incubator-nuttx/sched/pthread/pthread_mutexinit.c

145 lines
3.8 KiB
C

/****************************************************************************
* sched/pthread/pthread_mutexinit.c
*
* 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 <stdint.h>
#include <pthread.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/semaphore.h>
#include "pthread/pthread.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_mutex_init
*
* Description:
* Create a mutex
*
* Input Parameters:
* mutex - A reference to the mutex to be initialized
* attr - Mutex attribute object to be used
*
* Returned Value:
* 0 if successful. Otherwise, an error code.
*
****************************************************************************/
int pthread_mutex_init(FAR pthread_mutex_t *mutex,
FAR const pthread_mutexattr_t *attr)
{
int pshared = 0;
#ifdef CONFIG_PTHREAD_MUTEX_TYPES
uint8_t type = PTHREAD_MUTEX_DEFAULT;
#endif
#ifdef CONFIG_PRIORITY_INHERITANCE
# ifdef CONFIG_PTHREAD_MUTEX_DEFAULT_PRIO_INHERIT
uint8_t proto = PTHREAD_PRIO_INHERIT;
# else
uint8_t proto = PTHREAD_PRIO_NONE;
# endif
#endif
#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
#ifdef CONFIG_PTHREAD_MUTEX_DEFAULT_UNSAFE
uint8_t flags = 0;
#else
uint8_t flags = _PTHREAD_MFLAGS_ROBUST;
#endif
#endif
int ret = OK;
int status;
sinfo("mutex=%p attr=%p\n", mutex, attr);
if (!mutex)
{
ret = EINVAL;
}
else
{
/* Were attributes specified? If so, use them */
if (attr)
{
pshared = attr->pshared;
#ifdef CONFIG_PRIORITY_INHERITANCE
proto = attr->proto;
#endif
#ifdef CONFIG_PTHREAD_MUTEX_TYPES
type = attr->type;
#endif
#ifdef CONFIG_PTHREAD_MUTEX_BOTH
flags = attr->robust == PTHREAD_MUTEX_ROBUST ?
_PTHREAD_MFLAGS_ROBUST : 0;
#endif
}
/* Indicate that the semaphore is not held by any thread. */
mutex->pid = INVALID_PROCESS_ID;
/* Initialize the mutex like a semaphore with initial count = 1 */
status = nxsem_init(&mutex->sem, pshared, 1);
if (status < 0)
{
ret = -ret;
}
#ifdef CONFIG_PRIORITY_INHERITANCE
/* Initialize the semaphore protocol */
status = nxsem_set_protocol(&mutex->sem, proto);
if (status < 0)
{
ret = -status;
}
#endif
#ifndef CONFIG_PTHREAD_MUTEX_UNSAFE
/* Initial internal fields of the mutex */
mutex->flink = NULL;
mutex->flags = flags;
#endif
#ifdef CONFIG_PTHREAD_MUTEX_TYPES
/* Set up attributes unique to the mutex type */
mutex->type = type;
mutex->nlocks = 0;
#endif
}
sinfo("Returning %d\n", ret);
return ret;
}