ee5ca78921
* src/valarray-inst.cc, include/ext/atomicity.h, include/ext/concurrence.h, include/bits/basic_string.h, include/bits/fstream.tcc, include/ext/vstring.h: Fix comment typos. From-SVN: r128915
119 lines
3.7 KiB
C++
119 lines
3.7 KiB
C++
// Support for atomic operations -*- C++ -*-
|
|
|
|
// Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
|
|
//
|
|
// This file is part of the GNU ISO C++ Library. This library 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; either version 2, or (at your option)
|
|
// any later version.
|
|
|
|
// This 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 General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License along
|
|
// with this library; see the file COPYING. If not, write to the Free
|
|
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
|
|
// USA.
|
|
|
|
// As a special exception, you may use this file as part of a free software
|
|
// library without restriction. Specifically, if other files instantiate
|
|
// templates or use macros or inline functions from this file, or you compile
|
|
// this file and link it with other files to produce an executable, this
|
|
// file does not by itself cause the resulting executable to be covered by
|
|
// the GNU General Public License. This exception does not however
|
|
// invalidate any other reasons why the executable file might be covered by
|
|
// the GNU General Public License.
|
|
|
|
/** @file atomicity.h
|
|
* This is an internal header file, included by other library headers.
|
|
* You should not attempt to use it directly.
|
|
*/
|
|
|
|
#ifndef _GLIBCXX_ATOMICITY_H
|
|
#define _GLIBCXX_ATOMICITY_H 1
|
|
|
|
#include <bits/c++config.h>
|
|
#include <bits/gthr.h>
|
|
#include <bits/atomic_word.h>
|
|
|
|
_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
|
|
|
|
// Functions for portable atomic access.
|
|
// To abstract locking primitives across all thread policies, use:
|
|
// __exchange_and_add_dispatch
|
|
// __atomic_add_dispatch
|
|
#ifdef _GLIBCXX_ATOMIC_BUILTINS
|
|
static inline _Atomic_word
|
|
__exchange_and_add(volatile _Atomic_word* __mem, int __val)
|
|
{ return __sync_fetch_and_add(__mem, __val); }
|
|
|
|
static inline void
|
|
__atomic_add(volatile _Atomic_word* __mem, int __val)
|
|
{ __sync_fetch_and_add(__mem, __val); }
|
|
#else
|
|
_Atomic_word
|
|
__attribute__ ((__unused__))
|
|
__exchange_and_add(volatile _Atomic_word*, int);
|
|
|
|
void
|
|
__attribute__ ((__unused__))
|
|
__atomic_add(volatile _Atomic_word*, int);
|
|
#endif
|
|
|
|
static inline _Atomic_word
|
|
__exchange_and_add_single(_Atomic_word* __mem, int __val)
|
|
{
|
|
_Atomic_word __result = *__mem;
|
|
*__mem += __val;
|
|
return __result;
|
|
}
|
|
|
|
static inline void
|
|
__atomic_add_single(_Atomic_word* __mem, int __val)
|
|
{ *__mem += __val; }
|
|
|
|
static inline _Atomic_word
|
|
__attribute__ ((__unused__))
|
|
__exchange_and_add_dispatch(_Atomic_word* __mem, int __val)
|
|
{
|
|
#ifdef __GTHREADS
|
|
if (__gthread_active_p())
|
|
return __exchange_and_add(__mem, __val);
|
|
else
|
|
return __exchange_and_add_single(__mem, __val);
|
|
#else
|
|
return __exchange_and_add_single(__mem, __val);
|
|
#endif
|
|
}
|
|
|
|
static inline void
|
|
__attribute__ ((__unused__))
|
|
__atomic_add_dispatch(_Atomic_word* __mem, int __val)
|
|
{
|
|
#ifdef __GTHREADS
|
|
if (__gthread_active_p())
|
|
__atomic_add(__mem, __val);
|
|
else
|
|
__atomic_add_single(__mem, __val);
|
|
#else
|
|
__atomic_add_single(__mem, __val);
|
|
#endif
|
|
}
|
|
|
|
_GLIBCXX_END_NAMESPACE
|
|
|
|
// Even if the CPU doesn't need a memory barrier, we need to ensure
|
|
// that the compiler doesn't reorder memory accesses across the
|
|
// barriers.
|
|
#ifndef _GLIBCXX_READ_MEM_BARRIER
|
|
#define _GLIBCXX_READ_MEM_BARRIER __asm __volatile ("":::"memory")
|
|
#endif
|
|
#ifndef _GLIBCXX_WRITE_MEM_BARRIER
|
|
#define _GLIBCXX_WRITE_MEM_BARRIER __asm __volatile ("":::"memory")
|
|
#endif
|
|
|
|
#endif
|