JPH0619858A - Automatic return system for common resources - Google Patents

Abstract

PURPOSE:To automatically release the exclusive control of a common resource when a fault occurs in a processor in the middle of the exclusive control of the common resource, and to permit the other normal processor to use the common resource. CONSTITUTION:In a multiprocessor system where plural processors 2 respectively have the common resources, the respective processors 2 are provided with operating system parts 2a controlling a self operation and managing the common resources 1 which they themselves have and common resource management tables 2b storing processor ID specifying the processor that exclusively controls the common resources 1 which the processors 2 have. The system is the automatic return system of the common resource.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiprocessor system having a plurality of processors and activating them in parallel to perform processing. In particular, a common resource that can be commonly used by the plurality of processors is an arbitrary processor. The present invention relates to a multiprocessor system that performs exclusive control to prevent other processors from using the same when they are used.

[0002]

2. Description of the Related Art A computer system allocates hardware resources (hereinafter referred to as resources) consisting of a memory, a processor and an input / output device, and resources to individual tasks.
It is composed of a control program for controlling the operation, that is, software.

Recently, a multi-task system has been known in which a software has a function of enabling a plurality of tasks to be processed in parallel by a single processor by a time division multiplex system. The multitasking method has an advantage that resources can be efficiently shared among a plurality of tasks, the arithmetic processing can be performed at high speed, and the processing capacity of the entire computer system is improved.

However, since the amount of information processing has increased remarkably in recent years, there has been a problem that it takes a very long time to perform such information processing by one processor. Therefore, a multiprocessor system having a plurality of processors has become widespread. I'm doing it.

In some multiprocessor systems, resources such as a main memory are shared by a plurality of processors for operation. Among them, a method is known in which a plurality of common resources are allocated to each processor and the common resources can be used by tasks of other processors.

In order to prevent a plurality of processors from using the same common resource at the same time with respect to the above-mentioned common resource, that is, when any task is using the common resource, another task can use this common resource. Exclusive control is performed to prevent the use of.

This exclusive control is performed based on common resource management information called a semaphore. This semaphore consists of a queue of tasks for acquiring the number of available common resources and the required number of common resources. For example, when an arbitrary task uses a common resource, this task requests the acquisition of the number of common resources required by a system call. On the other hand, the processor that manages the common resource compares the requested number of common resources with the number of common resources that can be used at this time. As a result, when the number of available common resources is equal to or larger than the requested number of common resources, the processor permits the task to use the common resources. This allows the task to continue processing using the acquired common resource.

On the other hand, if the number of available common resources is less than the required number of common resources, that is, if the number of common resources requested by the requesting task cannot be obtained, the task returns the common resources from other tasks. I have to wait until it is done.

Then, when the common resource is returned, the number of common resources available at that time is compared with the number of common resources required by the task, and the number of available common resources exceeds the required number. For example, the task can be released from the wait state and the process can be re-executed using the common resource.

[0010]

However, in the above-mentioned method, if any processor fails during exclusive control of the common resource, the common resource remains in the exclusive control state even after the processor is restarted. Therefore, the other normal processors cannot use the common resource, resulting in a decrease in the capability of the entire multiprocessor system.

Therefore, the present invention has been made in view of the above-mentioned problems, and when a processor that is performing exclusive control of an arbitrary common resource cannot normally operate due to a failure, the exclusion of the common resource is performed. It is a technical object to automatically release control so that another normal processor can use this common resource and to improve the processing capability of the entire multiprocessor system.

[0012]

In order to solve the above-mentioned problems, the present invention is as follows. This will be described based on the principle diagram of FIG.

As a first means, the multiprocessor system according to the present invention comprises a plurality of processors 2 and a common resource 1 managed by each processor 2.
Here, each processor 2 has an operating system unit 2a and a common resource management table 2b, and the operating system unit 2a controls the operation of the processor 2 including itself and the common resource included in the processor 2. It manages 1.

On the other hand, the common resource management table 2b includes a common resource 1 for each common resource 1 included in the processor 2.
It stores a processor ID that identifies the processor 2 that exclusively controls the.

Further, in the common resource management table 2b,
Of the common resources 1 included in the processor 2, the number of usable resources, that is, the number of resources that are not exclusively controlled and the common resource 1 are exclusively controlled for each common resource ID that identifies the common resource 1 having the same function. The processor ID of the existing processor 2 and the number of common resources exclusively controlled by the processor 2 may be stored. In this case, when the operating system unit 2a receives the common resource ID and the use request number from any processor 2, the operating system unit 2a refers to the common resource management table 2b and compares the usable resource number with the use request number. If the number of available resources is equal to or greater than the number of required usages, the processor 2 is given permission to use and a value obtained by subtracting the number of required usages from the number of available resources is newly registered as the number of usable resources.

Further, the common resource management table 2b may be provided with a waiting management table for first-in first-out of the processor ID of the processor 2 which should wait for the use of any common resource 1 and the number of requests for use of the common resource 1.

On the other hand, as a second means, the multiprocessor system according to the present invention comprises a plurality of processors 2.
It is composed of a common resource 1 managed for each processor 2 and a shared memory 3 accessible by each processor 2.

The processor 2 includes an operating system section 2a that manages its own operation and also manages the common resource 1 of its own. The shared memory 3
Is a common resource ID that identifies the common resource 1 having the same function,
For each common resource ID, an exclusive control processor ID that specifies a processor 2 that is in exclusive control of the common resource 1, a management processor ID that specifies a processor 2 that includes the common resource 1, and an exclusion of the common resource 1 An exclusive control management table 3a is provided for registering the exclusive control number indicating the number of common resources under control.

[0019]

According to the first means, the operating system section 2a monitors the common resource management table 2b to determine whether or not the specific common resource 1 is exclusively controlled for a predetermined time or longer.

When the specific common resource 1 is exclusively controlled for a predetermined time or longer, the operating system section 2a detects the processor ID of the processor 2 which is exclusively controlling the common resource 1. Then, it is possible to forcibly cancel the exclusive control by the processor 2, notify the other processors 2 of the processor ID, and prompt the forced cancellation of the exclusive control for the common resource 1 included in each processor 2. When the operating system unit 2a receives a request for use of the common resource 1 from an arbitrary processor 2, the operating system unit 2a refers to the common resource management table 2b and compares the number of use requests with the number of available resources.

If the number of resources in the usable state is equal to or greater than the number of required usages, exclusive control is permitted for the processor 2 and a value obtained by subtracting the number of required usages from the number of usable states is newly set as the number of usable states. The value is stored in the common resource management table 2b, and a value obtained by adding the number of usage requests to the number of resources under exclusive control is newly stored as the number of resources under exclusive control.

On the other hand, in the above comparison between the number of use requests and the number of resources in the usable state, if the number of use requests exceeds the number of resources in the usable state, the number of use requests is calculated together with the processor ID of the processor 2. It is registered in the waiting management table in the common resource management table 2b. Then, when the common resource 1 is returned by the arbitrary processor 2, the usable number of the common resource 1 is compared again with the use request number. If the number of usable states is equal to or greater than the number of requests for use, the processor 2 is permitted to perform exclusive control of the common resource 1, and the processor ID is deleted from the waiting management table.

When the processor 2 in which a failure has occurred during exclusive control of an arbitrary common resource 1 is restarted from the failure, the operating system unit 2a in the processor 2 accesses the shared memory 3 to access the shared memory 3. , And the exclusive control management table 3a. Here, it is determined whether or not the processor ID of the processor itself is stored in the exclusive control processor ID, and if it is stored, the exclusive control of the common resource 1 can be automatically released.

From the above, when the processor 2 under exclusive control cannot operate normally due to a failure, the exclusive control can be automatically released, and the other processors 2 can
The common resource 1 can be used without undue waiting time.

[0025]

EXAMPLES Specific examples of the present invention will be described below. (Embodiment 1) FIG. 2 is a schematic block diagram of a multiprocessor system according to the first embodiment.

The multiprocessor system according to the first embodiment includes first to third processors 4a to 4c, a common resource 5 included in each processor 4, and a shared memory 6 accessible from each processor 4. In the first embodiment, each processor 4 is provided with three common resources 5.

FIG. 3 is an internal block diagram of the processor 4. The processor 4 according to the first embodiment controls its own operation in accordance with an instruction from a task assigned to itself, and also has its own common resources A to C (5a to 5c).
The common resource management table 40 and the operating system unit 44 that manages the.

The common resource management table 40 stores information for managing each common resource 5 included in the processor 4. This information will be described later. That is, when the processor 4 receives a request for using the common resource 5 from another processor 4, the processor 4 refers to the common resource management table 40 and determines whether to permit the use of the common resource 5.

FIG. 4 shows a concrete example of the common resource management table 40 in the first embodiment. Common resource management table 4
In 0, of the common resources 5 included in the processor 4,
A common resource ID is determined for each common resource 5 having the same function, and the number of resources, that is, the number of common resources 5 having the same function is stored for each common resource ID. Further, it stores the processor ID of each processor 4 constituting the multiprocessor system and the number of common resources 5 under exclusive control by the processor 4, and also stores the total number of common resources 5 under exclusive control. .

For example, in the first embodiment, each processor 4 has a common resource A (5a) and a common resource B (5).
b), the common resource management table 40 is divided into three areas because the common resource C (5c) has three common resources. In each of these areas, the number of usable resources and the value of the total number of exclusive controls, together with the processor ID of the first processor 4a constituting the multiprocessor system and the resources of the common resource exclusively controlled by the first processor 4a. Similarly, the number of the second processor 4b, the third processor 4c
Each processor ID and the number of common resources under exclusive control are stored.

Next, FIG. 5 is a diagram showing a process of changing the common resource management table by exclusive control. X in the figure
Is a specific example of the common resource management table 40 in the initial state.

When the exclusive control request for the common resource A (5a) is received from the first processor 4a, the operating system section 44 accesses the area of the common resource A (5a) in the common resource management table 40 and uses it. Refer to the number of available resources. When the number of available resources is 1 in X of the figure, and the exclusive control request from the first processor 4a is 1, the number of available resources-the number of exclusive control requests = 1-1 = 0 ≧ 0. The operating system unit 44 is
The exclusive control request of the first processor 4a is permitted. That is, the first processor 4a can use the common resource A (5a).

Here, the operating system unit 44
Sets the number of available resources to "0" in the common resource management table 40, updates the exclusive control number of the first processor 4a from "0" to "1", and sets the total exclusive control number to "1".
Update from 0 "to" 1 "(Y in the figure).

On the other hand, the number of usable resources is 1, and the first
When the number of exclusive control requests from the processor 4a is 2 or more, the number of usable resources-the number of exclusive control requests = 1-2 = -1 ≦ 0, and therefore the operating system unit 44
The first processor 4a is put on standby.

Further, when the common resource A (5a) is returned from the first processor 4a, the operating system section 44 can access and use the common resource A (5a) area of the common resource management table 40. Number of resources ”
The number of returned resources "1" is added to "0" to obtain "1", and the number of returned resources "1" is subtracted from the exclusive control number "1" of the first processor 4a to obtain "0". "Is newly stored. As a result, the total exclusive control number is necessarily" 0 ".
Becomes

Next, the operation process of the multiprocessor system when the processor 4 under exclusive control fails will be described with reference to the flowchart of FIG. The operating system unit 44 is the processor 4 to which it belongs.
The common resource management table 40 included in the common resource management table 40 is monitored (step 601), and whether there is a processor 4 that has used (exclusive control) the specific common resource 5 for a predetermined time or longer (step 602). If there is a processor 4 that exclusively controls the same common resource 5 for a predetermined time or longer, the processor ID of the processor 4 is recognized from the common resource management table 40 (step 603).

Further, by referring to another area of the common resource management table 40, the common resource 5 under the exclusive control by the processor 4 is recognized, and all the common resources 5 are forcibly controlled by the exclusive control by the processor 4. It is released (step 604).

The processor I of the processor 4 concerned
D is the operating system unit 4 of the other processor 4.
4 and prompts the processor 4 to cancel the exclusive control of the common resource 5 (step 605).

Therefore, according to the first embodiment, the arbitrary processor 4 recognizes the processor 4 that has failed during the exclusive control of the common resource 5 and recognizes it as the other processor 4.
The exclusive control can be automatically released by notifying that the normal processor 4 can continue the processing.

(Embodiment 2) FIG. 7 shows the internal configuration of the processor according to the second embodiment. In the multiprocessor system according to the second embodiment, each processor 4 is provided with a timer 41 for measuring a specific time in the configuration of the first embodiment.
Other configurations are the same as those in the first embodiment.

The operation process of this multiprocessor system will be described with reference to the flowchart of FIG. The operating system unit 44 activates the timer 41 when permitting the exclusive control of the common resource 5 to any processor 4 (step 801).

Then, when the timer 41 finishes measuring the specific time, it is judged whether or not the processor 4 is in the exclusive control of the common resource 5 by referring to the common resource management table 40 (step 802). Here, when the processor 4 is in the exclusive control of the common resource 5 even after the timer is activated,
The operating system unit 44 determines that the processor 4 has failed, recognizes the processor ID of the processor 4 from the common resource management table 40 (step 803), and the processor 4 excludes other common resources 5. Common resource management table 4 for controlling
If it is determined from 0, if there are common resources 5 under exclusive control, all of them are forcibly released (step 804).

Further, the operating system unit 44 notifies the operating system unit 44 of the other processor 4 of the processor ID, and prompts the processor 4 to forcibly cancel the exclusive control of the common resource 5.

Therefore, according to the second embodiment, the arbitrary processor 4 recognizes the processor 4 which has failed during the exclusive control of the common resource 5 and recognizes it.
The exclusive control can be automatically released by notifying that the normal processor 4 can continue the processing.

(Third Embodiment) FIG. 9 shows a schematic configuration of a multiprocessor system according to the third embodiment. Example 3
The multiprocessor system in FIG.
The common resource A (55
a), and similarly the second processor 4b has a common resource B
(55b) to the common resource C (5
5c). Further, the shared memory 6 accessible from each processor 4 is provided. A detailed description of this shared memory 6 will be given later.

FIG. 10 is an internal block diagram of the processor in the third embodiment. Processor 4 in the third embodiment
In addition to the configuration of the first embodiment described above, the operating system unit 44 is provided.

Next, FIG. 11 is a diagram showing the internal structure of the shared memory 6 in the third embodiment. The shared memory 6 in the third embodiment is provided with an exclusive control management table 6a for managing all the common resources 55 of the multiprocessor system in the first embodiment.

The exclusive control management table 6a has a common resource ID for each common resource 55 having the same function and the processor I of the processor 4 which exclusively controls the common resource 55.
D, the processor ID of the processor 4 on which the common resource 55 is dependent, and the exclusive control number of the exclusive control processor 4 are stored.

FIG. 12 is a diagram showing a process of changing the exclusive control management table 6a by exclusive control. In the figure, the exclusive control management table 6a of the common resource A (55a) included in the first processor 4a is extracted, and X in the figure is a specific example of the exclusive control management table 6a in the initial state.

Here, when the operating system unit 44 of the first processor 4a receives an exclusive control request for the common resource A (55a) from the second processor 4b, it accesses the shared memory 6 and executes the exclusive control management table 6a. The area of the common resource A (55a) is referred to.

Then, the number of usable resources is detected by referring to the exclusive control number. Here, assuming that the exclusive control request from the second processor 4b is 1, the number of usable resources-the number of exclusive control requests = 1-1 = 0 ≧ 0. Therefore, the operating system unit 44 is
The exclusive control request of the second processor 4b is permitted.

Then, the operating system unit 44 adds the processor ID of the second processor 4b to the exclusive control processor ID in the exclusive control management table 6a.
Is registered and the exclusive control number is set to "1" (Y in the figure).

On the other hand, when the exclusive control request from the second processor 4b is larger than the number of available resources, that is, when the number of available resources−the number of exclusive control requests ≦ 0, the second processor 4b is put on standby.

Further, the common resource A from the second processor 4b
When (55a) is returned, the operating system section 44 causes the common resource A of the exclusive control management table 6a to be returned.
The area (55a) is accessed, the exclusive control number is changed from "1" to "0", and the processor ID of the second processor 4b is erased from the exclusive control processor ID (C in the figure).

The operation process of the multiprocessor system in the third embodiment will be described with reference to the flowchart of FIG. When an arbitrary processor 4 recovers from a failure, the operating system unit 4 of this processor 4
4 accesses the exclusive control management table 6a of the shared memory 6 (step 1301), and sets its own processor I to the exclusive control processor ID of this exclusive control management table 6a.
It is determined whether or not D is registered (step 130).
2).

In the step 1302, when the processor ID of its own is not registered in the exclusive control processor ID of any of the common resources 55, the processor 4 continues the process before the occurrence of the failure (step 130).
5).

On the other hand, when the own processor ID is registered, the management processor ID is detected from the area of the registered common resource 55, and this management processor ID is detected.
Requesting the operating system unit 44 of the processor 4 corresponding to to cancel the exclusive control of the common resource 55 (step 1303).

Then, the own processor ID is deleted from the exclusive control processor ID of the exclusive control management table 6a (step 1304). Therefore, according to the third embodiment, the processor that has failed during exclusive control can release all the common resources 55 under exclusive control after the recovery from the failure, and other normal processors can use the released common resource. The resource 55 allows the processing to continue.

[0059]

As described above, according to the present invention, when the normal operation cannot be performed due to the failure of the processor during the exclusive control of the common resource, the exclusive control of the common resource is automatically released. , Other normal processors can make use of this common resource. Furthermore, it is possible to improve the processing capacity of the entire multiprocessor system.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a schematic configuration diagram of a multiprocessor system according to the first embodiment.

FIG. 3 is an internal configuration block diagram of a processor according to the first embodiment.

FIG. 4 is a specific example of a common resource management table according to the first embodiment.

FIG. 5 is a diagram showing a process of changing a common resource management table by exclusive control.

FIG. 6 is a flowchart showing an operation process of the multiprocessor system according to the first embodiment.

FIG. 7 is a diagram showing an internal configuration of a processor according to the second embodiment.

FIG. 8 is a flowchart showing an operation process of the multiprocessor system according to the second embodiment.

FIG. 9 is a schematic configuration diagram of a multiprocessor system according to a third embodiment.

FIG. 10 is an internal configuration diagram of a processor according to the third embodiment.

FIG. 11 is an internal configuration diagram of a shared memory according to the third embodiment.

FIG. 12 is a process of changing the exclusive control management table by exclusive control.

FIG. 13 is an operation flowchart of the multiprocessor system according to the third embodiment.

[Explanation of symbols]

 1-common resource 2-processor 2a-operating system section 2b-common resource management table 3-shared memory 3a-exclusive control management table 4-processor 4a-first processor 4b-second processor 4c 3rd processor 5 common resource 5a common resource A 5b common resource B 5c common resource C 6 shared memory 6a exclusive control management table 40 common resource management table 41・ Timer 44 ・ ・ Operating system 55 ・ ・ Common resource 55a ・ ・ Common resource A 55b ・ ・ Common resource B 55c ・ ・ Common resource C

Claims (4)

[Claims] 1. A plurality of processors (2) and a common resource (1) managed for each processor (2),
When an arbitrary processor (2) uses a specific resource, that resource is exclusively controlled to another processor (2).
In the multiprocessor system for preventing access from the above, each processor (2) controls an operation of the processor (2) and manages a common resource (1) included in the processor (2).
a) and the common resource (1) included in the processor (2)
I that identifies the processor that exclusively controls
A common resource management table (2b) for storing D, and the operating system unit (2a) monitors the common resource management table (2b) to identify a specific common resource (1).
When it is recognized that is under exclusive control for more than a predetermined time,
The processor ID of the processor (2) that exclusively controls the common resource (1) is detected, the exclusive control by this processor (2) is forcibly released, and the processor ID is notified to the other processor (2). A common resource automatic return method characterized by urging that the exclusive control for the common resource (1) included in each processor (2) is forcibly released. 2. The common resource management table (2b) includes, in each common resource (1) having the same function, the number of available common resources (1) and a processor (which constitutes the multiprocessor system). 2) Each processor ID,
The number of common resources exclusively controlled by the processor (2) is stored, and when the operating system unit (2a) receives a request for using the common resource (1) from an arbitrary processor (2), When the number of usable common resources (1) is equal to or greater than the number of required usage, the processor (2) is allowed to perform exclusive control of the common resource (1), and the common control during exclusive control of the processor (2) is performed. 2. The automatic common resource return system according to claim 1, wherein the number of required uses is added to the number of resources and the required number of uses is subtracted from the usable number. 3. A waiting management table in which the common resource management table (2b) first-in-first-out of the processor ID of the processor (2) that should wait for the use of an arbitrary common resource (1) and the number of requests for using the common resource (1). When the operating system unit (2a) receives a use request for the common resource (1) from the arbitrary processor (2), if the usable number of the common resource (1) is less than the use request number, Processor ID of the processor (2)
And the number of use requests are stored in the waiting management table, and when the common resource (1) is returned, the usable number of common resources (1) is compared again with the number of use requests,
If the usable number is equal to or larger than the use request number, exclusive control of the common resource (1) is permitted to the processor (2), and the processor (2) is read from the waiting management table.
3. The common resource automatic return method according to claim 2, wherein 4. A plurality of processors (2), a common resource (1) managed for each processor (2), and a single shared memory (3), and an arbitrary processor (2) is a specific resource. In a multiprocessor system in which resources are exclusively controlled to prevent access from another processor (2), the processor (2) controls the operation of the processor (2). In addition, an operating system unit (2a) that manages the common resource (1) included in itself is provided, and the shared memory (3) has a common resource (1) having the same function.
A common resource ID that identifies the common resource (1), an exclusive control processor ID that is stored for each common resource ID and that identifies a processor (2) that is in exclusive control of the common resource (1), Management processor ID storing the processor ID of 2) and the common resource (1)
An exclusive control management table (3a) for registering the number of exclusive controls for storing the number of common resources under exclusive control is provided, and the processor (2) is The operating system section (2
a) operates the processor (2) to access the shared memory (3) to access the exclusive control management table (3
The common resource automatic return method, which refers to the exclusive control processor ID of a) and automatically releases the exclusive control of the common resource (1) when its own processor ID is stored.