>Psychtoolbox>PsychTests

OMLBasicTest([screenid=max][, querystresstest = 0]) - Test basic correctness of OpenML timestamping.

Performs a sequence of 300 flips, acquires timestamps of
Flip completion according to OML_sync_control timestamping,
as well as a post-swap GetSecs timestamp and a timestamp of
the last vblank. If OpenML timestamping works correctly, then
all three timestamps should be almost identical, ie., the vblank
and flip timestamps should be identical, the GetSecs timestamp
only minimally later than the flip timestamp, depending on
system scheduling noise and load.

If the timestamps (minus a few outliers) disagree, then
something is likely broken in OpenML flip timestamping.

if the optional parameter ‘querystresstest’ is set to a
value > 0 then a stress test of vblank count and timestamp
queries is run for ‘querystresstest’ seconds and potential
trouble is reported.