/* sem_trywait -- wait on a semaphore.  Generic futex-using version.   Copyright (C) 2003 Free Software Foundation, Inc.   This file is part of the GNU C Library.   Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.   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 <sysdep.h>#include <lowlevellock.h>#include <internaltypes.h>#include <semaphore.h>#include <shlib-compat.h>int__new_sem_trywait (sem_t *sem){  int *futex = (int *) sem;  int val;  if (*futex > 0)    {      val = atomic_decrement_if_positive (futex);      if (val > 0)	return 0;    }  __set_errno (EAGAIN);  return -1;}versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1);#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_1)strong_alias (__new_sem_trywait, __old_sem_trywait)compat_symbol (libpthread, __old_sem_trywait, sem_trywait, GLIBC_2_0);#endif