OLD | NEW |
| (Empty) |
1 // Copyright 2014 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 MOJO_EDK_SYSTEM_CHANNEL_ENDPOINT_CLIENT_H_ | |
6 #define MOJO_EDK_SYSTEM_CHANNEL_ENDPOINT_CLIENT_H_ | |
7 | |
8 #include "base/macros.h" | |
9 #include "base/memory/ref_counted.h" | |
10 #include "base/memory/scoped_ptr.h" | |
11 #include "mojo/edk/system/system_impl_export.h" | |
12 | |
13 namespace mojo { | |
14 namespace system { | |
15 | |
16 class MessageInTransit; | |
17 | |
18 // Interface for receivers of messages from |ChannelEndpoint| (hence from | |
19 // |Channel|). |port| is simply the value passed to |ChannelEndpoint| on | |
20 // construction, and provides a lightweight way for an object to be the client | |
21 // of multiple |ChannelEndpoint|s. (|MessagePipe| implements this interface, in | |
22 // which case |port| is the port number for the |ProxyMessagePipeEndpoint| | |
23 // corresdponding to the |ChannelEndpoint|.) | |
24 // | |
25 // Implementations of this class should be thread-safe. |ChannelEndpointClient| | |
26 // *precedes* |ChannelEndpoint| in the lock order, so |ChannelEndpoint| should | |
27 // never call into this class with its lock held. (Instead, it should take a | |
28 // reference under its lock, release its lock, and make any needed call(s).) | |
29 // | |
30 // Note: As a consequence of this, all the client methods may be called even | |
31 // after |ChannelEndpoint::DetachFromClient()| has been called (so the | |
32 // |ChannelEndpoint| has apparently relinquished its pointer to the | |
33 // |ChannelEndpointClient|). | |
34 class MOJO_SYSTEM_IMPL_EXPORT ChannelEndpointClient | |
35 : public base::RefCountedThreadSafe<ChannelEndpointClient> { | |
36 public: | |
37 // Called by |ChannelEndpoint| in response to its |OnReadMessage()|, which is | |
38 // called by |Channel| when it receives a message for the |ChannelEndpoint|. | |
39 // (|port| is the value passed to |ChannelEndpoint|'s constructor as | |
40 // |client_port|.) | |
41 // | |
42 // This should return true if it accepted (and took ownership of) |message|. | |
43 virtual bool OnReadMessage(unsigned port, MessageInTransit* message) = 0; | |
44 | |
45 // Called by |ChannelEndpoint| when the |Channel| is relinquishing its pointer | |
46 // to the |ChannelEndpoint| (and vice versa). After this is called, | |
47 // |OnReadMessage()| will no longer be called. | |
48 virtual void OnDetachFromChannel(unsigned port) = 0; | |
49 | |
50 protected: | |
51 ChannelEndpointClient() {} | |
52 | |
53 virtual ~ChannelEndpointClient() {} | |
54 friend class base::RefCountedThreadSafe<ChannelEndpointClient>; | |
55 | |
56 private: | |
57 DISALLOW_COPY_AND_ASSIGN(ChannelEndpointClient); | |
58 }; | |
59 | |
60 } // namespace system | |
61 } // namespace mojo | |
62 | |
63 #endif // MOJO_EDK_SYSTEM_CHANNEL_ENDPOINT_CLIENT_H_ | |
OLD | NEW |