/****************************************************************************
 * sched/pthread/pthread_mutexdestroy.c
 *
 *   Copyright (C) 2007-2009 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 <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>

#include "pthread/pthread.h"

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: pthread_mutex_destroy
 *
 * Description:
 *   Destroy a mutex.
 *
 * Parameters:
 *   None
 *
 * Return Value:
 *   None
 *
 * Assumptions:
 *
 ****************************************************************************/

int pthread_mutex_destroy(FAR pthread_mutex_t *mutex)
{
  int ret = OK;
  int status;

  sinfo("mutex=0x%p\n", mutex);

  if (mutex == NULL)
    {
      ret = EINVAL;
    }
  else
    {
      /* Make sure the semaphore is stable while we make the following
       * checks
       */

      sched_lock();

      /* Is the semaphore available? */

      if (mutex->pid != -1)
        {
#ifndef CONFIG_DISABLE_SIGNALS
          /* Verify that the PID still exists.  We may be destroying the
           * mutex after cancelling a pthread and the mutex may have been
           * in a bad state owned by the dead pthread.
           */

         ret = kill(mutex->pid, 0);
         if (ret < 0)
           {
             /* The thread associated with the PID no longer exists */

             mutex->pid = -1;

             /* Destroy the semaphore */

             status = sem_destroy((FAR sem_t *)&mutex->sem);
             ret = (status != OK) ? get_errno() : OK;
            }
         else
#endif
           {
             ret = EBUSY;
           }
        }
      else
        {
          /* Destroy the semaphore */

          status = sem_destroy((FAR sem_t *)&mutex->sem);
          if (status != OK)
            {
              ret = get_errno();
            }
        }

      sched_unlock();
    }

  sinfo("Returning %d\n", ret);
  return ret;
}