https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97936
--- Comment #6 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:ad9cbcee543ecccd79fa49dafcd925532d2ce210 commit r11-5330-gad9cbcee543ecccd79fa49dafcd925532d2ce210 Author: Jonathan Wakely <jwak...@redhat.com> Date: Wed Nov 25 10:26:09 2020 +0000 libstdc++: Fix handling of futex wake [PR 97936] The __platform_wait function is supposed to wait until *addr != old. The futex syscall checks the initial value and returns EAGAIN if *addr != old is already true, which should cause __platform_wait to return. Instead it loops and keeps doing a futex wait, which keeps returning EAGAIN. libstdc++-v3/ChangeLog: PR libstdc++/97936 * include/bits/atomic_wait.h (__platform_wait): Return if futex sets EAGAIN. * testsuite/30_threads/latch/3.cc: Re-enable test. * testsuite/30_threads/semaphore/try_acquire_until.cc: Likewise.
