Function pthread_mutex_lock

components/libc/posix/pthreads/pthread_mutex.c:394–424

* @brief Locks a mutex. * * This function locks the mutex object pointed to by `mutex`. If the mutex is * already locked by another thread, the calling thread will block until the * mutex becomes available. * * @param[in,out] mutex Pointer to the mutex to be locked. * * @return * - 0 on success. * - Non-zero error code on failure, including: * - `EDEADLK`: A deadlock condition was det

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

    if (!mutex)
        return EINVAL;

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

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

        return EDEADLK;
    }
    rt_exit_critical();

    result = rt_mutex_take(&(mutex->lock), RT_WAITING_FOREVER);
    if (result == RT_EOK)
        return 0;

    return EINVAL;
}
RTM_EXPORT(pthread_mutex_lock);

/**