It is less than a year ago in week 22 I wrote a tip about how to measure the CPU usage for a piece of code in a program. I also mentioned that the tip was likely to produce wrong results when used in a CICS environment. Now I will reveal a piece of code that will work correctly for some CICS releases, but sadly enough not the newest ones. It is very easy to see if it does not work, because the CPU usage will be zero:

DATA DIVISION.
WORKING-STORAGE SECTION.
01  DFHMNTDS-POINTER POINTER.
01  WORKUSED PIC S9(9) BINARY.
01  LASTUSED PIC S9(9) BINARY.
01  CPUUSAGE PIC S9(9) BINARY.
LINKAGE SECTION.
01  DFHMNTDS.
  02  FILLER PIC X(1264).
  02  CPUTIME PIC S9(9) BINARY.
PROCEDURE DIVISION.
...
MOVE 0 TO LASTUSED
EXEC CICS
  COLLECT STATISTICS SET(DFHMNTDS-POINTER)
  MONITOR(EIBTASKN) NOHANDLE
END-EXEC
IF EIBRESP = 0
  SET ADDRESS OF DFHMNTDS TO DFHMNTDS-POINTER
  COMPUTE WORKUSED = CPUTIME / 62.5
  COMPUTE CPUUSAGE = WORKUSED - LASTUSED
  MOVE WORKUSED TO LASTUSED
ELSE
  MOVE 0 TO WORKUSED
  MOVE 999999999 TO CPUUSAGE
END-IF
... ALL THE WORK I WANT TO MEASURE
EXEC CICS
  COLLECT STATISTICS SET(DFHMNTDS-POINTER)
  MONITOR(EIBTASKN) NOHANDLE
END-EXEC
IF EIBRESP = 0
  SET ADDRESS OF DFHMNTDS TO DFHMNTDS-POINTER
  COMPUTE WORKUSED = CPUTIME / 62.5
  COMPUTE CPUUSAGE = WORKUSED - LASTUSED
  MOVE WORKUSED TO LASTUSED
ELSE
  MOVE 0 TO WORKUSED
  MOVE 999999999 TO CPUUSAGE
END-IF
DISPLAY 'MEASURED CPU CONSUMPTION IN 1/1000 SECONDS = ' CPUUSAGE
...

To make the above work first of all you must compile your program using compiler option PROCESS XOPTS(XP), because EXEC CICS COLLECT is a part of the systems progrmmer interface for CICS. If CPUUSAGE shows up as 999999999 it is because EXEC CICS COLLECT failed. If EXEC CICS COLLECT fails one of the measurements that needs to be set up in order to make CICS collect the CPU usage is not enabled. You need to ask the CICS systems programmer to enable those measurements. I am pretty confident that the correct measurements are enabled at almost all installations. If not the performance people cannot measure the CPU usage on transaction level using SMF.

Please be aware that CPUTIME on CICS has a low "resolution". It is only updated 62.5 times for each 1/1000 of a second. Therefore it can easily happen that the CPU usage turns out to be zero. I use the above piece of code to measure the CPU usage at transaction level. This is a vast improvement in comparison to waiting for the performance people to collect and distribute the same measurement.

The systems programmers I have talked to in order to make the above code work told me that it might not work for transactions running "threadsafe". So now you are warned if you think that the returned CPU usage does not look correct. I have compared the CPU usage returned by my example to the CPU usage recorded in SMF and it was a match. On the other hand I do not know if the transactions I have measured were running threadsafe or not. A threadsafe transaction runs on a socalled L8 TCB and according to the documentation I have been reading the L8 TCB usage is also counted in the CPUTIME field, but this may be subject for change in newer releases. By the way the CPUTIME field is called TMRCPUT in the assembleer macro describing the DFHMNTDS record. In SMF the same field is called USRCPUT.