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/*
* Copyright 2011 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_BASE_ATOMICOPS_H_
#define WEBRTC_BASE_ATOMICOPS_H_
#if defined(WEBRTC_WIN)
// Include winsock2.h before including <windows.h> to maintain consistency with
// win32.h. We can't include win32.h directly here since it pulls in
// headers such as basictypes.h which causes problems in Chromium where webrtc
// exists as two separate projects, webrtc and libjingle.
#include <winsock2.h>
#include <windows.h>
#endif // defined(WEBRTC_WIN)
namespace rtc {
class AtomicOps {
public:
#if defined(WEBRTC_WIN)
// Assumes sizeof(int) == sizeof(LONG), which it is on Win32 and Win64.
static int Increment(volatile int* i) {
return ::InterlockedIncrement(reinterpret_cast<volatile LONG*>(i));
}
static int Decrement(volatile int* i) {
return ::InterlockedDecrement(reinterpret_cast<volatile LONG*>(i));
}
static int AcquireLoad(volatile const int* i) {
return *i;
}
static void ReleaseStore(volatile int* i, int value) {
*i = value;
}
static int CompareAndSwap(volatile int* i, int old_value, int new_value) {
return ::InterlockedCompareExchange(reinterpret_cast<volatile LONG*>(i),
new_value,
old_value);
}
// Pointer variants.
template <typename T>
static T* AcquireLoadPtr(T* volatile* ptr) {
return *ptr;
}
template <typename T>
static T* CompareAndSwapPtr(T* volatile* ptr, T* old_value, T* new_value) {
return static_cast<T*>(::InterlockedCompareExchangePointer(
reinterpret_cast<PVOID volatile*>(ptr), new_value, old_value));
}
#else
static int Increment(volatile int* i) {
return __sync_add_and_fetch(i, 1);
}
static int Decrement(volatile int* i) {
return __sync_sub_and_fetch(i, 1);
}
static int AcquireLoad(volatile const int* i) {
return __atomic_load_n(i, __ATOMIC_ACQUIRE);
}
static void ReleaseStore(volatile int* i, int value) {
__atomic_store_n(i, value, __ATOMIC_RELEASE);
}
static int CompareAndSwap(volatile int* i, int old_value, int new_value) {
return __sync_val_compare_and_swap(i, old_value, new_value);
}
// Pointer variants.
template <typename T>
static T* AcquireLoadPtr(T* volatile* ptr) {
return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
}
template <typename T>
static T* CompareAndSwapPtr(T* volatile* ptr, T* old_value, T* new_value) {
return __sync_val_compare_and_swap(ptr, old_value, new_value);
}
#endif
};
}
#endif // WEBRTC_BASE_ATOMICOPS_H_
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