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- /* Copyright (C) 2015-2022 Free Software Foundation, Inc.
- Contributed by Alexander Monakov <amonakov@ispras.ru>
- This file is part of the GNU Offloading and Multi Processing Library
- (libgomp).
- Libgomp is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3, or (at your option)
- any later version.
- Libgomp 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 General Public License for
- more details.
- Under Section 7 of GPL version 3, you are granted additional
- permissions described in the GCC Runtime Library Exception, version
- 3.1, as published by the Free Software Foundation.
- You should have received a copy of the GNU General Public License and
- a copy of the GCC Runtime Library Exception along with this program;
- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
- <http://www.gnu.org/licenses/>. */
- /* This is an NVPTX specific implementation of a semaphore synchronization
- mechanism for libgomp. This type is private to the library. This
- semaphore implementation uses atomic instructions and busy waiting. */
- #ifndef GOMP_SEM_H
- #define GOMP_SEM_H 1
- typedef int gomp_sem_t;
- static inline void
- gomp_sem_init (gomp_sem_t *sem, int value)
- {
- *sem = value;
- }
- static inline void
- gomp_sem_destroy (gomp_sem_t *sem)
- {
- }
- static inline void
- gomp_sem_wait (gomp_sem_t *sem)
- {
- int count = __atomic_load_n (sem, MEMMODEL_ACQUIRE);
- for (;;)
- {
- while (count == 0)
- count = __atomic_load_n (sem, MEMMODEL_ACQUIRE);
- if (__atomic_compare_exchange_n (sem, &count, count - 1, false,
- MEMMODEL_ACQUIRE, MEMMODEL_RELAXED))
- return;
- }
- }
- static inline void
- gomp_sem_post (gomp_sem_t *sem)
- {
- (void) __atomic_add_fetch (sem, 1, MEMMODEL_RELEASE);
- }
- static inline int
- gomp_sem_getcount (gomp_sem_t *sem)
- {
- int count = __atomic_load_n (sem, MEMMODEL_RELAXED);
- if (count < 0)
- return -1;
- return count;
- }
- #endif /* GOMP_SEM_H */
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