Experimental Physics and
Industrial Control System

Freddie Akeroyd via Core-talk <core-talk at aps.anl.gov> · Sat, 19 Sep 2020 14:25:31 -0000

@Michael I guess you mean throw an exception rather than a build failure as GetTickCount() is only a fallback if there is a problem using QueryPerformanceCounter()? It looks like QueryPerformanceCounter() is guaranteed to be available on Windows XP and later, so we could drop GetTickCount() entirely if we only support XP and higher. There is some discussion on https://docs.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps about consistency of performance counters across multiple cores, but I think this only applies to Windows XP and earlier. Do we need to provide an option to allow the user to specify an alternative to QueryPerformanceCounter() (which on XP may mean we would have to monitor a rollover of GetTickCount()) or should we only support and implement  QueryPerformanceCounter() as the basis for monotonic time?

-- 
https://code.launchpad.net/~freddie-akeroyd/epics-base/+git/epics-base/+merge/391018
Your team EPICS Core Developers is requested to review the proposed merge of ~freddie-akeroyd/epics-base:fix_win32_monotonic_time into epics-base:7.0.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System