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#ifndef MY_ATOMIC_INCLUDED
#define MY_ATOMIC_INCLUDED
/* Copyright (c) 2006, 2016, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/*
This header defines five atomic operations:
my_atomic_add#(&var, what)
'Fetch and Add'
add 'what' to *var, and return the old value of *var
my_atomic_fas#(&var, what)
'Fetch And Store'
store 'what' in *var, and return the old value of *var
my_atomic_cas#(&var, &old, new)
An odd variation of 'Compare And Set/Swap'
if *var is equal to *old, then store 'new' in *var, and return TRUE
otherwise store *var in *old, and return FALSE
Usually, &old should not be accessed if the operation is successful.
my_atomic_load#(&var)
return *var
my_atomic_store#(&var, what)
store 'what' in *var
'#' is substituted by a size suffix - 32, 64, or ptr
(e.g. my_atomic_add64, my_atomic_fas32, my_atomic_casptr).
*/
/*
We choose implementation as follows:
------------------------------------
On Windows using Visual C++ the native implementation should be
preferrable. When using gcc we prefer the Solaris implementation
before the gcc because of stability preference, we choose gcc
builtins if available. If neither Visual C++ or gcc we still choose
the Solaris implementation on Solaris (mainly for SunStudio compilers).
*/
#if defined(_MSC_VER)
# include "atomic/generic-msvc.h"
#elif defined(HAVE_SOLARIS_ATOMIC)
# include "atomic/solaris.h"
#elif defined(HAVE_GCC_SYNC_BUILTINS) /* Use old __sync by default */
# include "atomic/gcc_sync.h"
#elif defined(HAVE_GCC_ATOMIC_BUILTINS) /* Use __atomic on e.g. powerpc */
# include "atomic/gcc_atomic.h"
#else
# error Native atomics support not found!
#endif
/*
the macro below defines (as an expression) the code that
will be run in spin-loops. Intel manuals recummend to have PAUSE there.
It is expected to be defined in include/atomic/ *.h files
*/
#ifndef LF_BACKOFF
#define LF_BACKOFF (1)
#endif
#endif /* MY_ATOMIC_INCLUDED */
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