Don't treat an incoming connection as an attempt to raise the limit.

Detect and close dead Bluetooth connections

See merge request briar/briar!1246

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java

@@ -9,6 +9,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -76,11 +77,12 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 	private volatile BluetoothAdapter adapter = null;
 
 	AndroidBluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
-			Executor ioExecutor, AndroidExecutor androidExecutor,
-			Context appContext, SecureRandom secureRandom, Clock clock,
-			Backoff backoff, PluginCallback callback, int maxLatency) {
-		super(connectionLimiter, ioExecutor, secureRandom, backoff, callback,
-				maxLatency);
+			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
+			SecureRandom secureRandom, AndroidExecutor androidExecutor,
+			Context appContext, Clock clock, Backoff backoff,
+			PluginCallback callback, int maxLatency, int maxIdleTime) {
+		super(connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
+				backoff, callback, maxLatency, maxIdleTime);
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
 		this.clock = clock;
@@ -172,9 +174,10 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		return wrapSocket(ss.accept());
 	}
 
-	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
-		return new AndroidBluetoothTransportConnection(this,
-				connectionLimiter, s);
+	private DuplexTransportConnection wrapSocket(BluetoothSocket s)
+			throws IOException {
+		return new AndroidBluetoothTransportConnection(this, connectionLimiter,
+				timeoutMonitor, s);
 	}
 
 	@Override

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPluginFactory.java

@@ -3,6 +3,7 @@ package org.briarproject.bramble.plugin.bluetooth;
 import android.content.Context;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -25,6 +26,7 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 
 	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
 	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
 	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
@@ -35,18 +37,20 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	private final SecureRandom secureRandom;
 	private final EventBus eventBus;
 	private final Clock clock;
+	private final TimeoutMonitor timeoutMonitor;
 	private final BackoffFactory backoffFactory;
 
 	public AndroidBluetoothPluginFactory(Executor ioExecutor,
 			AndroidExecutor androidExecutor, Context appContext,
 			SecureRandom secureRandom, EventBus eventBus, Clock clock,
-			BackoffFactory backoffFactory) {
+			TimeoutMonitor timeoutMonitor, BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
 		this.secureRandom = secureRandom;
 		this.eventBus = eventBus;
 		this.clock = clock;
+		this.timeoutMonitor = timeoutMonitor;
 		this.backoffFactory = backoffFactory;
 	}
 
@@ -63,12 +67,13 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		BluetoothConnectionLimiter connectionLimiter =
-				new BluetoothConnectionLimiterImpl();
+				new BluetoothConnectionLimiterImpl(eventBus, clock);
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
-				connectionLimiter, ioExecutor, androidExecutor, appContext,
-				secureRandom, clock, backoff, callback, MAX_LATENCY);
+				connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
+				androidExecutor, appContext, clock, backoff,
+				callback, MAX_LATENCY, MAX_IDLE_TIME);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothTransportConnection.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.plugin.bluetooth;
 
 import android.bluetooth.BluetoothSocket;
 
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
@@ -17,22 +18,26 @@ import static org.briarproject.bramble.util.AndroidUtils.isValidBluetoothAddress
 class AndroidBluetoothTransportConnection
 		extends AbstractDuplexTransportConnection {
 
-	private final BluetoothConnectionLimiter connectionManager;
+	private final BluetoothConnectionLimiter connectionLimiter;
 	private final BluetoothSocket socket;
+	private final InputStream in;
 
 	AndroidBluetoothTransportConnection(Plugin plugin,
-			BluetoothConnectionLimiter connectionManager,
-			BluetoothSocket socket) {
+			BluetoothConnectionLimiter connectionLimiter,
+			TimeoutMonitor timeoutMonitor, BluetoothSocket socket)
+			throws IOException {
 		super(plugin);
-		this.connectionManager = connectionManager;
+		this.connectionLimiter = connectionLimiter;
 		this.socket = socket;
+		in = timeoutMonitor.createTimeoutInputStream(
+				socket.getInputStream(), plugin.getMaxIdleTime() * 2);
 		String address = socket.getRemoteDevice().getAddress();
 		if (isValidBluetoothAddress(address)) remote.put(PROP_ADDRESS, address);
 	}
 
 	@Override
-	protected InputStream getInputStream() throws IOException {
-		return socket.getInputStream();
+	protected InputStream getInputStream() {
+		return in;
 	}
 
 	@Override
@@ -45,7 +50,7 @@ class AndroidBluetoothTransportConnection
 		try {
 			socket.close();
 		} finally {
-			connectionManager.connectionClosed(this);
+			connectionLimiter.connectionClosed(this, exception);
 		}
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/io/TimeoutMonitor.java

@@ -0,0 +1,15 @@
+package org.briarproject.bramble.api.io;
+
+import java.io.InputStream;
+
+public interface TimeoutMonitor {
+
+	/**
+	 * Returns an {@link InputStream} that wraps the given stream and allows
+	 * read timeouts to be detected.
+	 *
+	 * @param timeoutMs The read timeout in milliseconds. Timeouts will be
+	 * detected eventually but are not guaranteed to be detected immediately.
+	 */
+	InputStream createTimeoutInputStream(InputStream in, long timeoutMs);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/ConnectionRegistry.java

@@ -5,7 +5,8 @@ import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
 
@@ -20,15 +21,15 @@ public interface ConnectionRegistry {
 	/**
 	 * Registers a connection with the given contact over the given transport.
 	 * Broadcasts {@link ConnectionOpenedEvent}. Also broadcasts
-	 * {@link ConnectionStatusChangedEvent} if this is the only connection with
-	 * the contact.
+	 * {@link ContactConnectedEvent} if this is the only connection with the
+	 * contact.
 	 */
 	void registerConnection(ContactId c, TransportId t, boolean incoming);
 
 	/**
 	 * Unregisters a connection with the given contact over the given transport.
 	 * Broadcasts {@link ConnectionClosedEvent}. Also broadcasts
-	 * {@link ConnectionStatusChangedEvent} if this is the only connection with
+	 * {@link ContactDisconnectedEvent} if this is the only connection with
 	 * the contact.
 	 */
 	void unregisterConnection(ContactId c, TransportId t, boolean incoming);
@@ -44,9 +45,9 @@ public interface ConnectionRegistry {
 	boolean isConnected(ContactId c, TransportId t);
 
 	/**
-	 * Returns the connection status of the given contact via all transports.
+	 * Returns true if the given contact is connected via any transport.
 	 */
-	ConnectionStatus getConnectionStatus(ContactId c);
+	boolean isConnected(ContactId c);
 
 	/**
 	 * Registers a connection with the given pending contact. Broadcasts

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/ConnectionStatus.java

@@ -1,5 +0,0 @@
-package org.briarproject.bramble.api.plugin;
-
-public enum ConnectionStatus {
-	CONNECTED, RECENTLY_CONNECTED, DISCONNECTED
-}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/ContactConnectedEvent.java

@@ -3,31 +3,24 @@ package org.briarproject.bramble.api.plugin.event;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 
 import javax.annotation.concurrent.Immutable;
 
 /**
- * An event that is broadcast when a contact's connection status changes.
+ * An event that is broadcast when a contact connects that was not previously
+ * connected via any transport.
  */
 @Immutable
 @NotNullByDefault
-public class ConnectionStatusChangedEvent extends Event {
+public class ContactConnectedEvent extends Event {
 
 	private final ContactId contactId;
-	private final ConnectionStatus status;
 
-	public ConnectionStatusChangedEvent(ContactId contactId,
-			ConnectionStatus status) {
+	public ContactConnectedEvent(ContactId contactId) {
 		this.contactId = contactId;
-		this.status = status;
 	}
 
 	public ContactId getContactId() {
 		return contactId;
 	}
-
-	public ConnectionStatus getConnectionStatus() {
-		return status;
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/ContactDisconnectedEvent.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.plugin.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a contact disconnects and is no longer
+ * connected via any transport.
+ */
+@Immutable
+@NotNullByDefault
+public class ContactDisconnectedEvent extends Event {
+
+	private final ContactId contactId;
+
+	public ContactDisconnectedEvent(ContactId contactId) {
+		this.contactId = contactId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncSessionFactory.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.api.sync;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.transport.StreamWriter;
 
 import java.io.InputStream;
@@ -11,9 +12,9 @@ public interface SyncSessionFactory {
 
 	SyncSession createIncomingSession(ContactId c, InputStream in);
 
-	SyncSession createSimplexOutgoingSession(ContactId c, int maxLatency,
-			StreamWriter streamWriter);
+	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
+			int maxLatency, StreamWriter streamWriter);
 
-	SyncSession createDuplexOutgoingSession(ContactId c, int maxLatency,
-			int maxIdleTime, StreamWriter streamWriter);
+	SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
+			int maxLatency, int maxIdleTime, StreamWriter streamWriter);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/event/CloseSyncConnectionsEvent.java

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.sync.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when all sync connections using a given
+ * transport should be closed.
+ */
+@Immutable
+@NotNullByDefault
+public class CloseSyncConnectionsEvent extends Event {
+
+	private final TransportId transportId;
+
+	public CloseSyncConnectionsEvent(TransportId transportId) {
+		this.transportId = transportId;
+	}
+
+	public TransportId getTransportId() {
+		return transportId;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/BrambleCoreModule.java

@@ -9,6 +9,7 @@ import org.briarproject.bramble.db.DatabaseExecutorModule;
 import org.briarproject.bramble.db.DatabaseModule;
 import org.briarproject.bramble.event.EventModule;
 import org.briarproject.bramble.identity.IdentityModule;
+import org.briarproject.bramble.io.IoModule;
 import org.briarproject.bramble.keyagreement.KeyAgreementModule;
 import org.briarproject.bramble.lifecycle.LifecycleModule;
 import org.briarproject.bramble.plugin.PluginModule;
@@ -35,6 +36,7 @@ import dagger.Module;
 		DatabaseExecutorModule.class,
 		EventModule.class,
 		IdentityModule.class,
+		IoModule.class,
 		KeyAgreementModule.class,
 		LifecycleModule.class,
 		PluginModule.class,

bramble-core/src/main/java/org/briarproject/bramble/io/IoModule.java

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.io;
+
+import org.briarproject.bramble.api.io.TimeoutMonitor;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class IoModule {
+
+	@Provides
+	@Singleton
+	TimeoutMonitor provideTimeoutMonitor(TimeoutMonitorImpl timeoutMonitor) {
+		return timeoutMonitor;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/io/TimeoutInputStream.java

@@ -0,0 +1,104 @@
+package org.briarproject.bramble.io;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.Clock;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.annotation.concurrent.GuardedBy;
+
+@NotNullByDefault
+class TimeoutInputStream extends InputStream {
+
+	private final Clock clock;
+	private final InputStream in;
+	private final long timeoutMs;
+	private final CloseListener listener;
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private long readStartedMs = -1;
+
+	TimeoutInputStream(Clock clock, InputStream in, long timeoutMs,
+			CloseListener listener) {
+		this.clock = clock;
+		this.in = in;
+		this.timeoutMs = timeoutMs;
+		this.listener = listener;
+	}
+
+	@Override
+	public int read() throws IOException {
+		synchronized (lock) {
+			readStartedMs = clock.currentTimeMillis();
+		}
+		int input = in.read();
+		synchronized (lock) {
+			readStartedMs = -1;
+		}
+		return input;
+	}
+
+	@Override
+	public int read(byte[] b) throws IOException {
+		return read(b, 0, b.length);
+	}
+
+	@Override
+	public int read(byte[] b, int off, int len) throws IOException {
+		synchronized (lock) {
+			readStartedMs = clock.currentTimeMillis();
+		}
+		int read = in.read(b, off, len);
+		synchronized (lock) {
+			readStartedMs = -1;
+		}
+		return read;
+	}
+
+	@Override
+	public void close() throws IOException {
+		try {
+			in.close();
+		} finally {
+			listener.onClose(this);
+		}
+	}
+
+	@Override
+	public int available() throws IOException {
+		return in.available();
+	}
+
+	@Override
+	public void mark(int readlimit) {
+		in.mark(readlimit);
+	}
+
+	@Override
+	public boolean markSupported() {
+		return in.markSupported();
+	}
+
+	@Override
+	public void reset() throws IOException {
+		in.reset();
+	}
+
+	@Override
+	public long skip(long n) throws IOException {
+		return in.skip(n);
+	}
+
+	boolean hasTimedOut() {
+		synchronized (lock) {
+			return readStartedMs != -1 &&
+					clock.currentTimeMillis() - readStartedMs > timeoutMs;
+		}
+	}
+
+	interface CloseListener {
+
+		void onClose(TimeoutInputStream closed);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/io/TimeoutMonitorImpl.java

@@ -0,0 +1,96 @@
+package org.briarproject.bramble.io;
+
+import org.briarproject.bramble.api.io.TimeoutMonitor;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.Scheduler;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+import javax.inject.Inject;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+class TimeoutMonitorImpl implements TimeoutMonitor {
+
+	private static final Logger LOG =
+			getLogger(TimeoutMonitorImpl.class.getName());
+
+	private static final long CHECK_INTERVAL_MS = SECONDS.toMillis(10);
+
+	private final ScheduledExecutorService scheduler;
+	private final Executor ioExecutor;
+	private final Clock clock;
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private final List<TimeoutInputStream> streams = new ArrayList<>();
+
+	@GuardedBy("lock")
+	private Future<?> task = null;
+
+	@Inject
+	TimeoutMonitorImpl(@Scheduler ScheduledExecutorService scheduler,
+			@IoExecutor Executor ioExecutor, Clock clock) {
+		this.scheduler = scheduler;
+		this.ioExecutor = ioExecutor;
+		this.clock = clock;
+	}
+
+	@Override
+	public InputStream createTimeoutInputStream(InputStream in,
+			long timeoutMs) {
+		TimeoutInputStream stream = new TimeoutInputStream(clock, in,
+				timeoutMs, this::removeStream);
+		synchronized (lock) {
+			if (streams.isEmpty()) {
+				task = scheduler.scheduleWithFixedDelay(this::checkTimeouts,
+						CHECK_INTERVAL_MS, CHECK_INTERVAL_MS, MILLISECONDS);
+			}
+			streams.add(stream);
+		}
+		return stream;
+	}
+
+	private void removeStream(TimeoutInputStream stream) {
+		Future<?> toCancel = null;
+		synchronized (lock) {
+			if (streams.remove(stream) && streams.isEmpty()) {
+				toCancel = task;
+				task = null;
+			}
+		}
+		if (toCancel != null) toCancel.cancel(false);
+	}
+
+	@Scheduler
+	private void checkTimeouts() {
+		ioExecutor.execute(() -> {
+			List<TimeoutInputStream> snapshot;
+			synchronized (lock) {
+				snapshot = new ArrayList<>(streams);
+			}
+			for (TimeoutInputStream stream : snapshot) {
+				if (stream.hasTimedOut()) {
+					LOG.info("Input stream has timed out");
+					try {
+						stream.close();
+					} catch (IOException e) {
+						logException(LOG, INFO, e);
+					}
+				}
+			}
+		});
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/plugin/ConnectionManagerImpl.java

@@ -130,8 +130,8 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionWriter w) throws IOException {
 		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
 				w.getOutputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory.createSimplexOutgoingSession(c,
+		return syncSessionFactory.createSimplexOutgoingSession(
+				requireNonNull(ctx.getContactId()), ctx.getTransportId(),
 				w.getMaxLatency(), streamWriter);
 	}
 
@@ -139,8 +139,8 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionWriter w) throws IOException {
 		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
 				w.getOutputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory.createDuplexOutgoingSession(c,
+		return syncSessionFactory.createDuplexOutgoingSession(
+				requireNonNull(ctx.getContactId()), ctx.getTransportId(),
 				w.getMaxLatency(), w.getMaxIdleTime(), streamWriter);
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/ConnectionRegistryImpl.java

@@ -6,41 +6,30 @@ import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
-import static java.util.Collections.emptyList;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.DISCONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 
 @ThreadSafe
 @NotNullByDefault
@@ -49,30 +38,22 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	private static final Logger LOG =
 			getLogger(ConnectionRegistryImpl.class.getName());
 
-	private static final long RECENTLY_CONNECTED_MS = MINUTES.toMillis(1);
-	private static final long EXPIRY_INTERVAL_MS = SECONDS.toMillis(10);
-
 	private final EventBus eventBus;
-	private final Clock clock;
 
 	private final Object lock = new Object();
 	@GuardedBy("lock")
 	private final Map<TransportId, Multiset<ContactId>> contactConnections;
 	@GuardedBy("lock")
-	private final Map<ContactId, Counter> contactCounts;
+	private final Multiset<ContactId> contactCounts;
 	@GuardedBy("lock")
 	private final Set<PendingContactId> connectedPendingContacts;
 
 	@Inject
-	ConnectionRegistryImpl(EventBus eventBus, Clock clock,
-			@Scheduler ScheduledExecutorService scheduler) {
+	ConnectionRegistryImpl(EventBus eventBus) {
 		this.eventBus = eventBus;
-		this.clock = clock;
 		contactConnections = new HashMap<>();
-		contactCounts = new HashMap<>();
+		contactCounts = new Multiset<>();
 		connectedPendingContacts = new HashSet<>();
-		scheduler.scheduleWithFixedDelay(this::expireRecentConnections,
-				EXPIRY_INTERVAL_MS, EXPIRY_INTERVAL_MS, MILLISECONDS);
 	}
 
 	@Override
@@ -90,22 +71,12 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 				contactConnections.put(t, m);
 			}
 			m.add(c);
-
-			Counter counter = contactCounts.get(c);
-			if (counter == null) {
-				counter = new Counter();
-				contactCounts.put(c, counter);
-			}
-			if (counter.connections == 0) {
-				counter.disconnectedTime = 0;
-				firstConnection = true;
-			}
-			counter.connections++;
+			if (contactCounts.add(c) == 1) firstConnection = true;
 		}
 		eventBus.broadcast(new ConnectionOpenedEvent(c, t, incoming));
 		if (firstConnection) {
 			LOG.info("Contact connected");
-			eventBus.broadcast(new ConnectionStatusChangedEvent(c, CONNECTED));
+			eventBus.broadcast(new ContactConnectedEvent(c));
 		}
 	}
 
@@ -122,22 +93,12 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 			if (m == null || !m.contains(c))
 				throw new IllegalArgumentException();
 			m.remove(c);
-
-			Counter counter = contactCounts.get(c);
-			if (counter == null || counter.connections == 0) {
-				throw new IllegalArgumentException();
-			}
-			counter.connections--;
-			if (counter.connections == 0) {
-				counter.disconnectedTime = clock.currentTimeMillis();
-				lastConnection = true;
-			}
+			if (contactCounts.remove(c) == 0) lastConnection = true;
 		}
 		eventBus.broadcast(new ConnectionClosedEvent(c, t, incoming));
 		if (lastConnection) {
 			LOG.info("Contact disconnected");
-			eventBus.broadcast(
-					new ConnectionStatusChangedEvent(c, RECENTLY_CONNECTED));
+			eventBus.broadcast(new ContactDisconnectedEvent(c));
 		}
 	}
 
@@ -145,7 +106,7 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	public Collection<ContactId> getConnectedContacts(TransportId t) {
 		synchronized (lock) {
 			Multiset<ContactId> m = contactConnections.get(t);
-			if (m == null) return emptyList();
+			if (m == null) return Collections.emptyList();
 			List<ContactId> ids = new ArrayList<>(m.keySet());
 			if (LOG.isLoggable(INFO))
 				LOG.info(ids.size() + " contacts connected: " + t);
@@ -162,11 +123,9 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	}
 
 	@Override
-	public ConnectionStatus getConnectionStatus(ContactId c) {
+	public boolean isConnected(ContactId c) {
 		synchronized (lock) {
-			Counter counter = contactCounts.get(c);
-			if (counter == null) return DISCONNECTED;
-			return counter.connections > 0 ? CONNECTED : RECENTLY_CONNECTED;
+			return contactCounts.contains(c);
 		}
 	}
 
@@ -188,36 +147,4 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 		}
 		eventBus.broadcast(new RendezvousConnectionClosedEvent(p, success));
 	}
-
-	@Scheduler
-	private void expireRecentConnections() {
-		long now = clock.currentTimeMillis();
-		List<ContactId> disconnected = new ArrayList<>();
-		synchronized (lock) {
-			Iterator<Entry<ContactId, Counter>> it =
-					contactCounts.entrySet().iterator();
-			while (it.hasNext()) {
-				Entry<ContactId, Counter> e = it.next();
-				if (e.getValue().isExpired(now)) {
-					disconnected.add(e.getKey());
-					it.remove();
-				}
-			}
-		}
-		for (ContactId c : disconnected) {
-			eventBus.broadcast(
-					new ConnectionStatusChangedEvent(c, DISCONNECTED));
-		}
-	}
-
-	private static class Counter {
-
-		private int connections = 0;
-		private long disconnectedTime = 0;
-
-		private boolean isExpired(long now) {
-			return connections == 0 &&
-					now - disconnectedTime > RECENTLY_CONNECTED_MS;
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothConnectionLimiter.java

@@ -3,9 +3,30 @@ package org.briarproject.bramble.plugin.bluetooth;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 
+import static java.util.concurrent.TimeUnit.DAYS;
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
+
 @NotNullByDefault
 interface BluetoothConnectionLimiter {
 
+	/**
+	 * How long a connection must remain open before it's considered stable.
+	 */
+	long STABILITY_PERIOD_MS = SECONDS.toMillis(90);
+
+	/**
+	 * The minimum interval between attempts to raise the connection limit.
+	 * This is longer than {@link #STABILITY_PERIOD_MS} so we don't start
+	 * another attempt before knowing the outcome of the last one.
+	 */
+	long MIN_ATTEMPT_INTERVAL_MS = MINUTES.toMillis(2);
+
+	/**
+	 * The maximum interval between attempts to raise the connection limit.
+	 */
+	long MAX_ATTEMPT_INTERVAL_MS = DAYS.toMillis(2);
+
 	/**
 	 * Informs the limiter that key agreement has started.
 	 */
@@ -23,12 +44,12 @@ interface BluetoothConnectionLimiter {
 	boolean canOpenContactConnection();
 
 	/**
-	 * Informs the limiter that a contact connection has been opened. The
-	 * limiter may close the new connection if key agreement is in progress.
+	 * Informs the limiter that a contact connection has been opened.
 	 * <p/>
-	 * Returns false if the limiter has closed the new connection.
+	 * Returns true if the connection is allowed.
 	 */
-	boolean contactConnectionOpened(DuplexTransportConnection conn);
+	boolean contactConnectionOpened(DuplexTransportConnection conn,
+			boolean incoming);
 
 	/**
 	 * Informs the limiter that a key agreement connection has been opened.
@@ -37,11 +58,13 @@ interface BluetoothConnectionLimiter {
 
 	/**
 	 * Informs the limiter that the given connection has been closed.
+	 *
+	 * @param exception True if the connection was closed due to an exception.
 	 */
-	void connectionClosed(DuplexTransportConnection conn);
+	void connectionClosed(DuplexTransportConnection conn, boolean exception);
 
 	/**
-	 * Informs the limiter that all connections have been closed.
+	 * Informs the limiter that the Bluetooth adapter has been disabled.
 	 */
-	void allConnectionsClosed();
+	void bluetoothDisabled();
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothConnectionLimiterImpl.java

@@ -1,46 +1,59 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
+import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.sync.event.CloseSyncConnectionsEvent;
+import org.briarproject.bramble.api.system.Clock;
 
-import java.io.IOException;
-import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.logging.Logger;
 
+import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
+import javax.inject.Inject;
 
+import static java.lang.Math.min;
 import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 
 @NotNullByDefault
 @ThreadSafe
 class BluetoothConnectionLimiterImpl implements BluetoothConnectionLimiter {
 
 	private static final Logger LOG =
-			Logger.getLogger(BluetoothConnectionLimiterImpl.class.getName());
+			getLogger(BluetoothConnectionLimiterImpl.class.getName());
+
+	private final EventBus eventBus;
+	private final Clock clock;
 
 	private final Object lock = new Object();
-	// The following are locking: lock
-	private final LinkedList<DuplexTransportConnection> connections =
-			new LinkedList<>();
+	@GuardedBy("lock")
+	private final List<ConnectionRecord> connections = new LinkedList<>();
+	@GuardedBy("lock")
 	private boolean keyAgreementInProgress = false;
+	@GuardedBy("lock")
+	private int connectionLimit = 1;
+	@GuardedBy("lock")
+	private long timeOfLastAttempt = 0,
+			attemptInterval = MIN_ATTEMPT_INTERVAL_MS;
+
+	@Inject
+	BluetoothConnectionLimiterImpl(EventBus eventBus, Clock clock) {
+		this.eventBus = eventBus;
+		this.clock = clock;
+	}
 
 	@Override
 	public void keyAgreementStarted() {
-		List<DuplexTransportConnection> close;
 		synchronized (lock) {
 			keyAgreementInProgress = true;
-			close = new ArrayList<>(connections);
-			connections.clear();
 		}
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Key agreement started, closing " + close.size() +
-					" connections");
-		}
-		for (DuplexTransportConnection conn : close) tryToClose(conn);
+		LOG.info("Key agreement started");
+		eventBus.broadcast(new CloseSyncConnectionsEvent(ID));
 	}
 
 	@Override
@@ -55,62 +68,128 @@ class BluetoothConnectionLimiterImpl implements BluetoothConnectionLimiter {
 	public boolean canOpenContactConnection() {
 		synchronized (lock) {
 			if (keyAgreementInProgress) {
-				LOG.info("Can't open contact connection during key agreement");
+				LOG.info("Refusing contact connection during key agreement");
 				return false;
 			} else {
-				LOG.info("Can open contact connection");
-				return true;
+				long now = clock.currentTimeMillis();
+				return isContactConnectionAllowedByLimit(now);
 			}
 		}
 	}
 
 	@Override
-	public boolean contactConnectionOpened(DuplexTransportConnection conn) {
-		boolean accept = true;
+	public boolean contactConnectionOpened(DuplexTransportConnection conn,
+			boolean incoming) {
 		synchronized (lock) {
 			if (keyAgreementInProgress) {
 				LOG.info("Refusing contact connection during key agreement");
-				accept = false;
+				return false;
 			} else {
-				LOG.info("Accepting contact connection");
-				connections.add(conn);
+				long now = clock.currentTimeMillis();
+				if (incoming || isContactConnectionAllowedByLimit(now)) {
+					connections.add(new ConnectionRecord(conn, now));
+					if (!incoming && connections.size() > connectionLimit) {
+						LOG.info("Attempting to raise connection limit");
+						timeOfLastAttempt = now;
+					}
+					return true;
+				} else {
+					return false;
+				}
 			}
 		}
-		if (!accept) tryToClose(conn);
-		return accept;
 	}
 
 	@Override
 	public void keyAgreementConnectionOpened(DuplexTransportConnection conn) {
 		synchronized (lock) {
 			LOG.info("Accepting key agreement connection");
-			connections.add(conn);
-		}
-	}
-
-	private void tryToClose(DuplexTransportConnection conn) {
-		try {
-			conn.getWriter().dispose(false);
-			conn.getReader().dispose(false, false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
+			connections.add(
+					new ConnectionRecord(conn, clock.currentTimeMillis()));
 		}
 	}
 
 	@Override
-	public void connectionClosed(DuplexTransportConnection conn) {
+	public void connectionClosed(DuplexTransportConnection conn,
+			boolean exception) {
 		synchronized (lock) {
-			connections.remove(conn);
+			Iterator<ConnectionRecord> it = connections.iterator();
+			while (it.hasNext()) {
+				if (it.next().connection == conn) {
+					long now = clock.currentTimeMillis();
+					if (exception) connectionFailed(now);
+					else considerRaisingConnectionLimit(now);
+					it.remove();
+					break;
+				}
+			}
 			if (LOG.isLoggable(INFO))
 				LOG.info("Connection closed, " + connections.size() + " open");
 		}
 	}
 
 	@Override
-	public void allConnectionsClosed() {
+	public void bluetoothDisabled() {
 		synchronized (lock) {
+			LOG.info("Bluetooth disabled");
+			considerRaisingConnectionLimit(clock.currentTimeMillis());
 			connections.clear();
-			LOG.info("All connections closed");
+		}
+	}
+
+	@GuardedBy("lock")
+	private boolean isContactConnectionAllowedByLimit(long now) {
+		considerRaisingConnectionLimit(now);
+		if (connections.size() > connectionLimit) {
+			LOG.info("Refusing contact connection, above limit");
+			return false;
+		} else if (connections.size() < connectionLimit) {
+			LOG.info("Allowing contact connection, below limit");
+			return true;
+		} else if (now - timeOfLastAttempt >= attemptInterval) {
+			LOG.info("Allowing contact connection, at limit");
+			return true;
+		} else {
+			LOG.info("Refusing contact connection, at limit");
+			return false;
+		}
+	}
+
+	@GuardedBy("lock")
+	private void considerRaisingConnectionLimit(long now) {
+		int stable = 0;
+		for (ConnectionRecord rec : connections) {
+			if (now - rec.timeOpened >= STABILITY_PERIOD_MS) stable++;
+		}
+		if (stable > connectionLimit) {
+			LOG.info("Raising connection limit");
+			connectionLimit = stable;
+			attemptInterval = MIN_ATTEMPT_INTERVAL_MS;
+		}
+		if (LOG.isLoggable(INFO)) {
+			LOG.info(stable + " connections are stable, limit is "
+					+ connectionLimit);
+		}
+	}
+
+	@GuardedBy("lock")
+	private void connectionFailed(long now) {
+		if (connections.size() > connectionLimit &&
+				now - timeOfLastAttempt < STABILITY_PERIOD_MS) {
+			LOG.info("Connection failed above limit, increasing interval");
+			attemptInterval = min(attemptInterval * 2, MAX_ATTEMPT_INTERVAL_MS);
+		}
+	}
+
+	private static final class ConnectionRecord {
+
+		private final DuplexTransportConnection connection;
+		private final long timeOpened;
+
+		private ConnectionRecord(DuplexTransportConnection connection,
+				long timeOpened) {
+			this.connection = connection;
+			this.timeOpened = timeOpened;
 		}
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementListeningEvent;
@@ -60,12 +61,13 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			getLogger(BluetoothPlugin.class.getName());
 
 	final BluetoothConnectionLimiter connectionLimiter;
+	final TimeoutMonitor timeoutMonitor;
 
 	private final Executor ioExecutor;
 	private final SecureRandom secureRandom;
 	private final Backoff backoff;
 	private final PluginCallback callback;
-	private final int maxLatency;
+	private final int maxLatency, maxIdleTime;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	private volatile boolean running = false, contactConnections = false;
@@ -105,14 +107,17 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	abstract DuplexTransportConnection discoverAndConnect(String uuid);
 
 	BluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
-			Executor ioExecutor, SecureRandom secureRandom,
-			Backoff backoff, PluginCallback callback, int maxLatency) {
+			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
+			SecureRandom secureRandom, Backoff backoff,
+			PluginCallback callback, int maxLatency, int maxIdleTime) {
 		this.connectionLimiter = connectionLimiter;
+		this.timeoutMonitor = timeoutMonitor;
 		this.ioExecutor = ioExecutor;
 		this.secureRandom = secureRandom;
 		this.backoff = backoff;
 		this.callback = callback;
 		this.maxLatency = maxLatency;
+		this.maxIdleTime = maxIdleTime;
 	}
 
 	void onAdapterEnabled() {
@@ -125,7 +130,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	void onAdapterDisabled() {
 		LOG.info("Bluetooth disabled");
 		tryToClose(socket);
-		connectionLimiter.allConnectionsClosed();
+		connectionLimiter.bluetoothDisabled();
 		callback.transportDisabled();
 	}
 
@@ -141,8 +146,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@Override
 	public int getMaxIdleTime() {
-		// Bluetooth detects dead connections so we don't need keepalives
-		return Integer.MAX_VALUE;
+		return maxIdleTime;
 	}
 
 	@Override
@@ -227,13 +231,26 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
 				return;
 			}
-			backoff.reset();
-			if (connectionLimiter.contactConnectionOpened(conn))
+			LOG.info("Connection received");
+			if (connectionLimiter.contactConnectionOpened(conn, true)) {
+				backoff.reset();
 				callback.handleConnection(conn);
+			} else {
+				tryToClose(conn);
+			}
 			if (!running) return;
 		}
 	}
 
+	private void tryToClose(DuplexTransportConnection conn) {
+		try {
+			conn.getWriter().dispose(false);
+			conn.getReader().dispose(false, false);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
 	@Override
 	public void stop() {
 		running = false;
@@ -273,13 +290,10 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		String uuid = p.get(PROP_UUID);
 		if (isNullOrEmpty(uuid)) return;
 		ioExecutor.execute(() -> {
-			if (!isRunning() || !shouldAllowContactConnections()) return;
-			if (!connectionLimiter.canOpenContactConnection()) return;
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
 				backoff.reset();
-				if (connectionLimiter.contactConnectionOpened(d))
-					h.handleConnection(d);
+				h.handleConnection(d);
 			}
 		});
 	}
@@ -325,8 +339,12 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (isNullOrEmpty(uuid)) return null;
 		DuplexTransportConnection conn = connect(address, uuid);
 		if (conn == null) return null;
-		// TODO: Why don't we reset the backoff here?
-		return connectionLimiter.contactConnectionOpened(conn) ? conn : null;
+		if (connectionLimiter.contactConnectionOpened(conn, false)) {
+			return conn;
+		} else {
+			tryToClose(conn);
+			return null;
+		}
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/sync/DuplexOutgoingSession.java

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.Offer;
@@ -18,6 +19,7 @@ import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.Versions;
+import org.briarproject.bramble.api.sync.event.CloseSyncConnectionsEvent;
 import org.briarproject.bramble.api.sync.event.GroupVisibilityUpdatedEvent;
 import org.briarproject.bramble.api.sync.event.MessageRequestedEvent;
 import org.briarproject.bramble.api.sync.event.MessageSharedEvent;
@@ -71,6 +73,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	private final EventBus eventBus;
 	private final Clock clock;
 	private final ContactId contactId;
+	private final TransportId transportId;
 	private final int maxLatency, maxIdleTime;
 	private final StreamWriter streamWriter;
 	private final SyncRecordWriter recordWriter;
@@ -86,14 +89,15 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	private volatile boolean interrupted = false;
 
 	DuplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
-			EventBus eventBus, Clock clock, ContactId contactId, int maxLatency,
-			int maxIdleTime, StreamWriter streamWriter,
-			SyncRecordWriter recordWriter) {
+			EventBus eventBus, Clock clock, ContactId contactId,
+			TransportId transportId, int maxLatency, int maxIdleTime,
+			StreamWriter streamWriter, SyncRecordWriter recordWriter) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.clock = clock;
 		this.contactId = contactId;
+		this.transportId = transportId;
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
 		this.streamWriter = streamWriter;
@@ -223,6 +227,9 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		} else if (e instanceof LifecycleEvent) {
 			LifecycleEvent l = (LifecycleEvent) e;
 			if (l.getLifecycleState() == STOPPING) interrupt();
+		} else if (e instanceof CloseSyncConnectionsEvent) {
+			CloseSyncConnectionsEvent c = (CloseSyncConnectionsEvent) e;
+			if (c.getTransportId().equals(transportId)) interrupt();
 		}
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/sync/SimplexOutgoingSession.java

@@ -11,11 +11,13 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.Versions;
+import org.briarproject.bramble.api.sync.event.CloseSyncConnectionsEvent;
 import org.briarproject.bramble.api.transport.StreamWriter;
 
 import java.io.IOException;
@@ -56,6 +58,7 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 	private final Executor dbExecutor;
 	private final EventBus eventBus;
 	private final ContactId contactId;
+	private final TransportId transportId;
 	private final int maxLatency;
 	private final StreamWriter streamWriter;
 	private final SyncRecordWriter recordWriter;
@@ -65,12 +68,14 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 	private volatile boolean interrupted = false;
 
 	SimplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
-			EventBus eventBus, ContactId contactId, int maxLatency,
-			StreamWriter streamWriter, SyncRecordWriter recordWriter) {
+			EventBus eventBus, ContactId contactId, TransportId transportId,
+			int maxLatency, StreamWriter streamWriter,
+			SyncRecordWriter recordWriter) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.contactId = contactId;
+		this.transportId = transportId;
 		this.maxLatency = maxLatency;
 		this.streamWriter = streamWriter;
 		this.recordWriter = recordWriter;
@@ -123,6 +128,9 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 		} else if (e instanceof LifecycleEvent) {
 			LifecycleEvent l = (LifecycleEvent) e;
 			if (l.getLifecycleState() == STOPPING) interrupt();
+		} else if (e instanceof CloseSyncConnectionsEvent) {
+			CloseSyncConnectionsEvent c = (CloseSyncConnectionsEvent) e;
+			if (c.getTransportId().equals(transportId)) interrupt();
 		}
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/sync/SyncSessionFactoryImpl.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.SyncRecordReaderFactory;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
@@ -53,22 +54,23 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 	}
 
 	@Override
-	public SyncSession createSimplexOutgoingSession(ContactId c,
+	public SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
 			int maxLatency, StreamWriter streamWriter) {
 		OutputStream out = streamWriter.getOutputStream();
 		SyncRecordWriter recordWriter =
 				recordWriterFactory.createRecordWriter(out);
-		return new SimplexOutgoingSession(db, dbExecutor, eventBus, c,
+		return new SimplexOutgoingSession(db, dbExecutor, eventBus, c, t,
 				maxLatency, streamWriter, recordWriter);
 	}
 
 	@Override
-	public SyncSession createDuplexOutgoingSession(ContactId c, int maxLatency,
-			int maxIdleTime, StreamWriter streamWriter) {
+	public SyncSession createDuplexOutgoingSession(ContactId c,
+			TransportId t, int maxLatency, int maxIdleTime,
+			StreamWriter streamWriter) {
 		OutputStream out = streamWriter.getOutputStream();
 		SyncRecordWriter recordWriter =
 				recordWriterFactory.createRecordWriter(out);
-		return new DuplexOutgoingSession(db, dbExecutor, eventBus, clock, c,
+		return new DuplexOutgoingSession(db, dbExecutor, eventBus, clock, c, t,
 				maxLatency, maxIdleTime, streamWriter, recordWriter);
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/io/TimeoutInputStreamTest.java

@@ -0,0 +1,143 @@
+package org.briarproject.bramble.io;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.SettableClock;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+public class TimeoutInputStreamTest extends BrambleTestCase {
+
+	private static final long TIMEOUT_MS = MINUTES.toMillis(1);
+
+	private final long now = System.currentTimeMillis();
+
+	private AtomicLong time;
+	private UnresponsiveInputStream in;
+	private AtomicBoolean listenerCalled;
+	private TimeoutInputStream stream;
+	private CountDownLatch readReturned;
+
+	@Before
+	public void setUp() {
+		time = new AtomicLong(now);
+		in = new UnresponsiveInputStream();
+		listenerCalled = new AtomicBoolean(false);
+		stream = new TimeoutInputStream(new SettableClock(time), in,
+				TIMEOUT_MS, stream -> listenerCalled.set(true));
+		readReturned = new CountDownLatch(1);
+	}
+
+	@Test
+	public void testTimeoutIsReportedIfReadDoesNotReturn() throws Exception {
+		startReading();
+		try {
+			// The stream should not report a timeout
+			assertFalse(stream.hasTimedOut());
+
+			// Time passes
+			time.set(now + TIMEOUT_MS);
+
+			// The stream still shouldn't report a timeout
+			assertFalse(stream.hasTimedOut());
+
+			// Time passes
+			time.set(now + TIMEOUT_MS + 1);
+
+			// The stream should report a timeout
+			assertTrue(stream.hasTimedOut());
+
+			// The listener should not have been called yet
+			assertFalse(listenerCalled.get());
+
+			// Close the stream
+			stream.close();
+
+			// The listener should have been called
+			assertTrue(listenerCalled.get());
+		} finally {
+			// Allow the read to return
+			in.readFinished.countDown();
+		}
+	}
+
+	@Test
+	public void testTimeoutIsNotReportedIfReadReturns() throws Exception {
+		startReading();
+		try {
+			// The stream should not report a timeout
+			assertFalse(stream.hasTimedOut());
+
+			// Time passes
+			time.set(now + TIMEOUT_MS);
+
+			// The stream still shouldn't report a timeout
+			assertFalse(stream.hasTimedOut());
+
+			// Allow the read to finish and wait for it to return
+			in.readFinished.countDown();
+			readReturned.await(10, SECONDS);
+
+			// Time passes
+			time.set(now + TIMEOUT_MS + 1);
+
+			// The stream should not report a timeout as the read has returned
+			assertFalse(stream.hasTimedOut());
+
+			// The listener should not have been called yet
+			assertFalse(listenerCalled.get());
+
+			// Close the stream
+			stream.close();
+
+			// The listener should have been called
+			assertTrue(listenerCalled.get());
+		} finally {
+			// Allow the read to return in case an assertion was thrown
+			in.readFinished.countDown();
+		}
+	}
+
+	private void startReading() throws Exception {
+		// Start a background thread to read from the unresponsive stream
+		new Thread(() -> {
+			try {
+				assertEquals(123, stream.read());
+				readReturned.countDown();
+			} catch (IOException e) {
+				fail();
+			}
+		}).start();
+		// Wait for the background thread to start reading
+		assertTrue(in.readStarted.await(10, SECONDS));
+	}
+
+	private class UnresponsiveInputStream extends InputStream {
+
+		private final CountDownLatch readStarted = new CountDownLatch(1);
+		private final CountDownLatch readFinished = new CountDownLatch(1);
+
+		@Override
+		public int read() throws IOException {
+			readStarted.countDown();
+			try {
+				readFinished.await();
+				return 123;
+			} catch (InterruptedException e) {
+				throw new IOException(e);
+			}
+		}
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/plugin/ConnectionRegistryImplTest.java

@@ -7,20 +7,18 @@ import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
-import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.jmock.Expectations;
 import org.junit.Test;
 
 import java.util.Collection;
-import java.util.concurrent.ScheduledExecutorService;
 
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
@@ -32,9 +30,6 @@ import static org.junit.Assert.fail;
 public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 	private final EventBus eventBus = context.mock(EventBus.class);
-	private final Clock clock = context.mock(Clock.class);
-	private final ScheduledExecutorService scheduler =
-			context.mock(ScheduledExecutorService.class);
 
 	private final ContactId contactId = getContactId();
 	private final ContactId contactId1 = getContactId();
@@ -45,25 +40,17 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testRegisterAndUnregister() {
-		context.checking(new Expectations() {{
-			oneOf(scheduler).scheduleWithFixedDelay(with(any(Runnable.class)),
-					with(10_000L), with(10_000L), with(MILLISECONDS));
-		}});
-
-		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus, clock,
-				scheduler);
-		context.assertIsSatisfied();
+		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus);
 
 		// The registry should be empty
 		assertEquals(emptyList(), c.getConnectedContacts(transportId));
 		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
 
 		// Check that a registered connection shows up - this should
-		// broadcast a ConnectionOpenedEvent and a ConnectionStatusChangedEvent
+		// broadcast a ConnectionOpenedEvent and a ContactConnectedEvent
 		context.checking(new Expectations() {{
 			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(
-					ConnectionStatusChangedEvent.class)));
+			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
 		}});
 		c.registerConnection(contactId, transportId, true);
 		assertEquals(singletonList(contactId),
@@ -94,13 +81,11 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Unregister the other connection - this should broadcast a
-		// ConnectionClosedEvent and a ConnectionStatusChangedEvent
+		// ConnectionClosedEvent and a ContactDisconnectedEvent
 		context.checking(new Expectations() {{
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(System.currentTimeMillis()));
 			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
 			oneOf(eventBus).broadcast(with(any(
-					ConnectionStatusChangedEvent.class)));
+					ContactDisconnectedEvent.class)));
 		}});
 		c.unregisterConnection(contactId, transportId, true);
 		assertEquals(emptyList(), c.getConnectedContacts(transportId));
@@ -117,12 +102,12 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 		// Register both contacts with one transport, one contact with both -
 		// this should broadcast three ConnectionOpenedEvents and two
-		// ConnectionStatusChangedEvents
+		// ContactConnectedEvents
 		context.checking(new Expectations() {{
 			exactly(3).of(eventBus).broadcast(with(any(
 					ConnectionOpenedEvent.class)));
 			exactly(2).of(eventBus).broadcast(with(any(
-					ConnectionStatusChangedEvent.class)));
+					ContactConnectedEvent.class)));
 		}});
 		c.registerConnection(contactId, transportId, true);
 		c.registerConnection(contactId1, transportId, true);
@@ -137,14 +122,7 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testRegisterAndUnregisterPendingContacts() {
-		context.checking(new Expectations() {{
-			oneOf(scheduler).scheduleWithFixedDelay(with(any(Runnable.class)),
-					with(10_000L), with(10_000L), with(MILLISECONDS));
-		}});
-
-		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus, clock,
-				scheduler);
-		context.assertIsSatisfied();
+		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus);
 
 		context.checking(new Expectations() {{
 			oneOf(eventBus).broadcast(with(any(

bramble-core/src/test/java/org/briarproject/bramble/plugin/bluetooth/BluetoothConnectionLimiterImplTest.java

@@ -0,0 +1,182 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.sync.event.CloseSyncConnectionsEvent;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.SettableClock;
+import org.jmock.Expectations;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.briarproject.bramble.plugin.bluetooth.BluetoothConnectionLimiter.MIN_ATTEMPT_INTERVAL_MS;
+import static org.briarproject.bramble.plugin.bluetooth.BluetoothConnectionLimiter.STABILITY_PERIOD_MS;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class BluetoothConnectionLimiterImplTest extends BrambleMockTestCase {
+
+	private final EventBus eventBus = context.mock(EventBus.class);
+
+	private final DuplexTransportConnection conn1 =
+			context.mock(DuplexTransportConnection.class, "conn1");
+	private final DuplexTransportConnection conn2 =
+			context.mock(DuplexTransportConnection.class, "conn2");
+	private final DuplexTransportConnection conn3 =
+			context.mock(DuplexTransportConnection.class, "conn3");
+
+	private final long now = System.currentTimeMillis();
+
+	private AtomicLong time;
+	private BluetoothConnectionLimiter limiter;
+
+	@Before
+	public void setUp() {
+		time = new AtomicLong(now);
+		Clock clock = new SettableClock(time);
+		limiter = new BluetoothConnectionLimiterImpl(eventBus, clock);
+	}
+
+	@Test
+	public void testLimiterDoesNotAllowContactConnectionsDuringKeyAgreement() {
+		assertTrue(limiter.canOpenContactConnection());
+
+		expectCloseSyncConnectionsEvent();
+		limiter.keyAgreementStarted();
+
+		assertFalse(limiter.canOpenContactConnection());
+
+		limiter.keyAgreementEnded();
+
+		assertTrue(limiter.canOpenContactConnection());
+	}
+
+	@Test
+	public void testLimiterAllowsAttemptToRaiseLimitAtStartup() {
+		// First outgoing connection is allowed - we're below the limit of 1
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn1, false));
+
+		// Second outgoing connection is allowed - it's time to try raising
+		// the limit to 2
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn2, false));
+
+		// Third outgoing connection is not allowed - we're above the limit of 1
+		assertFalse(limiter.canOpenContactConnection());
+	}
+
+	@Test
+	public void testLimiterAllowsThirdConnectionAfterFirstTwoAreClosed() {
+		// First outgoing connection is allowed - we're below the limit of 1
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn1, false));
+
+		// Second outgoing connection is allowed - it's time to try raising
+		// the limit to 2
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn2, false));
+
+		// Third outgoing connection is not allowed - we're above the limit of 1
+		assertFalse(limiter.canOpenContactConnection());
+
+		// Close the first connection
+		limiter.connectionClosed(conn1, false);
+
+		// Third outgoing connection is not allowed - we're at the limit of 1
+		assertFalse(limiter.canOpenContactConnection());
+
+		// Close the second connection
+		limiter.connectionClosed(conn2, false);
+
+		// Third outgoing connection is allowed - we're below the limit of 1
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn3, false));
+	}
+
+	@Test
+	public void testLimiterRaisesLimitWhenConnectionsAreStable() {
+		// First outgoing connection is allowed - we're below the limit of 1
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn1, false));
+
+		// Second outgoing connection is allowed - it's time to try raising
+		// the limit to 2
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn2, false));
+
+		// Third outgoing connection is not allowed - we're above the limit of 1
+		assertFalse(limiter.canOpenContactConnection());
+
+		// Time passes
+		time.set(now + STABILITY_PERIOD_MS);
+
+		// Third outgoing connection is still not allowed - first two are now
+		// stable so limit is raised to 2, but we're already at the new limit
+		assertFalse(limiter.canOpenContactConnection());
+
+		// Time passes
+		time.set(now + MIN_ATTEMPT_INTERVAL_MS);
+
+		// Third outgoing connection is allowed - it's time to try raising
+		// the limit to 3
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn3, false));
+
+		// Fourth outgoing connection is not allowed - we're above the limit
+		// of 2
+		assertFalse(limiter.canOpenContactConnection());
+	}
+
+	@Test
+	public void testLimiterIncreasesIntervalWhenConnectionFailsAboveLimit() {
+		// First outgoing connection is allowed - we're below the limit of 1
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn1, false));
+
+		// Time passes
+		time.set(now + 1);
+
+		// Second outgoing connection is allowed - it's time to try raising
+		// the limit to 2
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn2, false));
+
+		// Time passes - the first connection is stable, the second isn't
+		time.set(now + STABILITY_PERIOD_MS);
+
+		// First connection fails. The second connection isn't stable yet, so
+		// the limiter considers this a failed attempt and doubles the interval
+		// between attempts
+		limiter.connectionClosed(conn1, true);
+
+		// Third outgoing connection is not allowed - we're still at the limit
+		// of 1
+		assertFalse(limiter.canOpenContactConnection());
+
+		// Time passes - nearly time for the second attempt
+		time.set(now + MIN_ATTEMPT_INTERVAL_MS * 2);
+
+		// Third outgoing connection is not allowed - we're still at the limit
+		// of 1
+		assertFalse(limiter.canOpenContactConnection());
+
+		// Time passes - now it's time for the second attempt
+		time.set(now + 1 + MIN_ATTEMPT_INTERVAL_MS * 2);
+
+		// Third outgoing connection is allowed - it's time to try raising the
+		// limit to 2 again
+		assertTrue(limiter.canOpenContactConnection());
+		assertTrue(limiter.contactConnectionOpened(conn3, false));
+	}
+
+	private void expectCloseSyncConnectionsEvent() {
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(
+					CloseSyncConnectionsEvent.class)));
+		}});
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/sync/SimplexOutgoingSessionTest.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
@@ -23,6 +24,7 @@ import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
 import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.bramble.test.TestUtils.getTransportId;
 
 public class SimplexOutgoingSessionTest extends BrambleMockTestCase {
 
@@ -36,14 +38,15 @@ public class SimplexOutgoingSessionTest extends BrambleMockTestCase {
 
 	private final Executor dbExecutor = new ImmediateExecutor();
 	private final ContactId contactId = getContactId();
+	private final TransportId transportId = getTransportId();
 	private final Message message = getMessage(new GroupId(getRandomId()));
 	private final MessageId messageId = message.getId();
 
 	@Test
 	public void testNothingToSend() throws Exception {
 		SimplexOutgoingSession session = new SimplexOutgoingSession(db,
-				dbExecutor, eventBus, contactId, MAX_LATENCY, streamWriter,
-				recordWriter);
+				dbExecutor, eventBus, contactId, transportId, MAX_LATENCY,
+				streamWriter, recordWriter);
 		Transaction noAckTxn = new Transaction(null, false);
 		Transaction noMsgTxn = new Transaction(null, false);
 
@@ -76,8 +79,8 @@ public class SimplexOutgoingSessionTest extends BrambleMockTestCase {
 	public void testSomethingToSend() throws Exception {
 		Ack ack = new Ack(singletonList(messageId));
 		SimplexOutgoingSession session = new SimplexOutgoingSession(db,
-				dbExecutor, eventBus, contactId, MAX_LATENCY, streamWriter,
-				recordWriter);
+				dbExecutor, eventBus, contactId, transportId, MAX_LATENCY,
+				streamWriter, recordWriter);
 		Transaction ackTxn = new Transaction(null, false);
 		Transaction noAckTxn = new Transaction(null, false);
 		Transaction msgTxn = new Transaction(null, false);

bramble-java/src/main/java/org/briarproject/bramble/plugin/DesktopPluginModule.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -9,6 +10,7 @@ import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.reliability.ReliabilityLayerFactory;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.plugin.bluetooth.JavaBluetoothPluginFactory;
 import org.briarproject.bramble.plugin.modem.ModemPluginFactory;
 import org.briarproject.bramble.plugin.tcp.LanTcpPluginFactory;
@@ -31,10 +33,11 @@ public class DesktopPluginModule extends PluginModule {
 	PluginConfig getPluginConfig(@IoExecutor Executor ioExecutor,
 			SecureRandom random, BackoffFactory backoffFactory,
 			ReliabilityLayerFactory reliabilityFactory,
-			ShutdownManager shutdownManager, EventBus eventBus) {
-		DuplexPluginFactory bluetooth =
-				new JavaBluetoothPluginFactory(ioExecutor, random, eventBus,
-						backoffFactory);
+			ShutdownManager shutdownManager, EventBus eventBus, Clock clock,
+			TimeoutMonitor timeoutMonitor) {
+		DuplexPluginFactory bluetooth = new JavaBluetoothPluginFactory(
+				ioExecutor, random, eventBus, clock, timeoutMonitor,
+				backoffFactory);
 		DuplexPluginFactory modem = new ModemPluginFactory(ioExecutor,
 				reliabilityFactory);
 		DuplexPluginFactory lan = new LanTcpPluginFactory(ioExecutor,

bramble-java/src/main/java/org/briarproject/bramble/plugin/bluetooth/JavaBluetoothPlugin.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -34,10 +35,11 @@ class JavaBluetoothPlugin extends BluetoothPlugin<StreamConnectionNotifier> {
 	private volatile LocalDevice localDevice = null;
 
 	JavaBluetoothPlugin(BluetoothConnectionLimiter connectionManager,
-			Executor ioExecutor, SecureRandom secureRandom,
-			Backoff backoff, PluginCallback callback, int maxLatency) {
-		super(connectionManager, ioExecutor, secureRandom, backoff, callback,
-				maxLatency);
+			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
+			SecureRandom secureRandom, Backoff backoff,
+			PluginCallback callback, int maxLatency, int maxIdleTime) {
+		super(connectionManager, timeoutMonitor, ioExecutor, secureRandom,
+				backoff, callback, maxLatency, maxIdleTime);
 	}
 
 	@Override
@@ -119,7 +121,9 @@ class JavaBluetoothPlugin extends BluetoothPlugin<StreamConnectionNotifier> {
 		return "btspp://" + address + ":" + uuid + ";name=RFCOMM";
 	}
 
-	private DuplexTransportConnection wrapSocket(StreamConnection s) {
-		return new JavaBluetoothTransportConnection(this, connectionLimiter, s);
+	private DuplexTransportConnection wrapSocket(StreamConnection s)
+			throws IOException {
+		return new JavaBluetoothTransportConnection(this, connectionLimiter,
+				timeoutMonitor, s);
 	}
 }

bramble-java/src/main/java/org/briarproject/bramble/plugin/bluetooth/JavaBluetoothPluginFactory.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -8,6 +9,7 @@ import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
+import org.briarproject.bramble.api.system.Clock;
 
 import java.security.SecureRandom;
 import java.util.concurrent.Executor;
@@ -21,22 +23,27 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 public class JavaBluetoothPluginFactory implements DuplexPluginFactory {
 
 	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
 	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
 	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
 	private final SecureRandom secureRandom;
-	private final BackoffFactory backoffFactory;
 	private final EventBus eventBus;
+	private final Clock clock;
+	private final TimeoutMonitor timeoutMonitor;
+	private final BackoffFactory backoffFactory;
 
 	public JavaBluetoothPluginFactory(Executor ioExecutor,
-			SecureRandom secureRandom, EventBus eventBus,
-			BackoffFactory backoffFactory) {
+			SecureRandom secureRandom, EventBus eventBus, Clock clock,
+			TimeoutMonitor timeoutMonitor, BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
 		this.secureRandom = secureRandom;
-		this.backoffFactory = backoffFactory;
 		this.eventBus = eventBus;
+		this.clock = clock;
+		this.timeoutMonitor = timeoutMonitor;
+		this.backoffFactory = backoffFactory;
 	}
 
 	@Override
@@ -52,11 +59,12 @@ public class JavaBluetoothPluginFactory implements DuplexPluginFactory {
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		BluetoothConnectionLimiter connectionLimiter =
-				new BluetoothConnectionLimiterImpl();
+				new BluetoothConnectionLimiterImpl(eventBus, clock);
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		JavaBluetoothPlugin plugin = new JavaBluetoothPlugin(connectionLimiter,
-				ioExecutor, secureRandom, backoff, callback, MAX_LATENCY);
+				timeoutMonitor, ioExecutor, secureRandom, backoff, callback,
+				MAX_LATENCY, MAX_IDLE_TIME);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-java/src/main/java/org/briarproject/bramble/plugin/bluetooth/JavaBluetoothTransportConnection.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
@@ -14,20 +15,24 @@ import javax.microedition.io.StreamConnection;
 class JavaBluetoothTransportConnection
 		extends AbstractDuplexTransportConnection {
 
-	private final BluetoothConnectionLimiter connectionManager;
+	private final BluetoothConnectionLimiter connectionLimiter;
 	private final StreamConnection stream;
+	private final InputStream in;
 
 	JavaBluetoothTransportConnection(Plugin plugin,
-			BluetoothConnectionLimiter connectionManager,
-			StreamConnection stream) {
+			BluetoothConnectionLimiter connectionLimiter,
+			TimeoutMonitor timeoutMonitor,
+			StreamConnection stream) throws IOException {
 		super(plugin);
+		this.connectionLimiter = connectionLimiter;
 		this.stream = stream;
-		this.connectionManager = connectionManager;
+		in = timeoutMonitor.createTimeoutInputStream(
+				stream.openInputStream(), plugin.getMaxIdleTime() * 2);
 	}
 
 	@Override
-	protected InputStream getInputStream() throws IOException {
-		return stream.openInputStream();
+	protected InputStream getInputStream() {
+		return in;
 	}
 
 	@Override
@@ -40,7 +45,7 @@ class JavaBluetoothTransportConnection
 		try {
 			stream.close();
 		} finally {
-			connectionManager.connectionClosed(this);
+			connectionLimiter.connectionClosed(this, exception);
 		}
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/AppModule.java

@@ -14,6 +14,7 @@ import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.network.NetworkManager;
@@ -122,11 +123,12 @@ public class AppModule {
 			LocationUtils locationUtils, EventBus eventBus,
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Clock clock) {
+			BatteryManager batteryManager, Clock clock,
+			TimeoutMonitor timeoutMonitor) {
 		Context appContext = app.getApplicationContext();
-		DuplexPluginFactory bluetooth =
-				new AndroidBluetoothPluginFactory(ioExecutor, androidExecutor,
-						appContext, random, eventBus, clock, backoffFactory);
+		DuplexPluginFactory bluetooth = new AndroidBluetoothPluginFactory(
+				ioExecutor, androidExecutor, appContext, random, eventBus,
+				clock, timeoutMonitor, backoffFactory);
 		DuplexPluginFactory tor = new AndroidTorPluginFactory(ioExecutor,
 				scheduler, appContext, networkManager, locationUtils, eventBus,
 				torSocketFactory, backoffFactory, resourceProvider,

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItem.java

@@ -2,38 +2,35 @@ package org.briarproject.briar.android.contact;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.DISCONNECTED;
-
 @NotThreadSafe
 @NotNullByDefault
 public class ContactItem {
 
 	private final Contact contact;
-	private ConnectionStatus status;
+	private boolean connected;
 
 	public ContactItem(Contact contact) {
-		this(contact, DISCONNECTED);
+		this(contact, false);
 	}
 
-	public ContactItem(Contact contact, ConnectionStatus status) {
+	public ContactItem(Contact contact, boolean connected) {
 		this.contact = contact;
-		this.status = status;
+		this.connected = connected;
 	}
 
 	public Contact getContact() {
 		return contact;
 	}
 
-	ConnectionStatus getConnectionStatus() {
-		return status;
+	boolean isConnected() {
+		return connected;
 	}
 
-	void setConnectionStatus(ConnectionStatus status) {
-		this.status = status;
+	void setConnected(boolean connected) {
+		this.connected = connected;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItemViewHolder.java

@@ -7,7 +7,6 @@ import android.widget.TextView;
 
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
 
@@ -17,8 +16,6 @@ import androidx.annotation.UiThread;
 import androidx.recyclerview.widget.RecyclerView;
 import im.delight.android.identicons.IdenticonDrawable;
 
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 
 @UiThread
@@ -30,7 +27,7 @@ public class ContactItemViewHolder<I extends ContactItem>
 	protected final ImageView avatar;
 	protected final TextView name;
 	@Nullable
-	private final ImageView bulb;
+	protected final ImageView bulb;
 
 	public ContactItemViewHolder(View v) {
 		super(v);
@@ -50,13 +47,10 @@ public class ContactItemViewHolder<I extends ContactItem>
 
 		if (bulb != null) {
 			// online/offline
-			ConnectionStatus status = item.getConnectionStatus();
-			if (status == CONNECTED) {
-				bulb.setImageResource(R.drawable.ic_connected);
-			} else if (status == RECENTLY_CONNECTED) {
-				bulb.setImageResource(R.drawable.ic_recently_connected);
+			if (item.isConnected()) {
+				bulb.setImageResource(R.drawable.contact_connected);
 			} else {
-				bulb.setImageResource(R.drawable.ic_disconnected);
+				bulb.setImageResource(R.drawable.contact_disconnected);
 			}
 		}
 

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListAdapter.java

@@ -39,7 +39,7 @@ public class ContactListAdapter extends
 		if (c1.getTimestamp() != c2.getTimestamp()) {
 			return false;
 		}
-		return c1.getConnectionStatus() == c2.getConnectionStatus();
+		return c1.isConnected() == c2.isConnected();
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListFragment.java

@@ -25,8 +25,8 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -53,6 +53,7 @@ import javax.inject.Inject;
 import androidx.annotation.UiThread;
 import androidx.core.app.ActivityCompat;
 import androidx.core.app.ActivityOptionsCompat;
+import androidx.core.util.Pair;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial.OnMenuItemClickListener;
@@ -136,15 +137,26 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 					ContactId contactId = item.getContact().getId();
 					i.putExtra(CONTACT_ID, contactId.getInt());
 
-					Bundle options = null;
-					// work-around for android bug #224270
 					if (SDK_INT >= 23 && !isSamsung7()) {
-						options = makeTransitionOptions(view);
-					}
-					if (options == null) {
-						startActivity(i);
+						ContactListItemViewHolder holder =
+								(ContactListItemViewHolder) list
+										.getRecyclerView()
+										.findViewHolderForAdapterPosition(
+												adapter.findItemPosition(item));
+						Pair<View, String> avatar =
+								Pair.create(holder.avatar,
+										getTransitionName(holder.avatar));
+						Pair<View, String> bulb =
+								Pair.create(holder.bulb,
+										getTransitionName(holder.bulb));
+						ActivityOptionsCompat options =
+								makeSceneTransitionAnimation(getActivity(),
+										avatar, bulb);
+						ActivityCompat.startActivity(getActivity(), i,
+								options.toBundle());
 					} else {
-						ActivityCompat.startActivity(getActivity(), i, options);
+						// work-around for android bug #224270
+						startActivity(i);
 					}
 				};
 		adapter = new ContactListAdapter(requireContext(),
@@ -159,15 +171,6 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		return contentView;
 	}
 
-	@Nullable
-	private Bundle makeTransitionOptions(View view) {
-		View avatar = view.findViewById(R.id.avatarView);
-		String name = requireNonNull(getTransitionName(avatar));
-		ActivityOptionsCompat options = makeSceneTransitionAnimation(
-				requireActivity(), view, name);
-		return options.toBundle();
-	}
-
 	@Override
 	public void onMenuItemClick(FloatingActionButton fab, @Nullable TextView v,
 			int itemId) {
@@ -229,9 +232,9 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 						ContactId id = c.getId();
 						GroupCount count =
 								conversationManager.getGroupCount(id);
-						ConnectionStatus status = connectionRegistry
-								.getConnectionStatus(c.getId());
-						contacts.add(new ContactListItem(c, status, count));
+						boolean connected =
+								connectionRegistry.isConnected(c.getId());
+						contacts.add(new ContactListItem(c, connected, count));
 					} catch (NoSuchContactException e) {
 						// Continue
 					}
@@ -262,9 +265,10 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		if (e instanceof ContactAddedEvent) {
 			LOG.info("Contact added, reloading");
 			loadContacts();
-		} else if (e instanceof ConnectionStatusChangedEvent) {
-			ConnectionStatusChangedEvent c = (ConnectionStatusChangedEvent) e;
-			setConnectionStatus(c.getContactId(), c.getConnectionStatus());
+		} else if (e instanceof ContactConnectedEvent) {
+			setConnected(((ContactConnectedEvent) e).getContactId(), true);
+		} else if (e instanceof ContactDisconnectedEvent) {
+			setConnected(((ContactDisconnectedEvent) e).getContactId(), false);
 		} else if (e instanceof ContactRemovedEvent) {
 			LOG.info("Contact removed, removing item");
 			removeItem(((ContactRemovedEvent) e).getContactId());
@@ -300,12 +304,12 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	}
 
 	@UiThread
-	private void setConnectionStatus(ContactId c, ConnectionStatus status) {
+	private void setConnected(ContactId c, boolean connected) {
 		adapter.incrementRevision();
 		int position = adapter.findItemPosition(c);
 		ContactListItem item = adapter.getItemAt(position);
 		if (item != null) {
-			item.setConnectionStatus(status);
+			item.setConnected(connected);
 			adapter.updateItemAt(position, item);
 		}
 	}

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItem.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.contact;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 
@@ -16,9 +15,9 @@ public class ContactListItem extends ContactItem {
 	private long timestamp;
 	private int unread;
 
-	public ContactListItem(Contact contact, ConnectionStatus status,
+	public ContactListItem(Contact contact, boolean connected,
 			GroupCount count) {
-		super(contact, status);
+		super(contact, connected);
 		this.empty = count.getMsgCount() == 0;
 		this.unread = count.getUnreadCount();
 		this.timestamp = count.getLatestMsgTime();

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItemViewHolder.java

@@ -7,6 +7,7 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
+import org.briarproject.briar.android.util.UiUtils;
 
 import java.util.Locale;
 
@@ -14,11 +15,8 @@ import javax.annotation.Nullable;
 
 import androidx.annotation.UiThread;
 
-import static android.view.View.INVISIBLE;
-import static android.view.View.VISIBLE;
 import static androidx.core.view.ViewCompat.setTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
-import static org.briarproject.briar.android.util.UiUtils.getAvatarTransitionName;
 
 @UiThread
 @NotNullByDefault
@@ -41,11 +39,10 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 		// unread count
 		int unreadCount = item.getUnreadCount();
 		if (unreadCount > 0) {
-			unread.setText(String.format(Locale.getDefault(), "%d",
-					unreadCount));
-			unread.setVisibility(VISIBLE);
+			unread.setText(String.format(Locale.getDefault(), "%d", unreadCount));
+			unread.setVisibility(View.VISIBLE);
 		} else {
-			unread.setVisibility(INVISIBLE);
+			unread.setVisibility(View.INVISIBLE);
 		}
 
 		// date of last message
@@ -57,7 +54,8 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 		}
 
 		ContactId c = item.getContact().getId();
-		setTransitionName(avatar, getAvatarTransitionName(c));
+		setTransitionName(avatar, UiUtils.getAvatarTransitionName(c));
+		setTransitionName(bulb, UiUtils.getBulbTransitionName(c));
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/controller/SharingControllerImpl.java

@@ -6,7 +6,8 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 
 import java.util.Collection;
 import java.util.HashSet;
@@ -17,8 +18,6 @@ import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
 
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-
 @NotNullByDefault
 public class SharingControllerImpl implements SharingController, EventListener {
 
@@ -61,14 +60,15 @@ public class SharingControllerImpl implements SharingController, EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof ConnectionStatusChangedEvent) {
-			ConnectionStatusChangedEvent c = (ConnectionStatusChangedEvent) e;
-			setConnectionStatus(c.getContactId());
+		if (e instanceof ContactConnectedEvent) {
+			setConnected(((ContactConnectedEvent) e).getContactId());
+		} else if (e instanceof ContactDisconnectedEvent) {
+			setConnected(((ContactDisconnectedEvent) e).getContactId());
 		}
 	}
 
 	@UiThread
-	private void setConnectionStatus(ContactId c) {
+	private void setConnected(ContactId c) {
 		if (listener == null) throw new IllegalStateException();
 		if (contacts.contains(c)) {
 			int online = getOnlineCount();
@@ -95,9 +95,7 @@ public class SharingControllerImpl implements SharingController, EventListener {
 	public int getOnlineCount() {
 		int online = 0;
 		for (ContactId c : contacts) {
-			if (connectionRegistry.getConnectionStatus(c) == CONNECTED) {
-				online++;
-			}
+			if (connectionRegistry.isConnected(c)) online++;
 		}
 		return online;
 	}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -13,6 +13,7 @@ import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
+import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -33,8 +34,8 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
@@ -124,8 +125,6 @@ import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -139,6 +138,7 @@ import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHME
 import static org.briarproject.briar.android.conversation.ImageActivity.DATE;
 import static org.briarproject.briar.android.conversation.ImageActivity.NAME;
 import static org.briarproject.briar.android.util.UiUtils.getAvatarTransitionName;
+import static org.briarproject.briar.android.util.UiUtils.getBulbTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_ATTACHMENTS_PER_MESSAGE;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_PRIVATE_MESSAGE_TEXT_LENGTH;
@@ -198,8 +198,8 @@ public class ConversationActivity extends BriarActivity
 	private ConversationAdapter adapter;
 	private Toolbar toolbar;
 	private CircleImageView toolbarAvatar;
+	private ImageView toolbarStatus;
 	private TextView toolbarTitle;
-	private TextView toolbarStatus;
 	private BriarRecyclerView list;
 	private LinearLayoutManager layoutManager;
 	private TextInputView textInputView;
@@ -237,8 +237,8 @@ public class ConversationActivity extends BriarActivity
 		// Custom Toolbar
 		toolbar = requireNonNull(setUpCustomToolbar(true));
 		toolbarAvatar = toolbar.findViewById(R.id.contactAvatar);
-		toolbarTitle = toolbar.findViewById(R.id.contactName);
 		toolbarStatus = toolbar.findViewById(R.id.contactStatus);
+		toolbarTitle = toolbar.findViewById(R.id.contactName);
 
 		observeOnce(viewModel.getContactAuthorId(), this, authorId -> {
 			requireNonNull(authorId);
@@ -257,6 +257,7 @@ public class ConversationActivity extends BriarActivity
 				this::onAddedPrivateMessage);
 
 		setTransitionName(toolbarAvatar, getAvatarTransitionName(contactId));
+		setTransitionName(toolbarStatus, getBulbTransitionName(contactId));
 
 		visitor = new ConversationVisitor(this, this, this,
 				viewModel.getContactDisplayName());
@@ -498,14 +499,14 @@ public class ConversationActivity extends BriarActivity
 
 	@UiThread
 	private void displayContactOnlineStatus() {
-		ConnectionStatus status =
-				connectionRegistry.getConnectionStatus(contactId);
-		if (status == CONNECTED) {
-			toolbarStatus.setText(R.string.online);
-		} else if (status == RECENTLY_CONNECTED) {
-			toolbarStatus.setText(R.string.recently_online);
+		if (connectionRegistry.isConnected(contactId)) {
+			toolbarStatus.setImageDrawable(ContextCompat.getDrawable(
+					ConversationActivity.this, R.drawable.contact_online));
+			toolbarStatus.setContentDescription(getString(R.string.online));
 		} else {
-			toolbarStatus.setText(R.string.offline);
+			toolbarStatus.setImageDrawable(ContextCompat.getDrawable(
+					ConversationActivity.this, R.drawable.contact_offline));
+			toolbarStatus.setContentDescription(getString(R.string.offline));
 		}
 	}
 
@@ -728,10 +729,16 @@ public class ConversationActivity extends BriarActivity
 				LOG.info("Messages acked");
 				markMessages(m.getMessageIds(), true, true);
 			}
-		} else if (e instanceof ConnectionStatusChangedEvent) {
-			ConnectionStatusChangedEvent c = (ConnectionStatusChangedEvent) e;
+		} else if (e instanceof ContactConnectedEvent) {
+			ContactConnectedEvent c = (ContactConnectedEvent) e;
 			if (c.getContactId().equals(contactId)) {
-				LOG.info("Connection status changed");
+				LOG.info("Contact connected");
+				displayContactOnlineStatus();
+			}
+		} else if (e instanceof ContactDisconnectedEvent) {
+			ContactDisconnectedEvent c = (ContactDisconnectedEvent) e;
+			if (c.getContactId().equals(contactId)) {
+				LOG.info("Contact disconnected");
 				displayContactOnlineStatus();
 			}
 		} else if (e instanceof ClientVersionUpdatedEvent) {

briar-android/src/main/java/org/briarproject/briar/android/introduction/ContactChooserFragment.java

@@ -12,7 +12,6 @@ import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -74,8 +73,7 @@ public class ContactChooserFragment extends BaseFragment {
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater,
-			@Nullable ViewGroup container,
+	public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 
 		View contentView = inflater.inflate(R.layout.list, container, false);
@@ -129,9 +127,9 @@ public class ContactChooserFragment extends BaseFragment {
 						ContactId id = c.getId();
 						GroupCount count =
 								conversationManager.getGroupCount(id);
-						ConnectionStatus status = connectionRegistry
-								.getConnectionStatus(c.getId());
-						contacts.add(new ContactListItem(c, status, count));
+						boolean connected =
+								connectionRegistry.isConnected(c.getId());
+						contacts.add(new ContactListItem(c, connected, count));
 					}
 				}
 				displayContacts(contacts);

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/GroupMemberListActivity.java

@@ -99,7 +99,7 @@ public class GroupMemberListActivity extends BriarActivity
 				supportFinishAfterTransition();
 			}
 		}
-		// TODO ConnectionStatusChangedEvent
+		// TODO ContactConnectedEvent and ContactDisconnectedEvent
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/GroupMemberListControllerImpl.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.android.controller.DbControllerImpl;
 import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
@@ -20,7 +19,6 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.DISCONNECTED;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 class GroupMemberListControllerImpl extends DbControllerImpl
@@ -52,11 +50,10 @@ class GroupMemberListControllerImpl extends DbControllerImpl
 						privateGroupManager.getMembers(groupId);
 				for (GroupMember m : members) {
 					ContactId c = m.getContactId();
-					ConnectionStatus status = DISCONNECTED;
-					if (c != null) {
-						status = connectionRegistry.getConnectionStatus(c);
-					}
-					items.add(new MemberListItem(m, status));
+					boolean online = false;
+					if (c != null)
+						online = connectionRegistry.isConnected(c);
+					items.add(new MemberListItem(m, online));
 				}
 				handler.onResult(items);
 			} catch (DbException e) {

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/MemberListAdapter.java

@@ -45,7 +45,7 @@ class MemberListAdapter extends
 
 	@Override
 	public boolean areContentsTheSame(MemberListItem m1, MemberListItem m2) {
-		if (m1.getConnectionStatus() != m2.getConnectionStatus()) return false;
+		if (m1.isOnline() != m2.isOnline()) return false;
 		if (m1.getContactId() != m2.getContactId()) return false;
 		if (m1.getStatus() != m2.getStatus()) return false;
 		return true;

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/MemberListItem.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.AuthorInfo.Status;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.api.privategroup.GroupMember;
 
 import javax.annotation.Nullable;
@@ -16,11 +15,11 @@ import javax.annotation.concurrent.NotThreadSafe;
 class MemberListItem {
 
 	private final GroupMember groupMember;
-	private ConnectionStatus status;
+	private boolean online;
 
-	MemberListItem(GroupMember groupMember, ConnectionStatus status) {
+	MemberListItem(GroupMember groupMember, boolean online) {
 		this.groupMember = groupMember;
-		this.status = status;
+		this.online = online;
 	}
 
 	Author getMember() {
@@ -44,12 +43,12 @@ class MemberListItem {
 		return groupMember.getContactId();
 	}
 
-	ConnectionStatus getConnectionStatus() {
-		return status;
+	boolean isOnline() {
+		return online;
 	}
 
-	void setConnectionStatus(ConnectionStatus status) {
-		this.status = status;
+	void setOnline(boolean online) {
+		this.online = online;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/MemberListItemHolder.java

@@ -5,7 +5,6 @@ import android.widget.ImageView;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.view.AuthorView;
 
@@ -15,8 +14,6 @@ import androidx.recyclerview.widget.RecyclerView;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 
 @UiThread
@@ -41,13 +38,10 @@ class MemberListItemHolder extends RecyclerView.ViewHolder {
 		// online status of visible contacts
 		if (item.getContactId() != null) {
 			bulb.setVisibility(VISIBLE);
-			ConnectionStatus status = item.getConnectionStatus();
-			if (status == CONNECTED) {
-				bulb.setImageResource(R.drawable.ic_connected);
-			} else if (status == RECENTLY_CONNECTED) {
-				bulb.setImageResource(R.drawable.ic_recently_connected);
+			if (item.isOnline()) {
+				bulb.setImageResource(R.drawable.contact_connected);
 			} else {
-				bulb.setImageResource(R.drawable.ic_disconnected);
+				bulb.setImageResource(R.drawable.contact_disconnected);
 			}
 		} else {
 			bulb.setVisibility(GONE);

briar-android/src/main/java/org/briarproject/briar/android/sharing/SharingStatusActivity.java

@@ -14,7 +14,6 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.briar.R;
@@ -105,7 +104,7 @@ abstract class SharingStatusActivity extends BriarActivity
 				supportFinishAfterTransition();
 			}
 		}
-		// TODO ConnectionStatusChangedEvent
+		// TODO ContactConnectedEvent and ContactDisconnectedEvent
 	}
 
 	@Override
@@ -135,9 +134,8 @@ abstract class SharingStatusActivity extends BriarActivity
 			try {
 				List<ContactItem> contactItems = new ArrayList<>();
 				for (Contact c : getSharedWith()) {
-					ConnectionStatus status =
-							connectionRegistry.getConnectionStatus(c.getId());
-					ContactItem item = new ContactItem(c, status);
+					boolean online = connectionRegistry.isConnected(c.getId());
+					ContactItem item = new ContactItem(c, online);
 					contactItems.add(item);
 				}
 				displaySharedWith(contactItems);

briar-android/src/main/java/org/briarproject/briar/android/util/UiUtils.java

@@ -238,6 +238,10 @@ public class UiUtils {
 		return "avatar" + c.getInt();
 	}
 
+	public static String getBulbTransitionName(ContactId c) {
+		return "bulb" + c.getInt();
+	}
+
 	public static OnClickListener getGoToSettingsListener(Context context) {
 		return (dialog, which) -> {
 			Intent i = new Intent();

briar-android/src/main/res/drawable-night/contact_connected.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24"
+        android:viewportWidth="24">
+
+	<path
+		android:fillColor="#abffffff"
+		android:pathData="M12,2 C6.48,2,2,6.48,2,12 S6.48,22,12,22 S22,17.52,22,12 S17.52,2,12,2 Z M12,20
+C7.58,20,4,16.42,4,12 S7.58,4,12,4 S20,7.58,20,12 S16.42,20,12,20 Z"/>
+
+	<path
+		android:fillColor="#95d220"
+		android:pathData="M10.8972,19.9503 C6.5514,19.3493,3.43091,15.2154,4.0625,10.896
+C4.55452,7.53099,7.09451,4.8236,10.394,4.14714
+C14.2569,3.35517,18.1698,5.54347,19.5236,9.25295
+C20.0698,10.7495,20.1616,12.4612,19.777,13.9758
+C19.5457,14.8864,18.8106,16.3388,18.2072,17.0771
+C16.4904,19.1779,13.581,20.3215,10.8973,19.9503 Z"
+		android:strokeLineCap="round"
+		android:strokeLineJoin="round"
+		android:strokeWidth="0.76779664"/>
+</vector>

briar-android/src/main/res/drawable-night/contact_disconnected.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0">
+	<path
+		android:fillColor="#abffffff"
+		android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zm0,18c-4.42,0 -8,-3.58 -8,-8s3.58,-8 8,-8 8,3.58 8,8 -3.58,8 -8,8z"/>
+</vector>

briar-android/src/main/res/drawable-night/ic_connected.xml

@@ -1,13 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="24"
-    android:viewportHeight="24">
-  <path
-      android:pathData="M12,12m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="1.5"
-      android:fillColor="#95d220"
-      android:strokeColor="#abffffff"
-      android:fillAlpha="1"/>
-</vector>

briar-android/src/main/res/drawable-night/ic_disconnected.xml

@@ -1,14 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="24"
-    android:viewportHeight="24">
-  <path
-      android:pathData="M12,12m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="1.5"
-      android:fillColor="#00000000"
-      android:strokeColor="#abffffff"
-      android:fillType="nonZero"
-      android:fillAlpha="1"/>
-</vector>

briar-android/src/main/res/drawable-night/ic_recently_connected.xml

@@ -1,20 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="24"
-    android:viewportHeight="24">
-  <path
-      android:pathData="M12,12m-7,0a7,7 0,1 1,14 0a7,7 0,1 1,-14 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="4.5"
-      android:fillColor="#00000000"
-      android:strokeColor="#95d220"
-      android:fillAlpha="1"/>
-  <path
-      android:pathData="M12,12m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="1.5"
-      android:fillColor="#00000000"
-      android:strokeColor="#abffffff"
-      android:fillAlpha="1"/>
-</vector>

briar-android/src/main/res/drawable/contact_connected.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:alpha="0.56"
+        android:viewportHeight="24"
+        android:viewportWidth="24">
+
+	<path
+		android:fillColor="#FF000000"
+		android:pathData="M12,2 C6.48,2,2,6.48,2,12 S6.48,22,12,22 S22,17.52,22,12 S17.52,2,12,2 Z M12,20
+C7.58,20,4,16.42,4,12 S7.58,4,12,4 S20,7.58,20,12 S16.42,20,12,20 Z"/>
+	<path
+		android:pathData="M0,0 L24,0 L24,24 L0,24 Z"/>
+	<path
+		android:fillColor="#95d220"
+		android:pathData="M10.8972,19.9503 C6.5514,19.3493,3.43091,15.2154,4.0625,10.896
+C4.55452,7.53099,7.09451,4.8236,10.394,4.14714
+C14.2569,3.35517,18.1698,5.54347,19.5236,9.25295
+C20.0698,10.7495,20.1616,12.4612,19.777,13.9758
+C19.5457,14.8864,18.8106,16.3388,18.2072,17.0771
+C16.4904,19.1779,13.581,20.3215,10.8973,19.9503 Z"
+		android:strokeLineCap="round"
+		android:strokeLineJoin="round"
+		android:strokeWidth="0.76779664"/>
+</vector>

briar-android/src/main/res/drawable/contact_disconnected.xml

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:alpha="0.56"
+        android:viewportHeight="24.0"
+        android:viewportWidth="24.0">
+	<path
+		android:fillColor="#FF000000"
+		android:pathData="M12,2C6.48,2 2,6.48 2,12s4.48,10 10,10 10,-4.48 10,-10S17.52,2 12,2zm0,18c-4.42,0 -8,-3.58 -8,-8s3.58,-8 8,-8 8,3.58 8,8 -3.58,8 -8,8z"/>
+</vector>

briar-android/src/main/res/drawable/ic_connected.xml

@@ -1,13 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="24"
-    android:viewportHeight="24">
-  <path
-      android:pathData="M12,12m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="1.5"
-      android:fillColor="#95d220"
-      android:strokeColor="#000000"
-      android:fillAlpha="0.56"/>
-</vector>

briar-android/src/main/res/drawable/ic_disconnected.xml

@@ -1,14 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="24"
-    android:viewportHeight="24">
-  <path
-      android:pathData="M12,12m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="1.5"
-      android:fillColor="#00000000"
-      android:strokeColor="#000000"
-      android:fillType="nonZero"
-      android:fillAlpha="1"/>
-</vector>

briar-android/src/main/res/drawable/ic_recently_connected.xml

@@ -1,20 +0,0 @@
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:viewportWidth="24"
-    android:viewportHeight="24">
-  <path
-      android:pathData="M12,12m-7,0a7,7 0,1 1,14 0a7,7 0,1 1,-14 0"
-      android:strokeAlpha="0.56"
-      android:strokeWidth="4.5"
-      android:fillColor="#ffffff"
-      android:strokeColor="#95d220"
-      android:fillAlpha="1"/>
-  <path
-      android:pathData="M12,12m-10,0a10,10 0,1 1,20 0a10,10 0,1 1,-20 0"
-      android:strokeAlpha="1"
-      android:strokeWidth="1.5"
-      android:fillColor="#00000000"
-      android:strokeColor="#000000"
-      android:fillAlpha="1"/>
-</vector>

briar-android/src/main/res/layout/activity_conversation.xml

@@ -18,50 +18,27 @@
 			android:layout_width="match_parent"
 			android:layout_height="wrap_content">
 
-			<RelativeLayout
-				android:layout_width="match_parent"
-				android:layout_height="wrap_content">
+			<LinearLayout
+				android:layout_width="wrap_content"
+				android:layout_height="match_parent"
+				android:orientation="horizontal">
 
-				<de.hdodenhof.circleimageview.CircleImageView
-					android:id="@+id/contactAvatar"
-					style="@style/BriarAvatar"
-					android:layout_width="40dp"
-					android:layout_height="40dp"
-					android:layout_alignParentStart="true"
-					android:layout_alignParentLeft="true"
-					android:layout_margin="4dp"
-					app:civ_border_color="@color/action_bar_text"
-					tools:src="@mipmap/ic_launcher_round" />
+				<include layout="@layout/contact_avatar_status" />
 
 				<com.vanniktech.emoji.EmojiTextView
 					android:id="@+id/contactName"
 					style="@style/TextAppearance.AppCompat.Widget.ActionBar.Title.Inverse"
 					android:layout_width="wrap_content"
-					android:layout_height="wrap_content"
-					android:layout_alignParentTop="true"
+					android:layout_height="match_parent"
 					android:layout_marginStart="@dimen/margin_medium"
 					android:layout_marginLeft="@dimen/margin_medium"
-					android:layout_toEndOf="@id/contactAvatar"
-					android:layout_toRightOf="@id/contactAvatar"
 					android:ellipsize="end"
+					android:gravity="center_vertical"
 					android:maxLines="1"
 					android:textColor="@color/action_bar_text"
 					tools:text="Contact Name of someone who chose a long name" />
 
-				<TextView
-					android:id="@+id/contactStatus"
-					style="@style/TextAppearance.AppCompat.Widget.ActionBar.Subtitle.Inverse"
-					android:layout_width="wrap_content"
-					android:layout_height="wrap_content"
-					android:layout_below="@id/contactName"
-					android:layout_marginStart="8dp"
-					android:layout_marginLeft="8dp"
-					android:layout_toEndOf="@id/contactAvatar"
-					android:layout_toRightOf="@id/contactAvatar"
-					android:textColor="@color/briar_text_secondary_inverse"
-					tools:text="Recently online" />
-
-			</RelativeLayout>
+			</LinearLayout>
 
 		</androidx.appcompat.widget.Toolbar>
 

briar-android/src/main/res/layout/contact_avatar_status.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+	xmlns:app="http://schemas.android.com/apk/res-auto"
+	xmlns:tools="http://schemas.android.com/tools"
+	android:layout_width="32dp"
+	android:layout_height="32dp"
+	tools:showIn="@layout/activity_conversation">
+
+	<de.hdodenhof.circleimageview.CircleImageView
+		android:id="@+id/contactAvatar"
+		style="@style/BriarAvatar"
+		android:layout_width="30dp"
+		android:layout_height="30dp"
+		app:civ_border_color="@color/action_bar_text"
+		tools:src="@mipmap/ic_launcher_round" />
+
+	<ImageView
+		android:id="@+id/contactStatus"
+		android:layout_width="15dp"
+		android:layout_height="15dp"
+		android:layout_gravity="bottom|end|right"
+		android:scaleType="fitCenter"
+		tools:ignore="ContentDescription"
+		tools:src="@drawable/contact_online" />
+
+</FrameLayout>

briar-android/src/main/res/layout/list_item_contact.xml

@@ -90,7 +90,7 @@
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
 		tools:ignore="ContentDescription"
-		tools:src="@drawable/ic_recently_connected" />
+		tools:src="@drawable/contact_connected" />
 
 	<View
 		android:id="@+id/divider"

briar-android/src/main/res/layout/list_item_contact_small.xml

@@ -40,6 +40,6 @@
 		android:layout_marginEnd="@dimen/listitem_horizontal_margin"
 		android:layout_marginRight="@dimen/listitem_horizontal_margin"
 		tools:ignore="ContentDescription"
-		tools:src="@drawable/ic_connected" />
+		tools:src="@drawable/contact_connected" />
 
 </LinearLayout>

briar-android/src/main/res/layout/list_item_group_member.xml

@@ -24,7 +24,7 @@
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintTop_toTopOf="parent"
 		tools:ignore="ContentDescription"
-		tools:src="@drawable/ic_connected" />
+		tools:src="@drawable/contact_connected" />
 
 	<TextView
 		android:id="@+id/creatorView"

briar-android/src/main/res/values/strings.xml

@@ -110,7 +110,6 @@
 	<string name="decline">Decline</string>
 	<string name="options">Options</string>
 	<string name="online">Online</string>
-	<string name="recently_online">Recently online</string>
 	<string name="offline">Offline</string>
 	<string name="send">Send</string>
 	<string name="allow">Allow</string>