[Bug libstdc++/54185] condition_variable not properly destructed

["architectbum at hotmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54185

--- Comment #6 from architectbum at hotmail dot com 2012-08-06 17:18:26 UTC ---
I don't have this_thread::sleep_for in my build, but presumably it wouldn't
help as the segfault comes inside the pthread_cond_wait function. The testcase
as written already ensures that NUM_THREADS-1 threads are actually waiting at
cond->wait when notify_all is called (thanks to the lock); the problem seems to
be a race between the final thread doing 'delete cc' and the other threads
clearing the part of pthread_cond_wait which assumes the condition variable's
address still points to a valid object.

To be clear, this isn't a bug with pthread, just the way which libstdc++ uses
it. If/when ~condition_variable (via delete) calls gthread_cond_destroy,
libpthread properly avoids the race.