rsyslog/runtime/atomic.h
Rainer Gerhards 8f8f65abb6 moved files to the runtime
there are still some files left which could go into the
runtime, but I think we will delete most of them once we
are done with the full modularization.
2008-04-16 10:26:54 +02:00

52 lines
2.3 KiB
C

/* This header supplies atomic operations. So far, we rely on GCC's
* atomic builtins. I have no idea if we can check them via autotools,
* but I am making the necessary provisioning to live without them if
* they are not available. Please note that you should only use the macros
* here if you think you can actually live WITHOUT an explicit atomic operation,
* because in the non-presence of them, we simply do it without atomicitiy.
* Which, for word-aligned data types, usually (but only usually!) should work.
*
* We are using the functions described in
* http:/gcc.gnu.org/onlinedocs/gcc/Atomic-Builtins.html
*
* THESE MACROS MUST ONLY BE USED WITH WORD-SIZED DATA TYPES!
*
* Copyright 2008 Rainer Gerhards and Adiscon GmbH.
*
* This file is part of the rsyslog runtime library.
*
* The rsyslog runtime 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 3 of the License, or
* (at your option) any later version.
*
* The rsyslog runtime 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 rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>.
*
* A copy of the GPL can be found in the file "COPYING" in this distribution.
* A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution.
*/
#include "config.h" /* autotools! */
#ifndef INCLUDED_ATOMIC_H
#define INCLUDED_ATOMIC_H
/* set the following to 1 if we have atomic operations (and #undef it otherwise) */
/* #define DO_HAVE_ATOMICS 1 */
/* for this release, we disable atomic calls because there seem to be some
* portability problems and we can not fix that without destabilizing the build.
* They simply came in too late. -- rgerhards, 2008-04-02
*/
/* make sure they are not used!
#define ATOMIC_INC(data) ((void) __sync_fetch_and_add(&data, 1))
#define ATOMIC_DEC_AND_FETCH(data) __sync_sub_and_fetch(&data, 1)
*/
#define ATOMIC_INC(data) (++(data))
#endif /* #ifndef INCLUDED_ATOMIC_H */