glibc/sysdeps/generic/atomicity.h
Roland McGrath 24cf21d780 2001-03-11 Roland McGrath <roland@frob.com>
* sysdeps/generic/atomicity.h (exchange_and_add, atomic_add,
	compare_and_swap): Add volatile qualifier to first arg, to bring
	these prototypes in line with all the other implementations.
	Add a #warning to remind the builder that these are not atomic.
2001-04-01 05:02:48 +00:00

55 lines
1.5 KiB
C

/* 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. 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 atomic
static inline int
__attribute__ ((unused))
exchange_and_add (volatile uint32_t *mem, int val)
{
int result = *mem;
*mem += val;
return result;
}
static inline void
__attribute__ ((unused))
atomic_add (volatile uint32_t *mem, int val)
{
*mem += val;
}
static inline int
__attribute__ ((unused))
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 */