// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // This file is an internal atomic implementation, use base/atomicops.h instead. #ifndef BASE_ATOMICOPS_INTERNALS_MAC_H_ #define BASE_ATOMICOPS_INTERNALS_MAC_H_ #include <libkern/OSAtomic.h> namespace base { namespace subtle { inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr, Atomic32 old_value, Atomic32 new_value) { Atomic32 prev_value; do { if (OSAtomicCompareAndSwap32(old_value, new_value, const_cast<Atomic32*>(ptr))) { return old_value; } prev_value = *ptr; } while (prev_value == old_value); return prev_value; } inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr, Atomic32 new_value) { Atomic32 old_value; do { old_value = *ptr; } while (!OSAtomicCompareAndSwap32(old_value, new_value, const_cast<Atomic32*>(ptr))); return old_value; } inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32 *ptr, Atomic32 increment) { return OSAtomicAdd32(increment, const_cast<Atomic32*>(ptr)); } inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32 *ptr, Atomic32 increment) { return OSAtomicAdd32Barrier(increment, const_cast<Atomic32*>(ptr)); } inline void MemoryBarrier() { OSMemoryBarrier(); } inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32 *ptr, Atomic32 old_value, Atomic32 new_value) { Atomic32 prev_value; do { if (OSAtomicCompareAndSwap32Barrier(old_value, new_value, const_cast<Atomic32*>(ptr))) { return old_value; } prev_value = *ptr; } while (prev_value == old_value); return prev_value; } inline Atomic32 Release_CompareAndSwap(volatile Atomic32 *ptr, Atomic32 old_value, Atomic32 new_value) { return Acquire_CompareAndSwap(ptr, old_value, new_value); } inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) { *ptr = value; } inline void Acquire_Store(volatile Atomic32 *ptr, Atomic32 value) { *ptr = value; MemoryBarrier(); } inline void Release_Store(volatile Atomic32 *ptr, Atomic32 value) { MemoryBarrier(); *ptr = value; } inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) { return *ptr; } inline Atomic32 Acquire_Load(volatile const Atomic32 *ptr) { Atomic32 value = *ptr; MemoryBarrier(); return value; } inline Atomic32 Release_Load(volatile const Atomic32 *ptr) { MemoryBarrier(); return *ptr; } #ifdef __LP64__ // 64-bit implementation on 64-bit platform inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64 *ptr, Atomic64 old_value, Atomic64 new_value) { Atomic64 prev_value; do { if (OSAtomicCompareAndSwap64(old_value, new_value, reinterpret_cast<volatile int64_t*>(ptr))) { return old_value; } prev_value = *ptr; } while (prev_value == old_value); return prev_value; } inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64 *ptr, Atomic64 new_value) { Atomic64 old_value; do { old_value = *ptr; } while (!OSAtomicCompareAndSwap64(old_value, new_value, reinterpret_cast<volatile int64_t*>(ptr))); return old_value; } inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64 *ptr, Atomic64 increment) { return OSAtomicAdd64(increment, reinterpret_cast<volatile int64_t*>(ptr)); } inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64 *ptr, Atomic64 increment) { return OSAtomicAdd64Barrier(increment, reinterpret_cast<volatile int64_t*>(ptr)); } inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64 *ptr, Atomic64 old_value, Atomic64 new_value) { Atomic64 prev_value; do { if (OSAtomicCompareAndSwap64Barrier( old_value, new_value, reinterpret_cast<volatile int64_t*>(ptr))) { return old_value; } prev_value = *ptr; } while (prev_value == old_value); return prev_value; } inline Atomic64 Release_CompareAndSwap(volatile Atomic64 *ptr, Atomic64 old_value, Atomic64 new_value) { // The lib kern interface does not distinguish between // Acquire and Release memory barriers; they are equivalent. return Acquire_CompareAndSwap(ptr, old_value, new_value); } inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) { *ptr = value; } inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) { *ptr = value; MemoryBarrier(); } inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) { MemoryBarrier(); *ptr = value; } inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) { return *ptr; } inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) { Atomic64 value = *ptr; MemoryBarrier(); return value; } inline Atomic64 Release_Load(volatile const Atomic64 *ptr) { MemoryBarrier(); return *ptr; } #endif // defined(__LP64__) } // namespace base::subtle } // namespace base #endif // BASE_ATOMICOPS_INTERNALS_MAC_H_