timedwait cond mtx timeout
waits on condition variable cond
with mutex mtx
until either the condition is signalled, or until
timeout
expires. Note that timeout
is an absolute Unix-time to
prevent time-related race conditions.
false
iff the timer expired, but this does not mean that
the condition is not true due to an unavoidable race condition in
the system call.man pthread_cond_timedwait
for details.