wtf/Atomics.h

   1 /*
   2  * Copyright (C) 2007, 2008, 2010 Apple Inc. All rights reserved.
   3  * Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com)
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1.  Redistributions of source code must retain the above copyright
  10  *     notice, this list of conditions and the following disclaimer.
  11  * 2.  Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  15  *     its contributors may be used to endorse or promote products derived
  16  *     from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *
  29  *
  30  * Note: The implementations of InterlockedIncrement and InterlockedDecrement are based
  31  * on atomic_increment and atomic_exchange_and_add from the Boost C++ Library. The license
  32  * is virtually identical to the Apple license above but is included here for completeness.
  33  *
  34  * Boost Software License - Version 1.0 - August 17th, 2003
  35  *
  36  * Permission is hereby granted, free of charge, to any person or organization
  37  * obtaining a copy of the software and accompanying documentation covered by
  38  * this license (the "Software") to use, reproduce, display, distribute,
  39  * execute, and transmit the Software, and to prepare derivative works of the
  40  * Software, and to permit third-parties to whom the Software is furnished to
  41  * do so, all subject to the following:
  42  *
  43  * The copyright notices in the Software and this entire statement, including
  44  * the above license grant, this restriction and the following disclaimer,
  45  * must be included in all copies of the Software, in whole or in part, and
  46  * all derivative works of the Software, unless such copies or derivative
  47  * works are solely in the form of machine-executable object code generated by
  48  * a source language processor.
  49  *
  50  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  51  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  52  * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  53  * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  54  * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  55  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  56  * DEALINGS IN THE SOFTWARE.
  57  */
  58
  59 #ifndef Atomics_h
  60 #define Atomics_h
  61
  62 #include "Platform.h"
  63
  64 #if OS(WINDOWS)
  65 #include <windows.h>
  66 #elif OS(DARWIN)
  67 #include <libkern/OSAtomic.h>
  68 #elif OS(ANDROID)
  69 #include <cutils/atomic.h>
  70 #elif COMPILER(GCC) && !OS(SYMBIAN)
  71 #if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 2))
  72 #include <ext/atomicity.h>
  73 #else
  74 #include <bits/atomicity.h>
  75 #endif
  76 #endif
  77
  78 namespace WTF {
  79
  80 #if OS(WINDOWS)
  81 #define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1
  82
  83 #if COMPILER(MINGW) || COMPILER(MSVC7_OR_LOWER) || OS(WINCE)
  84 inline int atomicIncrement(int* addend) { return InterlockedIncrement(reinterpret_cast<long*>(addend)); }
  85 inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); }
  86 #else
  87 inline int atomicIncrement(int volatile* addend) { return InterlockedIncrement(reinterpret_cast<long volatile*>(addend)); }
  88 inline int atomicDecrement(int volatile* addend) { return InterlockedDecrement(reinterpret_cast<long volatile*>(addend)); }
  89 #endif
  90
  91 #elif OS(DARWIN)
  92 #define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1
  93
  94 inline int atomicIncrement(int volatile* addend) { return OSAtomicIncrement32Barrier(const_cast<int*>(addend)); }
  95 inline int atomicDecrement(int volatile* addend) { return OSAtomicDecrement32Barrier(const_cast<int*>(addend)); }
  96
  97 #elif OS(ANDROID)
  98
  99 inline int atomicIncrement(int volatile* addend) { return android_atomic_inc(addend); }
 100 inline int atomicDecrement(int volatile* addend) { return android_atomic_dec(addend); }
 101
 102 #elif COMPILER(GCC) && !CPU(SPARC64) && !OS(SYMBIAN) // sizeof(_Atomic_word) != sizeof(int) on sparc64 gcc
 103 #define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1
 104
 105 inline int atomicIncrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, 1) + 1; }
 106 inline int atomicDecrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, -1) - 1; }
 107
 108 #endif
 109
 110 } // namespace WTF
 111
 112 #if USE(LOCKFREE_THREADSAFEREFCOUNTED)
 113 using WTF::atomicDecrement;
 114 using WTF::atomicIncrement;
 115 #endif
 116
 117 #endif // Atomics_h