Function pthread_mutex_unlock

components/libc/posix/pthreads/pthread_mutex.c:454–485

* @brief Unlocks a mutex. * * This function unlocks the mutex object pointed to by `mutex`. If other threads * are blocked waiting for the mutex, one of them will acquire the lock once it is * released. The calling thread must hold the lock on the mutex before calling * this function. * * @param[in,out] mutex Pointer to the mutex to be unlocked. * * @return * - 0 on success. * - Non-zer

 * @see pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_init
 */
int pthread_mutex_unlock(pthread_mutex_t *mutex)
{
    rt_err_t result;

    if (!mutex)
        return EINVAL;
    if (mutex->attr == -1)
    {
        /* init mutex */
        pthread_mutex_init(mutex, RT_NULL);
    }

    if (mutex->lock.owner != rt_thread_self())
    {
        int mtype;
        mtype = mutex->attr & MUTEXATTR_TYPE_MASK;

        /* error check, return EPERM */
        if (mtype == PTHREAD_MUTEX_ERRORCHECK)
            return EPERM;

        /* no thread waiting on this mutex */
        if (mutex->lock.owner == RT_NULL)
            return 0;
    }

    result = rt_mutex_release(&(mutex->lock));
    if (result == RT_EOK)
        return 0;

    return EINVAL;
}
RTM_EXPORT(pthread_mutex_unlock);

/**