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Diffstat (limited to 'Source/JavaScriptCore/wtf/Atomics.h')
| -rw-r--r-- | Source/JavaScriptCore/wtf/Atomics.h | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/wtf/Atomics.h b/Source/JavaScriptCore/wtf/Atomics.h new file mode 100644 index 000000000..5e10460c6 --- /dev/null +++ b/Source/JavaScriptCore/wtf/Atomics.h @@ -0,0 +1,196 @@ +/* + * Copyright (C) 2007, 2008, 2010 Apple Inc. All rights reserved. + * Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com) + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of + * its contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * + * Note: The implementations of InterlockedIncrement and InterlockedDecrement are based + * on atomic_increment and atomic_exchange_and_add from the Boost C++ Library. The license + * is virtually identical to the Apple license above but is included here for completeness. + * + * Boost Software License - Version 1.0 - August 17th, 2003 + * + * Permission is hereby granted, free of charge, to any person or organization + * obtaining a copy of the software and accompanying documentation covered by + * this license (the "Software") to use, reproduce, display, distribute, + * execute, and transmit the Software, and to prepare derivative works of the + * Software, and to permit third-parties to whom the Software is furnished to + * do so, all subject to the following: + * + * The copyright notices in the Software and this entire statement, including + * the above license grant, this restriction and the following disclaimer, + * must be included in all copies of the Software, in whole or in part, and + * all derivative works of the Software, unless such copies or derivative + * works are solely in the form of machine-executable object code generated by + * a source language processor. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT + * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE + * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#ifndef Atomics_h +#define Atomics_h + +#include "Platform.h" +#include "StdLibExtras.h" +#include "UnusedParam.h" + +#if OS(WINDOWS) +#include <windows.h> +#elif OS(DARWIN) +#include <libkern/OSAtomic.h> +#elif OS(QNX) +#include <atomic.h> +#elif OS(ANDROID) +#include <sys/atomics.h> +#elif COMPILER(GCC) +#if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 2)) +#include <ext/atomicity.h> +#else +#include <bits/atomicity.h> +#endif +#endif + +namespace WTF { + +#if OS(WINDOWS) +#define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1 + +#if COMPILER(MINGW) || COMPILER(MSVC7_OR_LOWER) || OS(WINCE) +inline int atomicIncrement(int* addend) { return InterlockedIncrement(reinterpret_cast<long*>(addend)); } +inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); } +#else +inline int atomicIncrement(int volatile* addend) { return InterlockedIncrement(reinterpret_cast<long volatile*>(addend)); } +inline int atomicDecrement(int volatile* addend) { return InterlockedDecrement(reinterpret_cast<long volatile*>(addend)); } +#endif + +#elif OS(DARWIN) +#define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1 + +inline int atomicIncrement(int volatile* addend) { return OSAtomicIncrement32Barrier(const_cast<int*>(addend)); } +inline int atomicDecrement(int volatile* addend) { return OSAtomicDecrement32Barrier(const_cast<int*>(addend)); } + +#elif OS(QNX) +#define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1 + +// Note, atomic_{add, sub}_value() return the previous value of addend's content. +inline int atomicIncrement(int volatile* addend) { return static_cast<int>(atomic_add_value(reinterpret_cast<unsigned volatile*>(addend), 1)) + 1; } +inline int atomicDecrement(int volatile* addend) { return static_cast<int>(atomic_sub_value(reinterpret_cast<unsigned volatile*>(addend), 1)) - 1; } + +#elif OS(ANDROID) + +inline int atomicIncrement(int volatile* addend) { return __atomic_inc(addend); } +inline int atomicDecrement(int volatile* addend) { return __atomic_dec(addend); } + +#elif COMPILER(GCC) && !CPU(SPARC64) // sizeof(_Atomic_word) != sizeof(int) on sparc64 gcc +#define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1 + +inline int atomicIncrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, 1) + 1; } +inline int atomicDecrement(int volatile* addend) { return __gnu_cxx::__exchange_and_add(addend, -1) - 1; } + +#endif + +inline bool weakCompareAndSwap(unsigned* location, unsigned expected, unsigned newValue) +{ +#if ENABLE(COMPARE_AND_SWAP) + bool result; +#if CPU(X86) || CPU(X86_64) + asm volatile( + "lock; cmpxchgl %3, %2\n\t" + "sete %1" + : "+a"(expected), "=q"(result), "+m"(*location) + : "r"(newValue) + : "memory" + ); +#elif CPU(ARM_THUMB2) + unsigned tmp; + asm volatile( + "movw %1, #1\n\t" + "ldrex %2, %0\n\t" + "cmp %3, %2\n\t" + "bne.n 0f\n\t" + "strex %1, %4, %0\n\t" + "0:" + : "+m"(*location), "=&r"(result), "=&r"(tmp) + : "r"(expected), "r"(newValue) + : "memory"); + result = !result; +#else +#error "Bad architecture for compare and swap." +#endif + return result; +#else + UNUSED_PARAM(location); + UNUSED_PARAM(expected); + UNUSED_PARAM(newValue); + CRASH(); + return 0; +#endif +} + +inline bool weakCompareAndSwap(void*volatile* location, void* expected, void* newValue) +{ +#if ENABLE(COMPARE_AND_SWAP) +#if CPU(X86_64) + bool result; + asm volatile( + "lock; cmpxchgq %3, %2\n\t" + "sete %1" + : "+a"(expected), "=q"(result), "+m"(*location) + : "r"(newValue) + : "memory" + ); + return result; +#else + return weakCompareAndSwap(bitwise_cast<unsigned*>(location), bitwise_cast<unsigned>(expected), bitwise_cast<unsigned>(newValue)); +#endif +#else // ENABLE(COMPARE_AND_SWAP) + UNUSED_PARAM(location); + UNUSED_PARAM(expected); + UNUSED_PARAM(newValue); + CRASH(); + return 0; +#endif // ENABLE(COMPARE_AND_SWAP) +} + +inline bool weakCompareAndSwap(volatile uintptr_t* location, uintptr_t expected, uintptr_t newValue) +{ + return weakCompareAndSwap(reinterpret_cast<void*volatile*>(location), reinterpret_cast<void*>(expected), reinterpret_cast<void*>(newValue)); +} + +} // namespace WTF + +#if USE(LOCKFREE_THREADSAFEREFCOUNTED) +using WTF::atomicDecrement; +using WTF::atomicIncrement; +#endif + +#endif // Atomics_h |