nptl/pthread_detach.c

   1 /* Copyright (C) 2002-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include "pthreadP.h"
  20 #include <atomic.h>
  21 #include <shlib-compat.h>
  22
  23 int
  24 ___pthread_detach (pthread_t th)
  25 {
  26   struct pthread *pd = (struct pthread *) th;
  27
  28   /* Make sure the descriptor is valid.  */
  29   if (INVALID_NOT_TERMINATED_TD_P (pd))
  30     /* Not a valid thread handle.  */
  31     return ESRCH;
  32
  33   int result = 0;
  34
  35   /* Mark the thread as detached.  */
  36   if (atomic_compare_and_exchange_bool_acq (&pd->joinid, pd, NULL))
  37     {
  38       /* There are two possibilities here.  First, the thread might
  39          already be detached.  In this case we return EINVAL.
  40          Otherwise there might already be a waiter.  The standard does
  41          not mention what happens in this case.  */
  42       if (IS_DETACHED (pd))
  43         result = EINVAL;
  44     }
  45   else
  46     /* Check whether the thread terminated meanwhile.  In this case we
  47        will just free the TCB.  */
  48     if ((pd->cancelhandling & EXITING_BITMASK) != 0)
  49       /* Note that the code in __free_tcb makes sure each thread
  50          control block is freed only once.  */
  51       __nptl_free_tcb (pd);
  52
  53   return result;
  54 }
  55 versioned_symbol (libc, ___pthread_detach, pthread_detach, GLIBC_2_34);
  56 libc_hidden_ver (___pthread_detach, __pthread_detach)
  57 #ifndef SHARED
  58 strong_alias (___pthread_detach, __pthread_detach)
  59 #endif
  60
  61 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_34)
  62 compat_symbol (libc, ___pthread_detach, pthread_detach, GLIBC_2_0);
  63 #endif