nuttx/sched/pthread_detach.c

/************************************************************************
 * sched/pthread_detach.c
 *
 *   Copyright (C) 2007, 2009, 2013 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 <sys/types.h>
#include <stdbool.h>
#include <pthread.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>

#include "os_internal.h"
#include "group_internal.h"
#include "pthread_internal.h"

/************************************************************************
 * Pre-processor Definitions
 ************************************************************************/

/************************************************************************
 * Private Type Declarations
 ************************************************************************/

/************************************************************************
 * Global Variables
 ************************************************************************/

/************************************************************************
 * Private Variables
 ************************************************************************/

/************************************************************************
 * Private Functions
 ************************************************************************/

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

/************************************************************************
 * Name: pthread_detach
 *
 * Description:
 *    A thread object may be "detached" to specify that the return value
 *    and completion status will not be requested.
 *
 *    The caller's task/thread must belong to the same "task group" as the
 *    pthread is (or was) a member of.  The thread may or may not still
 *    be running.
 *
 * Parameters:
 *   thread
 *
 * Return Value:
 *   0 if successful.  Otherwise, an error code.
 *
 * Assumptions:
 *
 ************************************************************************/

int pthread_detach(pthread_t thread)
{
  FAR struct tcb_s *rtcb = (FAR struct tcb_s *)g_readytorun.head;
  FAR struct task_group_s *group = rtcb->group;
  FAR struct join_s *pjoin;
  int ret;

  sdbg("Thread=%d group=%p\n", thread, group);
  DEBUGASSERT(group);

  /* Find the entry associated with this pthread. */

  (void)pthread_takesemaphore(&group->tg_joinsem);
  pjoin = pthread_findjoininfo(group, (pid_t)thread);
  if (!pjoin)
    {
      sdbg("Could not find thread entry\n");
      ret = EINVAL;
    }
  else
    {
      /* Has the thread already terminated? */

      if (pjoin->terminated)
        {
          /* YES.. just remove the thread entry. */

          pthread_destroyjoin(group, pjoin);
        }
      else
        {
          /* NO.. Just mark the thread as detached.  It
           * will be removed and deallocated when the
           * thread exits
           */

          pjoin->detached = true;
        }

      /* Either case is successful */

      ret = OK;
    }

  (void)pthread_givesemaphore(&group->tg_joinsem);

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