atomicops_internals_portable.h revision b8cf94937c52feb53b55c39e3f82094d27de464c
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 37b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratnamespace base { 38b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratnamespace subtle { 39b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 40b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// This implementation is transitional and maintains the original API for 41b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// atomicops.h. This requires casting memory locations to the atomic types, and 42b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// assumes that the API and the C++11 implementation are layout-compatible, 43b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// which isn't true for all implementations or hardware platforms. The static 44b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// assertion should detect this issue, were it to fire then this header 45b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// shouldn't be used. 46b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// 47b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// TODO(jfb) If this header manages to stay committed then the API should be 48b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat// modified, and all call sites updated. 49b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erattypedef volatile std::atomic<Atomic32>* AtomicLocation32; 50b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratstatic_assert(sizeof(*(AtomicLocation32) nullptr) == sizeof(Atomic32), 51b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat "incompatible 32-bit atomic layout"); 52b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 53b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void MemoryBarrier() { 54b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#if defined(__GLIBCXX__) 55b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // Work around libstdc++ bug 51038 where atomic_thread_fence was declared but 56b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat // not defined, leading to the linker complaining about undefined references. 57b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat __atomic_thread_fence(std::memory_order_seq_cst); 58b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#else 59b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::atomic_thread_fence(std::memory_order_seq_cst); 60b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#endif 61b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 62b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 63b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr, 64b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 old_value, 65b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 66b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 67b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 68b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 69b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed, 70b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 71b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 72b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 73b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 74b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr, 75b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 76b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr) 77b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->exchange(new_value, std::memory_order_relaxed); 78b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 79b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 80b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr, 81b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 increment) { 82b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + 83b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 84b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->fetch_add(increment, std::memory_order_relaxed); 85b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 86b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 87b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr, 88b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 increment) { 89b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + ((AtomicLocation32)ptr)->fetch_add(increment); 90b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 91b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 92b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr, 93b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 old_value, 94b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 95b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 96b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 97b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 98b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire, 99b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire); 100b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 101b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 102b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 103b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr, 104b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 old_value, 105b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic32 new_value) { 106b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr) 107b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 108b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 109b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_release, 110b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 111b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 112b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 113b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 114b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) { 115b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr)->store(value, std::memory_order_relaxed); 116b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 117b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 118b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) { 119b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr)->store(value, std::memory_order_relaxed); 120b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 121b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 122b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 123b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Release_Store(volatile Atomic32* ptr, Atomic32 value) { 124b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation32)ptr)->store(value, std::memory_order_release); 125b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 126b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 127b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) { 128b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr)->load(std::memory_order_relaxed); 129b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 130b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 131b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Acquire_Load(volatile const Atomic32* ptr) { 132b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr)->load(std::memory_order_acquire); 133b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 134b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 135b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic32 Release_Load(volatile const Atomic32* ptr) { 136b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 137b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation32)ptr)->load(std::memory_order_relaxed); 138b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 139b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 140b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#if defined(ARCH_CPU_64_BITS) 141b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 142b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erattypedef volatile std::atomic<Atomic64>* AtomicLocation64; 143b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratstatic_assert(sizeof(*(AtomicLocation64) nullptr) == sizeof(Atomic64), 144b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat "incompatible 64-bit atomic layout"); 145b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 146b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr, 147b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 old_value, 148b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 149b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 150b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 151b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 152b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed, 153b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 154b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 155b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 156b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 157b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr, 158b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 159b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr) 160b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->exchange(new_value, std::memory_order_relaxed); 161b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 162b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 163b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr, 164b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 increment) { 165b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + 166b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 167b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->fetch_add(increment, std::memory_order_relaxed); 168b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 169b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 170b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr, 171b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 increment) { 172b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return increment + ((AtomicLocation64)ptr)->fetch_add(increment); 173b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 174b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 175b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr, 176b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 old_value, 177b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 178b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 179b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 180b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 181b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire, 182b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_acquire); 183b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 184b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 185b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 186b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr, 187b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 old_value, 188b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat Atomic64 new_value) { 189b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr) 190b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ->compare_exchange_strong(old_value, 191b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat new_value, 192b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_release, 193b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat std::memory_order_relaxed); 194b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return old_value; 195b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 196b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 197b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) { 198b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr)->store(value, std::memory_order_relaxed); 199b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 200b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 201b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) { 202b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr)->store(value, std::memory_order_relaxed); 203b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 204b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 205b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 206b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline void Release_Store(volatile Atomic64* ptr, Atomic64 value) { 207b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat ((AtomicLocation64)ptr)->store(value, std::memory_order_release); 208b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 209b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 210b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) { 211b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr)->load(std::memory_order_relaxed); 212b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 213b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 214b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Acquire_Load(volatile const Atomic64* ptr) { 215b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr)->load(std::memory_order_acquire); 216b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 217b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 218b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Eratinline Atomic64 Release_Load(volatile const Atomic64* ptr) { 219b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat MemoryBarrier(); 220b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat return ((AtomicLocation64)ptr)->load(std::memory_order_relaxed); 221b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} 222b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 223b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#endif // defined(ARCH_CPU_64_BITS) 224b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} // namespace subtle 225b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat} // namespace base 226b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat 227b8cf94937c52feb53b55c39e3f82094d27de464cDaniel Erat#endif // BASE_ATOMICOPS_INTERNALS_PORTABLE_H_ 228