Implement store as an explicit atomic operation.

webrtc/base/atomicops.h

 /*
  *  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.
  */
 
@@ skipping 13 matching lines @@
 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 Load(volatile const int* i) {
+  static int AcquireLoad(volatile const int* i) {
     return *i;
   }
-  static void Store(volatile int* i, int value) {
+  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);
   }
 #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 Load(volatile const int* i) {
-    // Adding 0 is a no-op, so const_cast is fine.
-    return __sync_add_and_fetch(const_cast<volatile int*>(i), 0);
+  static int AcquireLoad(volatile const int* i) {
+    return __atomic_load_n(i, __ATOMIC_ACQUIRE);
   }
-  static void Store(volatile int* i, int value) {
-    __sync_synchronize();
-    *i = value;
+  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);
   }
 #endif
 };
 
 
 
 }
 
 #endif  // WEBRTC_BASE_ATOMICOPS_H_