uclibc-ng/libc/sysdeps/linux/common/bits/atomicity.h

/* Low-level functions for atomic operations.  Stub version.
   Copyright (C) 1997,2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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.  */

#ifndef _ATOMICITY_H
#define _ATOMICITY_H	1

#include <inttypes.h>

#warning stub atomicity functions are not really atomic

static inline int
__attribute_used__
exchange_and_add (volatile uint32_t *mem, int val)
{
  int result = *mem;
  *mem += val;
  return result;
}

static inline void
__attribute_used__
atomic_add (volatile uint32_t *mem, int val)
{
  *mem += val;
}

static inline int
__attribute_used__
compare_and_swap (volatile long int *p, long int oldval, long int newval)
{
  if (*p != oldval)
    return 0;

  *p = newval;
  return 1;
}

#endif /* atomicity.h */