JP3018549B2 - File destruction prevention mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a file destruction prevention mechanism in a computer, and more particularly to a file destruction prevention mechanism for preventing file destruction even if a deadlock occurs during execution of a program using an automatic commitment control function. About.

[0002]

2. Description of the Related Art If a kind of compiler specifies that automatic commitment control is used, a file (including a database) used in a source program described in a predetermined language to be translated is used. For files for which quiesce point establishment processing is possible, an automatic commitment control logic has been embedded so that quiesce point establishment processing is automatically performed at an appropriate location and return processing to the quiesce point is automatically performed when a deadlock occurs. Compilers that generate target programs have been reported.

By using a compiler having a function of embedding such automatic commitment control logic, the user does not need to be conscious of commitment control at the time of programming, and the program development efficiency is improved accordingly.

[0004]

By the way, when the target program in which the automatic commitment control logic is embedded is actually executed, the following problem is encountered.

In other words, if all the files used in the source program are files for which a quiesce point can be established, a quiesce point is established at an appropriate place for each file, and deadlock occurs. In this case, it is possible to return the state and control state of a plurality of files involved in the deadlock to the immediately preceding quiescent point, and to continue normal operation thereafter.

However, if files used in the source program include files for which quiesce point establishment processing cannot be performed because journals cannot be obtained, etc. Is not performed, if a deadlock occurs, a file may be restored to the immediately preceding still point and a file may not be restored, which may lead to file destruction.

For example, a record R1,
In the process of writing R2 and R3 to another file B, when record R1 is written to file B and a deadlock occurs at the time of writing the next record R2, if the quiesce point establishment process is possible for both, the previous The state of the files A and B and the state of control can be restored to a stationary point, for example, a point immediately before writing the record R1, and there is no problem.

However, if file A can be processed for establishing a quiesce point and file B cannot be processed for establishing a quiesce point, the state and control of file A are restored to the time immediately before the record R1 is written. Such a return is not performed, and the record R1 remains written. Therefore, when the processing is resumed, the record R1 is written again to the file B, two records R1 are recorded in the file B, and inconsistency occurs between the file A and the file B, and the file is destroyed. Connect.

As described above, in executing the target program in which the automatic commitment control logic is embedded, there is a possibility that the file may be destroyed as described above. The file was destroyed by the return process of, and the system was seriously damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to solve the problem that when a deadlock occurs during the execution of a program utilizing the automatic commitment control function, the program is executed when the deadlock occurs. An object of the present invention is to provide a file destruction prevention mechanism for preventing file destruction by terminating the recovery process and terminating abnormally when there is a possibility that file destruction may occur in the return process.

[0011]

In order to achieve the above object, a file destruction prevention mechanism according to the present invention provides a source program that uses an automatic commitment control function for a static point among files used in the source program. Is provided in a compiler that generates a target program embedded with automatic commitment control logic that automatically establishes a quiesce point for a file that can be established, and performs return processing to a quiesce point when a deadlock occurs. It is determined whether or not there is a file in which the quiesce point cannot be established in the source program, and the existence of the file prevents the return to the quiesce point in the interface information with the external routine generated in the compile unit. Means for setting the information to be executed and deadlocks during execution of the compilation unit By the provided within external routines called from compilation unit, return to the stationary point with reference to the calling interface information is prohibited in order to perform the return processing to the still point occurrence, stationary point Means for terminating the compile unit abnormally by terminating the return process for a file that can be established .

[0012]

In the file destruction prevention mechanism of the present invention, when translating a source program using the automatic commitment control function, it is determined whether or not there is a file in the source program for which quiesce point establishment processing cannot be performed. If it exists, the information prohibiting the return to the quiesce point is set in the interface information with the external routine generated in the compilation unit. If a deadlock occurs during the execution of the compile unit, an external routine for performing a process of returning to the quiesce point from the compile unit is called. At this time, the interface information of the caller is referred to, and If the return to the point is prohibited , the return processing is aborted for the file for which the still point establishment processing is possible, and the compile unit is abnormally terminated.

[0013]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.
101 is a source program, 102 is a compiler, 10
4 is a compile unit, 106 is a return processing routine to a stationary point (hereinafter simply referred to as a return processing routine), 108
Is a compile option. In FIG. 1, solid arrows indicate data flows, and broken arrows indicate control flows.

The file destruction prevention mechanism of the present embodiment is shown in FIG.
As shown in (1), an interface information setting means 103 is provided in a compiler 102 for translating a source program 101, and a return enable / disable determination means (hereinafter simply referred to as determination means) 1 in a return processing routine 106 is provided.
07 is provided.

The compiler 102 inputs and outputs the source program 101 created by the user, performs syntax analysis,
It performs semantic analysis and the like, and finally generates and outputs a compile unit (target program) 104 according to the source program 101. Also, this compiler 102
If the compile option 108 specifies that the source program 101 uses the automatic commitment control function, the file used in the source program 101 for which a quiesce point can be established The compile unit 104 implements automatic commitment control logic that automatically establishes a quiesce point at an appropriate place and automatically performs a return process (rollback process) to a quiesce point when a deadlock occurs.
It has a function to embed in.

If the source program 101 to be translated by the compiler 102 is a program that uses the automatic commitment control function, the interface information setting means 103 in the compiler 102 includes files in which a quiesce point establishment process cannot be performed. Determine if it exists,
This is a means for setting information prohibiting return to a quiescent point to interface information 105 with an external routine, which is generated in the compile unit 104 which is an output of the compiler 102 when it exists. FIG. 2 shows an example of the processing of the interface information setting means 103. Whether or not the file can be subjected to the quiesce point establishment process is determined in the same manner as whether or not the file is a target of the automatic commitment control. This is performed by holding the file organization method and the like in advance and comparing them with the file device type and file organization method of each file.

In this embodiment, the source program 10
1 uses the automatic commitment control function, it is assumed that there is at least one file in which quiesce point establishment processing can be performed. Therefore, if at least one file incapable of quiesce point establishment processing exists, In this case, it is determined that there are files that can be processed to establish a quiesce point and files that cannot be processed to establish a quiesce point. Of course, it is also possible to confirm both the existence of a file for which still point establishment processing is not possible and the existence of a file for which still point establishment processing is not possible.

The return processing routine 106 is an external routine called from the compiling unit 104 to perform a return processing to a quiescent point when a deadlock occurs.

Determination means 10 in return processing routine 106
7, when the return processing routine 106 is called due to the occurrence of a deadlock during the execution of the compile unit 104, the return to the quiesce point is performed by referring to the interface information 105 in the compile unit 104 that is the caller. This is a means for determining whether or not the compile unit is prohibited, and in the case where the compile unit is prohibited, terminates the processing of the return processing routine 106 and instructs an operating system (not shown) to abnormally terminate the compile unit. FIG. 3 shows an example of the processing of the determination means 107.

Next, the operation of the embodiment constructed as described above will be described with reference to the drawings.

The compiler 102 executes the source program 10
When the source program 101 uses the automatic commitment control function in the course of the translation process of generating the compile unit 104 by inputting the "1" and the compile option 108, the automatic commitment control logic is generated as in the related art. Compiler 10
2 is started.

When activated, the interface information setting means 103 performs the processing shown in FIG. That is, compiler 1
02 is the source program 10 currently performing the translation process
It is determined whether there is at least one file in which the establishment of the quiesce point cannot be performed because the journal cannot be obtained in step 1 (step 201). If no such file exists (NO in step 201), the processing in FIG. 2 ends.

However, if there is at least one file for which still point establishment processing is impossible (YE at step 201)
S), in the compile unit 104 generated by translating the source program 101 by the compiler 102, information indicating that the returning process to the quiesce point is prohibited is included in the interface information 105 which is information referred to from the external routine at the time of execution. The setting is made (step 202), and the processing of FIG. 2 is completed.

A compiling unit 104 generated by translating the source program 101 by the compiler 102
When a deadlock occurs during the execution process, the internal automatic commitment control logic calls the return routine 106 which is an external routine.

When called, the return processing routine 106 first operates the internal determination means 107.

As shown in FIG. 3, the judging means 107, as shown in FIG.
With reference to the interface information 105 in 04, it is determined whether or not the process of returning to the stationary point is prohibited (step 301). If not prohibited (step 301
NO), the process of FIG. 3 ends. Return processing routine 1
06 executes the original processing related to the return to the stationary point, and controls the compile unit 10 after the completion.
Return to 4.

On the other hand, if the return to the stationary point is prohibited (YES in step 301), the determination means 107 terminates the execution of the return processing routine 106 and sends the compile unit 1 to the operating system (not shown).
04 is abnormally terminated (step 302).
The process of FIG. 3 ends. As a result, the return to the stationary point by the return processing routine 106 is not performed, and the compile unit 104 ends abnormally. It should be noted that the action after the abnormal termination is left to each user.

If no deadlock occurs during the execution of the compiling unit 104, the return processing routine 106 is not called, and if there is no other failure, the compiling unit 104 is executed to the end and ends normally. Will be.

[0030]

According to the file destruction prevention mechanism of the present invention described above, when a source program using an automatic commitment control function is translated, a file that can be processed to establish a quiesce point and a file that cannot be processed are mixed in the source program. If it is determined that there is a possibility of causing file destruction due to the return process when a deadlock occurs due to the presence of a deadlock, set information that prohibits return to a quiesce point in the interface information in the compile unit and execute the compile unit Sometimes, if a deadlock occurs, and if the interface information prohibits the return to the quiesce point, the compile unit terminates abnormally and terminates the compile unit abnormally for files for which quiesce point establishment processing is possible. Deadlock of a program that uses functions It is possible to prevent the file destruction occurs.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating an example of a process of an interface information setting unit 103;

FIG. 3 is a flowchart illustrating an example of a process of a return enable / disable determination unit 107 for returning to a stationary point;

[Explanation of symbols]

101: Source program 108: Compile option 102: Compiler 103: Interface information setting means 104: Compile unit 105: Interface information 106: Routine processing routine for restoring to a stationary point 107: Meaning for determining whether or not restoration to a stationary point is possible

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G06F 12/00 531 G06F 9/45

Claims (1)

(57) [Claims] 1. For a source program using an automatic commitment control function, a quiesce point establishment process is automatically performed for a file that can be subjected to a quiesce point establishment process among files used in the source program, and a dead point is set. It is provided in a compiler for generating a target program in which automatic commitment control logic for performing a return process to a quiesce point when a lock occurs is provided, and whether or not a file in which a quiesce point establishment process cannot be performed exists in the source program. Means for setting information prohibiting return to a quiesce point to interface information with an external routine generated in the compilation unit due to the existence thereof, and when a deadlock occurs during execution of the compilation unit From the compile unit to perform the return process to the static point Provided in the external routines issued beauty, by referring to return to quiescent point is prohibited calling interface information, the still point establishment process
Means for terminating return processing for a possible file and terminating the compile unit abnormally.