* libs/libc/pthread/pthread_mutex_lock.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <pthread.h>
* Public Functions
****************************************************************************/
* Name: pthread_mutex_lock
*
* Description:
* The mutex object referenced by mutex is locked by calling
* pthread_mutex_lock(). If the mutex is already locked, the calling thread
* blocks until the mutex becomes available. This operation returns with
* the mutex object referenced by mutex in the locked state with the
* calling thread as its owner.
*
* If the mutex type is PTHREAD_MUTEX_NORMAL, deadlock detection is not
* provided. Attempting to relock the mutex causes deadlock. If a thread
* attempts to unlock a mutex that it has not locked or a mutex which is
* unlocked, undefined behavior results.
*
* If the mutex type is PTHREAD_MUTEX_ERRORCHECK, then error checking is
* provided. If a thread attempts to relock a mutex that it has already
* locked, an error will be returned. If a thread attempts to unlock a
* mutex that it has not locked or a mutex which is unlocked, an error will
* be returned.
*
* If the mutex type is PTHREAD_MUTEX_RECURSIVE, then the mutex maintains
* the concept of a lock count. When a thread successfully acquires a mutex
* for the first time, the lock count is set to one. Every time a thread
* relocks this mutex, the lock count is incremented by one. Each time the
* thread unlocks the mutex, the lock count is decremented by one. When the
* lock count reaches zero, the mutex becomes available for other threads
* to acquire. If a thread attempts to unlock a mutex that it has not
* locked or a mutex which is unlocked, an error will be returned.
*
* If a signal is delivered to a thread waiting for a mutex, upon return
* from the signal handler the thread resumes waiting for the mutex as if
* it was not interrupted.
*
* Input Parameters:
* mutex - A reference to the mutex to be locked.
*
* Returned Value:
* 0 on success or an errno value on failure. Note that the errno EINTR
* is never returned by pthread_mutex_lock().
*
* Assumptions:
*
* POSIX Compatibility:
* - This implementation does not return EAGAIN when the mutex could not be
* acquired because the maximum number of recursive locks for mutex has
* been exceeded.
*
****************************************************************************/
int pthread_mutex_lock(FAR pthread_mutex_t *mutex)
{
* the absolute time delay is a NULL value.
*/
return pthread_mutex_timedlock(mutex, NULL);
}