return your weight to the control process by return. 4. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 5. Process normal messages.

If the "normal message weight generation" is new and the status flag is R, the following processing is performed. This is because “the normal message transmitted by another PE that received reexecute (the generation of the weight is advanced by one)” is the reex
This is when it arrives before ecute. 1. Reset your state with the contents of the state buffer. Thus, re-execution from the state recorded in the state buffer starts. 2. Return your weight to the control process by return. 3. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 4. Process normal messages. If the two generations are equal, the following processing is performed. 1. Usually adds the weight of the message to its own weight. 2. Process normal messages.

FIGS. 33, 34 and 35 are explanatory diagrams of an example of “setting of checkpoint”. In each figure: Old = 2200 means that the value of the old generation weight counter is 220
Indicates that it is 0. W = 500n indicates "new generation weight 500". W = 800o indicates "weight of previous generation 800". Record (B0) indicates that B0 has been recorded in the status buffer. Msg indicates a normal message.

In FIG. 33A, the control process is as follows.
Record was sent to all PEs. Next, in FIG. 33B, the record arrives at PEb and PEc. PEb and PEc each recorded their status and returned their weights to the control process. Next, in FIG.
PEa and PEc have transmitted the normal messages msg1,2,3. The state of the PE has changed due to the transmission. ms
g1 and msg3 have the weight of the new generation, and msg2 has the weight of the previous generation. Proceeding to (b) of FIG. 34, msg1 having the weight of the new generation arrives at PEa whose weight is still the previous generation. PEa recorded the state and returned its weight to the control process.

In FIG. 35A, msg2 having the weight of the previous generation has arrived at PEb having the weight of the new generation. PEb recorded msg2 and returned the weight of msg2 to the control process. Thus, in FIG. 35 (b), it was confirmed that the control process received the return, the result of the weight addition became zero, and the checkpoint setting was completed. Thus, a consistent set of the states of the PE and the communication channel was obtained.

FIG. 36 is an explanatory diagram of the check point setting example of the specific example 9 viewed in the time axis direction. FIG. 37 is an explanatory diagram showing an example of re-execution of the specific example 9 in the same format as that of FIG.

<Effect of Embodiment 9> This method has the following effects. -It can also be applied to systems that pass messages. The information that each PE must have specially in order to set a checkpoint and re-execute the processing is only the “state flag value” and the “weight with generation”. These are P
It is constant regardless of the number of E. -The message required to detect the completion of the start of re-execution is "return". The number of transmitted messages is the sum of the number of PEs and the number of normal messages having the weight of the generation before being received during the re-execution processing. Each is proportional to the number of PEs. Since the status flag takes only two values, C and R, it can be realized with one bit.

<Specific Example 10> In the method described in Specific Example 9, when setting a checkpoint or starting re-execution, the control process first transmits checkpoint or rollback to set the value of the status flag of each PE. Needed. Here, a method in which such a status flag value setting message is unnecessary will be described.

(Configuration) The control process, the PE, and the message have weights. The sum of the weights is "a certain fixed value"
Initialization of each weight is performed so that Weights have generations. Initialize all weights to the same generation. The control process has an old generation weight counter. The old generation weight counter is used to detect that a message or PE having the weight of the previous generation no longer exists. Each PE has the following flags and buffers. Status flag: When a normal message of a different generation is received, the processing to be performed is determined by the value of this flag. Take either the value of C or R. Status buffer: "My status" and "copy of normal message" are recorded in this buffer. The set of contents of this buffer constitutes a checkpoint. Message buffer: Stores a normal message having a newer generation weight than its own weight. Cleared by initialization processing.

(Operation of Control Process) (Setting of Checkpoint) Setting of a checkpoint is started by the following processing, and completion of the setting is confirmed. (Start of setting) Perform the following processing. 1. Set your own weight in the old generation weight counter. 2. Set your weight to "a certain fixed value". 3. Advance one generation of your weight. 4. Send record to all PEs. Record is weighted, and your weight is reduced accordingly. The generation of the weight of the record is one ahead of the generation of the weight of the old generation weight counter. (Confirmation of setting completion) When return is received, the weight carried by return is added to the old generation weight counter. As a result, when the value of the old generation weight counter becomes "a certain fixed value", it can be confirmed that the checkpoint setting is completed. A set of contents of the status buffer of each PE at the time of confirming completion constitutes a checkpoint.

(Re-execution) Re-execution is started by the following processing, and it is confirmed that the re-execution has been started. (Start of re-execution) The following processing is performed. 1. Set your own weight in the old generation weight counter. 2. Set your weight to "a certain fixed value". 3. Advance one generation of your weight. 4. Send reexecute to all PEs. Reexecute is weighted and your weight is reduced accordingly. reexec
The generation of the weight of ute is one ahead of the generation of the weight of the old generation weight counter. (Confirmation of completion of re-execution) When return is received, the weight carried by return is added to the old-generation weight counter. As a result of the addition, the value of the old generation weight counter becomes "a certain fixed value"
When it becomes, it can be confirmed that the start of re-execution has been completed.

(Operation of PE) When record is received, the following processing is performed. The record weight generation is newer than the PE weight generation. 1. Set the status flag to C. 2. Clear the status buffer. 3. Record your status in the status buffer. 4. Return your weight to the control process by return. 5. Reset your weight with the weight of record. By this processing, the generation of the own weight is advanced by one. 6. If normal messages are stored in the message buffer, the following processing is performed for each of them. At this point, the generation of the own weight and the weight of the normal message are equal. (A) Add the weight of the normal message to its own weight. (B) Process normal messages. (C) Clear the message buffer.

When the reexecute is received, the following processing is performed. The weight generation of reexecute is newer than the generation of PE weights. 1. Set the status flag to R. 2. Reset your state with the contents of the state buffer. Thus, re-execution from the state recorded in the state buffer starts. 3. Return your weight to the control process by return. 4. Reset your weight with the reexecute weight. By this processing, the generation of the own weight is advanced by one. 5. If normal messages are stored in the message buffer, the following processing is performed for each of them. At this point, the generation of the own weight and the weight of the normal message are equal. (A) Add the weight of the normal message to its own weight. (B) Process normal messages. (C) Clear the message buffer.

When the normal message is received, the "generation of the weight of the normal message" is compared with the "generation of its own weight", and the following processing is performed. If the "own weight generation" is new and the status flag is C, the following processing is performed. 1. Normally the weight of the message is sent to the control process by return. 2. Record the contents of the normal message in the status buffer. 3. Process normal messages. If “own weight generation” is new and status flag is R,
Normally the weight of the message is sent to the control process by return.
Normally messages are discarded without processing. If the generation of the weight of the normal message is new, the normal message is stored in the message buffer without processing. If the two generations are equal, the following processing is performed. 1. Usually adds the weight of the message to its own weight. 2. Process normal messages.

FIG. 38 is an explanatory diagram showing a check point setting example of the specific example 10 viewed in the time axis direction. FIG.
38 is an explanatory diagram showing an example of re-execution of the specific example 10 in the same format as in FIG.

<Effect of Embodiment 10> In the present method, the status flag is set by record or execute reception. As a result, unlike the method shown in the specific example 9, the status flag value setting message (checkpoint, roll
back) is no longer needed. The PE receiving the record or execute can send a normal message at any time.
And the sent normal message is "record or
It is possible to arrive at a PE that has not yet received a reexecute. "PEs that have not received record or reexecute" do not know how to process the received normal message because the status flag is not set correctly. In the method shown in the specific example 9, the above situation was dealt with by "transmitting a status flag value setting message, setting a status flag, and then transmitting record or execute". In this method, we dealt with the problem by "waiting for the processing of a normal message that arrives before the record and reexecute until the record or execute is received."

FIG. 40 is an explanatory diagram of processing when a message of a new generation is received in the specific example 10.
(A) is an explanatory diagram at the time of setting a checkpoint. The new generation msg is stored and held in the message buffer, and the subsequent record reception indicates that a checkpoint has been set, records its state Aj in the state buffer, and returns its weight by return. (B) is an explanatory diagram in the case of re-execution. After storing a new generation of msg in the message buffer, I received a reexecute and found that it was a re-execution, reset my state with the contents of the state buffer, and returned my weight with return. The method has the following effects. -It can also be applied to systems that pass messages. The information that each PE must have specially in order to set a checkpoint and re-execute the processing is only the “state flag value” and the “weight with generation”. These are P
It is constant regardless of the number of E. -The message required to detect the completion of the start of re-execution is "return". The number of transmitted messages is the sum of the number of PEs and the number of “normal messages having the weight of the previous generation” received during the re-execution processing. Each is proportional to the number of PEs. Unlike the specific example 9, the status flag value setting message (checkpoint, rollback) is not required. Since the status flag takes only two values, C and R, it can be realized with one bit.

<Embodiment 11> In the method described in Embodiment 9, each PE has a status flag, and when the setting of a checkpoint or the re-execution is started, the control process causes the status flag value setting message (checkpoint, rollback) to set the status flag value. Example 10
In the method described above, the message for setting the status flag value is unnecessary, but the status flag is required. Here, a method in which neither the status flag nor the status flag value setting message is required will be described.

(Structure) The control process, the PE, and the message have weight. The sum of the weights is "a certain fixed value"
Initialization of each weight is performed so that Weights have generations. Initialize all weights to the same generation. The control process has an old generation weight counter. The old generation weight counter is used to detect that a message or PE having the weight of the previous generation no longer exists. Each PE has a status buffer. This buffer contains "your state"
And "copy of normal message". The set of contents of this buffer constitutes a checkpoint.

(Operation of Control Process) (Check Point Setting) Check point setting is started by the following processing, and completion of setting is confirmed. (Start of setting) Perform the following processing. 1. Set your own weight in the old generation weight counter. 2. Set your weight to "a certain fixed value". 3. Advance one generation of your weight. 4. Send record to all PEs. Record is weighted, and your weight is reduced accordingly. The generation of the weight of the record is one ahead of the generation of the weight of the old generation weight counter. (Confirmation of completion of setting) When return is received, the weight carried by return is added to the old generation weight counter. As a result, when the value of the old generation weight counter becomes "a certain fixed value", it can be confirmed that the checkpoint setting is completed. A set of contents of the status buffer of each PE at the time of confirming completion can constitute a checkpoint.

(Re-execution) Re-execution is started by the following processing, and it is confirmed that the re-execution has been started. (Start of re-execution) The following processing is performed. 1. Set your own weight in the old generation weight counter. 2. Set your weight to "a certain fixed value". 3. Advance two generations of your own weight. 4. Send reexecute to all PEs. Reexecute is weighted and your weight is reduced accordingly. reexec
The generation of the weight of ute is ahead of the generation of the weight of the old generation weight counter by two. (Confirmation of completion of re-execution) When return is received, the weight carried by return is added to the old-generation weight counter. As a result of the addition, the value of the old generation weight counter becomes "a certain fixed value"
When it becomes, it can be confirmed that the start of re-execution has been completed.

(Operation of PE) When record is received, "re
The generation of weight that cord has and the generation of its own weight
And performs the following processing. "Generation of record weights"
If is new, the following processing is performed. 1. Clear the status buffer. 2. Record your status in the status buffer. 3. Return your weight to the control process by return. 4. Reset your weight with the weight of record. By this processing, the generation of the own weight is advanced by one. If the two generations are equal, add the weight of record to your weight. When the reexecute is received, the “generation of the weight that reexecute has” and the “generation of its own weight” are compared, and the following processing is performed. If the "reexecute weight generation" is new, perform the following processing. 1. Reset your state with the contents of the state buffer. Thus, re-execution from the state recorded in the state buffer starts. 2. Return your weight to the control process by return. 3. Reset your weight with the reexecute weight. By this processing, the generation of the own weight advances by two. If the two generations are equal, add the weight of reexecute to your weight.

When a normal message is received, the "generation of the weight of the normal message" is compared with the "generation of its own weight", and the following processing is performed. If the “own weight generation” is newer by one generation, the following processing is performed. 1. Normally the weight of the message is sent to the control process by return. 2. Record the contents of the normal message in the status buffer. 3. Process normal messages. If the "generation of own weight" is new by two generations, the weight of the normal message is sent to the control process by return. Normally, the message itself is discarded without processing.

If the "generation of the weight of the normal message" is newer by one generation, the following processing is performed. 1. Clear the status buffer. 2. Record your status in the status buffer. 3. Return your weight to the control process by return. 4. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 5. Process normal messages. If the "normal message weight generation" is newer by two generations, the following processing is performed. 1. Reset your state with the contents of the state buffer. Thus, re-execution from the state recorded in the state buffer starts. 2. Return your weight to the control process by return. 3. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight advances by two. 4. Process normal messages. If the two generations are equal, the following processing is performed. 1. Usually adds the weight of the message to its own weight. 2. Process normal messages.

FIG. 41 is an explanatory diagram of the specific example 11 when a new generation normal message is received. (A) is an explanatory diagram of a checkpoint setting process. Since the msg of the generation i + 1 arrived at the PE of the generation i, it was found that the checkpoint was set. On the other hand, (b)
FIG. 9 is an explanatory diagram of a re-execution process. For the PE whose generation is i,
It was found that the msg of generation i + 2 arrived and was re-executed.

<Effect of Specific Example 11> When a PE receives a normal message of a different generation, it must be able to determine whether to perform "checkpoint setting" or "re-execution". In the methods shown in the specific examples 9 and 10, the PE is provided with a status flag, and the determination is made by setting the value of the flag by a message from the control process. On the other hand, this method dealt with how to change the generation.
Change the size of the generation by "checkpoint setting" and "re-execute".
By re-executing the process, two steps can be performed) so that only the generation can determine which one is the re-execution.

As a result, the present method has the following features. -It can also be applied to systems that pass messages. The only information that each PE must have specially in order to set a checkpoint and re-execute processing is the "weight with generation". These are constant regardless of the number of PEs. -The message required to detect the completion of the start of re-execution is "return". The number of transmitted messages is the sum of the number of PEs and the number of normal messages having the weight of the generation before reception during the re-execution processing. Both are PE
It is proportional to the number. Unlike the specific example 9, the PE does not need to have the flag indicating the state, and there is no need to change the flag value.

<Embodiment 12> In the methods described in Embodiments 9 and 10, there are only two generations of weight at most in any scene. The control process is the same generation and the previous generation. Therefore, if there are three generations, checkpoint setting and re-execution can be performed by the methods described in the specific examples 9 and 10. (Configuration) Only three generations are provided as weight generations. For example, 0 → 1 → 2 → 0 → 1 →. (Operation) The processing related to the generation of the weight is performed as follows. Processing to advance the generation of weights: "If 0, set to 1""1 if set to 2""2 if set to 0" Processing to compare weight generation: "1 is newer between 0 and 1""2 is newer in 1 and 2""0 is newer in 2 and 0"

FIG. 42 shows how the weight generation changes. FIG. 42 is an explanatory diagram illustrating a state of a change in the weight generation in the specific example 12. For example, when the control process transmits record in the state of (1), the generation is advanced by one and the state becomes the state of (2). When the checkpoint setting is completed, PE
The message generation is also new and is in the state (3). Next, when re-execution or checkpoint setting is started again, the control process advances the generation by one and enters the state (4). After that, at the stage when the re-execution is started or the checkpoint setting is completed, the generations of the PE and the message are also new and are in the state (5). The generation of the weight can be designated by any number or symbol other than 0, 1, and 2.

<Effect of Specific Example 12> Only three generations need to be weighted. This means that only two bits are needed.

<Thirteenth Embodiment> In the method described in the eleventh embodiment, as in the ninth and tenth embodiments, there are at most two generations of weight in any scene. However, unlike the specific examples 9 and 10, the following two patterns exist. -"Same generation" and "one previous generation" with the control process-"Same generation" and "two previous generations" with the control process A total of five to judge the new or old for two generations one or two generations apart One generation is needed. By preparing five generations, checkpoint setting and re-execution can be performed by the method described in the specific example 11.

(Configuration) Only five generations are provided as weight generations. For example, 0 → 1 → 2 → 3 → 4 → 0 → 1 → 2 →. (Operation) The processing relating to the generation of weights is described below. Processing to advance weight generation by one: "If 0, set to 1"
"If 1 then 2""2 if 3""3 if 4""4 if 0" Processing to advance two weight generations: "If 0, then 2"
"3 if 1""4 if 2""0 if 3""1 if 4" Processing to compare weight generations: "1 between 0 and 1 is 1""Newgeneration""2 is 1 generation new in 1 and 2""3 is 1 generation new in 2 and 3""4 is 1 in 3 and 4"
"New generation""0 is one generation newer in 4 and 0""0
In 2 and 4, 2 is newer by 2 generations. "In 1 and 3, 3 is newer by 2 generations.""In 2 and 4, 4 is newer by 2 generations."
"In 3 and 0, 0 is 2 generations newer""4 and 1 is 2 generations newer"

FIG. 43 shows an example of how the weight generation changes. FIG. 43 is an explanatory diagram showing how the weight generation changes in Example 13. For example, when the control process transmits record in the state of (1), the generation is advanced by one and the state becomes (2). When the checkpoint setting is completed, the PE and message generations are new (3)
It is a state of. When re-execution is started this time, the control process advances the generation by two, and enters the state (4). This is P
E can distinguish between the re-execution start state and the checkpoint setting state even if the normal message is received before the re-execute. When the control process confirms that the rerun has started,
The generations of PEs and messages are also advanced by two, and are in the state of (5). Hereinafter, similarly, for example, (6) and (7)
(8) The generation change of (9) occurs. Note that the generation of weights does not have to use numbers such as 0, 1, 2, 3, and 4. Any number and symbol may be used.

<Effect of Specific Example 13> Only five generations need to be weighted. This means that only three bits are needed. Note that the above specific examples 9 to 13 all have the following common effects. -It can also be applied to systems that pass messages. The amount of information that each PE must have in order to set a checkpoint and re-execute processing is constant regardless of the number of PEs. -The number of messages needed to detect the completion of the start of re-execution is proportional to the number of PEs.

<Specific Examples 14 to 19> A method in which one PE has a plurality of check points will be described. If checkpoint A is already set and checkpoint B is set, A will not be cleared and B
Is set. The first thing to do is "set checkpoints", but then "set checkpoints"
And "re-execute" may be performed in any order. A situation where two processes are being performed at the same time is not recognized. Certain "checkpoint setting or re-execution"
Starts after confirming that "checkpoint setting or re-execution" immediately before is completed. This confirmation is performed by a weighting method.

<Example 14> Here, a basic method in which the control process sends a control message notifying the start of processing to all PEs when setting a checkpoint or starting re-execution will be described. Each checkpoint is an ID for identification
have. This ID is specified at the time of setting. When performing re-execution, since a plurality of check points are generally set, the check point at which re-execution is started is designated by ID.

(Structure) The structure is the same as that of the ninth embodiment.
Each PE has a status record for storing a checkpoint instead of the status buffer of the ninth embodiment. The status record is
It consists of the following two fields and has an ID register that records the checkpoint to be set or the checkpointID indicating the checkpoint to start re-executing. ID field: Checkpoint ID (hereinafter, checkpoi
ntID). Status field: "My status" and "copy of normal message" are recorded in this field, and the set of contents constitutes a checkpoint. When the status record is allocated, it is cleared.

(Operation of Control Process) (Setting of Checkpoint) (Start of Setting) Determine the checkpoint ID to be set (called checkpointID). 2. A checkpoint control message (hereinafter abbreviated as checkpoint) is transmitted to all PEs. checkpoint is checkpoi
It has ntID as an argument. 3. It waits until an ackCheckpoint control message (hereinafter abbreviated as ackCheckpoint) is received from all PEs. Thereafter, the processing of 2 to 5 described in the specific example 9 (start of setting) is performed in the same manner. (Confirmation of Setting Completion) Since confirmation is performed in the same manner as in Example 9, the description is omitted.

(Re-execution) Re-execution can be started from any of the checkpoints that have been set. Specify the checkpointID to indicate the re-execution start check point. (Start of re-execution) A checkpoint to start re-execution is determined, and a checkpointID indicating the checkpoint is obtained. 2. A rollback control message (hereinafter abbreviated as rollback) is transmitted to all PEs. rollback has checkpointID indicating a checkpoint as an argument. 3. It waits until an ackRollback control message (hereinafter abbreviated as ackRollback) is received from all PEs. Thereafter, the processing of 2 to 5 described in the specific example 9 (start of re-execution) is performed in the same manner. (Confirmation of completion of re-execution) Since it is performed in the same manner as in the ninth embodiment, the description is omitted.

(Operation of PE) a: When a checkpoint is received, the following processing is performed. 1. Set the status flag to C. 2. The checkpoint ID carried by checkpoint is recorded in the ID register. 3. Allocate a new status record, ch to ID field
Record the eckpointID. 4. Return ackCheckpoint to the control process.

B: When record is received, “the generation of the weight that record has” and “the generation of its own weight” are compared.
One of the following three processes is performed. New generation of record weight Record your status in the status field of the status record indicated by the ID register. 2. Return your weight to the control process by return. 3. Reset your weight with the weight of record. By this processing, the generation of the own weight is advanced by one. Two generations are equal Add the weight of record to your own weight. “Generation of own weight” is new Send the weight of record to the control process by return.

C: When rollback is received, the following processing is performed. 1. Set the status flag to R. 2. The checkpointID carried by rollback is recorded in the ID register. 3. Send ackRollback to the control process.

D: When reexecute is received, "reexecu
The weight generation of te ”is compared with the“ own weight generation ”, and one of the following three processes is performed. “Reexecute weight generation” is new Reset your status with the contents of the status field of the status record indicated by the ID register. Thus, re-execution from the specified check point starts. 2. Return your weight to the control process by return. 3. Reset your weight with the reexecute weight. By this processing, the generation of the own weight is advanced by one. Two generations equal Add reexecute weight to their own weight. “Generation of own weight” is new Send the reexecute weight to the control process by return.

E: When a normal message is received, the "generation of the weight of the normal message" is compared with the "generation of its own weight", and one of the following five processes is performed. The “own weight generation” is new and the status flag is C1. Normally the weight of the message is sent to the control process by return. 2. The content of the normal message is recorded in the status field of the status record indicated by the ID register. 3. Process normal messages. The “own weight generation” is new and the status flag is R. As in the ninth embodiment, the weight of the normal message is sent to the control process by return. Normally, the message itself is discarded without processing. Do not process this regular message because you have already started the rerun. The "normal message weight generation" is new and the status flag is C1. Record your status in the status field of the status record indicated by the ID register. 2. Return your weight to the control process by return. 3. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 4. Process normal messages. The “normal message weight generation” is new and the status flag is R1. Reset your status with the contents of the status field of the status record indicated by the ID register. Thus, re-execution from the specified check point starts. 2. Return your weight to the control process by return. 3. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 4. Process normal messages. The following processes are performed in the same manner as in the ninth embodiment. 1. Usually adds the weight of the message to its own weight. 2. Process normal messages.

FIGS. 44 to 49 show processing examples. FIG.
In (a), the control process having a weight W of -2200o (o represents the weight of the previous generation) is performed for all PEs (500o
PEa with weight W of 900, PEb with weight W of 800o, 900o
Checkpoint (checkpointID = i)
d1) is sent. In FIG. 44 (b), checkpoi
Each PE recording the ntID returns an ackCheckpoint to the control process. In FIG. 45A, the control process transmits a record having a weight W of 500n to all PEs. By transmitting this record, the weight W of the control process is obtained.
Became -1500n. In FIG. 45 (b), since the generation of the weight W of the record is new, the PEb and PEc in which the record has arrived record their states (B0 for PEb and C0 for PEc) in the state buffer with the checkpoint ID of id1. (PEo is 800o, PEc is 900o) is sent to the control process by return. Further, each of the weights is set to the 500n weight W of the record.
And reset the weight by one.

In FIG. 46A, the normal messages msg1 to
The state of PEa and PEc that transmitted msg3 has changed due to transmission. In FIG. 46B, the weight W of the new generation
Arrives at the PEa having the weight W of the previous generation, the PEa records the state and returns its own weight to the control process. In FIG. 47A, the msg2 having the weight W of the previous generation has arrived at the PEb having the weight W of the new generation.
Is returned to the control process. In FIG. 47B, since the control process receives the return and adds the weight, the result becomes zero, and thus it is confirmed that the checkpoint setting is completed.

FIG. 48 is an explanatory diagram of the checkpoint setting example of the specific example 14 viewed in the time axis direction, and FIG. 49 is an explanatory diagram of the re-execution example of the specific example 14 viewed in the time axis direction as in FIG. It is.

(Effect) In addition to the effect of the ninth embodiment, one PE can have a plurality of check points.
The information that each PE must have specially in order to set a checkpoint and re-execute processing is described in “ID field of status record and chec stored in ID register.
kpointID "," state flag value ", and" weight with generation ". These are constant regardless of the number of PEs.

<Example 15> In the method described in Example 14, when setting a checkpoint or starting re-execution, the control process first transmits checkpoint or rollback to set the value of the status flag of each PE. Needed. Here, a method in which such a status flag value setting message is unnecessary will be described.

(Configuration) In addition to the configuration described in the embodiment 14, each PE has a message buffer. (Operation of control process) (Setting of checkpoint) (Start of setting) Send record to all PEs. record is checkp
Carry ointID. Record is weighted, and your weight is reduced accordingly. (Confirmation of Setting Completion) Since confirmation is performed in the same manner as in Example 9, the description is omitted.

(Re-execution) In order to perform the same operation as in the embodiment 14,
Description is omitted. (Start of re-execution) The following processing is performed. 1. A checkpoint to start re-execution is determined, and a checkpointID indicating the checkpoint is obtained. After this,
The processing of 2 to 5 described in the specific example 9 (start of re-execution) is similarly performed. (Confirmation of completion of re-execution) Since it is performed in the same manner as in the ninth embodiment, the description is omitted. (Operation of PE) When a: record is received, the following processing is performed. In addition, reco
The rd weight generation is newer than the PE weight generation. 1. Set the status flag to C. 2. Record the checkpointID carried by record in the ID register. 3. Allocate a new status record, ch to ID field
Record your status in the status field with the eckpointID. 4. Return your weight to the control process by return. 5. Reset your weight with the weight of record. By this processing, the generation of the own weight is advanced by one. 6. If normal messages are stored in the message buffer, the following processing is performed for each of them. At this point, the generation of the own weight and the weight of the normal message are equal. (A) Add the weight of the normal message to its own weight. (B) Process normal messages. (C) Clear the message buffer.

B: When reexecute is received, the following processing is performed. The regeneration weight generation is newer than the PE weight generation. 1. Set the status flag to R. 2. Reset your own status with the contents of the status field of the status record indicated by checkpointID carried by reexecute.
Thus, re-execution from the specified check point starts. 3. Return your weight to the control process by return. 4. Reset your weight with the reexecute weight. By this processing, the generation of the own weight is advanced by one. 5. If normal messages are stored in the message buffer, the following processing is performed for each of them. At this point, the generation of the own weight and the weight of the normal message are equal. (A) Add the weight of the normal message to its own weight. (B) Process normal messages. (C) Clear the message buffer.

C: When a normal message is received, the "generation of the weight of the normal message" is compared with the "generation of its own weight", and one of the following four processes is performed. The “own weight generation” is new and the status flag is C1. Normally the weight of the message is sent to the control process by return. 2. The content of the normal message is recorded in the status field of the status record indicated by the ID register. 3. Process normal messages. The “generation of own weight” is new and the status flag is R1. Normally the weight of the message is sent to the control process by return. Normally messages are discarded without processing. New generation of normal message weight The normal message is stored in the message buffer without processing. If the two generations are equal, the following processing is performed. 1. Usually adds the weight of the message to its own weight. 2. Process normal messages.

FIGS. 50 and 51 show processing examples. FIG.
0 is an explanatory diagram of the check point setting example of the specific example 15 as viewed in the time axis direction, and FIG. 51 is an explanatory diagram of a rerun example of the specific example 15 as viewed in the time axis direction as in FIG.

(Effect) The PE receiving record or reexecute can transmit a normal message at any time, and the transmitted normal message is “record or reexecute”.
It is possible to arrive at a PE that has not yet received a reexecute. The “PE that has not received record or reexecute” does not know how to process the received normal message because the status flag is not set correctly. You don't know if you should checkpoint or rerun. In this method, "re
The processing of the normal message that has arrived before the cord and reexecute is made to wait until a record or reexecute is received ”(see FIG. 52). ch
eckpoint, rollback) have an unnecessary effect. Each P to set checkpoints and re-execute processing
The information that E must have specially is "checkpointID stored in the ID field and ID register of the status record"
, The “state flag value”, and the weight with generation. These are constant regardless of the number of PEs.

<Embodiment 16> In the method described in Embodiment 15, processing of a normal message that has arrived before record and reexecute has to be made to wait until record or reexecute is received. A method that does not need to wait for processing even if a normal message is received will be described.

(Configuration) Each PE has a status switch in place of the status flag of the ninth embodiment. Status switch: Processing when sending a normal message,
Processing when a normal message of a different generation is received is determined by the value of this switch, and takes one of the values C, C ', R, and R'. The initial value is C.

(Operation of Control Process) (Setting of Checkpoint) (Start of Setting) Determine checkpointID indicating the checkpoint to be set. Thereafter, the description of the specific example 9 (start of setting) 2
To 5 are similarly performed. (Confirmation of Setting Completion) Since confirmation is performed in the same manner as in Example 9, the description is omitted. (Process after confirming the completion of setting) After confirming the completion of re-execution c
Send an ompleted control message (hereinafter abbreviated as completed) to all PEs. Weight completed and reduce your weight accordingly.

(Re-execution) (Start of re-execution) Since the process is performed in the same manner as in Example 14, the description is omitted. (Confirmation of Completion of Re-execution) Since the re-execution is performed in the same manner as in Example 9, the description is omitted. (Process after completion of re-execution) After confirming completion of re-execution
Send completed to all PEs. Weight completed and reduce your weight accordingly.

(Operation of PE) When a: record is received, “the generation of the weight held by record” is compared with “the generation of its own weight”, and one of the following three processes is performed. New generation of record weight Set the status switch to C '. 2. Record the checkpointID carried by record in the ID register. 3. Allocate a new status record, ch to ID field
Record your status in the status field with the eckpointID. 4. Return your weight to the control process by return. 5. Reset your weight with the weight of record. By this processing, the generation of the own weight is advanced by one. Two generations are equal Add the weight of record to your own weight. “Generation of own weight” is new Send the weight of record to the control process by return.

B: When reexecute is received, “reexecu
The weight generation of te ”is compared with the“ own weight generation ”, and one of the following three processes is performed. “Reexecute weight generation” is new Set the status switch to R '. 2. Record the checkpointID carried by reexecute in the ID register. 3. Reset your status using the contents of the status field of the status record indicated by checkpointID. Thus, re-execution from the specified check point starts. 4. Return your weight to the control process by return. 5. Reset your weight with the reexecute weight. By this processing, the generation of the own weight is advanced by one. Two generations are equal Add the reexecute weight to your weight. “Generation of own weight” is new Send the weight of record to the control process by return.

C: When completed is received, the following processing is performed according to the value of the state switch. In addition, completed
Is received only when the status switch is at C 'or R'. If the status switch is C ' Set the status switch to C. If the status switch is R'1. Set the status switch to R.

D: When a normal message is received, the "generation of the weight of the normal message" is compared with the "generation of its own weight", and one of the following five processes is performed. The “generation of own weight” is new and the state switch is C ′ Normally the weight of the message is sent to the control process by return. 2. The content of the normal message is recorded in the status field of the status record indicated by the ID register. 3. Process normal messages. The "own weight generation" is new and the state switch is R'1. Normally the weight of the message is sent to the control process by return. Normally messages are discarded without processing. The “normal message weight generation” is new and the “normal message state switch” is C ′ 1. Set the status switch to C '. 2. The checkpointID carried by the normal message is recorded in the ID register. 3. Allocate a new status record, ch to ID field
Record your status in the status field with the eckpointID. 4. Return your weight to the control process by return. 5. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 6. Process normal messages. The "normal message weight generation" is new and the "normal message state switch" is R'1. Set the status switch to R '. 2. The checkpointID carried by the normal message is recorded in the ID register. 3. Reset your status using the contents of the status field of the status record indicated by checkpointID. Thus, re-execution from the specified check point starts. 4. Return your weight to the control process by return. 5. Reset your own weight to the weight of the normal message.
By this processing, the generation of the own weight is advanced by one. 6. Process normal messages. Two generations are equal Usually adds the weight of the message to its own weight. 2. Process normal messages.

(Normal message transmission) If the status switch is C 'or R', two values of the status switch value (C 'or R') and the checkpoint ID recorded in the ID register are added to the message and transmitted.

FIGS. 53 and 54 show processing examples. FIG.
3 is an explanatory diagram of the checkpoint setting example of the specific example 16 viewed in the time axis direction, and FIG. 54 is an explanatory diagram of the re-execution example of the specific example 16 viewed in the time axis direction as in FIG.

(Effect) In this method, the normal message (sent when the status switch is C 'or R') also carries the value of the status switch and the checkpointID. The information of "whether to perform checkpoint setting or re-execution" and the checkpoint ID are transmitted to the PE not only by record or reexecute but also by a normal message. As a result, unlike the method shown in Embodiment 15, any ordinary message can be immediately processed,
Further, there is an effect that a message buffer is not required. The information that each PE must have specially in order to set checkpoints and re-execute processing is described in "chec to store in ID field and ID register of status record.
There are only "kpointID", "value of state switch", and "weight with generation". These are constant regardless of the number of PEs.

<Embodiment 17> In the methods described in Embodiments 14 to 16, all PEs send the return directly to the control process. For this reason, communication to the control process concentrates within a specific short time, and the reception channel of the control process may be crowded. Here, specific examples 14 to 16
"Return received by the control process
Need to be small ".

(Summary) A return communication path is provided, and each PE transmits a return along this path. FIG. 55 shows an example of the return communication path. Unlike the method described in the specific examples 14 to 16, several PEs send a return to another PE instead of the control process. The PE receiving the return performs the following processing. (a) After that, if you are sure to send a return yourself, r
Once the weights carried by eturn are stored in my place,
Send it when you send a return from yourself. (b) If it may not be possible to send a return from itself, the received return is forwarded as is. When the above (a) is performed, multiple returns (weights carried)
Are sent together (returned). For this reason, it can be expected that the number of returns received by the control process may be small.

(Configuration) The PE has a return destination register. This indicates "destination to send return". The contents of the return destination register of each PE in the example of FIG. 55 are shown below. PE-Content of destination register PEa-Control process PEb-PEa PEc-PEd PEd-PEa PEe-PEb PEf-PEb

(Operation) (Processing of PE when trying to send return) Return is sent to the destination indicated by the return destination register. (Process of PE when return is received) The "generation of weight carried by return" is compared with the "generation of own weight", and the following processing is performed. This will be described with reference to FIGS. 56 and 57.

If the two generations are equal as shown in FIG. 56 (a), the weight carried by return is added to its own weight as shown in FIG. 56 (b). If the two generations are equal, this corresponds to (a) described in the overview. The weight carried by return is the "previous generation". Therefore, the fact that the "generation of the weight carried by the received return" is equal to the "generation of the own weight" indicates that the own weight is still the "previous generation". Therefore, after this, a "new generation record or reexecuteor normal message" is always received, and a return carrying its own weight is transmitted. Fig. 57
If the “own weight generation” is new as shown in (a) (corresponding to (b) described in the outline), the PE is indicated by the return destination register as shown in FIG. 57 (b). retu
Send rn as it is.

FIG. 58 shows an example of a checkpoint setting process when the present method is applied to the method described in the fourteenth embodiment. When the return communication path shown in FIG. 58A is used, the checkpoint setting process is performed as shown in FIG.

(Effect) In the example of FIG. 58, the number of returns received by the control process is reduced. In the method described in the specific example 14, four returns are received by the control process, but in the present method, only two returns are required. As described above, an effect that “the number of returns received by the control process can be reduced” can be expected as compared with the method described in the specific examples 14 to 16.

<Embodiment 18> In the method described in Embodiment 17, depending on the timing, the control process receives
The number of turns may not decrease at all as compared with the method described in the embodiment 14. In fact, in the example of FIG. 58, when Pa receives record before receiving return from PEb, the control process has received the same four returns as in the method described in Example 14. Here, specific examples 14 to 16
This shows a method that “the number of returns received by the control process can be reduced irrespective of timing” as compared with the method described in “1.

(Summary) A return communication path is provided, and each PE transmits a return along this path. PE re
Know the PE that sends the turn. Do not send a return from yourself until a return is received from all of those PEs. (Structure) PE has the following registers, counters, switches,
Have a table. return destination register: indicates the destination PE to which the return is transmitted (same as that of the specific example 17) Return weight counter: Stores the weight to be returned. Initialize to zero. return transmission switch: Takes any value of notReady, ready, and done. The PE which is at the end of the communication path and does not receive the return is initialized to done. Other PE
Initializes to notReady. return receiving table: It has the following two fields. return transmission source PE: indicates a PE that transmits a return to itself. Receive flag: Takes any value of notReceived and received. Indicates whether a return has been received from the corresponding return source PE. Initialize to notReceived.

In the example of FIG. 55, r at the time of initial setting of PEb
The eturn reception table is shown below. PE at the end of the communication path that does not receive a return
(Pc and Pe, Pf in FIG. 55) are the return weight counter and return
There is no need to have a receiving table.

(Operation) When a record, reexecute, or normal message having a newer generation weight than its own weight is received and its own weight is reset with the weight of the received message, a return weight counter and return transmission are performed. The switch and return receiving table are also initialized. In addition, already retu
When initialization is performed by rn reception, only the reset of its own weight is performed, and other initialization is not performed.

(Processing of PE when trying to transmit return) a: Return The transmission switch sends a return to the destination indicated by the destination register. b: The return transmission switch adds ready “weight to be returned by return” to the return weight counter. c: The return transmission switch performs the following processing according to the value of the reception flag in the notReady return reception table. The values of the reception flags are all received. The return that carries the sum of the "weight to be returned by return" and the "weight stored in the return weight counter" is re
Turn Send to PE indicated by destination register. 2. Set return return switch to done. One or more receive flags are notReceived Set the return send switch to ready. 2. "Weight to be returned by return" is added to the return weight counter.

(Processing of PE when return is received) retu
The following processing is performed according to the value of the rn transmission switch. a: Return sending switch is done "generation of weight carried by return" and "generation of own weight"
And performs the following processing. Two generations are equal Initialize the return weight counter, return transmission switch, and return reception table. 2. The weight carried by return is added to the return weight counter. 3. Source P of the received return in the return reception table
The reception flag corresponding to E is set to received. The "own weight generation" sends the return as it is to the PE indicated by the new return destination register.

B: return transmission switch is ready The weight carried by return is added to the return weight counter. 2. Source P of the received return in the return reception table
The reception flag corresponding to E is set to received. 3. As a result of setting, the values of the reception flags are all received
If it becomes, the following processing is performed. 4. Carrying the "weight stored in the return weight counter"
Turn is sent to the PE indicated by the return destination register. 5. Set return return switch to done.

C: return transmission switch is notReady The weight carried by return is added to the return weight counter. 2. Source P of the received return in the return reception table
The reception flag corresponding to E is set to received.

FIGS. 59 and 6 show examples of the return transmission / reception processing.
0 is shown. Receiving a record having a weight W of 800n (FIG. 59)
According to (a)), the reset of the PE weight W, the return weight counter RW, the return transmission switch, and the return reception table are initialized. The PE tries to send a return by receiving a record with the weight of the new generation.
Since the turn transmission switch is notReady and there is a reception flag of notReceived, the return transmission switch is set to ready, and the weight W to be returned by return (own weight W of the previous generation W = 500o) is added to RW. As a result, the weight W is 50
It becomes 0o. When return is received from PEb and PEc (FIG. 59 (b)), the weight carried by return is added to the return weight counter RW, and the return received in the return reception table is returned.
Set the received flag RFs corresponding to the source PE of received to received, and carry the weight stored in the return weight counter RW.
send return to the PE indicated by the return destination register, and return
The rn transmission switch is set to done (FIG. 59 (c)).

Upon reception of a return having a weight W of 400 ° from PEb (FIG. 60 (a)), return weight counter RW and return
rn Initialize the transmission switch and return reception table,
The weight W (400o) carried by return is added to the return weight counter RW, and the reception flag RFs corresponding to PEb is received.
Set to ed. A record having a weight W of 800n is received. However, since initialization has already been performed by return reception, only the own weight is reset, and other initialization is not performed (FIG. 60 (b)). When a return having a weight W of 300o is received from PEc (FIG. 60 (c)), return
Add the weight carried by rn to the return weight counter RW, and retu
rn Set the reception flag RFs corresponding to the source PE of the return received in the reception table to received, send the return carrying the weight stored in the return weight counter RW to the PE indicated by the return destination register, and return transmission switch The done
(FIG. 60D).

(Effect) The number of returns received by the control process may be smaller than the methods described in the specific examples 14 to 16.

<Embodiment 19> In the method described in the embodiment 18, it is necessary for the PE to have information of "from which PE the return is received". Here, a method of obtaining the same effect as that of the specific example 18 by the information of “how many returns are received” will be described. (Summary) A communication path is provided, and each PE follows this path.
Send turn. The PE knows the minimum number of returns it receives. Do not send a return from yourself until you receive the minimum number of returns.

(Structure) The PE has a return reception counter indicating the number of unreceived returns instead of the return reception table of the eighteenth embodiment. Initially set to "Minimum number of returns to receive". The return reception counter at the time of initial setting of each PE in the example of the return communication path in FIG. 55 is shown below.

(Operation) When a record, reexecute, or normal message having a newer generation weight than its own weight is received and its own weight is reset by the weight of the received message, a return weight counter and return transmission are performed. The switch and return reception counter are also initialized. In addition, already retu
When initialization is performed by rn reception, only the reset of its own weight is performed, and other initialization is not performed.

(Process of PE When Attempting to Transmit Return) a. The return transmission switch transmits the return to the destination indicated by the done return transmission destination register. b: The return transmission switch adds ready “weight to be returned by return” to the return weight counter. c: The return transmission switch performs the following processing according to the value of the notReady return reception counter. return The value of the reception counter is zero. The return that carries the sum of the "weight to be returned by return" and the "weight stored in the return weight counter" is re
Turn Send to PE indicated by destination register. 2. Set return return switch to done. return The value of the reception counter is not zero. Set the return send switch to ready. 2. "Weight to be returned by return" is added to the return weight counter.

(Processing of PE when return is received) retu
The following processing is performed according to the value of the rn transmission switch. a. return transmission switch is done "generation of weight carried by return" and "generation of own weight"
And performs the following processing. Two generations are equal Initialize the return weight counter, return transmission switch, and return reception counter. 2. The weight carried by return is added to the return weight counter. 3. return Decrements the reception counter by one. The "own weight generation" sends the return as it is to the PE indicated by the new return destination register.

B. return Send switch is ready The weight carried by return is added to the return weight counter. 2. return Decrease the reception counter by one. 3. If the value of the reception counter becomes zero as a result of -1, carrying the "weight stored in the return weight counter"
Turn is sent to the PE indicated by the return destination register. retu
rn Set the transmission switch to done.

C. return Send switch is notReady The weight carried by return is added to the return weight counter. 2. return Decrements the reception counter by one.

FIGS. 61 and 6 show examples of the return transmission / reception processing.
It is shown in FIG. Receiving a record with a weight W of 800n (FIG. 61)
By (a)), the resetting of the PE weight W, the return weight counter RW, the return transmission switch, and the return reception counter are initialized. Receiving return (Fig. 61 (b))
Then, the weight carried by return is added to the return weight counter RW, and 1 is subtracted from the return reception counter. Since the return has been received twice and the subtraction has been performed twice, the reception counter has become zero. Therefore, the return carrying the weight (1200o) stored in the return weight counter RW is sent to the PE indicated by the return destination register. , The return transmission switch is set to done (FIG. 61 (c)).

Receiving return having weight W of 400o (FIG. 62)
According to (a)), the return weight counter RW, the return transmission switch, and the return reception counter are initialized, the weight W (400o) carried by the return is added to the return weight counter RW, and the reception flag RFs corresponding to PEb is added. Is set to received. By receiving a record with a weight W of 800n, P
Only the weight W of E is reset (FIG. 62 (b)). When a return having a weight W of 300o is received (FIG. 62 (c)), re
The weight carried by turn is added to the return weight counter RW, and re
Subtract 1 from the turn reception counter. As a result, the reception counter becomes zero, so a return carrying the weight (1200o) stored in the return weight counter RW is sent to the PE indicated by the return destination register, and the return transmission switch is set to done (FIG. 62 ( d)).

(Effect) The number of returns received by the control process may be smaller than the methods described in the specific examples 14 to 16. Further, as compared with the method described in the embodiment 18, it is only necessary to have information on at least how many returns are received.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a global state determination method according to the present invention.

FIG. 2 is a conceptual diagram of a multiprocessor system.

FIG. 3 is an explanatory diagram of an example of message transmission / reception and a state change of a PE.

FIG. 4 is an explanatory diagram (part 1) of the operation of the specific example 1.

FIG. 5 is an operation explanatory diagram (part 2) of the first specific example;

FIG. 6 is an operation explanatory diagram (part 3) of the first specific example;

FIG. 7 is an operation explanatory diagram (part 4) of the first specific example;

FIG. 8 is an operation explanatory view (part 5) of the specific example 1;

FIG. 9 is an explanatory diagram of a state determination method according to a specific example 2.

FIG. 10 is an operation explanatory diagram of a specific example 2.

FIG. 11 is an explanatory diagram of a method of a specific example 3.

FIG. 12 is an operation explanatory diagram of a specific example 3.

FIG. 13 is an explanatory diagram showing a method of Example 4;

FIG. 14 is an explanatory diagram of an operation in a specific example 4.

FIG. 15 is an operation explanatory diagram of the specific example 5;

FIG. 16 is an explanatory diagram of a method according to a specific example 6.

FIG. 17 is an operation explanatory diagram (part 1) of the specific example 6;

FIG. 18 is an operation explanatory diagram (part 2) of the specific example 6.

FIG. 19 is an operation explanatory diagram (part 3) of the specific example 6;

FIG. 20 is an operation explanatory diagram (part 4) of the specific example 6;

FIG. 21 is an explanatory diagram of a method according to the seventh embodiment.

FIG. 22 is an operation explanatory diagram (part 1) of the specific example 7;

FIG. 23 is an operation explanatory diagram (part 2) of the specific example 7;

FIG. 24 is an operation explanatory diagram (part 3) of the specific example 7;

FIG. 25 is an operation explanatory diagram (part 4) of the specific example 7;

FIG. 26 is an operation explanatory diagram (part 5) of the specific example 7;

FIG. 27 is an explanatory view (part 6) of the operation of the specific example 7;

FIG. 28 is a diagram illustrating an example of a change in generation in a specific example 8.

FIG. 29 is an explanatory diagram of an example of message transmission / reception and PE state change.

FIG. 30 is an explanatory diagram of an example of a correct check point.

FIG. 31 is an explanatory diagram of an example of an incorrect check point.

FIG. 32 is an explanatory diagram of an example of a weighting method.

FIG. 33 is an explanatory diagram (1/3) of the example 9 of “set checkpoint”;

FIG. 34 is an explanatory diagram (2/3) of “set checkpoint” in specific example 9;

FIG. 35 is an explanatory view (3/3) of “set checkpoint” in the specific example 9;

FIG. 36 is an explanatory diagram of an example of “set checkpoint” in specific example 9;

FIG. 37 is an explanatory diagram of an example of “re-execution” of the specific example 9;

FIG. 38 is an explanatory diagram of an example of “set checkpoint” in specific example 10;

FIG. 39 is an explanatory diagram of an example of “re-execution” of the specific example 10.

FIG. 40 is an explanatory diagram of processing when a new generation normal message of the specific example 10 is received.

FIG. 41 is an explanatory diagram of processing when a new generation normal message of the specific example 11 is received.

FIG. 42 is an explanatory diagram showing how the generation of weights changes in specific example 12.

FIG. 43 is an explanatory diagram of how the generation of the weight changes in specific example 13.

FIG. 44 is an explanatory diagram (part 1) of an example of setting checkpoints in specific example 14;

FIG. 45 is an explanatory diagram (part 2) of an example of setting checkpoints in specific example 14;

FIG. 46 is a diagram (part 3) illustrating an example of setting checkpoints in specific example 14;

FIG. 47 is a diagram (part 4) of an example of setting checkpoints in specific example 14;

FIG. 48 is an explanatory diagram of an example of setting a check point in the specific example 14.

FIG. 49 is an explanatory diagram of an example of re-execution of specific example 14;

FIG. 50 is an explanatory diagram of an example of setting checkpoints in specific example 15;

FIG. 51 is an explanatory diagram of an example of re-execution of specific example 15;

FIG. 52 is an explanatory diagram of processing when a new generation normal message is received according to specific example 15;

FIG. 53 is an explanatory diagram of an example of setting checkpoints in specific example 16;

FIG. 54 is an explanatory diagram of an example of re-execution of specific example 16;

FIG. 55 is an explanatory diagram of an example of a communication path in specific example 17;

FIG. 56 is an explanatory diagram of an example of processing at the time of return reception in the specific example 17;

FIG. 57 is an explanatory diagram of an example of a process at the time of return reception in the specific example 17;

FIG. 58 is an explanatory diagram of an example of setting a checkpoint in the specific example 17;

FIG. 59 is an explanatory diagram of a return transmission / reception process of the specific example 18;

FIG. 60 is an explanatory diagram of an example of the return transmission / reception process of the specific example 18.

FIG. 61 is an explanatory diagram of an example of the return transmission / reception process of the specific example 19;

FIG. 62 is an explanatory diagram of an example of the return transmission / reception process of the specific example 19;

[Explanation of symbols]

 Reference Signs List 1 decision process 3 global state buffer 5 state buffer 6 transmission buffer 7 reception buffer W1, W2, W3, W4, X weight

Claims (23)

[Claims] In a multiprocessor system for performing inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is Each processor has a global state buffer for storing the obtained global state, and each processor has a message switch indicating which control message corresponds to the state, a state buffer for saving its own state, and a received normal message. And a transmission buffer for storing a normal message pending transmission, and the message switch uses a not record (notReRecord) indicating that nothing is stored in the buffer.
Initialized to corded), the decision process sends a record control message with a given weight to all processors, clearing the global state buffer and instructing normal message transmission to be suspended,
When the processor receives the record control message, it stores its state in a state buffer, and calculates the sum of its own weight and the weight associated with the record control message. Is sent to the decision process with a return control message, the message switch is set to "recorded" indicating that the normal message transmission is suspended, the reception buffer and the transmission buffer are cleared, and then the message Switch is Recorded (recorde
Upon receiving the normal message, the processor in d) stores a copy of the normal message in the reception buffer, and returns the weight attached to the normal message each time.
The control message is transmitted to the decision process, and the normal message to be transmitted is suspended and stored in a transmission buffer. When the return process message is received from the processor, the decision process determines the weight attached to the return control message. When the result becomes a constant value obtained by adding all the weights in addition to the own weight, a request control message for a stored data request is sent to all the processors, and each processor , Upon receiving a request control message,
The contents of its own status buffer and the contents of the receive buffer are
An answer (answer) control message is sent to the decision process, the message switch is set to ready indicating that the stored data has been transmitted, and the decision process receives the answer (answer) control message, and the answer (answer) control message Stores the contents of the status buffer and the contents of the receive buffer carried in the global state buffer, and, upon receiving answer (answer) control messages from all the processors, generates a restart (restart) control message instructing restart of operation. Weights are sent to all processors, and their weights are reduced by that weight. When each processor receives a restart control message,
The weight added to the restart control message is added to its own weight. If the normal message is stored in the transmission buffer, the message is transmitted. If the message switch is ready, the message switch is transmitted. Set to NotRecorded,
A started (started) control message indicating that the operation has been resumed is transmitted to the decision process, and the decision process completes the process when the started (started) control message is received from all processors, and the global state buffer is returned. A method for determining a global state, comprising determining contents. 2. In a multiprocessor system for performing inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is Each processor has a global state buffer for storing the obtained global state, and each processor includes a message switch for indicating which control message corresponds to the state corresponding to the control message, and a transmission buffer for storing a normal message pending transmission. And the message switch is initialized to notRecorded, indicating that nothing is stored in the buffer, and the decision process clears the global state buffer and instructs it to suspend normal message transmission. Send a record control message to all processors with a predetermined weight,
When the processor receives the record control message, the processor returns its own weight, the sum of the weights attached to the record control message, and its own state. The control message is sent to the decision process, the message switch is set to "recorded" indicating that the normal message transmission is suspended, the transmission buffer is cleared, and then the message switch is set to "recorded".
When receiving the normal message, the processor in d) sends a copy of the normal message and the weight attached thereto to the return process message each time to the decision process, and transmits the normal message to be transmitted. When a return control message is received from a processor, the decision process returns a copy of the state of each processor or a copy of the normal message carried by the return control message to the global state buffer. And return
When the weight added to the control message is added to its own weight and the result becomes a constant value when all the weights are added, a proceed control message is sent to all processors, and When the processor receives the proceed control message,
Sends a proceeded control message to the decision process, ready message switch
When the decision process receives a proceeded control message from all the processors, the decision process assigns a weight to the restart control message instructing the restart of the operation and sends the weighted restart control message to all the processors. Only reduce the weight of its own, each processor receives a restart control message,
The weight attached to the restart control message is added to its own weight. If the message switch is ready, not record (notRecorde)
set to d) and send a started control message to the decision process indicating that the operation has been resumed, and if a normal message is stored in the transmit buffer, send them. Receiving a started control message from the processor, and completing the processing to determine the contents of the global state buffer. 3. In a multiprocessor system for performing inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is Each processor has a global state buffer for storing the obtained global state, and each processor includes a message switch for indicating which control message corresponds to the state corresponding to the control message, and a transmission buffer for storing a normal message pending transmission. And the message switch is initialized to notRecorded, indicating that nothing is stored in the buffer, and the decision process clears the global state buffer and instructs it to suspend normal message transmission. Send a record control message to all processors with a predetermined weight,
When the processor receives the record control message, the processor determines the sum of its own weight and the weight attached to the record control message by adding the return control message to the return control message. Send to the process, set the message switch to "recorded" to indicate that normal message transmission is suspended, clear the transmit buffer, and then switch to the "recorded" state.
When receiving the normal message, the processor in d) transmits the weight attached to the normal message to the decision process with the return control message added thereto, and suspends the transmission of the normal message to be transmitted. When the return control message is received from the processor, the weight added to the return control message is added to its own weight, and the result adds all the weights. When the value becomes a certain value at the time of the request, a request (request) control message is sent to all the processors. When each processor receives the request (control) message,
Answer (answe)
r) send a control message to the decision process, set the message switch to ready, and the decision process receives the answer (answer) control message and sends the state and transmission of the processor carried by the answer control message When the contents of the buffer and the contents of the buffer are stored in the global state buffer and an answer (answer) control message is received from all the processors, the restart control message instructing the restart of the operation is weighted and sent to all the processors. , Reduce its own weight by that weight, and when each processor receives a restart control message,
The weight attached to the restart control message is added to its own weight. If the message switch is ready, not record (notRecorde)
set to d) and send a started control message to the decision process indicating that the operation has been resumed, and if a normal message is stored in the transmit buffer, send them. Receiving a started control message from the processor, and completing the processing to determine the contents of the global state buffer. 4. In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, there is no clock for controlling the entire system, and each processor and the network channel There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is Each processor has a global state buffer for storing the obtained global state and a reception counter for counting the number of received messages.Each processor has a message switch that indicates which control message corresponds to the state, and a pending transmission state. The message switch has a transmission buffer for storing a normal message and a transmission counter for counting the number of message transmissions, and the message switch does not record (not not) to indicate that nothing is stored in the buffer.
Recorded), the decision process clears the global state buffer and the receive counter, and indicates that the record (re
cord) A control message is transmitted to all processors with a predetermined weight, and its weight is reduced by the weight. When the processor receives the record control message, the processor receives its own weight and record. The sum of the weights attached to the control message is sent to the decision process with the return control message, the message switch is set to “recorded” indicating that the normal message transmission is suspended, the transmission buffer and the transmission counter are set. And then switch the message switch to record
Upon receiving the normal message, the processor in d) sends the weight attached to the normal message to the decision process in a return control message each time,
The normal message to be transmitted is suspended and stored in a transmission buffer, a copy of the normal message is sent to a decision process in a report control message, a transmission counter is incremented, and the decision process is executed by the processor. ) When the control message is received, a copy of the normal message carried by the report control message is stored in the global state buffer, the reception counter is incremented, and the return (re)
turn) control message, the return (re
turn) When the weight attached to the control message is added to its own weight and the result becomes a constant value when all the weights are added, a request control message is sent to all processors. When each processor receives a request control message,
Answer the contents of the transmission counter and its status (answer)
The control message is sent to the decision process and the message switch is set to ready. When the decision process receives an answer control message from the processor, the decision process globally describes the state of the processor carried by the answer control message. Stored in the status buffer, decremented the reception counter by the number of transmission counters carried by the answer (answer) control message, received answer (answer) control messages from all processors, and based on the value of the reception counter Is cleared, the restart control message instructing restart of operation is weighted and sent to all processors, and the weight of the processor is reduced by that weight. ) When a control message is received,
The weight attached to the restart control message is added to its own weight. If the message switch is ready, not record (notRecorde)
set to d) and send a started control message to the decision process indicating that the operation has been resumed, and if a normal message is stored in the transmit buffer, send them. Receiving a started control message from the processor, and completing the processing to determine the contents of the global state buffer. 5. In a multiprocessor system for performing inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, and there is no clock for controlling the entire system. There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is Each processor has a global state buffer for storing the obtained global state, and each processor includes a message switch for indicating which control message corresponds to the state corresponding to the control message, and a transmission buffer for storing a normal message pending transmission. And the message switch is initialized to notRecorded, indicating that nothing is stored in the buffer, and the decision process clears the global state buffer and instructs it to suspend normal message transmission. Send a record control message to all processors with a predetermined weight,
When the processor receives the record control message, the processor determines the sum of its own weight and the weight attached to the record control message by adding the return control message to the return control message. Send to the process, set the message switch to "recorded" to indicate that normal message transmission is suspended, clear the transmit buffer, and then switch to the "recorded" state.
When receiving the normal message, the processor in d) transmits the weight attached to the normal message to the decision process with the return control message added thereto, and suspends the transmission of the normal message to be transmitted. A copy of the normal message is stored in the transmit buffer and a copy of the normal message is sent to the decision process in a report control message. When the decision process receives the report control message from the processor, the decision process carries the report control message. When a copy of the normal message is stored in the global state buffer and a return (return) control message is received, the weight attached to the return (return) message is added to its own weight, and the result becomes If the weighted value becomes a constant value, the request (Request) sends a control message to all the processors, each processor receives the request (request) control message,
Sends its state with the answer control message to the decision process, sets the message switch to ready, and when the decision process receives an answer control message from the processor, the answer control message And the state of the received processor is stored in the global state buffer, and when an answer (answer) control message is received from all the processors, a weight is assigned to the restart control message instructing the restart of the operation and all the processors are weighted. And the processor reduces its own weight by that weight. When each processor receives the restart control message,
The weight attached to the restart control message is added to its own weight. If the message switch is ready, not record (notRecorde)
set to d) and send a started control message to the decision process indicating that the operation has been resumed, and if a normal message is stored in the transmit buffer, send them. Receiving a started control message from the processor, and completing the processing to determine the contents of the global state buffer. 6. The processor according to claim 1, wherein the processor whose message switch is ready receives its normal message switch from another processor, and resets its own message switch to a not record. (NotRecorded) and resume normal operation. 7. In a multiprocessor system for performing inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, there is no clock for controlling the entire system, and each processor and the network channel There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is A global state buffer for storing the obtained global state, and an old generation weight counter for counting the weight of the old generation.The decision process clears the global state buffer, and stores the A weight is set, the self weight is set to the constant value, the generation is advanced by one, and a request control message instructing to notify a state is transmitted to all processors with a predetermined weight, and the weight is transmitted. Each processor reduces its weight by the amount it receives, and when each processor receives a request control message,
The request (request) control message weight generation is compared with its own weight generation, and the request (req
uest) If the generation of the weight of the control message is new, the self state and the self weight are attached to a return control message and sent to the decision process, and the request (req
uest) The weight of the control message is set to its own weight. If both are the same, the weight of the request control message is added to its own weight. When a normal message is received, the generation of the weight of the normal message and its own Comparing the generation of the weight, if both are the same, add the weight of the normal message to its own weight, and if the generation of its own weight is newer, control the return of the copy of the normal message and the weight of the normal message (return) Attached to the message and sent to the decision process. Normally, if the generation of the message is new, return its state and weight (re
turn) control message sent to the decision process, the normal message weight is set to its own weight, when the decision process receives the return (return) control message, the weight attached to the return (return) control message is the old generation weight In addition to the counter, return (retu
rn) The state of each processor added to the control message and a copy of the normal message are stored in the global state buffer, and when the value of the old generation weight counter reaches the constant value, the contents of the global state buffer at that time are globally stored. A global state determination method, characterized by determining a state. 8. In a multiprocessor system that performs inter-processor processing by asynchronous message communication, a finite number of processors are connected via a network channel, there is no clock for controlling the entire system, and each processor and the network channel are connected to each other. There is a decision process that operates under the control of a unique clock, and performs a process of determining the global state of the system. The weight of the normal message transmitted by each processor to another processor is different from the weight of the processor. This decision process has weights to cancel the sum, and the system is controlled so that when all these weights are added, the system is controlled to be a constant value, and the decision process and the messages transmitted and received between each processor to determine the global state are controlled Call the message, the decision process is A global state buffer for storing the obtained global state, and an old generation weight counter for counting the weight of the old generation.The decision process clears the global state buffer, and stores the A weight is set, the own weight is set to the constant value, the generation is advanced by one, and a record control message instructing to save the state is transmitted to all processors with a predetermined weight, and the weight is transmitted. Each processor has its own state buffer that stores its own state. When a processor receives a record control message, it generates the weight of the record control message and its own weight. If the generation of the weight of the record control message is newer, the own state is stored in the state buffer, and the Return your weight (retur
n) The control message is sent to the decision process, and the weight of the record control message is set to its own weight. If both are the same, the weight of the record control message is added to its own weight. , The normal message weight generation is compared with its own weight generation, and if both are the same, the normal message weight is added to its own weight. Is stored in the status buffer, the weight of the normal message is appended to the return control message, and sent to the decision process. If the normal message generation is newer, its state is stored in the status buffer. Is sent to the decision process in a return control message, and the weight of the normal message is set to its own weight. When the source receives the return control message, the weight attached to the return control message is added to the old generation weight counter, and when the value of the old generation weight counter reaches the constant value, the decision process is executed. request) sends a control message to all processors. When each processor receives a request control message, each processor determines its own status stored in the status buffer and a copy of the normal message by an answer control message. Process, clears the status buffer, and the decision process stores in the global status buffer a copy of each processor's status and a normal message attached to the answer control message, and the answer from all processors. ) When the control message is received, for the current global state A global state determination method, comprising determining the contents of a buffer to a global state. 9. The global state determination method according to claim 7, wherein three or more symbols whose order is relatively clear are used as generations to be added to each weight. 10. A finite number of processors (hereinafter referred to as PEs) are connected to each other via a network. The PEs communicate with each other by asynchronous message communication, and there is no clock for controlling the whole system. The PEs and network channels operate independently according to their clocks, and each PE can send messages to other PEs, record their status and received messages, and provide instructions for setting checkpoints. There is a special process (called a control process) that issues a message. The control process and all PEs can perform message communication with each other. Messages that are sent and received by PEs for normal processing are called normal messages. Control process and P to set points
The messages transmitted and received by the group E are called control messages. The control process, the PE and the messages have weights, the sum of all weights takes a predetermined constant value, the weights have generations, and all the weights have the same generation. Initialize, the control process has an old generation weight counter, each PE has a state buffer, and the control process has to checkpoint
Checkpoint control message (below)
Checkpoint is sent to all PEs, and checkpoint recognition (ackCheckpoint) is sent from all PEs.
) Wait until a control message (hereinafter referred to as ackCheckpoint) is received, set its own weight in the old generation weight counter, set its own weight to a certain fixed value, advance its own weight by one generation, (Record) Sends a control message (hereinafter referred to as record) to all PEs, assigns a weight to the record, and reduces its own weight by that amount. When the PE receives the checkpoint, the PE clears the status buffer and clears the ackCheckpoint. Is returned to the control process, and when record is received, the "generation of the weight that record has" and "the generation of its own weight" are compared, and if the "generation of the weight of record" is new, Record in the state buffer, send its own weight to the control process with a return control message (hereinafter referred to as "return"), reset its own weight with the weight of record, and if the two generations are equal, the weight of record When the PE receives a normal message, the PE compares the “generation of the weight that the normal message has” with the “generation of its own weight”, and if the “generation of its own weight” is new, For example, return the weight of the normal message to the control process by return, record the contents of the normal message in the status buffer, process the normal message, and if the "generation of the weight of the normal message" is new, return its own weight by return. Sends to the control process, records its state in the state buffer, resets its own weight with the weight of the normal message, processes the normal message, and if the two generations are equal, the weight of the normal message is its own weight In addition, when the control process receives the return, the control process adds the weight carried by the return to the old generation weight counter, and as a result, the old generation weight counter is added. If the value of the counter reaches a certain fixed value, it is confirmed that the checkpoint setting is completed, and the set of the contents of the status buffer of each PE at the time of confirming the completion constitutes the checkpoint. A checkpoint setting method characterized in that: 11. A finite number of processors (hereinafter referred to as PEs) are connected to each other via a network. The PEs communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. PEs and network channels operate independently according to their clocks, each PE can send messages to other PEs, record their status and received messages, set checkpoints and re-execute There is a special process (referred to as a control process) that issues an instruction of the following. The control process and all PEs can perform message communication with each other. The control process and PEs send and receive each other to set up and re-execute checkpoints The control process, the PE and the message have weights, the sum of all weights takes a predetermined constant value, the weight has a generation, and all weights are initialized to the same generation, and the control The process has an old generation weight counter, each PE has a status flag and a status buffer, and the status flag takes only one of C indicating that a checkpoint is being set and R indicating that the process is being re-executed. To set a checkpoint,
Checkpoint control message (below)
Checkpoint is sent to all PEs, and checkpoint recognition (ackCheckpoint) is sent from all PEs.
) Wait until a control message (hereinafter referred to as ackCheckpoint) is received, set its own weight in the old generation weight counter, set its own weight to a certain fixed value, advance its own weight by one generation, (Record) Sends a control message (hereinafter referred to as record) to all PEs, assigns a weight to the record, and reduces its own weight by that amount. When the PE receives the checkpoint, the PE sets the status flag to C. AckCheckpoint is returned to the control process, and when record is received, the "generation of the weight of record" is compared with the "generation of its own weight". If the "generation of the weight of record" is new, the status buffer , Record its own state in the state buffer, send its own weight to the control process with a return control message (hereinafter referred to as return), reset its own weight with the weight of record, If the generations are equal, the weight of record is added to its own weight, and when the control receives the return, the control process adds the weight carried by return to the old generation weight counter, and as a result, the value of the old generation weight counter is determined. When the value reaches a certain value, it is confirmed that the checkpoint setting has been completed, and the control process executes a re-execution preparation (rollback) control message (hereinafter referred to as “rollback”) in order to perform re-execution.
Is sent to all PEs and re-execution preparation recognition (ackR
ollback) control message (hereinafter ackRollback)
Wait until all the PEs receive it, set their own weight in the old generation weight counter, set their own weight to a certain fixed value, advance their own weight by one generation, and execute again (reexecute) control Message (hereafter reexecute
) To all PEs, weight reexecute and reduce their weights by that amount. When the PE receives the rollback, the PE sets the status flag to R, sends ackRollback to the control process, When reexecute is received, "reexecute's weight generation" is compared with "own weight generation", and if "reexecute weight generation" is new, its own state is set with the contents of the state buffer. Fix, re-weight yourself
Turn to send to the control process, reset its own weight with the reexecute weight, and if the two generations are equal, add the reexecute weight to their own weight.When the control process receives the return, return carries When the weight is added to the old generation weight counter and the value of the old generation weight counter becomes a certain fixed value, it can be confirmed that the re-execution has been started. , Compare the “generation of the weight that the normal message has” with the “generation of its own weight”, and if the “generation of its own weight” is new and the status flag is C,
Normally the weight of the message is sent to the control process by return,
Record the contents of the normal message in the status buffer, process the normal message, and if the "own weight generation" is new and the status flag is R,
Normally the weight of the message is sent to the control process by return,
Normal messages are discarded without processing. If the "normal message weight generation" is new and the status flag is C, the status buffer is cleared, its status is recorded in the status buffer, and its own weight is returned to the control process. And reset its own weight with the weight of the normal message, process the normal message, and if the "generation of the weight of the normal message" is new and the status flag is R, set its own status with the contents of the status buffer. Fix, send own weight to control process by return, reset own weight with normal message weight, process normal message, add normal message weight to own weight if two generations are equal A checkpointing and re-execution method characterized by processing a normal message. 12. A finite number of processors (hereinafter referred to as PEs) are connected to each other via a network. The PEs communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. The PEs and network channels operate independently according to their clocks, and each PE can send messages to other PEs, record their status and received messages, and provide instructions for setting checkpoints. There is a special process (called a control process) that issues a message. The control process and all PEs can perform message communication with each other. Messages that are sent and received by PEs for normal processing are called normal messages. Control process and P to set points
The messages transmitted and received by the group E are called control messages. The control process, the PE and the messages have weights, the sum of all weights takes a predetermined constant value, the weights have generations, and all the weights have the same generation. Initialization, the control process has an old generation weight counter, each PE has a status buffer and a message buffer, the message buffer is cleared by initialization processing, and the control process uses the old generation weight to checkpoint. Set your own weight in the counter, set your own weight to a certain fixed value, advance your weight by one generation, and send a record control message (hereafter, record) to all PEs And weight the record,
Its weight is reduced by that amount, and when the PE receives record, it clears the status buffer,
Record your state in the state buffer and retu your weight
rn Control message (hereinafter referred to as "return") is sent to the control process, and its own weight is reset by the weight of record. If normal messages are stored in the message buffer, the message weight is applied to those messages. Is added to its own weight and then processed, and the message buffer is cleared. When the PE receives the normal message, the PE compares the "generation of the weight that the normal message has" with the "generation of its own weight" If the “own weight generation” is new, the normal message weight is sent to the control process by return, the contents of the normal message are recorded in the status buffer, the normal message is processed, and the “normal message weight generation” is returned. Is newer, the normal message is stored in the message buffer, and if the two generations are equal, the normal message weight is The control process processes the normal message in addition to the weight of the minute, and upon receiving the return, the control process adds the weight carried by the return to the old generation weight counter, and as a result, the value of the old generation weight counter is a fixed constant value. , It is confirmed that the setting of the checkpoint is completed, and the set of contents of the status buffer of each PE at the time of confirming the completion constitutes a checkpoint. . 13. A finite number of processors (hereinafter referred to as PEs) are connected to each other via a network. The PEs communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. PEs and network channels operate independently according to their clocks, each PE can send messages to other PEs, record their status and received messages, set checkpoints and re-execute There is a special process (referred to as a control process) that issues an instruction of the following. The control process and all PEs can perform message communication with each other. The control process and PEs send and receive each other to set up and re-execute checkpoints The control process, the PE and the message have weights, the sum of all weights takes a predetermined constant value, the weight has a generation, and all weights are initialized to the same generation, and the control The process has an old-generation weight counter, each PE has a status flag, a status buffer, and a message buffer. The status flag takes only one of the values C indicating that a checkpoint is being set and R indicating re-execution. The buffer is cleared by initialization processing, and the control process sets its own weight in the old generation weight counter, sets its own weight to a certain fixed value, and sets its own weight to perform checkpoint setting. Advance the generation by one, send a record control message (hereafter, record) to all PEs, assign a weight to the record,
The weight is reduced by that amount, and when the PE receives record, it sets the status flag to C,
Clears the status buffer, records its status in the status buffer, and returns its weight to the return control message
rn)) and send it to the control process to record your weight
If the normal message is stored in the message buffer, the message weight is added to its own weight and then processed, and the message buffer is cleared. Upon receiving the return, the control process adds the weight carried by the return to the old generation weight counter, and when the value of the old generation weight counter reaches a certain fixed value, the checkpoint setting is completed. It is confirmed that the control process sets its own weight in the old generation weight counter, sets its own weight to a constant value, advances the generation of its own weight by one, and performs the re-execution ( reexecute) control message (hereinafter reexecute
Is sent to all PEs, and the reexecute is weighted and its own weight is reduced by that amount. When the reexecute is received, the PE sets the status flag to R and sets its status to the status buffer. Set again with the content,
Send your weight to the control process with return, reset your weight with the weight of execute, and if normal messages are stored in the message buffer, change the weight of the message to those weights for those messages After receiving the return, the control process adds the weight carried by return to the old generation weight counter, and as a result, there is a value of the old generation weight counter. When the fixed value is reached, it is possible to confirm that the re-execution has started. When the PE receives the normal message, the PE determines the "generation of the weight that the normal message has" and the "generation of its own weight". If the "own weight generation" is new and the status flag is C,
Normally the weight of the message is sent to the control process by return,
Record the contents of the normal message in the status buffer, process the normal message, and if the "own weight generation" is new and the status flag is R,
Normally the weight of the message is sent to the control process by return,
Normal messages are discarded without processing, if the "normal message weight generation" is newer, the normal message is stored in the message buffer, and if the two generations are equal, the normal message weight is added to its own weight, A checkpointing and re-execution method characterized by processing a normal message. 14. A finite number of processors (hereinafter referred to as PEs) are connected to each other via a network. The PEs communicate with each other by asynchronous message communication, and there is no clock for controlling the entire system. PEs and network channels operate independently according to their clocks, each PE can send messages to other PEs, record their status and received messages, set checkpoints and re-execute There is a special process (referred to as a control process) that issues an instruction of the following. The control process and all PEs can perform message communication with each other. The control process and PEs send and receive each other to set up and re-execute checkpoints The control process, the PE and the message have weights, the sum of all weights takes a predetermined constant value, the weight has a generation, and all weights are initialized to the same generation, and the control The process has an old generation weight counter, and the control process sets its own weight to the old generation weight counter, sets its own weight to a constant value, and sets one Proceeding and sending a record control message (hereinafter referred to as “record”) to all PEs, assigning a weight to the record and reducing its own weight by that amount, and the PE receives “record, Compare the current generation of weight with the generation of own weight.If the new generation of record is new, clear the status buffer and record your status in the status buffer. Sends its own weight to the control process with a return control message (hereinafter referred to as "return"), resets its own weight with the weight of record, and if the two generations are equal, adds the weight of record to its own weight and When the process receives the return, the process adds the weight carried by the return to the old generation weight counter, and when the old generation weight counter reaches a certain fixed value, the checkpoint setting is completed. The control process sets its own weight in the old generation weight counter, sets its own weight to a certain fixed value, advances its own weight by two generations, and executes Execution (reexecute) control message (hereinafter reexecute)
Is sent to all PEs, and the reexecute is weighted, and its own weight is reduced by that amount. When the PE receives the reexecute, the PE executes "the generation of the weight that reexecute has" and "its own weight." Generation), and if the "reexecute weight generation" is newer, reset its own state with the contents of the state buffer and re-set its own weight.
Turn to send to the control process, reset its own weight with the reexecute weight, and if the two generations are equal, add the reexecute weight to their own weight.When the control process receives the return, return carries When the weight is added to the old generation weight counter and the value of the old generation weight counter becomes a certain fixed value, it can be confirmed that the re-execution has been started. , Compare the "generation of the weight that the normal message has" with the "generation of its own weight". If the "generation of its own weight" is newer by one generation, send the weight of the normal message to the control process by return, Record the content of the normal message in the status buffer, process the normal message, and if the "own weight generation" is newer by two generations, send the weight of the normal message to the control process by return Normal messages are discarded without processing. If the "normal message weight generation" is newer by one generation, the status buffer is cleared, its status is recorded in the status buffer, and its own weight is returned to the control process. Send, reset its own weight with the weight of the normal message, process the normal message, and if the "generation of the weight of the normal message" is newer by two generations, reset its own state with the contents of the state buffer, Return your weight to the control process with return, reset your weight with the weight of the normal message, process the normal message, and if the two generations are equal, add the weight of the normal message to your weight, A checkpointing and re-execution method characterized by processing a message. 15. The method according to claim 10, wherein three types of generations of A, B, and C are provided as weight generations, and the process of advancing the weight generation is B if A, and C if B. , C, it is assumed to be the processing of A, and the new and old of the weight generation, B is newer in A and B, C is newer in B and C, A is newer in C and A, A checkpoint setting method characterized by having been determined. 16. The method according to claim 11, wherein three types of generations of A, B, and C are provided as weight generations, and the processing of advancing the weight generation is B if A, and C if B. , C, it is assumed to be the processing of A, and the new and old of the weight generation, B is newer in A and B, C is newer in B and C, A is newer in C and A, Checkpoint setting and re-execution method characterized by the defined. 17. The method according to claim 14, wherein five types of generations of A, B, C, D, and E are provided as weight generations, and the process of advancing the weight generation by one is performed.
, B for C, C for D, D for E, E for A, and A for C to advance the weight generation by two. ,
It is assumed that the processing is B for D, C for E, D for A, and E for B, and that the weight generation is new and old. , B and C have C one generation newer, C and D have D one generation new, D and E have E one generation newer,
In E and A, A is one generation newer, in A and C, C is two generations newer, in B and D, D is two generations newer, and in C and E, E is two generations newer, D and A checkpoint setting and re-execution method, wherein A is determined to be two generations newer for A, and B is determined to be two generations newer for E and B. 18. A finite number of processors (hereinafter, referred to as PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous message communication, and overtaking of a message occurs on the communication channel. There is no guarantee that messages will arrive in the order in which they were sent, there is no clock governing the entire system, each PE and network channel will operate independently according to their own clocks, and each PE will send messages to all other PEs. There is a special process (called a control process) that can send, record its status and received messages, and issue checkpointing and re-execution instructions. The control process and all PEs PEs can send and receive messages to each other for normal processing. A message transmitted and received by the control process and the PE group to perform checkpoint setting and re-execution is called a control message. The control process, the PE and the message have a weight, and all weights are The sum has a constant value, the weight has a generation, all weights are initialized to the same generation, the control process has an old generation weight counter, each PE has a status flag, a status record, an ID register, and a status record. Consists of an ID field and a status field. The status flag takes a value of either C or R, and the status field is cleared at the stage of allocation. The control process performs a check to set a checkpoint. Determine the point ID (called checkpointID) and checkpoint control message (hereinafter ch eckp
oint) to all PEs and checkpoint
It has eckpointID as an argument, and ackCheckpoint control messages (hereinafter a
ckCheckpoint), set its own weight in the old generation weight counter, set its own weight to a certain value, advance its own weight by one, and record control message (hereinafter abbreviated as record) Is sent to all PEs, the record is weighted, and its own weight is reduced by that amount. When the PE receives the checkpoint, the PE sets the status flag to C and records the checkpoint ID carried by the checkpoint in the ID register. Then, allocate a new status record, record the checkpoint ID in the ID field, return the ackCheckpoint to the control process, and when receiving the record, compare the `` generation of the weight that record has '' with the `` generation of your own weight ''. If the "generation of record weight" is new, record its own state in the state field of the state record indicated by the ID register, and write its own weight in the return control message (hereinafter referred to as "return"). To the control process, resets its own weight to the weight of record, and if the two generations are equal, adds the weight of record to its own weight.The control process receives the return and returns the weight carried by return. Is added to the old generation weight counter.As a result, if the value of the old generation weight counter becomes a constant value, it is confirmed that the checkpoint setting is completed, and the status field of each PE at the time of confirming the completion is checked. The set constitutes a checkpoint, and the control process determines the checkpoint to start the re-execution, finds the checkpoint ID indicating the check point, and performs a roll.
Sends a back control message (hereinafter referred to as rollback) to all PEs, and rollback has a checkpointID as an argument, and an ackRollback control message (hereinafter referred to as ackRollback)
Waits until all PEs have received it, sets its own weight in the old generation weight counter, sets its weight to a constant value, advances its weight by one generation, r
Sends an eexecute control message (hereinafter referred to as reexecute) to all PEs, weights the reexecute, and reduces its own weight by that amount. When the PE receives the rollback, the PE sets the status flag to R, Records the checkpointID carried by the user in the ID register, sends ackRollback to the control process, and when reexecute is received, compares the "generation of the weight that reexecute has" with the "generation of its own weight", and If the `` generation '' is new, reset its own state with the contents of the state field of the state record indicated by the ID register, send its own weight to the control process with return, reset its own weight with the weight of reexecute, If the two generations are equal, add the weight of reexecute to their own weight, and when the control receives the return, add the weight carried by return to the old generation weight counter and add the result When the value of the old generation weight counter reaches a certain value, it is possible to confirm that the re-execution has been started. When the PE receives the normal message, the PE determines, "the generation of the weight that the normal message has" and "own own". Weight generation ”, and if“ own weight generation ”is new and the status flag is C,
Normally the weight of the message is sent to the control process by return,
Record the content of the normal message in the status field of the status record indicated by the ID register, process the normal message, and if the "own weight generation" is new and the status flag is R,
Normally the weight of the message is sent to the control process by return,
Discard the normal message without processing it. If the "normal message weight generation" is new and the status flag is C, record your status in the status field of the status record indicated by the ID register, and control your weight with return. To the process, reset its own weight with the weight of the normal message, process the normal message, and if the "normal message weight generation" is new and the status flag is R, the status field of the status record indicated by the ID register Reset your state with the contents and re-weight yourself
Turn to send to the control process, reset its own weight with the weight of the normal message, process the normal message, and if the two generations are equal, add the weight of the normal message to its own weight and process the normal message Checkpoint setting and re-execution method characterized by the above-mentioned. 19. A finite number of processors (hereinafter referred to as PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous message communication, and overtaking of a message occurs on the communication channel. There is no guarantee that messages will arrive in the order in which they were sent, there is no clock governing the entire system, each PE and network channel will operate independently according to their own clocks, and each PE will send messages to all other PEs. There is a special process (called a control process) that can send, record its status and received messages, and issue checkpointing and re-execution instructions. The control process and all PEs PEs can send and receive messages to each other for normal processing. A message is called a normal message, a message sent and received by the control process and the PE group for setting and re-executing a checkpoint is called a control message. The control process, the PE and the message have a weight, and the sum of all weights Takes a constant value, weights have generations, all weights are initialized to the same generation, control process has old generation weight counter, each PE has status flag and status record, ID register, message buffer, The status record consists of an ID field and a status field. The status flag takes either the value of C or R. The status field is cleared at the stage of allocation, the message buffer is cleared by initialization, and the control process Checkpoint to set, to set checkpoint To determine the checkpointID that shows, to set up their own weight to the old generation weight counter, set their own weight at a constant value, advanced one generation of their own weight, and sends the record to all of the PE, record the checkpointID
, The record is weighted, and its own weight is reduced by that amount. When the PE receives the record, the PE sets the status flag to C, records the checkpointID carried by the record in the ID register, Allocate new record, ch to ID field
Record your status in the status field with the eckpointID,
Return your weight to the control process with return, reset your weight with the weight of record, and if the message buffer contains normal messages, add those weights to your own weight and process them When the return is received, the control process adds the weight carried by return to the old generation weight counter, and if the addition results in a value of the old generation weight counter becoming a constant value, the control process checkspoints. Is completed, the set of status fields of each PE at the time of confirming the completion constitutes a checkpoint, and the control process determines a checkpoint to start re-execution in order to perform re-execution. , Find a checkpointID indicating the checkpoint, set its own weight in the old generation weight counter, set its own weight to a certain value, Promoting the generation of minute of weight one, r
Send eexecute to all PEs, reexecute checkp
ointID as an argument, weight reexecute,
When the PE receives the reexecute, the PE sets the status flag to R, and resets its own status with the contents of the status field of the status record indicated by the checkpointID carried by the reexecute. Send the weight to the control process with return, reset its own weight with the reexecute weight, and if the message buffer normally contains messages, add those weights to your own weight and process them, When the message buffer is cleared and the control process receives the return, the control process adds the weight carried by the return to the old generation weight counter, and starts the re-execution if the value of the old generation weight counter becomes a constant value as a result. When the PE receives the normal message, the PE compares the “generation of the weight that the normal message has” with the “generation of its own weight”. If "My weight of generation" is a new state flag is C,
Normally the weight of the message is sent to the control process by return,
Record the content of the normal message in the status field of the status record indicated by the ID register, process the normal message, and if the "own weight generation" is new and the status flag is R,
Normally the weight of the message is sent to the control process by return,
The normal message is discarded without processing, and if the "normal message weight generation" is new, the normal message is stored in the message buffer without processing, and if the two generations are equal, the normal message weight is set to Checkpoint setting and re-execution method characterized by processing a normal message in addition to the weight of the checkpoint. 20. A finite number of processors (hereinafter, referred to as PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous message communication, and overtaking of a message occurs on the communication channel. There is no guarantee that messages will arrive in the order in which they were sent, there is no clock governing the entire system, each PE and network channel will operate independently according to their own clocks, and each PE will send messages to all other PEs. There is a special process (called a control process) that can send, record its status and received messages, and issue checkpointing and re-execution instructions. The control process and all PEs PEs can send and receive messages to each other for normal processing. A message is called a normal message, a message sent and received by the control process and the PE group for setting and re-executing a checkpoint is called a control message. The control process, the PE and the message have a weight, and the sum of all weights Takes a constant value, weights have generations, all weights are initialized to the same generation, the control process has an old generation weight counter, each PE has a state switch and a state record, an ID register, and the state record is It consists of an ID field and a status field. The status switch takes one of the values C, C ', R, and R', the initial value is C, the status field is cleared at the stage of allocation, and the control process To set the checkpoint, determine the checkpointID indicating the checkpoint to be set, and Set its own weight in the counter, set its own weight to a constant value, advance its own weight by one generation, re
Sends cord to all PEs, record has checkpointID as an argument, weights record, reduces its own weight by that amount, and PE receives the record, and says, "Generation of the weight that record has "And" own weight generation ". If the" record weight generation "is new, set the status flag to C ', record the checkpointID carried by record in the ID register, and update the status record. Assign the checkpoint ID in the ID field, record your status in the status field, send your weight to the control process with return, reset your weight with the weight of record, and if the two generations are equal, record When the control process receives the return, the control process adds the weight carried by the return to the old generation weight counter, and checks if the value of the old generation weight counter becomes a constant value as a result. It is confirmed that the setting of the point has been completed, and a set of the status fields of each PE at the time of confirming the completion constitutes a checkpoint. When the control process confirms the completion of the checkpoint setting, a complete control message (hereinafter, completed) Is sent to all PEs, completed is given a weight, its own weight is reduced by that amount, and the control process determines a checkpoint to start the re-execution and performs a check Find the checkpoint ID indicating the point, set its own weight in the old generation weight counter, set its own weight to a constant value, advance the generation of its own weight by one, r
Send eexecute to all PEs, reexecute checkp
ointID as an argument, weight reexecute,
When the PE receives the reexecute, the PE compares “the generation of the weight that reexecute has” and “the generation of its own weight”. If the “generation of the weight of reexecute” is new, , Set the status flag to R 'and checkpointID carried by reexecute
Record it in the ID register, reset its own status with the contents of the status field of the status record indicated by checkpointID, send its weight to the control process by return, and
resets with the reexecute weight, if the two generations are equal, adds the reexecute weight to its own weight, and upon receiving the return, the control process adds the weight carried by return to the old generation weight counter and adds As a result, when the value of the old generation weight counter becomes a constant value, it can be confirmed that the re-execution has been started. When the control process confirms the completion of the re-execution start, com
Sends a pleted control message (hereinafter abbreviated as completed) to all PEs, weights completed, reduces its own weight by that amount, and when the PE receives completed, the state switch sets C ′
Then, if the status switch is R ', then set it to R. When the PE receives the normal message, the PE sets "the generation of the weight that the normal message has" and "the generation of its own weight". If the "generation of own weight" is new and the status switch is C ', the weight of the normal message is sent to the control process by return, and the content of the normal message is recorded in the status field of the status record indicated by the ID register. If the normal message is processed and the "own weight generation" is new and the state switch is R ', the weight of the normal message is sent to the control process by return, and the normal message is discarded without processing. If the "generation" is new and the "normal message status flag" is C ', the status switch is set to C'.
Record the checkpointID carried by the normal message in the ID register, allocate a new status record, record the checkpoint ID in the ID field, record your status in the status field, send your weight to the control process by return, If the weight is reset to the normal message weight, the normal message is processed, and if the “normal message weight generation” is new and the “normal message status flag” is R ′, the status switch is set to R ′.
The checkpointID carried by the normal message is recorded in the ID register, the state is reset using the contents of the state field of the state record indicated by the checkpointID, the weight is sent to the control process by return, and the weight is If the two generations are equal, add the weight of the normal message to its own weight, process the normal message, and process the normal message. If the status switch is C 'or R', the value of the status switch and the checkpoint ID recorded in the ID register are sent to a normal message and transmitted. 21. A finite number of processors (hereinafter referred to as PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous message communication, and overtaking of a message occurs on the communication channel. There is no guarantee that messages will arrive in the order in which they were sent, there is no clock governing the entire system, each PE and network channel will operate independently according to their own clocks, and each PE will send messages to all other PEs. There is a special process (called a control process) that can send, record its status and received messages, and issue checkpointing and re-execution instructions. The control process and all PEs The PE can perform message communication with each other, and the PE has a return destination register indicating the return destination. Return, send return to the destination indicated by the destination register, and when return is received, compare "generation of weight carried by return" with "generation of own weight" .If the two generations are equal, return Checkpoint setting and re-execution characterized by sending the received return to the destination indicated by the destination register as is and adding the weight carried by return to the own weight if the "own weight generation" is new Method. 22. A finite number of processors (hereinafter referred to as PEs) are connected to each other by a logical communication channel, and the PEs communicate with each other by asynchronous message communication, and overtaking of a message occurs on the communication channel. There is no guarantee that messages will arrive in the order in which they were sent, there is no clock governing the entire system, each PE and network channel will operate independently according to their own clocks, and each PE will send messages to all other PEs. There is a special process (called a control process) that can send, record its status and received messages, and issue checkpointing and re-execution instructions. The control process and all PEs PEs can send and receive messages to each other for normal processing. A message is called a normal message, a message sent and received by the control process and the PE group for setting and re-executing a checkpoint is called a control message. The control process, the PE and the message have a weight, and the sum of all weights Takes a constant value, the weight has a generation, all weights are initialized to the same generation, and the PE has a return destination register and a return weight counter, re
It has a turn transmission switch and a return reception table. The return reception table consists of the return source PE and the reception flag.The return weight counter is initialized to zero, and the return transmission switch sets any value of notReady, ready, or done. Take, PEs that do not receive return initialize to done,
The other PEs are initialized to notReady, the receive flag takes either the value of notReceived or received, and initialized to notReceived, and the PE has a newer generation weight than its own weight generation
record, reexecute or normal message received,
When the weight of the received message resets its own weight, the return weight counter, the return transmission switch, and the return reception table are initialized. When the PE tries to transmit the return, the return of the PE
If the transmission switch is done, return is sent to the destination indicated by the return transmission destination register. If the return transmission switch of the PE is ready, "retu
rn to return with rn) to the rejection weight counter, if the return transmission switch of that PE is notReady and the values of the reception flags in the return reception table are all received,
The return that carries the sum of the "weight to be returned by return" and the "weight stored in the return weight counter" is return
Send to the PE indicated by the transmission destination register, set the return transmission switch to done, and if the return transmission switch of that PE is notReady and one or more reception flags in the return reception table are notReceived, set the return transmission switch to ready. , "Retu
rn to return with "rn" to the return weight counter, and when the PE receives the return, the return transmission switch is done.
If `` the generation of weight carried by return '' is equal to `` the generation of own weight '', initialize the return weight counter, return transmission switch, and return reception table, and add the weight carried by return to the return weight counter. In the return reception table, set the reception flag corresponding to the source PE of the received return to received, and set the return transmission switch to done so that "own weight generation" is newer than "return weight carried generation". Then return
The return is sent as it is to the PE indicated by the destination register, and if the return transmission switch is ready, the weight carried by the return is added to the return weight counter, and the return reception table corresponds to the source PE of the received return. Set the receive flag to received, and if all the values of the receive flags are set to received, send the return carrying the weight stored in the return weight counter to the PE indicated by the return destination register, and send the return. Set the switch to done, and if the return transmission switch is notReady, add the weight carried by return to the return weight counter, and set the reception flag corresponding to the source PE of the received return in the return reception table to received Checkpoint setting and re-execution method characterized by the above-mentioned. 23. The PE has a return destination register, a return weight counter, a return transmission switch, and a return reception counter. The return weight counter is initialized to zero, and the return transmission switch is one of notReady, ready, and done. The PE that does not receive a return is initialized to done,
The other PEs are initialized to notReady, the reception counter is initialized to "the minimum number of returns to receive", and the PE has a newer generation weight than its own.
record, reexecute or normal message received,
When the weight of the received message resets its own weight, the return weight counter, the return transmission switch, and the return reception counter are initialized, and when the PE tries to transmit the return, the return of the PE returns.
If the transmission switch is done, return is sent to the destination indicated by the return transmission destination register. If the return transmission switch of the PE is ready, "retu
rn to be returned with rn ”is added to the return weight counter, and the return transmission switch of that PE returns
rn If the value of the reception counter is zero, send a return carrying the sum of the "weight to be returned by return" and the "weight stored in the return weight counter" to the PE indicated by the return destination register, and send the return Set the switch to done, if the return transmission switch of the PE is notReady and the value of the return reception counter is not zero, set the return transmission switch to ready, and set the "weight to return on return" to the return weight counter. When the PE receives the return, the return switch is set to done.
If `` the generation of weight carried by return '' is equal to `` the generation of own weight '', initialize the return weight counter, return transmission switch, and return reception counter, and add the weight carried by return to the return weight counter. Return return counter is decremented by 1. If the return transmission switch is done and "own weight generation" is newer than "return weight generation", return
The return is sent to the PE indicated by the destination register as it is, and if the return transmission switch is ready, the weight carried by return is added to the return weight counter, the return reception counter is decremented by 1, and the result of the decrement is -1. If the value of is zero, retu carries the weight stored in the return weight counter
sends rn to the PE indicated by the return destination register, and returns
A checkpoint setting and re-execution method, wherein the transmission switch is set to done, and if the return transmission switch is notReady, the weight carried by return is added to the return weight counter, and the return reception counter is decremented by one.