Created a stock implementation of the MessageLoopProxy interface than can be used to create an implementation that targets the current thread's message loop.

BUG=None
TEST=Unit tests provided.

Review URL: http://codereview.chromium.org/1837003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@46591 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 61 insertions, 0 deletions

diff --git a/base/message_loop_proxy_impl.h b/base/message_loop_proxy_impl.h
new file mode 100644
index 0000000..f895532
--- /dev/null
+++ b/base/message_loop_proxy_impl.h
@@ -0,0 +1,61 @@
+// Copyright (c) 2010 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.
+
+#ifndef BASE_MESSAGE_LOOP_PROXY_IMPL_H_
+#define BASE_MESSAGE_LOOP_PROXY_IMPL_H_
+
+#include "base/lock.h"
+#include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
+
+namespace base {
+
+// A stock implementation of MessageLoopProxy that takes in a MessageLoop
+// and keeps track of its lifetime using the MessageLoop DestructionObserver.
+// For now a MessageLoopProxyImpl can only be created for the current thread.
+class MessageLoopProxyImpl : public MessageLoopProxy,
+                             public MessageLoop::DestructionObserver {
+ public:
+  ~MessageLoopProxyImpl();
+
+  // MessageLoopProxy implementation
+  virtual bool PostTask(const tracked_objects::Location& from_here,
+                        Task* task);
+  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                               Task* task, int64 delay_ms);
+  virtual bool PostNonNestableTask(const tracked_objects::Location& from_here,
+                                   Task* task);
+  virtual bool PostNonNestableDelayedTask(
+      const tracked_objects::Location& from_here,
+      Task* task,
+      int64 delay_ms);
+  virtual bool BelongsToCurrentThread();
+
+// MessageLoop::DestructionObserver implementation
+  void WillDestroyCurrentMessageLoop();
+
+ protected:
+  // Override OnDestruct so that we can delete the object on the target message
+  // loop if it still exists.
+  virtual void OnDestruct();
+
+ private:
+  MessageLoopProxyImpl();
+  bool PostTaskHelper(const tracked_objects::Location& from_here,
+                      Task* task, int64 delay_ms, bool nestable);
+
+  // For the factory method to work
+  friend class MessageLoopProxy;
+
+  // The lock that protects access to target_message_loop_.
+  Lock message_loop_lock_;
+  MessageLoop* target_message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(MessageLoopProxyImpl);
+};
+
+}  // namespace base
+
+#endif  // BASE_MESSAGE_LOOP_PROXY_IMPL_H_
+