nptl/pthread_detach.c

   1 /* Copyright (C) 2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include "pthreadP.h"
  22 #include <atomic.h>
  23
  24
  25 int
  26 pthread_detach (th)
  27      pthread_t th;
  28 {
  29   struct pthread *pd = (struct pthread *) th;
  30   int result = 0;
  31
  32   /* Mark the thread as detached.  */
  33   if (atomic_compare_and_exchange_acq (&pd->joinid, pd, NULL) != 0)
  34     {
  35       /* There are two possibilities here.  First, the thread might
  36          already be detached.  In this case we return EINVAL.
  37          Otherwise there might already be a waiter.  The standard does
  38          not mention what happens in this case.  */
  39       if (IS_DETACHED (pd))
  40         result = EINVAL;
  41     }
  42   else
  43     /* Check whether the thread terminated meanwhile.  In this case we
  44        will just free the TCB.  */
  45     if ((pd->cancelhandling & EXITING_BITMASK) != 0)
  46       /* Note that the code in __free_tcb makes sure each thread
  47          control block is freed only once.  */
  48       __free_tcb (pd);
  49
  50   return result;
  51 }