JPH05113897A - Computer system - Google Patents

Abstract

PURPOSE:To guarantee the identifier of process targeted as a restart object under environment in which a check point/re-start function is supplied. CONSTITUTION:A process identifier mapping table 103 in which Information being used to guarantee a process identifier when a re-start operation is performed is stored is provided, and control for the information is performed by a process identifier marking means 5 and a process identifier marking release means 7, also, a process identifier check means 6 is attached on a process generating means 2, and furthermore, a process identifier mapping file 104, a process identifier saving means 8, and a process identifier recovery means 9 to obtain guarantee in the completion/re-start of a system are provided, thereby, the identifier of the process targeted as the re-start object can be guaranteed. In such a manner, it is possible to attain the easy use of the check point/re-start function, the simplification and efficiency of system configuration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used for guaranteeing a process identifier in a computer system. The present invention is
The present invention relates to a computer system that can guarantee an identifier of a process targeted for restart in an environment that provides a checkpoint / restart function.

[0002]

2. Description of the Related Art Conventionally, a process identifier guarantee method has not been particularly established in a system that does not provide a checkpoint / restart function, and the process identifier itself is prepared by the system when a new process is created. The process identifiers were assigned in ascending order until the maximum process identifier was reached. Also, when the maximum process identifier is reached, the allocation is restarted in ascending order again.

[0003]

The above-mentioned conventional method does not cause any special problem in the system which does not provide the checkpoint / restart function, but in the case of providing the checkpoint / restart function. ,
If it is not guaranteed that the process identifier stored in the restart file at the time of checkpoint is the same as the process identifier after restart, there is a problem that the operation of the corresponding process after restart cannot be guaranteed.

The present invention solves such a problem, and an object thereof is to provide a system capable of guaranteeing the identifier of a process to be restarted in an environment providing a checkpoint / restart function. And

[0005]

According to the present invention, a basic operating system is provided, and a process generation means for generating a process to which a central processing unit is assigned, and a checkpoint request when a process is executed are checked. Checkpoint execution means for executing point processing, a restart file that freezes and holds the process state in a re-executable state when executing that processing, and a restart file stored in the restart file by a restart request A process identifier mapping table for mapping process identifiers in a computer system provided with restart execution means for restarting the execution of a process from information, and a process control table that holds various control information of processes including a process identifier storage area. Set up, check Stores the necessary information to the restart file when receiving a breakpoint request,
A process identifier marking means for marking the process identifier of the corresponding process at a corresponding position in the process identifier mapping table, and the use of the marked process identifier in response to a use request from another process generating means is prohibited. And a process identifier checking means.

When the restart request is received, the process control table is secured so that necessary information can be re-executed from the restart file, and the process identifier stored in the restart file is assigned to the process control. A process identifier marking cancellation means for canceling the marking of the corresponding part of the process identifier mapping table set in the table;
A process identifier mapping file for saving the process identifier mapping table, and the process identifier storing information necessary for the next restart when a process checkpoint request is received at the time of a system termination request A process identifier saving means for saving the mapping table in the process identifier mapping file, and the contents of the process identifier mapping file are restored in the process identifier mapping table at the next system startup, and the previous contents are retained even after the system is restarted. A process identifier recovery unit that enables restart of process execution based on the content of the restart file can be provided.

[0007]

[Function] When a checkpoint request is issued, necessary information is stored in the restart file, and the process identifier of the corresponding process is marked at the corresponding position in the process identifier mapping table by the process identifier marking means, and the marking is performed. The process identifier used for performing the process is not used by the process identifier checking means when another process is generated, and when a restart request for the process is issued, the process identifier is guaranteed to be available at the same time as at the checkpoint.

As a result, the user who uses the checkpoint / restart function does not need to pay special attention to the process identifier, and the system construction side does not have to always consider the compatibility of the process identifier. By simplifying the point / restart function and other functions at the design stage, special consideration regarding system termination / restart can be eliminated.

Further, when a restart request is issued, necessary information is secured from the restart file in the process control table so that it can be executed again, and at that time, the process identifier stored in the restart file is processed. By setting it in the control table and then canceling the marking of the corresponding part of the process identifier mapping table by the process identifier marking cancellation means, it is not necessary to save the corresponding process identifier for restart processing, and normal processing is possible. Can be

Further, the process identifier saving table saves the process identifier mapping table storing the information required for the next restart at the time of the system termination request or the process checkpoint request to the process identifier mapping file by the process identifier saving means. Then, at the next system startup, the contents of the process identifier mapping file are restored in the process identifier mapping table by the process identifier recovery means, and after the system is restarted, the process execution is restarted based on the contents of the previous restart file. Can be enabled.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention.

In the embodiment of the present invention, a basic operating system 1 is provided, and a process generation means 2 for generating a process which is a target of central processing unit allocation (not shown) and a checkpoint request during process execution are received. Checkpoint execution means 3 for executing a checkpoint process, a restart file 101 that freezes and holds the process state in a re-executable state when the process is executed, and a restart file 101 in response to a restart request. The process includes a restart execution unit 4 that restarts the execution of the process from the stored information, and a process control table 102 that holds various control information of the process including a process identifier storage area. Further, as a feature of the present invention, the process identifier is provided. Process identifier mapping table A process identifier marking means 5 is provided for storing the necessary information in the restart file 101 when a checkpoint request is received, and for marking the process identifier of the corresponding process at a corresponding point in the process identifier mapping table 103. And a process identifier check means 6 that prevents the marked process identifier from being used when another process is created and guarantees that the process identifier can be used at the same time as at the checkpoint when there is a corresponding restart request. The process control table 102 is secured so that necessary information can be executed again from the restart file 101 when a restart request is received, and the process identifier stored in the restart file 101 is used as the process control table. Set in the 02,
A process identifier marking canceling means 7 for canceling the marking of the corresponding part of the process identifier mapping table 103, a process identifier mapping file 104 for saving the process identifier mapping table 103,
The process identifier mapping file 104 stores the process identifier mapping table 103 in which the information required for the next restart when the process checkpoint request is received at the time of the system termination request is stored.
And the process identifier mapping file 1 for the next system startup.
The content of 04 is the process identifier mapping table 103
And a process identifier recovery unit 9 that enables the process to be restarted based on the contents of the previous restart file 101 even after the system is restarted.

FIG. 2 is a diagram showing the structure of the process identifier mapping table in the embodiment of the present invention. For example,
If a checkpoint request is issued to a process whose process identifier is "30", this process identifier "3"
If "0" is not saved, the operation after restart is not guaranteed. In this case, in order to recognize the identifiers 0, 1, and 2 from the leftmost end, the 30th bit from the leftmost end is turned on, and the identifier is not used. This process is
It is carried out by the process identifier marking means 5. After that, the bit in the on state is turned off by the process identifier marking canceling means 7, so that the identifier can be used normally.

FIG. 3 is a flow chart showing the flow of processing from the checkpoint executing means to the process identifier marking means in the embodiment of the present invention, and FIG. 4 is the flow of processing from the normal process generating means to the process identifier checking means in the embodiment of the present invention. It is a flowchart showing.

When a checkpoint request is issued to the process having the process identifier "30" (step 3-
1), the checkpoint execution means 3 is started, and first,
The state of the process with the process identifier “30” is frozen (step 3-2). Then, the restart file 101 which stores the state of this process is prepared (step 3-3). Restart file 101 prepared after that
The information necessary for the process restart, such as the process control table 102 and the file management table, is stored in the.

At this time, since the process identifier "30" of the process is already stored in the process identifier storage area in the process control table 102, it is automatically stored in the restart file 101 (step 3).
-4).

Next, control is passed to the process identifier marking means 5, and the process identifier marking means 5 turns on the state of the corresponding portion of the process identifier "30" in the process identifier mapping table 103 (step 3-5). As a result, the process identifier saving process in the checkpoint process ends (step 3-
6).

During normal process generation, as shown in FIG. 4, the process generation means 2 is first called to acquire a process identifier (step 4-1). Since the process identifier recently acquired is stored in the process identifier state variable 105, the next identifier is judged and determined from this variable (step 4-2).

The process identifier is the maximum process identifier 10.
If the number exceeds 6, then the younger identifier is picked up again (step 4-3). When the identifier is determined, the process identifier checking means 6 compares it with the process identifier mapping table 103 to check whether the identifier is marked (on state) at the checkpoint (step 4-4). If it is marked (on state), another identifier is taken again (step 4-3). As a result, if the unmarked process identifier can be finally obtained (step 4-6), the process generation means 2 continues the normal processing.

FIG. 5 is a flow chart showing the flow of processing from the restart execution means to the process identifier marking cancellation means in the embodiment of the present invention.

When a restart request is issued to the process with the process identifier "30" (step 5-1), the restart execution means 4 is activated to open the restart file 101 of the request (step 5-). 2) From the restart file 101, information necessary for re-execution of the processes is sequentially prepared in the memory (step 5-3). As a part of the processing, the process control table 102 is restored. As the process identifier, the identifier “30” stored in the restart file 101 is directly restored to the process identifier storage area on the process control table 102 (step 5-4).

At this point in time, the process identifier has been assigned to the process for which the restart request has been made, so the process identifier marking canceling means 7 turns off the flag of the corresponding part of the process identifier mapping table 103 stored for restart. (Step 5-
5).

FIG. 6 is a flow chart showing the processing flow of the process identifier saving means at the time of system termination in the embodiment of the present invention, and FIG. 7 shows the processing flow of the process identifier restoration means at the time of system restart in the embodiment of the present invention. It is a flowchart shown.

When a system termination request is given (step 6-1), it is judged whether or not the checkpoint request flag 107 indicating that there is a checkpoint request that has not been restarted during system operation is in the on state. If it is on (step 6-2), the contents of the process identifier mapping table 103 are needed at the time of startup in order to guarantee the state of the process identifier mapping table 103 even after system restart. The process identifier mapping file 104, which is a part of the system environment file to be stored, is secured and saved therein (step 6-3). After that, normal system termination processing is performed.

Subsequently, when the system is restarted (step 7-1), the process identifier mapping file 10 is stored in the system environment file to be referenced at the time of startup.
4 is determined (step 7-2), and if there is, the process identifier restoring means 9 secures the process identifier mapping table 103 and restores the contents of the process identifier mapping file 104 (step 7-).
3). As a result, even after the system is restarted, the process identifier mapping table 103 restores the environment similar to the environment at the time of storing it in the previous restart file 101. Therefore, the process identifier is guaranteed and the corresponding restart file 101 is restored. It is possible to re-execute the process from.

[0026]

As described above, according to the present invention, when the checkpoint / restart function is provided, the contents of the restart file in which the process identifier is collected at the checkpoint and the contents to be reset at the restart are set. Guarantees that the process IDs are the same and that the process identifier is guaranteed even if the system is shut down or restarted between the checkpoint and the restart, so that the user who uses the checkpoint / restart function can There is no need to pay special attention to the process identifier, and it is not necessary to always consider the compatibility of the process identifier when building the checkpoint / restart function on the system construction side. Other functions can be simplified at the design stage and can be used for system shutdown / restart Special consideration of and can be eliminated. As a result, there is an effect that the checkpoint / restart function can be easily used, and an efficient system construction and operation can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a process identifier mapping table in the embodiment of the present invention.

FIG. 3 is a flowchart showing the flow of processing by the checkpoint executing means to the process identifier marking means in the embodiment of the present invention.

FIG. 4 is a flow chart showing the flow of processing by the process identifier check means from the process generation means in the embodiment of the present invention.

FIG. 5 is a flowchart showing the flow of processing from the restart execution means to the process identifier marking cancellation means in the embodiment of the present invention.

FIG. 6 is a flowchart showing a processing flow of a process identifier saving means at the time of system termination in the embodiment of the present invention.

FIG. 7 is a flowchart showing a processing flow of a process identifier recovery unit at the time of restarting the system in the embodiment of the present invention.

[Explanation of symbols]

 1 Basic Operating System 2 Process Generation Means 3 Checkpoint Execution Means 4 Restart Execution Means 5 Process Identifier Marking Means 6 Process Identifier Checking Means 7 Process Identifier Marking Canceling Means 8 Process Identifier Saving Means 9 Process Identifier Restoring Means 101 Restart File 102 Processes Control table 103 Process identifier mapping table 104 Process identifier mapping file 105 Process identifier state variable 106 Maximum process identifier 107 Checkpoint request flag

Claims (3)

[Claims] 1. A basic operating system is provided, and a process generation means for generating a process to which a central processing unit is allocated, and a checkpoint execution for executing a checkpoint process when a checkpoint request is accepted during process execution. Means, a restart file that freezes and holds the process state in a re-executable state when executing the processing, and restarts the process execution from the information stored in the restart file by a restart request. In a computer system provided with a restart execution means and a process control table that holds various process control information including a process identifier storage area, a process identifier mapping table for mapping process identifiers is provided to receive checkpoint requests. In this case, the necessary information is stored in the restart file, and the process identifier marking means for marking the process identifier of the corresponding process in the corresponding portion in the process identifier mapping table and the process identifier for which marking has been performed are separated. And a process identifier checking means for prohibiting use of the process requesting means from the process generating means. 2. The process control table is secured so that necessary information can be re-executed from the restart file when a restart request is received, and the process identifier stored in the restart file is stored in the process control table. The computer system according to claim 1, further comprising a process identifier marking canceling unit that is set in a process control table and cancels marking of a corresponding portion of the process identifier mapping table. 3. A process identifier mapping file for saving the process identifier mapping table and information required for the next restart when a process checkpoint request is received when a system termination request is stored. And a process identifier saving means for saving the process identifier mapping table in the process identifier mapping file, and at the next system startup, restore the contents of the process identifier mapping file into the process identifier mapping table and restart the system. The computer system according to claim 1, further comprising a process identifier recovery unit that enables execution of a process to be resumed based on the content of the restart file of the previous time even after the raising.