nptl/pthread_detach.c

   1 /* Copyright (C) 2002, 2003 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
  31   /* Make sure the descriptor is valid.  */
  32   if (INVALID_NOT_TERMINATED_TD_P (pd))
  33     /* Not a valid thread handle.  */
  34     return ESRCH;
  35
  36   int result = 0;
  37
  38   /* Mark the thread as detached.  */
  39   if (atomic_compare_and_exchange_bool_acq (&pd->joinid, pd, NULL))
  40     {
  41       /* There are two possibilities here.  First, the thread might
  42          already be detached.  In this case we return EINVAL.
  43          Otherwise there might already be a waiter.  The standard does
  44          not mention what happens in this case.  */
  45       if (IS_DETACHED (pd))
  46         result = EINVAL;
  47     }
  48   else
  49     /* Check whether the thread terminated meanwhile.  In this case we
  50        will just free the TCB.  */
  51     if ((pd->cancelhandling & EXITING_BITMASK) != 0)
  52       /* Note that the code in __free_tcb makes sure each thread
  53          control block is freed only once.  */
  54       __free_tcb (pd);
  55
  56   return result;
  57 }