Convert all remaining explicit LeakyLazyInstanceTraits users to ::Leaky

base/lazy_instance.h

 // Copyright (c) 2012 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 55 matching lines @@
     // Use placement new to initialize our instance in our preallocated space.
     // The parenthesis is very important here to force POD type initialization.
     return new (instance) Type();
   }
   static void Delete(Type* instance) {
     // Explicitly call the destructor.
     instance->~Type();
   }
 };
 
+// We pull out some of the functionality into non-templated functions, so we
+// can implement the more complicated pieces out of line in the .cc file.
+namespace internal {
+
 // Use LazyInstance<T>::Leaky for a less-verbose call-site typedef; e.g.:
 // base::LazyInstance<T>::Leaky my_leaky_lazy_instance;
 // instead of:
 // base::LazyInstance<T, LeakyLazyInstanceTraits<T> > my_leaky_lazy_instance;

[wtc, 2012/01/24 19:39:53]

Nit: In this sample code, LeakyLazyInstanceTraits needs to be
qualified as base::internal::LeakyLazyInstanceTraits, right?

[Ami GONE FROM CHROMIUM, 2012/01/24 20:27:30]

Right; done.

 // (especially when T is MyLongTypeNameImplClientHolderFactory).
+// Only use this internal::-qualified verbose form to extend this traits class
+// (depending on its implementation details).
 template <typename Type>
 struct LeakyLazyInstanceTraits {
   static const bool kRegisterOnExit = false;
   static const bool kAllowedToAccessOnNonjoinableThread = true;
 
   static Type* New(void* instance) {
     return DefaultLazyInstanceTraits<Type>::New(instance);
   }
   static void Delete(Type* instance) {
   }
 };
 
-// We pull out some of the functionality into non-templated functions, so we
-// can implement the more complicated pieces out of line in the .cc file.
-namespace internal {
-
 // Our AtomicWord doubles as a spinlock, where a value of
 // kBeingCreatedMarker means the spinlock is being held for creation.
 static const subtle::AtomicWord kLazyInstanceStateCreating = 1;
 
 // Check if instance needs to be created. If so return true otherwise
 // if another thread has beat us, wait for instance to be created and
 // return false.
 BASE_EXPORT bool NeedsLazyInstance(subtle::AtomicWord* state);
 
 // After creating an instance, call this to register the dtor to be called
@@ skipping 10 matching lines @@
  public:
   // Do not define a destructor, as doing so makes LazyInstance a
   // non-POD-struct. We don't want that because then a static initializer will
   // be created to register the (empty) destructor with atexit() under MSVC, for
   // example. We handle destruction of the contained Type class explicitly via
   // the OnExit member function, where needed.
   // ~LazyInstance() {}
 
   // Convenience typedef to avoid having to repeat Type for leaky lazy
   // instances.
-  typedef LazyInstance<Type, LeakyLazyInstanceTraits<Type> > Leaky;
+  typedef LazyInstance<Type, internal::LeakyLazyInstanceTraits<Type> > Leaky;
 
   Type& Get() {
     return *Pointer();
   }
 
   Type* Pointer() {
 #ifndef NDEBUG
     // Avoid making TLS lookup on release builds.
     if (!Traits::kAllowedToAccessOnNonjoinableThread)
       ThreadRestrictions::AssertSingletonAllowed();
@@ skipping 60 matching lines @@
     LazyInstance<Type, Traits>* me =
         reinterpret_cast<LazyInstance<Type, Traits>*>(lazy_instance);
     Traits::Delete(me->instance());
     subtle::Release_Store(&me->private_instance_, 0);
   }
 };
 
 }  // namespace base
 
 #endif  // BASE_LAZY_INSTANCE_H_