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1 // Copyright 2013 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 BASE_ASYNC_SOCKET_IO_HANDLER_H_ | |
6 #define BASE_ASYNC_SOCKET_IO_HANDLER_H_ | |
7 | |
8 #include "base/message_loop/message_loop.h" | |
9 #include "base/sync_socket.h" | |
10 #include "base/threading/non_thread_safe.h" | |
11 | |
12 namespace base { | |
13 | |
14 // Extends the CancelableSyncSocket class to allow reading from a socket | |
15 // asynchronously on a TYPE_IO message loop thread. This makes it easy to share | |
16 // a thread that uses a message loop (e.g. for IPC and other things) and not | |
17 // require a separate thread to read from the socket. | |
18 // | |
19 // Example usage (also see the unit tests): | |
20 // | |
21 // class SocketReader { | |
22 // public: | |
23 // SocketReader(base::CancelableSyncSocket* socket) | |
24 // : socket_(socket), buffer_() { | |
25 // io_handler.Initialize(socket_->handle(), | |
26 // base::Bind(&SocketReader::OnDataAvailable, | |
27 // base::Unretained(this)); | |
28 // } | |
29 // | |
30 // void AsyncRead() { | |
31 // CHECK(io_handler.Read(&buffer_[0], sizeof(buffer_))); | |
32 // } | |
33 // | |
34 // private: | |
35 // void OnDataAvailable(int bytes_read) { | |
36 // if (ProcessData(&buffer_[0], bytes_read)) { | |
37 // // Issue another read. | |
38 // CHECK(io_handler.Read(&buffer_[0], sizeof(buffer_))); | |
39 // } | |
40 // } | |
41 // | |
42 // base::AsyncSocketIoHandler io_handler; | |
43 // base::CancelableSyncSocket* socket_; | |
44 // char buffer_[kBufferSize]; | |
45 // }; | |
46 // | |
47 class BASE_EXPORT AsyncSocketIoHandler | |
48 : public NON_EXPORTED_BASE(base::NonThreadSafe), | |
49 // The message loop callback interface is different based on platforms. | |
50 #if defined(OS_WIN) | |
51 public NON_EXPORTED_BASE(base::MessageLoopForIO::IOHandler) { | |
52 #else | |
53 public NON_EXPORTED_BASE(base::MessageLoopForIO::Watcher) { | |
54 #endif | |
55 public: | |
56 AsyncSocketIoHandler(); | |
57 ~AsyncSocketIoHandler() override; | |
58 | |
59 // Type definition for the callback. The parameter tells how many | |
60 // bytes were read and is 0 if an error occurred. | |
61 typedef base::Callback<void(int)> ReadCompleteCallback; | |
62 | |
63 // Initializes the AsyncSocketIoHandler by hooking it up to the current | |
64 // thread's message loop (must be TYPE_IO), to do async reads from the socket | |
65 // on the current thread. The |callback| will be invoked whenever a Read() | |
66 // has completed. | |
67 bool Initialize(base::SyncSocket::Handle socket, | |
68 const ReadCompleteCallback& callback); | |
69 | |
70 // Attempts to read from the socket. The return value will be |false| | |
71 // if an error occurred and |true| if data was read or a pending read | |
72 // was issued. Regardless of async or sync operation, the | |
73 // ReadCompleteCallback (see above) will be called when data is available. | |
74 bool Read(char* buffer, int buffer_len); | |
75 | |
76 private: | |
77 #if defined(OS_WIN) | |
78 // Implementation of IOHandler on Windows. | |
79 void OnIOCompleted(base::MessageLoopForIO::IOContext* context, | |
80 DWORD bytes_transfered, | |
81 DWORD error) override; | |
82 #elif defined(OS_POSIX) | |
83 // Implementation of base::MessageLoopForIO::Watcher. | |
84 void OnFileCanWriteWithoutBlocking(int socket) override {} | |
85 void OnFileCanReadWithoutBlocking(int socket) override; | |
86 | |
87 void EnsureWatchingSocket(); | |
88 #endif | |
89 | |
90 base::SyncSocket::Handle socket_; | |
91 #if defined(OS_WIN) | |
92 base::MessageLoopForIO::IOContext* context_; | |
93 bool is_pending_; | |
94 #elif defined(OS_POSIX) | |
95 base::MessageLoopForIO::FileDescriptorWatcher socket_watcher_; | |
96 // |pending_buffer_| and |pending_buffer_len_| are valid only between | |
97 // Read() and OnFileCanReadWithoutBlocking(). | |
98 char* pending_buffer_; | |
99 int pending_buffer_len_; | |
100 // |true| iff the message loop is watching the socket for IO events. | |
101 bool is_watching_; | |
102 #endif | |
103 ReadCompleteCallback read_complete_; | |
104 | |
105 DISALLOW_COPY_AND_ASSIGN(AsyncSocketIoHandler); | |
106 }; | |
107 | |
108 } // namespace base. | |
109 | |
110 #endif // BASE_ASYNC_SOCKET_IO_HANDLER_H_ | |
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