On Wed, Jan 22, 2014 at 07:05:23PM +0100, Paolo Carlini wrote: > a couple of tsan tests: > > c-c++-common/tsan/simple_race.c > g++.dg/tsan/default_options.C > > relatively often fail for me at various optimization levels (eg, in > my last run the former at -O2: no WARNING: ThreadSanitizer... thus > the test failed). > > Is this a known issue? The machine I'm talking about is otherwise > very stable (i980x, glibc2.18, nothing special)
Yes, this is known, unfortunately the implementation of libtsan is in itself racy, thus it sometimes doesn't report a problem when it should. See https://groups.google.com/forum/#!topic/thread-sanitizer/KIok3F_b1oI We have yet to decide what to do with the tests, either kill them altogether, add some nanosleeps to increase probability of succeeding, run the test internally several times until the problem is reported, etc. Jakub
