OLD | NEW |
| (Empty) |
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef MEDIA_AUDIO_SCOPED_LOOP_OBSERVER_H_ | |
6 #define MEDIA_AUDIO_SCOPED_LOOP_OBSERVER_H_ | |
7 | |
8 #include "base/memory/ref_counted.h" | |
9 #include "base/message_loop/message_loop.h" | |
10 #include "base/message_loop/message_loop_proxy.h" | |
11 | |
12 namespace base { | |
13 class WaitableEvent; | |
14 } | |
15 | |
16 namespace media { | |
17 | |
18 // A common base class for AudioOutputDevice and AudioInputDevice that manages | |
19 // a message loop pointer and monitors it for destruction. If the object goes | |
20 // out of scope before the message loop, the object will automatically remove | |
21 // itself from the message loop's list of destruction observers. | |
22 // NOTE: The class that inherits from this class must implement the | |
23 // WillDestroyCurrentMessageLoop virtual method from DestructionObserver. | |
24 class ScopedLoopObserver | |
25 : public base::MessageLoop::DestructionObserver { | |
26 public: | |
27 explicit ScopedLoopObserver( | |
28 const scoped_refptr<base::MessageLoopProxy>& message_loop); | |
29 | |
30 protected: | |
31 virtual ~ScopedLoopObserver(); | |
32 | |
33 // Accessor to the loop that's used by the derived class. | |
34 const scoped_refptr<base::MessageLoopProxy>& message_loop() { return loop_; } | |
35 | |
36 private: | |
37 // Call to add or remove ourselves from the list of destruction observers for | |
38 // the message loop. | |
39 void ObserveLoopDestruction(bool enable, base::WaitableEvent* done); | |
40 | |
41 // A pointer to the message loop's proxy. In case the loop gets destroyed | |
42 // before this object goes out of scope, PostTask etc will fail but not crash. | |
43 scoped_refptr<base::MessageLoopProxy> loop_; | |
44 | |
45 DISALLOW_COPY_AND_ASSIGN(ScopedLoopObserver); | |
46 }; | |
47 | |
48 } // namespace media. | |
49 | |
50 #endif // MEDIA_AUDIO_SCOPED_LOOP_OBSERVER_H_ | |
OLD | NEW |