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/*
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2023-03-24 WangXiaoyao Complete testcase for synchronization
*/
#ifndef __SEMAPHORE_H__
#define __SEMAPHORE_H__
#include <stdatomic.h>
typedef struct {
atomic_int count;
} semaphore_t;
void semaphore_init(semaphore_t *sem, int count)
{
atomic_init(&sem->count, count);
}
void semaphore_wait(semaphore_t *sem)
{
int count;
do {
count = atomic_load(&sem->count);
} while (count == 0 || !atomic_compare_exchange_weak(&sem->count, &count, count - 1));
}
void semaphore_signal(semaphore_t *sem)
{
atomic_fetch_add(&sem->count, 1);
}
#endif /* __SEMAPHORE_H__ */
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