1 files changed, 79 insertions, 0 deletions
diff --git a/webrtc/rtc_base/atomic_ops.h b/webrtc/rtc_base/atomic_ops.h
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+++ b/webrtc/rtc_base/atomic_ops.h
@@ -0,0 +1,79 @@
+/*
+ *  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 RTC_BASE_ATOMIC_OPS_H_
+#define RTC_BASE_ATOMIC_OPS_H_
+
+#if defined(WEBRTC_WIN)
+// clang-format off
+// clang formating would change include order.
+
+// Include winsock2.h before including <windows.h> to maintain consistency with
+// win32.h. To include win32.h directly, it must be broken out into its own
+// build target.
+#include <winsock2.h>
+#include <windows.h>
+// clang-format on
+#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
+};
+
+}  // namespace rtc
+
+#endif  // RTC_BASE_ATOMIC_OPS_H_