nptl/old_pthread_cond_signal.c

   1 /* Copyright (C) 2002-2015 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <stdlib.h>
  21 #include "pthreadP.h"
  22 #include <atomic.h>
  23 #include <shlib-compat.h>
  24
  25
  26 #if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
  27 int
  28 __pthread_cond_signal_2_0 (cond)
  29      pthread_cond_2_0_t *cond;
  30 {
  31   if (cond->cond == NULL)
  32     {
  33       pthread_cond_t *newcond;
  34
  35 #if LLL_LOCK_INITIALIZER == 0
  36       newcond = (pthread_cond_t *) calloc (sizeof (pthread_cond_t), 1);
  37       if (newcond == NULL)
  38         return ENOMEM;
  39 #else
  40       newcond = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
  41       if (newcond == NULL)
  42         return ENOMEM;
  43
  44       /* Initialize the condvar.  */
  45       (void) pthread_cond_init (newcond, NULL);
  46 #endif
  47
  48       if (atomic_compare_and_exchange_bool_acq (&cond->cond, newcond, NULL))
  49         /* Somebody else just initialized the condvar.  */
  50         free (newcond);
  51     }
  52
  53   return __pthread_cond_signal (cond->cond);
  54 }
  55 compat_symbol (libpthread, __pthread_cond_signal_2_0, pthread_cond_signal,
  56                GLIBC_2_0);
  57 #endif