JPH04295932A - Previous check mechanism for file destruction - Google Patents

Abstract

PURPOSE:To check the possibility of file destruction, caused by a rollback in case of a deadlock, at the time of translation by a compiler which has an automatic commitment control function. CONSTITUTION:When a source program 101 is translated, the area analyzing means 104 of the compiler 102 analyzes definitions regarding files in the source program 101 and registers information, showing whether or not an establishment process at a stationary point is possible, in an information table 109, file by file. A check actuating means 106 when deciding that the source program 101 uses the automatic commitment control function automatically from compilation options 111 actuates a check means 107, which refers to the information table 109 to check whether or not there are files for which the stationary point establishment process is impossible, and outputs an error message 110 indicating that there is the possibility of the destruction of the contents of the files due to the rollback in case of a deadlock when there are the files.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to language processing systems for computers, and more particularly to a file destruction advance check mechanism for checking programs that may cause file destruction at the time of compilation.

0002

[Background Art] If a type of compiler specifies that automatic commitment control is to be used, some files (including databases) used in a source program written in a predetermined language to be translated are For files that can be processed to establish a quiescent point, automatic commitment control logic is embedded that automatically establishes a quiescent point at an appropriate location and automatically returns to the quiescent point when a deadlock occurs. A compiler that generates a target program has been reported.

By using a compiler that has the function of embedding such automatic commitment control logic, the user does not need to be aware of commitment control when programming, and the efficiency of program development is improved accordingly.

0004

[Problems to be Solved by the Invention] By the way, when I actually executed a target program in which automatic commitment control logic was embedded, I encountered the following problem.

That is, if all the files used in the source program are files that can be processed to establish a quiescent point, the quiescent point is established at an appropriate location for each file, and if a deadlock occurs. In such cases, it is possible to restore the states and control states of the multiple files involved in the deadlock to the previous quiescent point and continue normal operation thereafter.

However, if some of the files used in the source program are mixed with files for which the quiesce point establishment process cannot be performed due to reasons such as the inability to obtain a journal, the quiesce point cannot be established for such files. Establishment processing is not performed, so if a deadlock occurs, some files will be able to return to the previous quiescent point and some files will not be able to return, which may lead to file destruction.

For example, record R1 of a certain file A,
In the process of writing R2 and R3 to another file B, if a deadlock occurs when record R1 is written to file B and the next record R2 is attempted to be written, if the process of establishing a quiet point is possible for both, the immediately preceding There is no problem because the states of files A and B and the control state can be restored to a stationary point, for example, to the point immediately before record R1 is written.

However, if file A is capable of establishing a quiet point and file B is not, the state and control of file A will be returned to the point immediately before record R1 was written, but for file B, No such return is made, and record R1 remains written. Therefore, when the process is restarted, record R1 will be written to file B again, and 2 records will be written in file B.
records R1 are recorded, file A and file B
This may cause a conflict between the files and files, leading to file destruction.

As described above, there is a possibility of file destruction as described above in the execution of a target program in which automatic commitment control logic is embedded, but conventionally there was no mechanism for checking this in advance. Therefore, it has been difficult to prevent file destruction.

The present invention has been made in view of the above circumstances, and its purpose is to check the possibility of file destruction when compiling a source program that uses the automatic commitment control function, and to check the possibility of file destruction. The object of the present invention is to provide a file destruction advance check mechanism that notifies the user with an error message if there is such a possibility.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the file destruction pre-check mechanism of the present invention checks the files used in the source program using the automatic commitment control function. In a compiler that generates an objective program embedded with automatic commitment control logic that automatically establishes a quiesce point for files that can perform quiesce point establishment processing and also performs processing to return to a quiesce point when a deadlock occurs. , a means for registering in an information table information indicating whether or not a quiescent point establishment process is possible by analyzing definitions related to files in a source program; and a means for determining whether or not the source program uses an automatic commitment control function. With respect to the means and the source program determined to use the automatic commitment control function by this means, it is checked whether or not there is a file for which the quiesce point establishment process cannot be performed by referring to the information table, and if there is, and a means for outputting an error message.

0012

[Operation] In the file destruction advance check mechanism of the present invention, when a source program that uses the automatic commitment control function is translated, definitions related to files in the source program are analyzed to determine whether a quiescent point can be established for each file. At the same time, it is determined whether the source program uses the automatic commitment control function, and if the automatic commitment control function is used, the information table is referenced to establish a quiescent point. It is checked whether there are any files that cannot be processed,
If it exists, an error message will be output to the effect that there may be an inconsistency in the contents of the file when performing a backward return.

[0013]

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

FIG. 1 is a diagram showing the main part of a compiler equipped with a file destruction pre-check mechanism according to an embodiment of the present invention.

[0015] This compiler 102 inputs a source program 101 created by a user and performs syntax analysis, semantic analysis, etc. using functional units such as a syntactic analysis unit 103 and a semantic analysis unit 105, which are essential to the compiler. The program outputs necessary information to the program information 108 and the information table 109, and finally generates and outputs a target program (not shown) according to the source program 101.

[0016] Furthermore, if the compile option 111 specifies that the source program 101 uses the automatic commitment control function, the compiler 102 saves the static point of the files used in the source program 101. Automatic commitment control logic that automatically establishes a quiescing point at an appropriate location for files that can be established, and automatically returns to the quiescing point (rollback process) when a deadlock occurs. It has a function to be embedded in the target program.

In this embodiment, such a compiler 10
The syntactic analysis unit 103 of 2 is provided with an area analysis unit 104, and the semantic analysis unit 105 is provided with a check activation unit 106 and a file mixture check unit that allows/disables static point establishment processing (
107 (hereinafter simply referred to as check means) is provided.

The area analysis means 104 analyzes the file definition in the source program 101, and in addition to the conventionally obtained information regarding the file, it also obtains information indicating whether or not the file is a file for which a static point establishment process is possible. This is a means for generating information and registering this information in the information table 109 one entry per file. Note that whether or not a file can be processed to establish a quiesce point is determined in the same way as whether or not the file is subject to automatic commitment control. This is done by storing file organization methods, etc. in advance and comparing them with the file device type, file organization method, etc. of each file.

The check activation means 106 determines whether or not the source program 101 uses the automatic commitment control function based on the program information 108 that is part of the analysis result of the syntax analysis unit 103, and uses the automatic commitment control function. An example of the process is shown in FIG. 2. Note that the syntax analysis unit 103 determines whether or not the source program 101 uses the automatic commitment control function based on the compile option 111, and sets it in the program information 108.

The checking means 107 sequentially reads the contents of the information table 109 to check whether there is a file in the source program 101 that cannot be processed to establish a static point, and if so, an error message 110 is sent. An example of the processing is shown in FIG. In addition, in this embodiment, since the source program 101 uses the automatic commitment control function, it is assumed that at least one file exists in the source program 101 that can be processed to establish a quiescent point. If there is a file that cannot be processed, it is determined that there is a mixture of files that can be processed to establish a static point and files that cannot be processed to establish a static point. Of course, it is also possible to detect both the existence of a file that can be processed to establish a static point and the existence of a file that cannot be processed to establish a static point, and output an error message accordingly.

Next, the operation of this embodiment configured as described above will be explained with reference to the respective figures.

When the source program 101 and the compile option 111 are given and the compiler 102 is activated, the compiler 102 first parses the syntax of the source program 101 in the syntax analysis unit 103 . At this time, the syntax analysis unit 103 checks whether the source program 101 uses the automatic commitment control function using the compile option 111, and stores this information in the program information 10.
Register to 8.

[0023] Furthermore, the area analysis means 104 in the syntax analysis unit 103 analyzes the definition of the file in the source program 101, and in addition to the attributes conventionally analyzed, determines whether it is possible to establish a static point. The attributes of are also registered in the information table 109.

Next, semantic analysis is performed in the semantic analysis section 105. At this time, as shown in FIG.
8 to determine whether the source program 101 is a program that uses the automatic commitment control function (
Step 201). If the automatic commitment control function is not to be used (NO in step 201), the process of FIG. 2 is ended, but if the automatic commitment control function is to be used (YES in step 201), the checking means 107 is activated (step 202).

When activated, the checking means 107 starts the process shown in FIG. First, information table 109 to 1
Information for the entries is read (step 301), and it is determined whether the end of the information table 109 has been detected (step 302). If the end of the information table 109 is detected (YES in step 302), the process of FIG. 3 is ended.

[0026] If the end of the information table 109 is not detected (NO in step 302), that is, if one valid entry of the information table 109 is read in step 301, the information for this read one entry is checked and the file concerned is checked. It is determined whether or not the file has an attribute that allows static point establishment processing (step 303). If the file is capable of static point establishment processing (YES in step 303), the process returns to step 301 to process the next entry in the information table 109.

On the other hand, if the file cannot be processed to establish a static point (NO in step 303), an error message 110 is output to the effect that "inconsistency may occur in the file contents during rollback." (Step 3
04), return to step 301 to process the next entry.

The checking means 107 continues in step 30 until the end of the information table 109 is detected in step 302.
1. Repeat steps 303 and 304.

[0029]

[Effects of the Invention] According to the file destruction advance check mechanism of the present invention as described above, when translating a source program that uses the automatic commitment control function, it is possible to avoid problems caused by the mixture of files that are capable of static point establishment processing and files that are not. Since the possibility of file destruction occurring during rollback can be checked, file destruction caused by overlooking such a possibility and performing rollback can be prevented in advance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main parts of a compiler equipped with a file destruction advance check mechanism according to the present invention.

FIG. 2 is a flowchart showing an example of processing by the check activation means 106.

FIG. 3 is a flowchart illustrating an example of processing by the file coexistence checking unit 107 that allows/disables static point establishment processing.

[Explanation of symbols]

101...Source program 102...Compiler 103...Syntax analysis unit 104...Area analysis unit 105...Semantic analysis unit 106...Check activation unit 107...Still point establishment processing enabled/disabled file mixture checking unit 108...Program information 109...Information table 110... Error message 111...Compile options

Claims (1)

[Claims] [Claim 1] For a source program that uses the automatic commitment control function, a quiesce point establishment process is automatically performed for files that are capable of quiesce point establishment processing among files used in the source program. In a compiler that generates a target program embedded with automatic commitment control logic that performs processing to return to a quiescent point when a deadlock occurs, is it possible to establish a quiescent point by analyzing file definitions in the source program? means for registering information indicative of the automatic commitment control function in an information table; means for determining whether or not the source program uses the automatic commitment control function; A file destruction pre-check mechanism characterized by comprising means for checking a table to see if there is a file for which static point establishment processing is not possible, and for outputting an error message if there is a file.