Detect and recycle dangling websockets.

src/org/thoughtcrime/securesms/service/IncomingMessageObserver.java

@@ -1,11 +1,18 @@
 package org.thoughtcrime.securesms.service;
 
 import android.app.Service;
+import android.content.BroadcastReceiver;
 import android.arch.lifecycle.DefaultLifecycleObserver;
 import android.arch.lifecycle.LifecycleOwner;
 import android.arch.lifecycle.ProcessLifecycleOwner;
 import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkRequest;
+import android.net.NetworkInfo;
+import android.os.Build;
 import android.os.IBinder;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -28,6 +35,7 @@
 import org.whispersystems.signalservice.api.SignalServiceMessagePipe;
 import org.whispersystems.signalservice.api.SignalServiceMessageReceiver;
 
+import java.io.IOException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
@@ -46,6 +54,14 @@ public class IncomingMessageObserver implements InjectableType, ConstraintObserv
   private final Context           context;
   private final NetworkConstraint networkConstraint;
 
+  public static AtomicReference<SignalServiceMessagePipe> pipeReference = new AtomicReference<>();
+  public static AtomicReference<SignalServiceMessagePipe> unidentifiedPipeReference = new AtomicReference<>();
+
+  private final MessageRetrievalThread retrievalThread;
+
+  private BroadcastReceiver connectivityChangeReceiver;
+  private ConnectivityManager.NetworkCallback connectivityChangeCallback;
+
   private boolean appVisible;
 
   @Inject SignalServiceMessageReceiver receiver;
@@ -58,10 +74,13 @@ public IncomingMessageObserver(@NonNull Context context) {
     this.networkConstraint = new NetworkConstraint.Factory(ApplicationContext.getInstance(context)).create();
 
     new NetworkConstraintObserver(ApplicationContext.getInstance(context)).register(this);
-    new MessageRetrievalThread().start();
+
+    retrievalThread = new MessageRetrievalThread();
+    retrievalThread.start();
 
     if (TextSecurePreferences.isFcmDisabled(context)) {
       ContextCompat.startForegroundService(context, new Intent(context, ForegroundService.class));
+      setupNetworkMonitoring();
     }
 
     ProcessLifecycleOwner.get().getLifecycle().addObserver(new DefaultLifecycleObserver() {
@@ -108,10 +127,12 @@ private synchronized boolean isConnectionNecessary() {
   }
 
   private synchronized void waitForConnectionNecessary() {
-    try {
-      while (!isConnectionNecessary()) wait();
-    } catch (InterruptedException e) {
-      throw new AssertionError(e);
+    while (!isConnectionNecessary()) {
+      try {
+        wait();
+      } catch (InterruptedException e) {
+        Log.d(TAG, "Retrieval thread interrupted while not connected; ignoring.");
+      }
     }
   }
 
@@ -153,7 +174,7 @@ public void run() {
         SignalServiceMessagePipe unidentifiedLocalPipe = unidentifiedPipe;
 
         try {
-          while (isConnectionNecessary()) {
+          while (isConnectionNecessary() && !interrupted()) {
             try {
               Log.i(TAG, "Reading message...");
               localPipe.read(REQUEST_TIMEOUT_MINUTES, TimeUnit.MINUTES,
@@ -167,6 +188,10 @@ public void run() {
               Log.w(TAG, e);
             }
           }
+        } catch (InterruptedException e) {
+          Log.d(TAG, "Retrieval thread interrupted.");
+        } catch (IOException e) {
+          Log.d(TAG, "Message pipe failed: " + e.getMessage());
         } catch (Throwable e) {
           Log.w(TAG, e);
         } finally {
@@ -185,6 +210,78 @@ public void uncaughtException(Thread t, Throwable e) {
     }
   }
 
+  private void setupNetworkMonitoring() {
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+      final ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+      connectivityChangeCallback = new ConnectivityManager.NetworkCallback() {
+        private Network current;
+
+        private void update(Network network) {
+          final Network previous = current;
+          current = network;
+
+          Log.d(TAG, "Currently active network: " + network);
+
+          if (previous != null && (current == null || !current.equals(previous))) {
+            Log.d(TAG,
+                  "Active network changed (" + previous + " -> " + current +
+                  "); interrupting the retrieval thread to recycle the pipe.");
+
+            retrievalThread.interrupt();
+          }
+        }
+
+        @Override
+        public void onAvailable(Network network) {
+          final ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+          update(connectivityManager.getActiveNetwork());
+        }
+
+        @Override
+        public void onLost(Network network) {
+          final ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+          update(connectivityManager.getActiveNetwork());
+        }
+      };
+
+      connectivityManager.registerNetworkCallback(new NetworkRequest.Builder().build(),
+                                                  connectivityChangeCallback);
+    } else {
+      connectivityChangeReceiver = new BroadcastReceiver() {
+        private int current = -1;
+
+        @Override
+        public void onReceive(Context context, Intent intent) {
+          final ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+          final NetworkInfo info = connectivityManager.getActiveNetworkInfo();
+          final int previous = current;
+
+          if (info == null) {
+            current = -1;
+          } else if (info.isConnected()) {
+            current = info.getType();
+          }
+
+          Log.d(TAG, "Currently active network: " + current);
+
+          if (previous != -1 && previous != current) {
+            Log.d(TAG,
+                  "Active network changed (" + previous + " -> " + current +
+                  "); interrupting the retrieval thread to recycle the pipe.");
+            retrievalThread.interrupt();
+          }
+        }
+      };
+
+      context.registerReceiver(connectivityChangeReceiver,
+                               new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
+    }
+  }
+
   public static class ForegroundService extends Service {
 
     @Override