1 /* sem_wait -- 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>
31 __sem_wait_cleanup (void *arg)
33 struct sparc_new_sem *isem = (struct sparc_new_sem *) arg;
36 atomic_decrement (&isem->nwaiters);
39 __sparc32_atomic_do_lock24 (&isem->lock);
41 __sparc32_atomic_do_unlock24 (&isem->lock);
49 struct sparc_new_sem *isem = (struct sparc_new_sem *) sem;
54 val = atomic_decrement_if_positive (&isem->value);
57 __sparc32_atomic_do_lock24 (&isem->lock);
60 isem->value = val - 1;
63 __sparc32_atomic_do_unlock24 (&isem->lock);
70 atomic_increment (&isem->nwaiters);
72 /* Already done above while still holding isem->lock. */;
74 pthread_cleanup_push (__sem_wait_cleanup, isem);
78 /* Enable asynchronous cancellation. Required by the standard. */
79 int oldtype = __pthread_enable_asynccancel ();
81 err = lll_futex_wait (&isem->value, 0,
82 isem->private ^ FUTEX_PRIVATE_FLAG);
84 /* Disable asynchronous cancellation. */
85 __pthread_disable_asynccancel (oldtype);
87 if (err != 0 && err != -EWOULDBLOCK)
95 val = atomic_decrement_if_positive (&isem->value);
98 __sparc32_atomic_do_lock24 (&isem->lock);
101 isem->value = val - 1;
102 __sparc32_atomic_do_unlock24 (&isem->lock);
112 pthread_cleanup_pop (0);
115 atomic_decrement (&isem->nwaiters);
118 __sparc32_atomic_do_lock24 (&isem->lock);
120 __sparc32_atomic_do_unlock24 (&isem->lock);