1 /* sem_timedwait -- wait on a semaphore. Generic futex-using version.
2 Copyright (C) 2003-2014 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>
28 #include <shlib-compat.h>
31 extern void __sem_wait_cleanup (void *arg) attribute_hidden;
33 /* This is in a seperate function in order to make sure gcc
34 puts the call site into an exception region, and thus the
35 cleanups get properly run. */
37 __attribute__ ((noinline))
38 do_futex_timed_wait (struct new_sem *isem, struct timespec *rt)
40 int err, oldtype = __pthread_enable_asynccancel ();
42 err = lll_futex_timed_wait (&isem->value, 0, rt,
43 isem->private ^ FUTEX_PRIVATE_FLAG);
45 __pthread_disable_asynccancel (oldtype);
50 sem_timedwait (sem_t *sem, const struct timespec *abstime)
52 struct new_sem *isem = (struct new_sem *) sem;
55 if (atomic_decrement_if_positive (&isem->value) > 0)
58 if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
64 atomic_increment (&isem->nwaiters);
66 pthread_cleanup_push (__sem_wait_cleanup, isem);
74 /* Get the current time. */
75 __gettimeofday (&tv, NULL);
77 /* Compute relative timeout. */
78 sec = abstime->tv_sec - tv.tv_sec;
79 nsec = abstime->tv_nsec - tv.tv_usec * 1000;
86 /* Already timed out? */
89 __set_errno (ETIMEDOUT);
97 err = do_futex_timed_wait(isem, &rt);
98 if (err != 0 && err != -EWOULDBLOCK)
105 if (atomic_decrement_if_positive (&isem->value) > 0)
112 pthread_cleanup_pop (0);
114 atomic_decrement (&isem->nwaiters);