pthread_detach.c

/*
 * pthread_detach.c
 *
 * Description:
 * This translation unit implements functions related to thread
 * synchronisation.
 *
 * --------------------------------------------------------------------------
 *
 *      pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999-2021 pthreads-win32 / pthreads4w contributors
 *
 *      Homepage1: http://sourceware.org/pthreads-win32/
 *      Homepage2: http://sourceforge.net/projects/pthreads4w/
 *
 *      The current list of contributors is contained
 *      in the file CONTRIBUTORS included with the source
 *      code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 * 
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation; either
 *      version 2 of the License, or (at your option) any later version.
 * 
 *      This library is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *      Lesser General Public License for more details.
 * 
 *      You should have received a copy of the GNU Lesser General Public
 *      License along with this library in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *
 * --------------------------------------------------------------------------
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "pthread.h"
#include "implement.h"

/*
 * Not needed yet, but defining it should indicate clashes with build target
 * environment that should be fixed.
 */
#if !defined(WINCE)
#  include <signal.h>
#endif


int
pthread_detach (pthread_t thread)
     /*
      * ------------------------------------------------------
      * DOCPUBLIC
      *      This function detaches the given thread.
      *
      * PARAMETERS
      *      thread
      *              an instance of a pthread_t
      *
      *
      * DESCRIPTION
      *      This function detaches the given thread. You may use it to
      *      detach the main thread or to detach a joinable thread.
      *      NOTE:   detached threads cannot be joined;
      *              storage is freed immediately on termination.
      *
      * RESULTS
      *              0               successfully detached the thread,
      *              EINVAL          thread is not a joinable thread,
      *              ENOSPC          a required resource has been exhausted,
      *              ESRCH           no thread could be found for 'thread',
      *
      * ------------------------------------------------------
      */
{
  int result;
  BOOL destroyIt = PTW32_FALSE;
  ptw32_thread_t * tp = (ptw32_thread_t *) thread.p;
  ptw32_mcs_local_node_t reuseLock;

  ptw32_mcs_lock_acquire(&ptw32_thread_reuse_lock, &reuseLock);

  if (NULL == tp
      || thread.x != tp->ptHandle.x)
    {
      result = ESRCH;
    }
  else if (PTHREAD_CREATE_DETACHED == tp->detachState)
    {
      result = EINVAL;
    }
  else
    {
      ptw32_mcs_local_node_t stateLock;
      /*
       * Joinable ptw32_thread_t structs are not scavenged until
       * a join or detach is done. The thread may have exited already,
       * but all of the state and locks etc are still there.
       */
      result = 0;

      ptw32_mcs_lock_acquire (&tp->stateLock, &stateLock);
      if (tp->state < PThreadStateLast)
        {
          tp->detachState = PTHREAD_CREATE_DETACHED;
          if (tp->state == PThreadStateExiting)
          {
            destroyIt = PTW32_TRUE;
          }
        }
      else if (tp->detachState != PTHREAD_CREATE_DETACHED)
        {
          /*
           * Thread is joinable and has exited or is exiting.
           */
          destroyIt = PTW32_TRUE;
        }
      ptw32_mcs_lock_release (&stateLock);
    }

  ptw32_mcs_lock_release(&reuseLock);

  if (result == 0)
    {
      /* Thread is joinable */

      if (destroyIt)
	{
	  /* The thread has exited or is exiting but has not been joined or
	   * detached. Need to wait in case it's still exiting.
	   */
	  (void) WaitForSingleObject(tp->threadH, INFINITE);
	  ptw32_threadDestroy (thread);
	}
    }

  return (result);

}				/* pthread_detach */