123456789101112131415161718192021222324252627282930313233343536373839404142434445 |
- /* sem_post -- post to a POSIX semaphore. Powerpc version.
- Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 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
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
- #include <errno.h>
- #include <sysdep.h>
- #include <lowlevellock.h>
- #include <internaltypes.h>
- #include <semaphore.h>
- int
- sem_post (sem_t *sem)
- {
- struct new_sem *isem = (struct new_sem *) sem;
- __asm__ __volatile__ (__lll_rel_instr ::: "memory");
- atomic_increment (&isem->value);
- __asm__ __volatile__ (__lll_acq_instr ::: "memory");
- if (isem->nwaiters > 0)
- {
- int err = lll_futex_wake (&isem->value, 1,
- isem->private ^ FUTEX_PRIVATE_FLAG);
- if (__builtin_expect (err, 0) < 0)
- {
- __set_errno (-err);
- return -1;
- }
- }
- return 0;
- }
|