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Diffstat (limited to 'apps/SdkController/src/com/android/tools/sdkcontroller/lib/Connection.java')
| -rw-r--r-- | apps/SdkController/src/com/android/tools/sdkcontroller/lib/Connection.java | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/apps/SdkController/src/com/android/tools/sdkcontroller/lib/Connection.java b/apps/SdkController/src/com/android/tools/sdkcontroller/lib/Connection.java new file mode 100644 index 000000000..cb5086905 --- /dev/null +++ b/apps/SdkController/src/com/android/tools/sdkcontroller/lib/Connection.java @@ -0,0 +1,412 @@ +/* + * Copyright (C) 2012 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not + * use this file except in compliance with the License. You may obtain a copy of + * the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations under + * the License. + */ + +package com.android.tools.sdkcontroller.lib; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.nio.ByteOrder; +import java.util.ArrayList; +import java.util.List; + +import android.util.Log; +import android.net.LocalServerSocket; +import android.net.LocalSocket; + +import com.android.tools.sdkcontroller.lib.Channel; +import com.android.tools.sdkcontroller.service.ControllerService; + +/** + * Encapsulates a connection between SdkController service and the emulator. On + * the device side, the connection is bound to the UNIX-domain socket named + * 'android.sdk.controller'. On the emulator side the connection is established + * via TCP port that is used to forward I/O traffic on the host machine to + * 'android.sdk.controller' socket on the device. Typically, the port forwarding + * can be enabled using adb command: + * <p/> + * 'adb forward tcp:<TCP port number> localabstract:android.sdk.controller' + * <p/> + * The way communication between the emulator and SDK controller service works + * is as follows: + * <p/> + * 1. Both sides, emulator and the service have components that implement a particular + * type of emulation. For instance, AndroidSensorsPort in the emulator, and + * SensorChannel in the application implement sensors emulation. + * Emulation channels are identified by unique names. For instance, sensor emulation + * is done via "sensors" channel, multi-touch emulation is done via "multi-touch" + * channel, etc. + * <p/> + * 2. Channels are connected to emulator via separate socket instance (though all + * of the connections share the same socket address). + * <p/> + * 3. Connection is initiated by the emulator side, while the service provides + * its side (a channel) that implement functionality and exchange protocol required + * by the requested type of emulation. + * <p/> + * Given that, the main responsibilities of this class are: + * <p/> + * 1. Bind to "android.sdk.controller" socket, listening to emulator connections. + * <p/> + * 2. Maintain a list of service-side channels registered by the application. + * <p/> + * 3. Bind emulator connection with service-side channel via port name, provided by + * the emulator. + * <p/> + * 4. Monitor connection state with the emulator, and automatically restore the + * connection once it is lost. + */ +public class Connection { + /** UNIX-domain name reserved for SDK controller. */ + public static final String SDK_CONTROLLER_PORT = "android.sdk.controller"; + /** Tag for logging messages. */ + private static final String TAG = "SdkControllerConnection"; + /** Controls debug logging */ + private static final boolean DEBUG = false; + + /** Server socket used to listen to emulator connections. */ + private LocalServerSocket mServerSocket = null; + /** Service that has created this object. */ + private ControllerService mService; + /** + * List of connected emulator sockets, pending for a channel to be registered. + * <p/> + * Emulator may connect to SDK controller before the app registers a channel + * for that connection. In this case (when app-side channel is not registered + * with this class) we will keep emulator connection in this list, pending + * for the app-side channel to register. + */ + private List<Socket> mPendingSockets = new ArrayList<Socket>(); + /** + * List of registered app-side channels. + * <p/> + * Channels that are kept in this list may be disconnected from (or pending + * connection with) the emulator, or they may be connected with the + * emulator. + */ + private List<Channel> mChannels = new ArrayList<Channel>(); + + /** + * Constructs Connection instance. + */ + public Connection(ControllerService service) { + mService = service; + if (DEBUG) Log.d(TAG, "SdkControllerConnection is constructed."); + } + + /** + * Binds to the socket, and starts the listening thread. + */ + public void connect() { + if (DEBUG) Log.d(TAG, "SdkControllerConnection is connecting..."); + // Start connection listener. + new Thread(new Runnable() { + @Override + public void run() { + runIOLooper(); + } + }, "SdkControllerConnectionIoLoop").start(); + } + + /** + * Stops the listener, and closes the socket. + * + * @return true if connection has been stopped in this call, or false if it + * has been already stopped when this method has been called. + */ + public boolean disconnect() { + // This is the only place in this class where we will null the + // socket object. Since this method can be called concurrently from + // different threads, lets do this under the lock. + LocalServerSocket socket; + synchronized (this) { + socket = mServerSocket; + mServerSocket = null; + } + if (socket != null) { + if (DEBUG) Log.d(TAG, "SdkControllerConnection is stopping I/O looper..."); + // Stop accepting new connections. + wakeIOLooper(socket); + try { + socket.close(); + } catch (Exception e) { + } + + // Close all the pending sockets, and clear pending socket list. + if (DEBUG) Log.d(TAG, "SdkControllerConnection is closing pending sockets..."); + for (Socket pending_socket : mPendingSockets) { + pending_socket.close(); + } + mPendingSockets.clear(); + + // Disconnect all the emualtors. + if (DEBUG) Log.d(TAG, "SdkControllerConnection is disconnecting channels..."); + for (Channel channel : mChannels) { + if (channel.disconnect()) { + channel.onEmulatorDisconnected(); + } + } + if (DEBUG) Log.d(TAG, "SdkControllerConnection is disconnected."); + } + return socket != null; + } + + /** + * Registers SDK controller channel. + * + * @param channel SDK controller emulator to register. + * @return true if channel has been registered successfully, or false if channel + * with the same name is already registered. + */ + public boolean registerChannel(Channel channel) { + for (Channel check_channel : mChannels) { + if (check_channel.getChannelName().equals(channel.getChannelName())) { + Loge("Registering a duplicate Channel " + channel.getChannelName()); + return false; + } + } + if (DEBUG) Log.d(TAG, "Registering Channel " + channel.getChannelName()); + mChannels.add(channel); + + // Lets see if there is a pending socket for this channel. + for (Socket pending_socket : mPendingSockets) { + if (pending_socket.getChannelName().equals(channel.getChannelName())) { + // Remove the socket from the pending list, and connect the registered channel with it. + if (DEBUG) Log.d(TAG, "Found pending Socket for registering Channel " + + channel.getChannelName()); + mPendingSockets.remove(pending_socket); + channel.connect(pending_socket); + } + } + return true; + } + + /** + * Checks if at least one socket connection exists with channel. + * + * @return true if at least one socket connection exists with channel. + */ + public boolean isEmulatorConnected() { + for (Channel channel : mChannels) { + if (channel.isConnected()) { + return true; + } + } + return !mPendingSockets.isEmpty(); + } + + /** + * Gets Channel instance for the given channel name. + * + * @param name Channel name to get Channel instance for. + * @return Channel instance for the given channel name, or NULL if no + * channel has been registered for that name. + */ + public Channel getChannel(String name) { + for (Channel channel : mChannels) { + if (channel.getChannelName().equals(name)) { + return channel; + } + } + return null; + } + + /** + * Gets connected emulator socket that is pending for service-side channel + * registration. + * + * @param name Channel name to lookup Socket for. + * @return Connected emulator socket that is pending for service-side channel + * registration, or null if no socket is pending for service-size + * channel registration. + */ + private Socket getPendingSocket(String name) { + for (Socket socket : mPendingSockets) { + if (socket.getChannelName().equals(name)) { + return socket; + } + } + return null; + } + + /** + * Wakes I/O looper waiting on connection with the emulator. + * + * @param socket Server socket waiting on connection. + */ + private void wakeIOLooper(LocalServerSocket socket) { + // We wake the looper by connecting to the socket. + LocalSocket waker = new LocalSocket(); + try { + waker.connect(socket.getLocalSocketAddress()); + } catch (IOException e) { + Loge("Exception " + e + " in SdkControllerConnection while waking up the I/O looper."); + } + } + + /** + * Loops on the local socket, handling emulator connection attempts. + */ + private void runIOLooper() { + if (DEBUG) Log.d(TAG, "In SdkControllerConnection I/O looper."); + do { + try { + // Create non-blocking server socket that would listen for connections, + // and bind it to the given port on the local host. + mServerSocket = new LocalServerSocket(SDK_CONTROLLER_PORT); + LocalServerSocket socket = mServerSocket; + while (socket != null) { + final LocalSocket sk = socket.accept(); + if (mServerSocket != null) { + onAccept(sk); + } else { + break; + } + socket = mServerSocket; + } + } catch (IOException e) { + Loge("Exception " + e + "SdkControllerConnection I/O looper."); + } + if (DEBUG) Log.d(TAG, "Exiting SdkControllerConnection I/O looper."); + + // If we're exiting the internal loop for reasons other than an explicit + // disconnect request, we should reconnect again. + } while (disconnect()); + } + + /** + * Accepts new connection from the emulator. + * + * @param sock Connecting socket. + * @throws IOException + */ + private void onAccept(LocalSocket sock) throws IOException { + final ByteBuffer handshake = ByteBuffer.allocate(ProtocolConstants.QUERY_HEADER_SIZE); + + // By protocol, first byte received from newly connected emulator socket + // indicates host endianness. + Socket.receive(sock, handshake.array(), 1); + final ByteOrder endian = (handshake.getChar() == 0) ? ByteOrder.LITTLE_ENDIAN : + ByteOrder.BIG_ENDIAN; + handshake.order(endian); + + // Right after that follows the handshake query header. + handshake.position(0); + Socket.receive(sock, handshake.array(), handshake.array().length); + + // First int - signature + final int signature = handshake.getInt(); + assert signature == ProtocolConstants.PACKET_SIGNATURE; + // Second int - total query size (including fixed query header) + final int remains = handshake.getInt() - ProtocolConstants.QUERY_HEADER_SIZE; + // After that - header type (which must be SDKCTL_PACKET_TYPE_QUERY) + final int msg_type = handshake.getInt(); + assert msg_type == ProtocolConstants.PACKET_TYPE_QUERY; + // After that - query ID. + final int query_id = handshake.getInt(); + // And finally, query type (which must be ProtocolConstants.QUERY_HANDSHAKE for + // handshake query) + final int query_type = handshake.getInt(); + assert query_type == ProtocolConstants.QUERY_HANDSHAKE; + // Verify that received is a query. + if (msg_type != ProtocolConstants.PACKET_TYPE_QUERY) { + // Message type is not a query. Lets read and discard the remainder + // of the message. + if (remains > 0) { + Loge("Unexpected handshake message type: " + msg_type); + byte[] discard = new byte[remains]; + Socket.receive(sock, discard, discard.length); + } + return; + } + + // Receive query data. + final byte[] name_array = new byte[remains]; + Socket.receive(sock, name_array, name_array.length); + + // Prepare response header. + handshake.position(0); + handshake.putInt(ProtocolConstants.PACKET_SIGNATURE); + // Handshake reply is just one int. + handshake.putInt(ProtocolConstants.QUERY_RESP_HEADER_SIZE + 4); + handshake.putInt(ProtocolConstants.PACKET_TYPE_QUERY_RESPONSE); + handshake.putInt(query_id); + + // Verify that received query is in deed a handshake query. + if (query_type != ProtocolConstants.QUERY_HANDSHAKE) { + // Query is not a handshake. Reply with failure. + Loge("Unexpected handshake query type: " + query_type); + handshake.putInt(ProtocolConstants.HANDSHAKE_RESP_QUERY_UNKNOWN); + sock.getOutputStream().write(handshake.array()); + return; + } + + // Handshake query data consist of SDK controller channel name. + final String channel_name = new String(name_array); + if (DEBUG) Log.d(TAG, "Handshake received for channel " + channel_name); + + // Respond to query depending on service-side channel availability + final Channel channel = getChannel(channel_name); + Socket sk = null; + + if (channel != null) { + if (channel.isConnected()) { + // This is a duplicate connection. + Loge("Duplicate connection to a connected Channel " + channel_name); + handshake.putInt(ProtocolConstants.HANDSHAKE_RESP_DUP); + } else { + // Connecting to a registered channel. + if (DEBUG) Log.d(TAG, "Emulator is connected to a registered Channel " + channel_name); + handshake.putInt(ProtocolConstants.HANDSHAKE_RESP_CONNECTED); + } + } else { + // Make sure that there are no other channel connections for this + // channel name. + if (getPendingSocket(channel_name) != null) { + // This is a duplicate. + Loge("Duplicate connection to a pending Socket " + channel_name); + handshake.putInt(ProtocolConstants.HANDSHAKE_RESP_DUP); + } else { + // Connecting to a channel that has not been registered yet. + if (DEBUG) Log.d(TAG, "Emulator is connected to a pending Socket " + channel_name); + handshake.putInt(ProtocolConstants.HANDSHAKE_RESP_NOPORT); + sk = new Socket(sock, channel_name, endian); + mPendingSockets.add(sk); + } + } + + // Send handshake reply. + sock.getOutputStream().write(handshake.array()); + + // If a disconnected channel for emulator connection has been found, + // connect it. + if (channel != null && !channel.isConnected()) { + if (DEBUG) Log.d(TAG, "Connecting Channel " + channel_name + " with emulator."); + sk = new Socket(sock, channel_name, endian); + channel.connect(sk); + } + + mService.notifyStatusChanged(); + } + + /*************************************************************************** + * Logging wrappers + **************************************************************************/ + + private void Loge(String log) { + mService.addError(log); + Log.e(TAG, log); + } +} |