glibc/nptl/old_pthread_cond_signal.c

/* Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <errno.h>
#include <stdlib.h>
#include "pthreadP.h"
#include <atomic.h>
#include <shlib-compat.h>


#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
int
__pthread_cond_signal_2_0 (cond)
     pthread_cond_2_0_t *cond;
{
  if (cond->cond == NULL)
    {
      pthread_cond_t *newcond;

#if LLL_LOCK_INITIALIZER == 0
      newcond = (pthread_cond_t *) calloc (sizeof (pthread_cond_t), 1);
      if (newcond == NULL)
	return ENOMEM;
#else
      newcond = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
      if (newcond == NULL)
	return ENOMEM;

      /* Initialize the condvar.  */
      (void) pthread_cond_init (newcond, NULL);
#endif

      if (atomic_compare_and_exchange_bool_acq (&cond->cond, newcond, NULL))
	/* Somebody else just initialized the condvar.  */
	free (newcond);
    }

  return __pthread_cond_signal (cond->cond);
}
compat_symbol (libpthread, __pthread_cond_signal_2_0, pthread_cond_signal,
	       GLIBC_2_0);
#endif