Re: callbackRequestDelayed question

[Michael Davidsaver via Core-talk <core-talk at aps.anl.gov>]

Hi Mark,

On 11/12/25 1:51 PM, Mark Rivers wrote:

Yes, but it appears from my results that EPICS timers are actually using the result of epicsThreadSleepQuantum() even though as you say it “has no reality”. 

timer.cpp:    this->exp = expire - ( this->queue.notify.quantum () / 2.0 );

I would love to remove that -quantum/2 .  As you note, it causes timers to expire early.  However, doing so caused problems on RTOSs, which I assume is still the case.

https://bugs.launchpad.net/epics-base/+bug/1861612/comments/12

https://github.com/epics-base/epics-base/issues/106

(I have to admit that I have been patching this out of my builds for some time)

This is the result of a git grep -i for “quantum” in /usr/local/epics/base/modules/libcom/src/timer

timer.cpp:    this->exp = expire - ( this->queue.notify.quantum () / 2.0 );

Filtering out the declarations and plumbing, I think this is the only remaining usage.