Home | History | Annotate | Download | only in wtf
      1 /*
      2  * Copyright (C) 2007, 2008, 2010 Apple Inc. All rights reserved.
      3  * Copyright (C) 2007 Justin Haygood (jhaygood (at) 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
    118