| // 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_H_ |
| #define BASE_MESSAGE_LOOP_PROXY_H_ |
| #pragma once |
| |
| #include "base/basictypes.h" |
| #include "base/ref_counted.h" |
| #include "base/task.h" |
| |
| namespace base { |
| |
| struct MessageLoopProxyTraits; |
| |
| // This class provides a thread-safe refcounted interface to the Post* methods |
| // of a message loop. This class can outlive the target message loop. |
| class MessageLoopProxy |
| : public base::RefCountedThreadSafe<MessageLoopProxy, |
| MessageLoopProxyTraits> { |
| public: |
| // These are the same methods in message_loop.h, but are guaranteed to either |
| // get posted to the MessageLoop if it's still alive, or be deleted otherwise. |
| // They return true iff the thread existed and the task was posted. Note that |
| // even if the task is posted, there's no guarantee that it will run, since |
| // the target thread may already have a Quit message in its queue. |
| virtual bool PostTask(const tracked_objects::Location& from_here, |
| Task* task) = 0; |
| virtual bool PostDelayedTask(const tracked_objects::Location& from_here, |
| Task* task, int64 delay_ms) = 0; |
| virtual bool PostNonNestableTask(const tracked_objects::Location& from_here, |
| Task* task) = 0; |
| virtual bool PostNonNestableDelayedTask( |
| const tracked_objects::Location& from_here, |
| Task* task, |
| int64 delay_ms) = 0; |
| // A method which checks if the caller is currently running in the thread that |
| // this proxy represents. |
| virtual bool BelongsToCurrentThread() = 0; |
| |
| template <class T> |
| bool DeleteSoon(const tracked_objects::Location& from_here, |
| T* object) { |
| return PostNonNestableTask(from_here, new DeleteTask<T>(object)); |
| } |
| template <class T> |
| bool ReleaseSoon(const tracked_objects::Location& from_here, |
| T* object) { |
| return PostNonNestableTask(from_here, new ReleaseTask<T>(object)); |
| } |
| |
| // Factory method for creating an implementation of MessageLoopProxy |
| // for the current thread. |
| static scoped_refptr<MessageLoopProxy> CreateForCurrentThread(); |
| |
| protected: |
| friend struct MessageLoopProxyTraits; |
| |
| virtual ~MessageLoopProxy() { } |
| |
| // Called when the proxy is about to be deleted. Subclasses can override this |
| // to provide deletion on specific threads. |
| virtual void OnDestruct() { |
| delete this; |
| } |
| }; |
| |
| struct MessageLoopProxyTraits { |
| static void Destruct(MessageLoopProxy* proxy) { |
| proxy->OnDestruct(); |
| } |
| }; |
| |
| } // namespace base |
| |
| #endif // BASE_MESSAGE_LOOP_PROXY_H_ |
| |