RE: Best way to check if a program is running

[qsrvbas@xxxxxxxxxxxx (Tom Liotta)]

rpg400-l-request@xxxxxxxxxxxx wrote:

>  10. RE: Best way to check if a program is running (York, Albert)
>
>The only problem with this approach is that you cannot save the library
>while the program is running, even if you use save while active, because you
>can't get a lock on it.

Well, actually, under many circumstances if not all, you _can_ save the library 
even with SAVLIB because you _can_ get a lock on it if the locks are set as 
needed. Consider the following example CLP named TSTALCPGM:

   ALCOBJ     OBJ((TSTALCPGM *PGM *EXCL)) WAIT(0)
   monmsg   ( cpf1002 )   exec( do )
      SNDPGMMSG  MSG('ALCOBJ *EXCL failed.') TOPGMQ(*EXT)
      return
   enddo

   ALCOBJ     OBJ((TSTALCPGM *PGM *SHRRD)) WAIT(0)
   monmsg   ( cpf1002 )   exec( do )
      SNDPGMMSG  MSG('ALCOBJ *SHRRD failed.') TOPGMQ(*EXT)
      return
   enddo

   DLCOBJ     OBJ((TSTALCPGM *PGM *EXCL))

/* Do logical work here... */
   dlyjob 30

   DLCOBJ     OBJ((TSTALCPGM *PGM *SHRRD))

The initial *EXCL lock is done to verify that no other locks exist. This *EXCL 
lock is extremely transient, essentially replaced immediately by the *SHRRD 
lock. Once the work is done -- or the job ends -- the remaining *SHRRD lock is 
gone. In the meantime, except for those milliseconds when *EXCL is held, 
there's no problem.

Bonus thought... Further, since this example was based on OPM, the program 
associated space can be updated to hold the same info you'd store in the 
*dtaara, except you wouldn't be limited to 2k bytes. (I haven't had to find how 
to do similar with ILE.)

Tom Liotta

-- 
Tom Liotta
The PowerTech Group, Inc.
19426 68th Avenue South
Kent, WA 98032
Phone  253-872-7788 x313
Fax    253-872-7904
http://www.powertech.com


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