Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/Atomics.h

-/*
- * Copyright (C) 2007, 2008, 2010, 2012 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 <wtf/Platform.h>
-#include <wtf/StdLibExtras.h>
-#include <wtf/UnusedParam.h>
-
-#if OS(WINDOWS)
-#include <windows.h>
-#elif OS(QNX)
-#include <atomic.h>
-#elif OS(ANDROID)
-#include <sys/atomics.h>
-#endif
-
-namespace WTF {
-
-#if OS(WINDOWS)
-#define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1
-
-#if OS(WINCE)
-inline int atomicIncrement(int* addend) { return InterlockedIncrement(reinterpret_cast<long*>(addend)); }
-inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); }
-#elif COMPILER(MINGW) || COMPILER(MSVC7_OR_LOWER)
-inline int atomicIncrement(int* addend) { return InterlockedIncrement(reinterpret_cast<long*>(addend)); }
-inline int atomicDecrement(int* addend) { return InterlockedDecrement(reinterpret_cast<long*>(addend)); }
-
-inline int64_t atomicIncrement(int64_t* addend) { return InterlockedIncrement64(reinterpret_cast<long long*>(addend)); }
-inline int64_t atomicDecrement(int64_t* addend) { return InterlockedDecrement64(reinterpret_cast<long 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)); }
-
-inline int64_t atomicIncrement(int64_t volatile* addend) { return InterlockedIncrement64(reinterpret_cast<long long volatile*>(addend)); }
-inline int64_t atomicDecrement(int64_t volatile* addend) { return InterlockedDecrement64(reinterpret_cast<long long volatile*>(addend)); }
-#endif
-
-#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)
-#define WTF_USE_LOCKFREE_THREADSAFEREFCOUNTED 1
-
-// Note, __atomic_{inc, dec}() return the previous value of addend's content.
-inline int atomicIncrement(int volatile* addend) { return __atomic_inc(addend) + 1; }
-inline int atomicDecrement(int volatile* addend) { return __atomic_dec(addend) - 1; }
-
-#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 __sync_add_and_fetch(addend, 1); }
-inline int atomicDecrement(int volatile* addend) { return __sync_sub_and_fetch(addend, 1); }
-
-inline int64_t atomicIncrement(int64_t volatile* addend) { return __sync_add_and_fetch(addend, 1); }
-inline int64_t atomicDecrement(int64_t volatile* addend) { return __sync_sub_and_fetch(addend, 1); }
-
-#endif
-
-#if OS(WINDOWS)
-inline bool weakCompareAndSwap(volatile unsigned* location, unsigned expected, unsigned newValue)
-{
-#if OS(WINCE)
-    return InterlockedCompareExchange(reinterpret_cast<LONG*>(const_cast<unsigned*>(location)), static_cast<LONG>(newValue), static_cast<LONG>(expected)) == static_cast<LONG>(expected);
-#else
-    return InterlockedCompareExchange(reinterpret_cast<LONG volatile*>(location), static_cast<LONG>(newValue), static_cast<LONG>(expected)) == static_cast<LONG>(expected);
-#endif
-}
-
-inline bool weakCompareAndSwap(void*volatile* location, void* expected, void* newValue)
-{
-    return InterlockedCompareExchangePointer(location, newValue, expected) == expected;
-}
-#else // OS(WINDOWS) --> not windows
-#if COMPILER(GCC) && !COMPILER(CLANG) // Work around a gcc bug 
-inline bool weakCompareAndSwap(volatile unsigned* location, unsigned expected, unsigned newValue) 
-#else
-inline bool weakCompareAndSwap(unsigned* location, unsigned expected, unsigned newValue)
-#endif
-{
-#if ENABLE(COMPARE_AND_SWAP)
-#if CPU(X86) || CPU(X86_64)
-    unsigned char result;
-    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;
-    unsigned result;
-    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:"
-        : "+Q"(*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 false;
-#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)
-}
-#endif // OS(WINDOWS) (end of the not-windows case)
-
-inline bool weakCompareAndSwapUIntPtr(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));
-}
-
-#if CPU(ARM_THUMB2)
-
-inline void memoryBarrierAfterLock()
-{
-    asm volatile("dmb" ::: "memory");
-}
-
-inline void memoryBarrierBeforeUnlock()
-{
-    asm volatile("dmb" ::: "memory");
-}
-
-#else
-
-inline void memoryBarrierAfterLock() { }
-inline void memoryBarrierBeforeUnlock() { }
-
-#endif
-
-} // namespace WTF
-
-#if USE(LOCKFREE_THREADSAFEREFCOUNTED)
-using WTF::atomicDecrement;
-using WTF::atomicIncrement;
-#endif
-
-#endif // Atomics_h