| initial.commit | 09911bf | 2008-07-26 23:55:29 | [diff] [blame^] | 1 | // Copyright 2008, Google Inc. |
| 2 | // All rights reserved. |
| 3 | // |
| 4 | // Redistribution and use in source and binary forms, with or without |
| 5 | // modification, are permitted provided that the following conditions are |
| 6 | // met: |
| 7 | // |
| 8 | // * Redistributions of source code must retain the above copyright |
| 9 | // notice, this list of conditions and the following disclaimer. |
| 10 | // * Redistributions in binary form must reproduce the above |
| 11 | // copyright notice, this list of conditions and the following disclaimer |
| 12 | // in the documentation and/or other materials provided with the |
| 13 | // distribution. |
| 14 | // * Neither the name of Google Inc. nor the names of its |
| 15 | // contributors may be used to endorse or promote products derived from |
| 16 | // this software without specific prior written permission. |
| 17 | // |
| 18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | |
| 30 | #ifndef CHROME_COMMON_IPC_CHANNEL_H__ |
| 31 | #define CHROME_COMMON_IPC_CHANNEL_H__ |
| 32 | |
| 33 | #include <queue> |
| 34 | |
| 35 | #include "base/message_loop.h" |
| 36 | #include "chrome/common/ipc_message.h" |
| 37 | |
| 38 | namespace IPC { |
| 39 | |
| 40 | //------------------------------------------------------------------------------ |
| 41 | |
| 42 | class Channel : public MessageLoop::Watcher, |
| 43 | public Message::Sender { |
| 44 | // Security tests need access to the pipe handle. |
| 45 | friend class ChannelTest; |
| 46 | |
| 47 | public: |
| 48 | // Implemented by consumers of a Channel to receive messages. |
| 49 | class Listener { |
| 50 | public: |
| 51 | // Called when a message is received. |
| 52 | virtual void OnMessageReceived(const Message& message) = 0; |
| 53 | |
| 54 | // Called when the channel is connected and we have received the internal |
| 55 | // Hello message from the peer. |
| 56 | virtual void OnChannelConnected(int32 peer_pid) {} |
| 57 | |
| 58 | // Called when an error is detected that causes the channel to close. |
| 59 | // This method is not called when a channel is closed normally. |
| 60 | virtual void OnChannelError() {} |
| 61 | }; |
| 62 | |
| 63 | enum Mode { |
| 64 | MODE_SERVER, |
| 65 | MODE_CLIENT |
| 66 | }; |
| 67 | |
| 68 | // The maximum message size in bytes. Attempting to receive a |
| 69 | // message of this size or bigger results in a channel error. |
| 70 | enum { |
| 71 | kMaximumMessageSize = 256 * 1024 * 1024 |
| 72 | }; |
| 73 | |
| 74 | // Initialize a Channel. |
| 75 | // |
| 76 | // @param channel_id |
| 77 | // Identifies the communication Channel. |
| 78 | // @param mode |
| 79 | // Specifies whether this Channel is to operate in server mode or client |
| 80 | // mode. In server mode, the Channel is responsible for setting up the |
| 81 | // IPC object, whereas in client mode, the Channel merely connects |
| 82 | // to the already established IPC object. |
| 83 | // @param listener |
| 84 | // Receives a callback on the current thread for each newly received |
| 85 | // message. |
| 86 | // |
| 87 | Channel(const std::wstring& channel_id, Mode mode, Listener* listener); |
| 88 | |
| 89 | ~Channel() { Close(); } |
| 90 | |
| 91 | // Connect the pipe. On the server side, this will initiate |
| 92 | // waiting for connections. On the client, it attempts to |
| 93 | // connect to a pre-existing pipe. Note, calling Connect() |
| 94 | // will not block the calling thread and may complete |
| 95 | // asynchronously. |
| 96 | bool Connect(); |
| 97 | |
| 98 | // Close this Channel explicitly. May be called multiple times. |
| 99 | void Close(); |
| 100 | |
| 101 | // Modify the Channel's listener. |
| 102 | void set_listener(Listener* listener) { listener_ = listener; } |
| 103 | |
| 104 | // Send a message over the Channel to the listener on the other end. |
| 105 | // |
| 106 | // @param message |
| 107 | // The Message to send, which must be allocated using operator new. This |
| 108 | // object will be deleted once the contents of the Message have been sent. |
| 109 | // |
| 110 | // FIXME bug 551500: the channel does not notice failures, so if the |
| 111 | // renderer crashes, it will silently succeed, leaking the parameter. |
| 112 | // At least the leak will be fixed by... |
| 113 | // |
| 114 | virtual bool Send(Message* message); |
| 115 | |
| 116 | // Process any pending incoming and outgoing messages. Wait for at most |
| 117 | // max_wait_msec for pending messages if there are none. Returns true if |
| 118 | // there were no pending messages or if pending messages were successfully |
| 119 | // processed. Returns false if there are pending messages that cannot be |
| 120 | // processed for some reason (e.g., because ProcessIncomingMessages would be |
| 121 | // re-entered). |
| 122 | // TODO(darin): Need a better way of dealing with the recursion problem. |
| 123 | bool ProcessPendingMessages(DWORD max_wait_msec); |
| 124 | |
| 125 | private: |
| 126 | const std::wstring PipeName(const std::wstring& channel_id) const; |
| 127 | bool CreatePipe(const std::wstring& channel_id, Mode mode); |
| 128 | bool ProcessConnection(); |
| 129 | bool ProcessIncomingMessages(); |
| 130 | bool ProcessOutgoingMessages(); |
| 131 | |
| 132 | // MessageLoop::Watcher implementation |
| 133 | virtual void OnObjectSignaled(HANDLE object); |
| 134 | |
| 135 | private: |
| 136 | enum { |
| 137 | BUF_SIZE = 4096 |
| 138 | }; |
| 139 | |
| 140 | struct State { |
| 141 | State(); |
| 142 | ~State(); |
| 143 | OVERLAPPED overlapped; |
| 144 | bool is_pending; |
| 145 | }; |
| 146 | |
| 147 | State input_state_; |
| 148 | State output_state_; |
| 149 | |
| 150 | HANDLE pipe_; |
| 151 | Listener* listener_; |
| 152 | |
| 153 | // Messages to be sent are queued here. |
| 154 | std::queue<Message*> output_queue_; |
| 155 | |
| 156 | // We read from the pipe into this buffer |
| 157 | char input_buf_[BUF_SIZE]; |
| 158 | |
| 159 | // Large messages that span multiple pipe buffers, get built-up using |
| 160 | // this buffer. |
| 161 | std::string input_overflow_buf_; |
| 162 | |
| 163 | // In server-mode, we have to wait for the client to connect before we |
| 164 | // can begin reading. We make use of the input_state_ when performing |
| 165 | // the connect operation in overlapped mode. |
| 166 | bool waiting_connect_; |
| 167 | |
| 168 | // This flag is set when processing incoming messages. It is used to |
| 169 | // avoid recursing through ProcessIncomingMessages, which could cause |
| 170 | // problems. TODO(darin): make this unnecessary |
| 171 | bool processing_incoming_; |
| 172 | |
| 173 | // The Hello message is internal to the Channel class. It is sent |
| 174 | // by the peer when the channel is connected. The message contains |
| 175 | // just the process id (pid). The message has a special routing_id |
| 176 | // (MSG_ROUTING_NONE) and type (HELLO_MESSAGE_TYPE). |
| 177 | enum { |
| 178 | HELLO_MESSAGE_TYPE = MAXWORD // Maximum value of message type (WORD), |
| 179 | // to avoid conflicting with normal |
| 180 | // message types, which are enumeration |
| 181 | // constants starting from 0. |
| 182 | }; |
| 183 | }; |
| 184 | |
| 185 | } |
| 186 | |
| 187 | #endif // CHROME_COMMON_IPC_CHANNEL_H__ |