smart-green-house/rtt-uart-nb/rt-thread/components/libc/pthreads/pthread_spin.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-10-26     Bernard      the first version
 */

#include <pthread.h>

int pthread_spin_init (pthread_spinlock_t *lock, int pshared)
{
    if (!lock)
        return EINVAL;

    lock->lock = 0;

    return 0;
}

int pthread_spin_destroy (pthread_spinlock_t *lock)
{
    if (!lock)
        return EINVAL;

    return 0;
}

int pthread_spin_lock (pthread_spinlock_t *lock)
{
    if (!lock)
        return EINVAL;

    while (!(lock->lock))
    {
        lock->lock = 1;
    }

    return 0;
}

int pthread_spin_trylock (pthread_spinlock_t *lock)
{
    if (!lock)
        return EINVAL;

    if (!(lock->lock))
    {
        lock->lock = 1;

        return 0;
    }

    return EBUSY;
}

int pthread_spin_unlock (pthread_spinlock_t *lock)
{
    if (!lock)
        return EINVAL;
    if (!(lock->lock))
        return EPERM;

    lock->lock = 0;

    return 0;
}