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82 lines
1.4 KiB
C
82 lines
1.4 KiB
C
/*
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* Copyright (C) 2013 Freie Universität Berlin
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup pthread
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* @{
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* @file
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* @brief Spin locks.
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* @author Christian Mehlis <mehlis@inf.fu-berlin.de>
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* @author René Kijewski <kijewski@inf.fu-berlin.de>
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* @author Joakim Nohlgård <joakim.nohlgard@eistec.se>
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* @}
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*/
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#include "pthread.h"
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#include "atomic.h"
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int pthread_spin_init(pthread_spinlock_t *lock, int pshared)
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{
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if (lock == NULL) {
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return EINVAL;
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}
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(void) pshared;
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ATOMIC_VALUE(lock->value) = 0;
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return 0;
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}
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int pthread_spin_destroy(pthread_spinlock_t *lock)
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{
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if (lock == NULL) {
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return EINVAL;
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}
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(void) lock;
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return 0;
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}
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int pthread_spin_lock(pthread_spinlock_t *lock)
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{
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if (lock == NULL) {
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return EINVAL;
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}
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while (atomic_set_to_one(&(lock->value)) == 0) {
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/* spin */
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}
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return 0;
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}
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int pthread_spin_trylock(pthread_spinlock_t *lock)
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{
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if (lock == NULL) {
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return EINVAL;
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}
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if (atomic_set_to_one(&(lock->value)) == 0) {
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return EBUSY;
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}
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return 0;
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}
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int pthread_spin_unlock(pthread_spinlock_t *lock)
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{
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if (lock == NULL) {
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return EINVAL;
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}
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if (atomic_set_to_zero(&(lock->value)) == 0) {
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return EPERM;
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}
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return 0;
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}
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