1 files changed, 238 insertions, 0 deletions
diff --git a/android/WALT/app/src/main/java/org/chromium/latency/walt/WaltTcpConnection.java b/android/WALT/app/src/main/java/org/chromium/latency/walt/WaltTcpConnection.java
new file mode 100644
index 0000000..ee9c143
--- /dev/null
+++ b/android/WALT/app/src/main/java/org/chromium/latency/walt/WaltTcpConnection.java
@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2016 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 org.chromium.latency.walt;
+
+import android.content.Context;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.net.SocketTimeoutException;
+
+
+public class WaltTcpConnection implements WaltConnection {
+
+    // The local ip on ARC++ to connect to underlying ChromeOS
+    private static final String SERVER_IP = "192.168.254.1";
+    private static final int SERVER_PORT = 50007;
+    private static final int TCP_READ_TIMEOUT_MS = 200;
+
+    private final SimpleLogger logger;
+    private HandlerThread networkThread;
+    private Handler networkHandler;
+    private final Object readLock = new Object();
+    private boolean messageReceived = false;
+    private Utils.ListenerState connectionState = Utils.ListenerState.STOPPED;
+    private int lastRetVal;
+    static final int BUFF_SIZE = 1024 * 4;
+    private byte[] buffer = new byte[BUFF_SIZE];
+
+    private final Handler mainHandler = new Handler();
+    private RemoteClockInfo remoteClock = new RemoteClockInfo();
+
+    private Socket socket;
+    private OutputStream outputStream = null;
+    private InputStream inputStream = null;
+
+    private WaltConnection.ConnectionStateListener connectionStateListener;
+
+    // Singleton stuff
+    private static WaltTcpConnection instance;
+    private static final Object LOCK = new Object();
+
+    public static WaltTcpConnection getInstance(Context context) {
+        synchronized (LOCK) {
+            if (instance == null) {
+                instance = new WaltTcpConnection(context.getApplicationContext());
+            }
+            return instance;
+        }
+    }
+
+    private WaltTcpConnection(Context context) {
+        logger = SimpleLogger.getInstance(context);
+    }
+
+    public void connect() {
+        connectionState = Utils.ListenerState.STARTING;
+        networkThread = new HandlerThread("NetworkThread");
+        networkThread.start();
+        networkHandler = new Handler(networkThread.getLooper());
+        logger.log("Started network thread for TCP bridge");
+        networkHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
+                    socket = new Socket(serverAddr, SERVER_PORT);
+                    socket.setSoTimeout(TCP_READ_TIMEOUT_MS);
+                    outputStream = socket.getOutputStream();
+                    inputStream = socket.getInputStream();
+                    logger.log("TCP connection established");
+                    connectionState = Utils.ListenerState.RUNNING;
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    logger.log("Can't connect to TCP bridge: " + e.getMessage());
+                    connectionState = Utils.ListenerState.STOPPED;
+                    return;
+                }
+
+                // Run the onConnect callback, but on main thread.
+                mainHandler.post(new Runnable() {
+                    @Override
+                    public void run() {
+                        WaltTcpConnection.this.onConnect();
+                    }
+                });
+            }
+        });
+
+    }
+
+    public void onConnect() {
+        if (connectionStateListener != null) {
+            connectionStateListener.onConnect();
+        }
+    }
+
+    public synchronized boolean isConnected() {
+        return connectionState == Utils.ListenerState.RUNNING;
+    }
+
+    public void sendByte(char c) throws IOException {
+        outputStream.write(Utils.char2byte(c));
+    }
+
+    public void sendString(String s) throws IOException {
+        outputStream.write(s.getBytes("UTF-8"));
+    }
+
+    public synchronized int blockingRead(byte[] buff) {
+
+        messageReceived = false;
+
+        networkHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                lastRetVal = -1;
+                try {
+                    synchronized (readLock) {
+                        lastRetVal = inputStream.read(buffer);
+                        messageReceived = true;
+                        readLock.notifyAll();
+                    }
+                } catch (SocketTimeoutException e) {
+                    messageReceived = true;
+                    lastRetVal = -2;
+                }
+                catch (Exception e) {
+                    e.printStackTrace();
+                    messageReceived = true;
+                    lastRetVal = -1;
+                    // TODO: better messaging / error handling here
+                }
+            }
+        });
+
+        // TODO: make sure length is ok
+        // This blocks on readLock which is taken by the blocking read operation
+        try {
+            synchronized (readLock) {
+                while (!messageReceived) readLock.wait(TCP_READ_TIMEOUT_MS);
+            }
+        } catch (InterruptedException e) {
+            return -1;
+        }
+
+        if (lastRetVal > 0) {
+            System.arraycopy(buffer, 0, buff, 0, lastRetVal);
+        }
+
+        return lastRetVal;
+    }
+
+
+    private void updateClock(String cmd) throws IOException {
+        sendString(cmd);
+        int retval = blockingRead(buffer);
+        if (retval <= 0) {
+            throw new IOException("WaltTcpConnection, can't sync clocks");
+        }
+        String s = new String(buffer, 0, retval);
+        String[] parts = s.trim().split("\\s+");
+        // TODO: make sure reply starts with "clock"
+        long wallBaseTime = Long.parseLong(parts[1]);
+        remoteClock.baseTime = wallBaseTime - RemoteClockInfo.uptimeZero();
+        remoteClock.minLag = Integer.parseInt(parts[2]);
+        remoteClock.maxLag = Integer.parseInt(parts[3]);
+    }
+
+    public RemoteClockInfo syncClock() throws IOException {
+        updateClock("bridge sync");
+        logger.log("Synced clocks via TCP bridge:\n" + remoteClock);
+        return remoteClock;
+    }
+
+    public void updateLag() {
+        try {
+            updateClock("bridge update");
+        } catch (IOException e) {
+            logger.log("Failed to update clock lag: " + e.getMessage());
+        }
+    }
+
+    public void setConnectionStateListener(ConnectionStateListener connectionStateListener) {
+        this.connectionStateListener = connectionStateListener;
+    }
+
+    // A way to test if there is a TCP bridge to decide whether to use it.
+    // Some thread dancing to get around the Android strict policy for no network on main thread.
+    public static boolean probe() {
+        ProbeThread probeThread = new ProbeThread();
+        probeThread.start();
+        try {
+            probeThread.join();
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+        return probeThread.isReachable;
+    }
+
+    private static class ProbeThread extends Thread {
+        public boolean isReachable = false;
+        private final String TAG = "ProbeThread";
+
+        @Override
+        public void run() {
+            Socket socket = new Socket();
+            try {
+                InetSocketAddress remoteAddr = new InetSocketAddress(SERVER_IP, SERVER_PORT);
+                socket.connect(remoteAddr, 50 /* timeout in milliseconds */);
+                isReachable = true;
+                socket.close();
+            } catch (Exception e) {
+                Log.i(TAG, "Probing TCP connection failed: " + e.getMessage());
+            }
+        }
+    }
+}