Re: data queue's and locks

["Mark S. Waterbury" <mark.s.waterbury@xxxxxxx>]

Hi, Rob:

It seems to me the "best simple" solution is to issue:

   ALCOBJ   OBJ((*LIBL/EXCLEIACT *DTAQ *SHRRD))

in the "listener" program that reads from the data queue. Then, your 
logic below should work.

Cheers,

Mark S. Waterbury

> rob@xxxxxxxxx wrote:
> Problem:  I want to send a *SHUTDOWN command to a data queue, but I do not 
> want to do so, if the data queue job is already dead.  Tried some simple 
> little logic like
> PGM
>
> DCL &QNAME     *CHAR   10  VALUE(EXCLEIACT)
> DCL &QLIB      *CHAR   10  VALUE(*LIBL)
> DCL &QLEN      *DEC     5  VALUE(9)
> DCL &QDATA     *CHAR    9  VALUE('*SHUTDOWN')
> DCL &QWAIT     *DEC     5  VALUE(0) /* Seconds to wait */
>
>
> /* Check lock status.*/
> ALCOBJ     OBJ((&QLIB/&QNAME *DTAQ *EXCL)) WAIT(&qwait)
> MONMSG     MSGID(CPF1002) EXEC(DO)
>   /* Data queue in use therefore EXCLEIACT is running. */
>   RCVMSG     MSGTYPE(*LAST) /* Clear the unable to allocate message from 
> job queue */
>   /* Send the shutdown command */
>   CALL       PGM(QSNDDTAQ) PARM(&QNAME &QLIB &QLEN &QDATA)
> ENDDO
>
> ENDPGM
>
> However there is no lock on the object even if the data queue reader job 
> is at this call stack:
>
> Type  Program 
>    1  QCMD       QSYS 
>       EXCLEIACT  GDIHQ
>       EXCLEIACT  GDIHQ
>       QRCVDTAQ   QSYS 
>
> So, I guess my options include:
> 1 - Modifying the reader program to do some sort of ALCOBJ to get this 
> logic to work.
> 2 - Using the list jobs api to see if the EXCLEIACT job is running.
> 3 - Modifying the reader program to clear the data queue upon start (which 
> may cause issues with other stacked up entries).
>
> Rob Berendt
>