JPH05334104A - Data control device in datagram type inter-multiprocessor socket communication - Google Patents

Abstract

PURPOSE:To prevent data from being lost and to prevent the order of processes from being inverted by providing this data control device with a numbering transmitting part, a receiving side busy detecting part and a saved transmitting data list part. CONSTITUTION:A transmitting part 60 is provided with a numbering transmitting part 240, a save list managing part 250 including a saved transmitting data list 340, a receiving side busy detecting part 230, and a resending data retrieving part 260. The numbering transmitting part 240 adds a serial number and a self-process name to transmitting data. The selecting part 230 detects whether the busy status of the receiving side is normal or not, and when the status is normal, data are transmitted to complete transmission. At the time of busy status, processing is repeated until a transmittable state is set up and then transmission is completed. In the case of retrial-over, processing abnormally ends. The save list managing part 250 stores a regulated quantity of data in the list 340 for resending the data when some transmitting data is lost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data control method for datagram type multi-process socket communication, and more particularly to a system for frequently transmitting and receiving data between a large number of processes.

[0002]

2. Description of the Related Art The socket interface is 4.2 /
This is a function provided as a method of interprocess communication in 4.3BSD UNIX. Currently, two types of communication in the socket are defined: connection type and datagram type.

Conventionally, unlike the connection type, the datagram type does not support measures against data loss, duplication and sequence inversion at the protocol level, and is inferior to the connection type in terms of reliability of data transfer. There is.

However, when frequently transmitting and receiving data in a plurality of processes, in the connection type, it is necessary to establish a connection for the communication partner, and the management of the plurality of connections is complicated even after the establishment. In addition, the receiving process side has a drawback that the order of data between the sending processes is not guaranteed. (The order within one connection is guaranteed.) In comparison with this, in the datagram type, it is possible to send by simply specifying an identifier for each process and specifying that identifier, and the receiving side also Since the data of all the partner processes only needs to be received by one local process queue, the order of the data between the sending processes is guaranteed.

Due to the above points, when data is exchanged between multi-processes, datagram-type socket communication is adopted although the reliability of data transfer is poor.

[0006]

In the conventional datagram type socket communication, there is a possibility that transfer data may be lost, duplicated, or reversed in order, as described above.

Therefore, a first technical object of the present invention is to provide a receiving apparatus in which lost data can be easily detected during transmission, data loss can be avoided, and sequence inversion between processes can be avoided. is there.

A second technical object of the present invention is to provide a transmitting apparatus capable of avoiding data loss and detecting sequence inversion / duplication / loss during communication.

A third technical object of the present invention is to provide a data control device including the transmitting device and the receiving device.

[0010]

According to the present invention, a numbering transmission unit for avoiding order inversion / duplication of transfer data in socket communication between datagram type multi-processes, and a transmission destination busy. (EN) A transmitting apparatus having a partner busy detection unit for avoiding loss of transmission data at the time, and a save transmission data list unit for holding transmission data in response to a retransmission request.

According to the present invention, the receive queue (hereinafter,
The Recv queue retention data discharge part for avoiding transmission failure due to overflow of the Recv queue), the reception data list part for chaining the sorted reception data, and the temporary data being saved out of order By updating, adding, and referring to the waiting data list part and the list, the received data can be sorted and lost.
A receiving device is provided which is provided with a list management unit for detecting duplication and a list management table used for speeding up access at the time of updating / adding / referring a list.

According to the present invention, there is obtained a data control device comprising the transmitting device and the receiving device.

[0013]

The data control device for datagram-type multi-process socket communication of the present invention comprises a transmitter and a receiver.

Further, in the transmitting apparatus of the present invention, the numbering transmitting section avoids order inversion / duplication of transfer data in socket communication between datagram type multi-processes. The partner busy detection unit avoids loss of transmission data when the transmission partner is busy. The save transmission data list section holds transmission data for responding to a retransmission request.

Further, in the receiving apparatus of the present invention, Re
The cv queue retention data discharge part is a receive queue (hereinafter,
It is possible to avoid transmission being impossible due to overflow of the Recv queue). The received data list section is
Chain the received data sorted. The waiting data list section saves temporary data when the order is out of order.

The list management unit sorts the received data and loses data by updating, adding and referring to the list.
Detect duplicates. The list management table is used to speed up access when updating, adding, or referencing the list.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is an overall configuration diagram of a data control apparatus according to an embodiment of the present invention, showing a processing configuration of a multi-process data transfer system and a processing flow. FIG. 2 is a diagram showing a processing method of the accumulated data discharging unit of the Recv queue of FIG. FIG. 3 is a diagram showing a method of receiving data from another process, respectively. FIG. 4 is a diagram showing details of the list management table of FIG. FIG. 5 shows a transmission method to another process, and FIG. 6 shows a processing method of the other party busy detection unit at the time of transmission related to FIG. FIG. 7 is a diagram showing a retransmission method when data is lost. FIG. 8 is a diagram showing a structural diagram of each list.

In FIG. 1, the data control device comprises a receiving section 50, a transmitting section 60 and a processing section 70. The receiving unit 50 includes a Recv queue retention data discharging unit 210,
The list management unit 220, the list management table 330, the reception data 310, the waiting data 320, and the retransmission request unit 223 are provided. In addition, the list management unit 220
Received data sorting section 221 and waiting check section 22
2 and a retransmission request unit 223.

The transmitting unit 60 has a busy destination detecting unit 23 for the other party.
0, a numbering transmission unit 240, a save list management unit 250 having save transmission data, and a retransmission data search unit 2
And 60.

Recv queue retention data discharge unit 210
Receives all the data stored in the Recv queue 160 inside the process at the time of a reception request.

This data is dispatched to the resend request data 24 and the normal reception data 14. Specifically, as shown in FIG. 2, the Recv queue retention data discharging unit 210 sets the socket to non-blocking (S1
Next, it is judged whether or not there is received data (step S2), and if there is, the data is stored (step S3).
If not, the socket non-blocking is canceled (step S4), and it is judged whether or not there is accumulated data (step S4).
(5 steps), if there is, data reception processing is performed (S6).
Step), if there is no standby (S7 step).

FIG. 3 shows the data processing operation of the receiving section. When there is a data reception request, the processing unit 70 (S
In step 11), in order to prevent the Recv queue 160 from overflowing, the data stored in the Recv queue 160 is fetched by the Recv queue discharging unit 210. Next, the Recv queue retention data discharging unit 210
Judges whether it is the normal reception data 14 of the retransmission data 24 from the data taken in (step S12), and if it is the retransmission request processing data, performs the retransmission request processing (S14 ') and then returns to step S13. ..

On the other hand, if the data is not the resend request data, it is sent to the list management unit 220, and the reception data sorting unit checks the reception number added at the time of transmission in order to avoid sequence inversion, duplication, and loss (step S15). .. If the reception number is normal and the order is correct, the reception data list 3
10 (step S16). If the received data is not continuous with the data of the same sender process chained to the received data list, do not add it to the received data,
Each process is saved in the waiting data list through the line 20. When data is added to the received data list 310, the list of the waiting data section 320 of the transmission origin process of the added data is always removed from the waiting data list and added to the receiving data list 310 through the line 19 ( (S16 stage). If the number of the received data is the same as the data in the list 310, the data is discarded (S16 'stage),
Return to step S13. After all the data that has been temporarily fetched into the process is subjected to the above processing, the waiting data section 3
The re-delivery request unit 223 makes a re-delivery request for the lost data by comparing the data of the 20 list with the data of the received data 310 list (step S20). The collation between the data of the waiting data section 320 and the received data list 310 and the order determination can be omitted by referring to the list management table each time.

After the completion of all the reception processing, the top data of the reception data list 310 is returned to the processing unit that has made the reception request (step S21). (Addition is made for the accumulated data.) FIG. 4 shows the list management table 330. As shown in FIG. 4, each data list for each communication source (reception data list 331, waiting data list 332, save transmission data list 333)
It has the leading numbers 334, 336, 338 and the ending numbers 335, 337, 339 as information. The received data list 331 is not the actual head / end of the list because the data of multiple processes are mixed. This information is updated as each list is updated.

Therefore, if the lost data is detected with reference to the list management table 330, the following formula 1 is obtained. Explaining FIG. 4 as an example, in process A,

[0027]

[Equation 1]

By the method as described above, lost data is detected for all processes and a resend request is made.

After the completion of all the reception processing, the top data of the reception data list is returned to the processing unit which made the reception request (see FIG. 4). Returning to FIG. 1, the transmission unit 60 includes a numbering transmission unit 240, a save list management unit 250 having a save transmission data list 340, and a partner busy detection unit 23.
0, a retransmission data search unit 260.

FIG. 5 shows the operation of the transmitter 60. 1 and further referring to FIG. 5, the numbering transmitter 240
Adds a serial number and its process name to the transmitted data.

The save list management unit 250 retains a specified number of data in the save transmission data list 340 for resending when the transmission data is lost. At this time, it is determined whether the number of lists of save transmission data is less than or equal to a prescribed number or not (step S42).

When the number of save transmission data lists 340 exceeds the specified number, the data at the head of the list is discarded, the chain replacement list is updated (S43 '), and new data is added. If the number is less than the specified number, it is added to the list (S43), the other party busy detection unit is driven, and the transmission is completed (S44 step). In this case, the specified number held in the transmission unit is the Max value of the number of data that can be stored in the Recv queue. This value can be determined by the following formula.

Number of save data = data size (byte) / R
ecv queue Max size (byte) The Recv queue size is a value specified by the system, and a value obtained by dividing this by 1 data size can be stored in the Recv queue.
It is the number of ax data.

In the receiving process, when all sorts of data discharged from the Recv queue have been sorted, the list management table is checked and a resend request is made. for that reason,
In consideration of the case where the data stored in the Recv queue are all from the same process and the data in it is lost, the minimum value of the number of data that needs to be retained by the transmitter is the number of save data. ..

FIG. 6 shows the operation of the partner busy detector 230. The partner busy detection unit 230 detects whether or not the busy status of the partner is normal, and if it is normal, it transmits and completes the transmission. When busy, the transmission is repeated until the transmission becomes possible, and in the case of retry over, abnormal termination occurs.

FIG. 7 shows the operation of the retransmission data search section. The resend data search unit searches the save transmission data list 340 for the number key (S31) in response to the resend request (S30) from the resend request unit 223 of the receiving unit. The save transmission data equal to or smaller than the number of retransmission request data is discarded (step S32), and then the other party busy detector is driven to retransmit the data.

Finally, regarding the structure of each data list,
This is shown in FIG. The structure diagram of Fig. 8 shows a received data list in which received data is arranged in order, a waiting data list for saving out-of-order data, a saved transmission data list for holding transmission data for retransmission, etc. , Has a multi-layer structure.

[0038]

As described above, the following effects are brought about by using the data control system in the multi-process socket communication (datagram type) of the present invention.

The following phenomena occurring in datagram type socket communication are avoided. (1) When all the data stored in the Recv queue is fetched into the process at the time of one reception request, R is transmitted at the time of transmission.
Transmission data will not be lost due to ecv queue overflow. Furthermore, data loss can be avoided by detecting the busy state of the other process during transmission and retrying until the transmission becomes possible. (2) It is possible to detect order inversion / duplication / loss during communication by numbering the data during transmission. (3) When the order inversion occurs, the received data can be sorted by temporarily saving it in the order data list. (4) Lost data can be easily detected by making it possible to detect lost data easily by having the list management table with the information of the head number and end number of the waiting data list and the received data list. Can be avoided. (5) By chaining the reception data of all the partner processes in the reception data list in the order stored in the Recv queue, it is possible to avoid the order inversion between the processes.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of the present invention.

FIG. 2 is a detailed processing flow of a Recv queue retention data discharging unit.

FIG. 3 is a processing flow of a reception method.

FIG. 4 is a list management table used when detecting lost data / confirming the order of received data in a reception process.

FIG. 5 is a processing flow of a transmission method.

FIG. 6 is a processing flow of a partner busy detection unit at the time of data transmission of FIG.

FIG. 7 is a processing flow of a retransmission method.

FIG. 8 is a diagram showing a structure of each data list.

[Explanation of symbols]

10-13 Transmission Data to Process E 14 Reception Data from Other Process 16 Return Data for Reception Request of Processing Unit (First Data of Received Data List) 24 Resend Request Data from Other Process 28 Transmission Data for Transmission Request of Processing Unit 31 Data sent to other processes 110-150 1 Process groups that make up the system 160 Recv queue of process E 210 Recv queue accumulated data discharge unit 220 List management unit 221 Received data sort unit 222 Waiting check unit 223 Resend request unit 230 Other party Destination busy detection unit 240 Numbering transmission unit 250 Save list management unit 260 Retransmission data search unit 310 Received data list 320 Waiting data unit 330 List management table 340 Save transmission data list

Claims (3)

[Claims] 1. A numbering transmission unit for avoiding order inversion / duplication of transfer data in socket communication between datagram type multi-processes, and for avoiding loss of transmission data when the transmission destination is busy. And a save transmission data list section for holding transmission data for responding to a retransmission request. 2. A Recv queue retention data discharge unit for avoiding transmission failure due to Recv queue overflow, a reception data list unit for chaining sorted reception data, and temporary data out of order. The waiting data list part to be saved and the list are updated,
A list management unit that sorts received data and detects data loss and duplication by adding and referencing, and a list management table that is used to speed up access when updating, adding, or referencing the list. A receiving device comprising: 3. A data control device comprising the transmitting device according to claim 1 and the receiving device according to claim 2.