The job that submits itself to the jobq as it's last step will continue running forever unless it gets some data that crashes it. A Prestart job will hang or crash, and another will start (up to the max limit of course).
Mark Murphy
STAR BASE Consulting, Inc.
mmurphy@xxxxxxxxxxxxxxx
-----"D*B" <dieter.bender@xxxxxxxxxxxx> wrote: -----
To: "Midrange Systems Technical Discussion" <midrange-l@xxxxxxxxxxxx>
From: "D*B" <dieter.bender@xxxxxxxxxxxx>
Date: 09/16/2016 03:12AM
Subject: Re: Prestart jobs... how does it work ?
<Alan>
The point being you must use one of two program names supplied by IBM. You
cannot just put the name of a program you want to run.
</Alan>
... seems only be half of the truth. Workmanagement Guilde says:
"Examples for ADDPJE
Example 1: Specifying Additional Prestart Jobs
ADDPJE SBSD(QGPL/PJSBS) PGM(QGPL/PGM1) INLJOBS(15)
THRESHOLD(5) ADLJOBS(10) WAIT(*NO)"
They don't tell how the example PGM1 is looking like, but it seems to be
possible to make a user written programm a prestarted job. Communication
between a listener - acting as dispatcher - and the clients is done by
takedescriptor or via sendmsg() recvmeg(). There are examples available, but
they don't tell how to make it a prestarted job.
In my opinion prestarted jobs where the first attempt for AS/400 to enable
Threading support, without having Threading capable job environments. The
"threads" are implemented by independent jobs, without shared memory to each
other. Sharing information between the jobs is done by the programmer and
some OS400 specific APIs. Later on Unix like thread modell came to AS/400
and since then it was possible to write true multithreaded applications
(with some restrictions to RPG and COBOL).
@Jim: Interesting idea to replace an AJE with a PJE to get automatic restart
capabilities - I didn't try to do so, because there is a very basic
alternative:
create a JOBQ with only one running JOB and let your programm first submit
itself to this Q. Once submitted, it will run forever.
Dieter
midrange.com
