/* Wait on a semaphore with a timeout. Generic version. Copyright (C) 2005 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include int __sem_timedwait_internal (sem_t *restrict sem, const struct timespec *restrict timeout) { struct __pthread *self; __pthread_spin_lock (&sem->__lock); if (sem->__value > 0) /* Successful down. */ { sem->__value --; __pthread_spin_unlock (&sem->__lock); return 0; } /* Add ourselves to the queue. */ self = _pthread_self (); __pthread_enqueue (&sem->__queue, self); __pthread_spin_unlock (&sem->__lock); /* Block the thread. */ if (timeout) { error_t err; if (timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000) { errno = EINVAL; return -1; } err = __pthread_timedblock (self, timeout); if (err) /* We timed out. We may need to disconnect ourself from the waiter queue. FIXME: What do we do if we get a wakeup message before we disconnect ourself? It may remain until the next time we block. */ { assert (err == ETIMEDOUT); __pthread_spin_lock (&sem->__lock); if (self->prevp) __pthread_dequeue (self); __pthread_spin_unlock (&sem->__lock); errno = err; return -1; } } else __pthread_block (self); return 0; } int __sem_timedwait (sem_t *restrict sem, const struct timespec *restrict timeout) { return __sem_timedwait_internal (sem, timeout); } weak_alias (__sem_timedwait, sem_timedwait);