Experimental Physics and
Industrial Control System

Benjamin Franksen <[email protected]> · Fri, 12 Apr 2002 00:13:56 +0200

Frank Lenkszus wrote:
> 
> @(#)SNC/SEQ Version 1.9.2.Beta12 : Mon Jan 10 11:45:25 2000
> 
> with EPICS 3.13.2 under vxWorks on an mvme167.
> 
> In attempt to set the task priority, I'm invoking the
> following:
> 
> seq &dpCorr, "priority=86,  U=DP"
> 
> I can't seem to make this work;i.e, the task priority
> always turns out to be 100 no matter what I set "priority="
> to.

I experienced the same with seq 1.9.5 under epics 3.13.6. Seq limits
task priorities to values greater than or equal to SPAWN_PRIORITY which
is defined in seq.h:

	#define SPAWN_PRIORITY            100

See function seq in file seq_main.c:

	if (pSP->taskPriority < SPAWN_PRIORITY)
		pSP->taskPriority = SPAWN_PRIORITY;

SPAWN_PRIORITY is also used as task priority for the auxiliary task
(also in function seq) and for task deletion, see function sprog_delete
in file seq_task.c:

	taskSpawn("tSeqCleanup", SPAWN_PRIORITY-1, VX_FP_TASK, 8000,
	 (FUNCPTR)seq_cleanup, tid, (int)pSP, (int)cleanupSem, 0,0,0,0,0,0,0);

To summarize, it looks as if SPAWN_PRIORITY could safely be set to a
value less than 100.

Can people more familiar with the seq code comment?

Ben
-- 
Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
(BESSY) GmbH, Control System Group
Albert-Einstein-Straße 15, 12489 Berlin, +49 30 6392 4862, www.bessy.de

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System