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- /****************************************************************************
- * sched/pthread/pthread_condwait.c
- *
- * Copyright (C) 2007-2009, 2012, 2016 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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 <nuttx/config.h>
- #include <unistd.h>
- #include <pthread.h>
- #include <sched.h>
- #include <errno.h>
- #include <debug.h>
- #include <nuttx/cancelpt.h>
- #include "pthread/pthread.h"
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: int pthread_cond_wait
- *
- * Description:
- * A thread can wait for a condition variable to be signalled or broadcast.
- *
- * Input Parameters:
- * None
- *
- * Returned Value:
- * None
- *
- * Assumptions:
- *
- ****************************************************************************/
- int pthread_cond_wait(FAR pthread_cond_t *cond, FAR pthread_mutex_t *mutex)
- {
- int status;
- int ret;
- sinfo("cond=0x%p mutex=0x%p\n", cond, mutex);
- /* pthread_cond_wait() is a cancellation point */
- (void)enter_cancellation_point();
- /* Make sure that non-NULL references were provided. */
- if (cond == NULL || mutex == NULL)
- {
- ret = EINVAL;
- }
- /* Make sure that the caller holds the mutex */
- else if (mutex->pid != (int)getpid())
- {
- ret = EPERM;
- }
- else
- {
- /* Give up the mutex */
- sinfo("Give up mutex / take cond\n");
- sched_lock();
- mutex->pid = -1;
- ret = pthread_mutex_give(mutex);
- /* Take the semaphore */
- status = pthread_sem_take((FAR sem_t *)&cond->sem, false);
- if (ret == OK)
- {
- /* Report the first failure that occurs */
- ret = status;
- }
- sched_unlock();
- /* Reacquire the mutex.
- *
- * When cancellation points are enabled, we need to hold the mutex
- * when the pthread is canceled and cleanup handlers, if any, are
- * entered.
- */
- sinfo("Reacquire mutex...\n");
- status = pthread_mutex_take(mutex, false);
- if (ret == OK)
- {
- /* Report the first failure that occurs */
- ret = status;
- }
- /* Was all of the above successful? */
- if (ret == OK)
- {
- mutex->pid = getpid();
- }
- }
- leave_cancellation_point();
- sinfo("Returning %d\n", ret);
- return ret;
- }
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