1b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Copyright (c) 2014 The Chromium Authors. All rights reserved. 2b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Use of this source code is governed by a BSD-style license that can be 3b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// found in the LICENSE file. 4b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 5b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// This file is an internal atomic implementation, use atomicops.h instead. 6b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// 7b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// This implementation uses C++11 atomics' member functions. The code base is 8b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// currently written assuming atomicity revolves around accesses instead of 9b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// C++11's memory locations. The burden is on the programmer to ensure that all 10b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// memory locations accessed atomically are never accessed non-atomically (tsan 11b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// should help with this). 12b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// 13b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// TODO(jfb) Modify the atomicops.h API and user code to declare atomic 14b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// locations as truly atomic. See the static_assert below. 15b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// 16b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// Of note in this implementation: 17b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// * All NoBarrier variants are implemented as relaxed. 18b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// * All Barrier variants are implemented as sequentially-consistent. 19b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// * Compare exchange's failure ordering is always the same as the success one 20b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// (except for release, which fails as relaxed): using a weaker ordering is 21b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// only valid under certain uses of compare exchange. 22b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// * Acquire store doesn't exist in the C11 memory model, it is instead 23b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// implemented as a relaxed store followed by a sequentially consistent 24b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// fence. 25b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// * Release load doesn't exist in the C11 memory model, it is instead 26b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// implemented as sequentially consistent fence followed by a relaxed load. 27b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// * Atomic increment is expected to return the post-incremented value, whereas 28b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// C11 fetch add returns the previous value. The implementation therefore 29b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// needs to increment twice (which the compiler should be able to detect and 30b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// optimize). 31b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 32b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#ifndef BASE_ATOMICOPS_INTERNALS_PORTABLE_H_ 33b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#define BASE_ATOMICOPS_INTERNALS_PORTABLE_H_ 34b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 35b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#include <atomic> 36b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 37cce46a0c214b37e8da48c522c83037e8ffa4f9fdAlex Vakulenko#include "build/build_config.h" 38cce46a0c214b37e8da48c522c83037e8ffa4f9fdAlex Vakulenko 39b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratnamespace base { 40b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratnamespace subtle { 41b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 42b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// This implementation is transitional and maintains the original API for 43b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// atomicops.h. This requires casting memory locations to the atomic types, and 44b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// assumes that the API and the C++11 implementation are layout-compatible, 45b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// which isn't true for all implementations or hardware platforms. The static 46b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// assertion should detect this issue, were it to fire then this header 47b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// shouldn't be used. 48b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// 49b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// TODO(jfb) If this header manages to stay committed then the API should be 50b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// modified, and all call sites updated. 51b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erattypedef volatile std::atomic<Atomic32>* AtomicLocation32; 52b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratstatic_assert(sizeof(*(AtomicLocation32) nullptr) == sizeof(Atomic32), 53b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat "incompatible 32-bit atomic layout"); 54b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 55b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void MemoryBarrier() { 56b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#if defined(__GLIBCXX__) 57b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Work around libstdc++ bug 51038 where atomic_thread_fence was declared but 58b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // not defined, leading to the linker complaining about undefined references. 59b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat __atomic_thread_fence(std::memory_order_seq_cst); 60b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#else 61b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::atomic_thread_fence(std::memory_order_seq_cst); 62b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#endif 63b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 64b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 65b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr, 66b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 old_value, 67b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 68b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 69b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 70b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 71b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed, 72b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 73b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 74b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 75b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 76b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr, 77b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 78b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr) 79b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->exchange(new_value, std::memory_order_relaxed); 80b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 81b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 82b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr, 83b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 increment) { 84b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + 85b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 86b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->fetch_add(increment, std::memory_order_relaxed); 87b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 88b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 89b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr, 90b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 increment) { 91b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + ((AtomicLocation32)ptr)->fetch_add(increment); 92b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 93b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 94b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr, 95b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 old_value, 96b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 97b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 98b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 99b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 100b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire, 101b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire); 102b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 103b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 104b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 105b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr, 106b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 old_value, 107b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 108b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 109b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 110b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 111b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_release, 112b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 113b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 114b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 115b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 116b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) { 117b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr)->store(value, std::memory_order_relaxed); 118b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 119b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 120b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) { 121b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr)->store(value, std::memory_order_relaxed); 122b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 123b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 124b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 125b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Release_Store(volatile Atomic32* ptr, Atomic32 value) { 126b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr)->store(value, std::memory_order_release); 127b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 128b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 129b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) { 130b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr)->load(std::memory_order_relaxed); 131b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 132b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 133b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Acquire_Load(volatile const Atomic32* ptr) { 134b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr)->load(std::memory_order_acquire); 135b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 136b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 137b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Release_Load(volatile const Atomic32* ptr) { 138b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 139b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr)->load(std::memory_order_relaxed); 140b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 141b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 142b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#if defined(ARCH_CPU_64_BITS) 143b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 144b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erattypedef volatile std::atomic<Atomic64>* AtomicLocation64; 145b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratstatic_assert(sizeof(*(AtomicLocation64) nullptr) == sizeof(Atomic64), 146b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat "incompatible 64-bit atomic layout"); 147b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 148b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr, 149b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 old_value, 150b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 151b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 152b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 153b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 154b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed, 155b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 156b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 157b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 158b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 159b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr, 160b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 161b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr) 162b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->exchange(new_value, std::memory_order_relaxed); 163b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 164b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 165b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr, 166b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 increment) { 167b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + 168b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 169b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->fetch_add(increment, std::memory_order_relaxed); 170b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 171b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 172b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr, 173b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 increment) { 174b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + ((AtomicLocation64)ptr)->fetch_add(increment); 175b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 176b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 177b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr, 178b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 old_value, 179b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 180b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 181b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 182b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 183b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire, 184b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire); 185b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 186b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 187b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 188b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr, 189b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 old_value, 190b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 191b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 192b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 193b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 194b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_release, 195b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 196b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 197b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 198b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 199b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) { 200b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr)->store(value, std::memory_order_relaxed); 201b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 202b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 203b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) { 204b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr)->store(value, std::memory_order_relaxed); 205b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 206b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 207b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 208b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Release_Store(volatile Atomic64* ptr, Atomic64 value) { 209b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr)->store(value, std::memory_order_release); 210b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 211b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 212b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) { 213b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr)->load(std::memory_order_relaxed); 214b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 215b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 216b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Acquire_Load(volatile const Atomic64* ptr) { 217b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr)->load(std::memory_order_acquire); 218b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 219b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 220b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Release_Load(volatile const Atomic64* ptr) { 221b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 222b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr)->load(std::memory_order_relaxed); 223b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 224b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 225b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#endif // defined(ARCH_CPU_64_BITS) 226b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} // namespace subtle 227b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} // namespace base 228b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 229b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#endif // BASE_ATOMICOPS_INTERNALS_PORTABLE_H_ 230