nptl/old_pthread_cond_wait.c

   1 /* Copyright (C) 2002-2023 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 <stdlib.h>
  20 #include "pthreadP.h"
  21 #include <atomic.h>
  22 #include <shlib-compat.h>
  23
  24
  25 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_3_2)
  26 int
  27 __pthread_cond_wait_2_0 (pthread_cond_2_0_t *cond, pthread_mutex_t *mutex)
  28 {
  29   if (cond->cond == NULL)
  30     {
  31       pthread_cond_t *newcond;
  32
  33       newcond = (pthread_cond_t *) calloc (sizeof (pthread_cond_t), 1);
  34       if (newcond == NULL)
  35         return ENOMEM;
  36
  37       if (atomic_compare_and_exchange_bool_acq (&cond->cond, newcond, NULL))
  38         /* Somebody else just initialized the condvar.  */
  39         free (newcond);
  40     }
  41
  42   return __pthread_cond_wait (cond->cond, mutex);
  43 }
  44 compat_symbol (libpthread, __pthread_cond_wait_2_0, pthread_cond_wait,
  45                GLIBC_2_0);
  46 #endif