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

base/lazy_instance.h

 // Copyright (c) 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.
 
 // The LazyInstance<Type, Traits> class manages a single instance of Type,
 // which will be lazily created on the first time it's accessed.  This class is
 // useful for places you would normally use a function-level static, but you
 // need to have guaranteed thread-safety.  The Type constructor will only ever
 // be called once, even if two threads are racing to create the object.  Get()
 // and Pointer() will always return the same, completely initialized instance.
@@ skipping 19 matching lines @@
 //
 //     MyClass* ptr = my_instance.Pointer();
 //     ptr->DoDoDo();  // MyClass::DoDoDo
 //   }
 
 #ifndef BASE_LAZY_INSTANCE_H_
 #define BASE_LAZY_INSTANCE_H_
 
 #include "base/atomicops.h"
 #include "base/basictypes.h"
+#include "base/dynamic_annotations.h"
 
 namespace base {
 
 template <typename Type>
 struct DefaultLazyInstanceTraits {
   static void New(void* instance) {
     // Use placement new to initialize our instance in our preallocated space.
     // The parenthesis is very important here to force POD type initialization.
     new (instance) Type();
   }
@@ skipping 39 matching lines @@
     return *Pointer();
   }
 
   Type* Pointer() {
     Type* instance = reinterpret_cast<Type*>(&buf_);
 
     // We will hopefully have fast access when the instance is already created.
     if (base::subtle::NoBarrier_Load(&state_) != STATE_CREATED)
       EnsureInstance(instance, Traits::New, Traits::Delete);
 
+    // This annotation helps race detectors recognize correct lock-less
+    // synchronization between different threads calling Pointer().
+    // We suggest dynamic race detection tool that
+    // "ctor(instance)" in EnsureInstance(...) happens before
+    // "return instance" in Pointer().
+    // See the corresponding HAPPENS_BEFORE in EnsureInstance(...).
+    ANNOTATE_HAPPENS_AFTER(&state_);
+
     return instance;
   }
 
  private:
   int8 buf_[sizeof(Type)];  // Preallocate the space for the Type instance.
 
   DISALLOW_COPY_AND_ASSIGN(LazyInstance);
 };
 
 }  // namespace base
 
 #endif  // BASE_LAZY_INSTANCE_H_