90 lines
1.8 KiB
C
90 lines
1.8 KiB
C
/*
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* Copyright (c) 2015, Xilinx Inc. and Contributors. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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/*
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* @file generic/mutex.h
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* @brief Generic mutex primitives for libmetal.
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*/
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#ifndef __METAL_MUTEX__H__
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#error "Include metal/mutex.h instead of metal/generic/mutex.h"
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#endif
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#ifndef __METAL_GENERIC_MUTEX__H__
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#define __METAL_GENERIC_MUTEX__H__
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#include <metal/atomic.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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typedef struct {
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atomic_int v;
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} metal_mutex_t;
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#define METAL_MUTEX_UNLOCKED 0
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#define METAL_MUTEX_LOCKED 1
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/*
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* METAL_MUTEX_INIT - used for initializing an mutex element in a static struct
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* or global
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*/
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#define METAL_MUTEX_INIT(m) { ATOMIC_VAR_INIT(METAL_MUTEX_UNLOCKED) }
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/*
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* METAL_MUTEX_DEFINE - used for defining and initializing a global or
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* static singleton mutex
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*/
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#define METAL_MUTEX_DEFINE(m) metal_mutex_t m = METAL_MUTEX_INIT(m)
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static inline void __metal_mutex_init(metal_mutex_t *mutex)
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{
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atomic_store(&mutex->v, METAL_MUTEX_UNLOCKED);
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}
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static inline void __metal_mutex_deinit(metal_mutex_t *mutex)
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{
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(void)mutex;
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}
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static inline int __metal_mutex_try_acquire(metal_mutex_t *mutex)
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{
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int unlocked = METAL_MUTEX_UNLOCKED;
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if (atomic_compare_exchange_strong(&mutex->v, &unlocked,
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METAL_MUTEX_LOCKED)) {
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return 1; /* acquired */
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} else {
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return 0; /* not acquired */
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}
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}
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static inline void __metal_mutex_acquire(metal_mutex_t *mutex)
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{
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int unlocked = METAL_MUTEX_UNLOCKED;
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while (!atomic_compare_exchange_weak(&mutex->v, &unlocked,
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METAL_MUTEX_LOCKED)) {
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;
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}
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}
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static inline void __metal_mutex_release(metal_mutex_t *mutex)
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{
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atomic_store(&mutex->v, METAL_MUTEX_UNLOCKED);
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}
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static inline int __metal_mutex_is_acquired(metal_mutex_t *mutex)
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{
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return atomic_load(&mutex->v);
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}
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#ifdef __cplusplus
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}
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#endif
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#endif /* __METAL_GENERIC_MUTEX__H__ */
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