Experimental Physics and
Industrial Control System

Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov> · Mon, 9 Jan 2023 12:22:39 -0800

On 1/6/23 09:24, Andrew Johnson via Tech-talk wrote:

epicsThreadSleepQuantum

This function returns the minimum slumber interval obtainable with epicsThreadSleep() in seconds. On most OS there is a system scheduler interrupt interval which determines the value of this parameter. Knowledge of this parameter is used by the various components of EPICS to improve scheduling of software tasks in time when the reduction of average time scheduling errors is important. If this parameter is unknown or is unpredictable for a particular OS then it is safe to return zero.

I obviously forgot that last sentence when I wrote the code in dbScan.c which divides by the quantum, so that should get fixed although nobody has actually reported being hit by it in over 10 years.

To my mind, we should drop this last sentence.  There are simply too many places where
"epicsThreadSleep(epicsThreadSleepQuantum())" is called.  eg. epicsThreadOnce()
in posix/osdThread.c

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System