https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91486
--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:f33a43f9f7eab7482837662821abb7fd02cb4350 commit r11-3653-gf33a43f9f7eab7482837662821abb7fd02cb4350 Author: Mike Crowe <m...@mcrowe.com> Date: Mon Oct 5 11:12:38 2020 +0100 libstdc++: Use correct duration for atomic_futex wait on custom clock [PR 91486] As Jonathan Wakely pointed out[1], my change in commit f9ddb696a289cc48d24d3d23c0b324cb88de9573 should have been rounding to the target clock duration type rather than the input clock duration type in __atomic_futex_unsigned::_M_load_when_equal_until just as (e.g.) condition_variable does. As well as fixing this, let's create a rather contrived test that fails with the previous code, but unfortunately only when run on a machine with an uptime of over 208.5 days, and even then not always. [1] https://gcc.gnu.org/pipermail/libstdc++/2020-September/051004.html libstdc++-v3/ChangeLog: PR libstdc++/91486 * include/bits/atomic_futex.h: (__atomic_futex_unsigned::_M_load_when_equal_until): Use target clock duration type when rounding. * testsuite/30_threads/async/async.cc (test_pr91486_wait_for): Rename from test_pr91486. (float_steady_clock): New class for test. (test_pr91486_wait_until): New test.
