1 /* sem_timedwait -- wait on a semaphore. Generic futex-using version.
2 Copyright (C) 2003, 2007 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
22 #include <lowlevellock.h>
23 #include <internaltypes.h>
24 #include <semaphore.h>
29 extern void __sem_wait_cleanup (void *arg) attribute_hidden;
33 sem_timedwait (sem_t *sem, const struct timespec *abstime)
35 struct new_sem *isem = (struct new_sem *) sem;
38 if (atomic_decrement_if_positive (&isem->value) > 0)
41 if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
47 atomic_increment (&isem->nwaiters);
49 pthread_cleanup_push (__sem_wait_cleanup, isem);
57 /* Get the current time. */
58 __gettimeofday (&tv, NULL);
60 /* Compute relative timeout. */
61 sec = abstime->tv_sec - tv.tv_sec;
62 nsec = abstime->tv_nsec - tv.tv_usec * 1000;
69 /* Already timed out? */
73 __set_errno (ETIMEDOUT);
82 /* Enable asynchronous cancellation. Required by the standard. */
83 int oldtype = __pthread_enable_asynccancel ();
85 err = lll_futex_timed_wait (&isem->value, 0, &rt,
86 isem->private ^ FUTEX_PRIVATE_FLAG);
88 /* Disable asynchronous cancellation. */
89 __pthread_disable_asynccancel (oldtype);
91 if (err != 0 && err != -EWOULDBLOCK)
98 if (atomic_decrement_if_positive (&isem->value) > 0)
105 pthread_cleanup_pop (0);
107 atomic_decrement (&isem->nwaiters);