/**************************************************************************** * sched/pthread/pthread_mutexinit.c * * Copyright (C) 2007-2009, 2011, 2016-2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include "pthread/pthread.h" /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: pthread_mutex_init * * Description: * Create a mutex * * Parameters: * None * * Return Value: * None * * Assumptions: * ****************************************************************************/ 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 uint8_t proto = PTHREAD_PRIO_INHERIT; #endif #ifndef CONFIG_PTHREAD_MUTEX_UNSAFE #ifdef CONFIG_PTHREAD_MUTEX_DEFAULT_UNSAFE uint8_t robust = PTHREAD_MUTEX_STALLED; #else uint8_t robust = PTHREAD_MUTEX_ROBUST; #endif #endif int ret = OK; int status; sinfo("mutex=0x%p attr=0x%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 robust = attr->robust; #endif } /* Indicate that the semaphore is not held by any thread. */ mutex->pid = -1; /* Initialize the mutex like a semaphore with initial count = 1 */ status = sem_init((FAR sem_t *)&mutex->sem, pshared, 1); if (status != OK) { ret = get_errno(); } #ifdef CONFIG_PRIORITY_INHERITANCE /* Initialize the semaphore protocol */ status = sem_setprotocol((FAR sem_t *)&mutex->sem, proto); if (status != OK) { ret = get_errno(); } #endif #ifndef CONFIG_PTHREAD_MUTEX_UNSAFE /* Initial internal fields of the mutex */ mutex->flink = NULL; mutex->flags = (robust == PTHREAD_MUTEX_ROBUST ? _PTHREAD_MFLAGS_ROBUST : 0); #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; }