Added dynamic annotation files into base/...,...

base/atomic_ref_count.h

 // Copyright (c) 2006-2008 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 is a low level implementation of atomic semantics for reference
 // counting.  Please use base/ref_counted.h directly instead.
+//
+// The implementation includes annotations to avoid some false positives
+// when using data race detection tools.
 
 #ifndef BASE_ATOMIC_REF_COUNT_H_
 #define BASE_ATOMIC_REF_COUNT_H_
 
 #include "base/atomicops.h"
+#include "base/dynamic_annotations.h"
 
 namespace base {
 
 typedef subtle::Atomic32 AtomicRefCount;
 
 // Increment a reference count by "increment", which must exceed 0.
 inline void AtomicRefCountIncN(volatile AtomicRefCount *ptr,
                                AtomicRefCount increment) {
   subtle::NoBarrier_AtomicIncrement(ptr, increment);
 }
 
 // Decrement a reference count by "decrement", which must exceed 0,
 // and return whether the result is non-zero.
 // Insert barriers to ensure that state written before the reference count
 // became zero will be visible to a thread that has just made the count zero.
 inline bool AtomicRefCountDecN(volatile AtomicRefCount *ptr,
                                AtomicRefCount decrement) {
-  return subtle::Barrier_AtomicIncrement(ptr, -decrement) != 0;
+  ANNOTATE_HAPPENS_BEFORE(ptr);
+  bool res = (subtle::Barrier_AtomicIncrement(ptr, -decrement) != 0);
+  if (!res) {
+    ANNOTATE_HAPPENS_AFTER(ptr);
+  }
+  return res;
 }
 
 // Increment a reference count by 1.
 inline void AtomicRefCountInc(volatile AtomicRefCount *ptr) {
   base::AtomicRefCountIncN(ptr, 1);
 }
 
 // Decrement a reference count by 1 and return whether the result is non-zero.
 // Insert barriers to ensure that state written before the reference count
 // became zero will be visible to a thread that has just made the count zero.
 inline bool AtomicRefCountDec(volatile AtomicRefCount *ptr) {
   return base::AtomicRefCountDecN(ptr, 1);
 }
 
 // Return whether the reference count is one.  If the reference count is used
 // in the conventional way, a refrerence count of 1 implies that the current
 // thread owns the reference and no other thread shares it.  This call performs
 // the test for a reference count of one, and performs the memory barrier
 // needed for the owning thread to act on the object, knowing that it has
 // exclusive access to the object.
 inline bool AtomicRefCountIsOne(volatile AtomicRefCount *ptr) {
-  return subtle::Acquire_Load(ptr) == 1;
+  bool res = (subtle::Acquire_Load(ptr) == 1);
+  if (res) {
+    ANNOTATE_HAPPENS_AFTER(ptr);
+  }
+  return res;
 }
 
 // Return whether the reference count is zero.  With conventional object
 // referencing counting, the object will be destroyed, so the reference count
 // should never be zero.  Hence this is generally used for a debug check.
 inline bool AtomicRefCountIsZero(volatile AtomicRefCount *ptr) {
-  return subtle::Acquire_Load(ptr) == 0;
+  bool res = (subtle::Acquire_Load(ptr) == 0);
+  if (res) {
+    ANNOTATE_HAPPENS_AFTER(ptr);
+  }
+  return res;
 }
 
 }  // namespace base
 
 #endif  // BASE_ATOMIC_REF_COUNT_H_