JP2000339179A - Inter-process communication system in computer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a congestion state, and to prevent the delay of a message even at the time of temporarily receiving a plurality of message transmission requests from a plurality of user processes. SOLUTION: In this system, shared memories 111 and 112 for writing messages, and pipes 121 and 122 with names for recording the leading addresses of the messages written in the shared memories 111 and 112 as message identifiers, and semaphores 131 and 132 for operating exclusive control to the shared memories 111 and 112 according to the increase and decrease of semaphore values are provided among respective processes 101-103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-process communication system for transmitting and receiving a large number of messages between processes in a computer system, for example, an operating system for monitoring and operating a communication device (NE).

[0002]

2. Description of the Related Art In recent years, in computer systems,
Mutual data between multiple processes with different functions,
Inter-process communication for transmitting and receiving messages and utilizing the functions of the own process and the other process is actively performed.

In such a conventional inter-process communication system of a computer system, a communication control process is provided in an operating system so that messages can be transmitted and received between processes without having a communication control function in each process. By this communication control process, communication between all processes in the system is realized.

[0004]

However, in the conventional inter-process communication system in the computer system, since the inter-process communication is performed through the communication control process, a large number of message transmission requests are issued to a large number of messages. When they are received from the user process almost simultaneously, there is a risk of falling into a congestion state.

Particularly, in an operating system for monitoring and operating a communication device (NE), when an autonomous message from the communication device frequently occurs due to a failure of the communication device or the like, or when a maintenance command is input to the communication device, Such a congestion state is assumed when a large amount of command responses are received from the.

The communication control process not only handles autonomous messages and command responses, but also transmits and receives messages within the operating system. Therefore, when such a congestion occurs, even if a message transmission request is issued to the communication control process, the notification is delayed.

[0007] Therefore, as for the communication that can be performed without the intervention of the communication control process, if the communication can be performed directly between the processes as much as possible, such a congestion state does not occur and a message delay occurs. Disappears.

[0008]

The present invention employs the following structure to solve the above problems. <Configuration 1> An inter-process communication system for a computer system according to the first aspect of the present invention is an inter-process communication system in a computer system for performing message communication between processes, wherein each process writes and reads messages. A memory, a named pipe for recording the head address of the message written in the shared memory as a message identifier, and a shared memory and a named pipe when transmitting from the message transmitting process to the receiving process. message,
Control means for writing the message identifier, reading the message from the shared memory according to the message identifier, and transmitting the message to the receiving process.

<Configuration 2> In the inter-process communication system of the computer system according to the second aspect of the present invention, the control means is a semaphore that rewrites a semaphore value and performs exclusive control on a shared memory.

<Configuration 3> The inter-process communication system of the computer system according to the third aspect of the present invention includes an environment file for storing a shared memory key for operating a shared memory and a semaphore key for operating a semaphore. I have.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below using specific examples. <Specific Example 1> In specific example 1, a shared memory is provided between processes, and messages are written to and read from the shared memory to perform inter-process communication. FIG. 1 is a block diagram showing the configuration of the inter-process communication system of the first embodiment, FIG. 2 is a block diagram showing the entire configuration of the first embodiment, and FIG. 3 is a block diagram showing the hardware configuration of the first embodiment. is there.

As shown in FIG. 3, the computer system comprises a communication device (NE) 1, a control device 2, a magnetic disk device (denoted as “HD” in the drawing) 3, and a memory (M in the drawing).
M ”. ) 4, Interface ("I / O" in the figure)
It is written. 5) is connected to a line 6.

The communication device (NE) 1 is a device monitored and operated by the operating system 100,
The operating system 100 receives, for example, an autonomous message from the communication device 1 when an abnormality occurs in the communication device 1, and inputs a maintenance command to the communication device 1 to perform a command response from the communication device 1 during maintenance. Receive.

In the operating system 100, as shown in FIG. 2, transmission processes (hereinafter, simply referred to as "processes") 101 to 103, a communication control process 140, messages 151, 152, and the like are generated.

The processes 101 to 103 process autonomous messages and command responses from the NE 1.
Note that the number of processes to be generated is not limited to three. The communication control process 140 is a process for realizing communication between the messages 151 and 152 generated in the system, and includes a reception processing unit 141, a transmission processing unit 142, and a message queue 143.

The reception processing unit 141 is a block for receiving the message 151, and the transmission processing unit 142 is a block for transmitting processing to the message 152. The message queue 143 is a queue for performing processing queuing control.

At the time of the initial startup of the process, the operating system 100, as shown in FIG.
1, 112, named pipes 121 and 122, and semaphores 131 and 132 are generated.

[0018] Shared memories 111 and 112 are arranged between the processes 101 to 103. This shared memory 11
Reference numerals 1 and 112 denote memories for reading and writing messages from two processes in two directions. The named pipes 121 and 122 indicate the process numbers of the receiving processes.

The semaphores 131 and 132 are shared memory 1
The semaphores 131 and 132 are control units that perform exclusive control on the shared memories 111 and 112 so that accesses to the shared memories 11 and 112 are not performed at the same time. The semaphores 131 and 132 set the semaphore value to “0”, for example, and
1, 112 are locked and set to "1" to release the lock, that is, unlock.

For example, when the semaphore 131
When writing to the shared memory 111
Locks the shared memory 11 from another process.
1 cannot be written, and only the process 101 can write to the shared memory 111. Note that the initial values of the semaphores 131 and 132 are set to “1”.

Shared memories 111 and 112, semaphore 13
In order to generate or operate 1,132, it is necessary to assign a shared memory key and a semaphore key as unique numbers in one computer system.

In the first embodiment, an environment file is provided in the computer system, and a shared memory key and a semaphore key are stored in the environment file in the environment file. FIG.
Is an explanatory diagram showing an example of the environment file. This environment file is always available. Therefore, the operation of the shared memory and the semaphore can be performed on the transmission side and the reception side.

When there are a plurality of processes for transmitting and receiving a message, a process name using the shared memory key and the semaphore key is set in this environment file, and the process name and the shared memory key and the semaphore key are used. Is associated with. Thus, when the function is changed, even when the number of processes for transmitting and receiving a large number of messages is increased or decreased or changed, only the environment file needs to be corrected. However, messages can be sent and received without this environment file.

<Operation> In the specific example 1, the process 10
1, 102 will be described as a message transmitting side and a message receiving side, respectively, but are not limited to the specific example 1.

The shared memories 111 and 112, the named pipes 121 and 122, and the semaphores 131 and 132 used for transmitting and receiving messages are generated when the process 102 is initially started. The process 102 waits until a message from the process 101 is received.

The semaphore value of the semaphore 131 is "0" as described above. Also, processes 101 and 1
The shared memory key and the semaphore key corresponding to 02 are extracted from the environment file, and the operations of the shared memories 111 and 112 and the semaphores 131 and 132 can be performed.

FIG. 5 is a flowchart showing the message transmission operation of the first embodiment. In step (denoted by “S” in the figure) 1, when an error occurs in the communication device 1 or when a maintenance command is input, for example,
Receive an autonomous message or a command response from In response to this autonomous message and command response, the process 10
If it becomes necessary to utilize the function of step 2,
Proceed to.

In step 2, the semaphore value of the semaphore 131 is set to "0" to lock the shared memory 111 so that other processes 102 cannot write to the shared memory 111.

When the semaphore value is already "0", writing to the shared memory 111 cannot be performed because the shared memory 111 is locked by another semaphore. Wait until the semaphore value becomes “1”.

In step 3, a message is written to the shared memory 111. When the writing to the shared memory 111 is completed, the process proceeds to step 4. In step 4, the semaphore value is set to “1” and the shared memory 111
To unlock.

In step 5, the head address of the written message is stored in the named pipe 121 as a message identifier. In this way, the lower process 10
2 can receive the message.

FIG. 6 is a flowchart showing the message receiving operation of the first embodiment. In step 11, the state is set so that the message can be received. In step 12, the message identifier stored by the process 101 is extracted from the named pipe 121.

In step 13, the semaphore value of the semaphore 131 is set to "0" and the shared memory 111 is locked, as in the case of transmission. This ensures the reliability of the message even at the time of reception. If the semaphore value is already “0”, the process waits until the semaphore value becomes “1” as in the case of the message transmission by the process 101.

In step 14, the named pipe 121
Shared memory 1 according to the message identifier retrieved from
The message is read from 11. When the reading of the message is completed, the process proceeds to step 15 and the semaphore 13
Set the semaphore value of 1 to "1". As a result, the lock of the shared memory 111 is released, and another process can write to the shared memory 111. In this way, inter-process communication is performed.

<Effect of Specific Example 1> According to the specific example 1 as described above, the shared memories 111 and 112 are generated between the processes 101 to 103, so that the autonomous message from the communication device 1 or When a command response is received, communication is directly performed between the processes 101 to 103 without going through the communication control process 140. Therefore, when a large number of message transmission requests are issued from many user processes, the communication device 1 can be prevented from becoming congested even when an autonomous message or command response from the OS 1 frequently occurs.
It is also possible to prevent delays in message communication inside and the like.

Also, since the semaphores 131 and 132 perform exclusive control on the shared memories 111 and 112, access to the shared memories 111 and 112 is performed even when a plurality of processes write and read requests for messages at the same time. Are not performed at the same time, and the reliability of the message is improved.

Further, since an environment file is provided and the shared memory key and the semaphore key are stored in this environment file, even if the number of processes for transmitting and receiving messages is increased or decreased due to a change in function, this environment file is used. If only the file is modified, it is possible to cope without changing the inter-process communication processing, which is particularly advantageous for a system handling a large amount of data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an inter-process communication system of a specific example 1.

FIG. 2 is a block diagram illustrating an entire configuration of a specific example 1.

FIG. 3 is a block diagram illustrating a hardware configuration of a specific example 1.

FIG. 4 is an explanatory diagram illustrating an example of an environment file of a specific example 1.

FIG. 5 is a flowchart illustrating a message transmission operation of the first specific example.

FIG. 6 is a flowchart illustrating a message receiving operation according to the first embodiment.

[Explanation of symbols]

 1 Communication device (NE) 100 Operating system 111, 112 Shared memory 121, 122 Named pipe 131, 132 Semaphore

Continuing on the front page (72) Inventor Hikari Sesha 3-2-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Masaya Koyabu 3-9-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation F-term (reference) 5B098 AA09 GA04 GB14 GD04 GD15

Claims (3)

[Claims] An inter-process communication system in a computer system for performing message communication between processes, a shared memory for each process to write and read a message, and a start address of the message written to the shared memory. A named pipe for recording as a message identifier and a message and a message identifier are written to the shared memory and named pipe when sending from the message sending process to the receiving process, and the message is written from the shared memory according to the message identifier. Control means for reading and transmitting to a receiving process. 2. The inter-process communication system according to claim 1, wherein the control unit is a semaphore that rewrites a semaphore value to perform exclusive control on a shared memory. 3. The inter-process communication system according to claim 2, further comprising an environment file for storing a shared memory key for operating the shared memory and a semaphore key for operating the semaphore. .