DBUGHOOK: COBOL program performance analysis tool

Description

Produces system usage statistics for a COBOL program by creating revised source code with "hooks" to capture run-time statistics. Aids in restructuring programs for maximum performance.

Categories

Program Development

System Operation

Related files

DBUGHOOK: Object file for utility.

DBUGS: Subroutine; created by DBUGHOOK.

User Instructions

DBUGHOOK uses the WITH DEBUGGING option in COBOL--along with calls to subroutine DBUGS--to capture and report on the internal system usage statistics of a COBOL program. A revised version of the source file is constructed with the "hooks" for system information, executed within the utility, and the statistics gathered and summarized.

Source programs for use with DBUGHOOK should meet several requirements:

• The source program must contain the optional SOURCE-COMPUTER statement in the CONFIGURATION SECTION, and this statement must lie immediately below the CONFIGURATION SECTION header in the program. (DBUGHOOK will add WITH DEBUGGING MODE to the statement.)

• The library and volume clauses in COPY statements within the source program will be ignored, generating a correction GETPARM for the location of the file. For this reason, it is best to remove COPY statements and substitute the related source lines.

• If COPY statements are retained, the copy libraries must be located on the system volume.

• DBUGHOOK will assume that all subroutines are located in USERSUBS on the system volume. All other locations will generate correction GETPARMs.

The process of analyzing programs with DBUGHOOK is as follows:
1. At the main process screen, specify the location of the source file and press PF(01) to insert debugging code.

2. DBUGHOOK will create a revised version of the program in library DBUGSRC on the system volume. This version contains the subroutine calls to capture debugging code and pass it back to DBUGHOOK. After creating the source file, DBUGHOOK compiles the program and links to USERSUBS on the system volume.

3. The subroutine that gathers the run-time information (DBUGS) will be created by DBUGHOOK if not found; DBUGHOOK will assume it is located in USERSUBS on the system volume.

4. If additional linkage is needed, select PF(02) to re-link the program.

5. Execute the revised program by pressing PF(03).

6. After completion, the statistics are gathered by pressing PF(04); at this point, the reports have been created and the user can exit (PF(16)) or display the reports (PF(05)).

DBUGHOOK prepares two reports: one sorted alphabetically by paragraph name, the other by line number. The first report shows the name of the paragraph, the number of times it was executed, CPU time, and the source line (line number and code) preceding it. The second report lists the source file with the CPU time (raw time and percent of the total), the number of times executed, disk accesses, and program paging activity.

Programmer Instructions

Interactive use only.

Example of use

Summarizes program activity at the program level. Pinpoints performance bottlenecks by recording the resources required for each operation. Should be used for performance tuning on large or frequently-run programs.

Comments

Awkward and difficult to use, but provides unbeatable statistics. Great for illustrating the effects of various coding techniques.