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

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

@@ -50,7 +50,7 @@ class AndroidBluetoothTransportConnection
 		try {
 			socket.close();
 		} finally {
-			connectionLimiter.connectionClosed(this);
+			connectionLimiter.connectionClosed(this, exception);
 		}
 	}
 }

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

@@ -1,130 +0,0 @@
-package org.briarproject.bramble.api.connection;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginConfig;
-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.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.sync.Priority;
-
-import java.util.Collection;
-
-/**
- * Keeps track of which contacts are currently connected by which transports.
- */
-@NotNullByDefault
-public interface ConnectionRegistry {
-
-	/**
-	 * Registers an incoming connection from the given contact over the given
-	 * transport. The connection's {@link Priority priority} can be set later
-	 * via {@link #setPriority(ContactId, TransportId, InterruptibleConnection,
-	 * Priority)} if a priority record is received from the contact.
-	 * <p>
-	 * Broadcasts {@link ConnectionOpenedEvent}. Also broadcasts
-	 * {@link ContactConnectedEvent} if this is the only connection with the
-	 * contact.
-	 */
-	void registerIncomingConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn);
-
-	/**
-	 * Registers an outgoing connection to the given contact over the given
-	 * transport.
-	 * <p>
-	 * Broadcasts {@link ConnectionOpenedEvent}. Also broadcasts
-	 * {@link ContactConnectedEvent} if this is the only connection with the
-	 * contact.
-	 * <p>
-	 * If the registry has any "better" connections with the given contact, the
-	 * given connection will be interrupted. If the registry has any "worse"
-	 * connections with the given contact, those connections will be
-	 * interrupted.
-	 * <p>
-	 * Connection A is considered "better" than connection B if both
-	 * connections have had their priorities set, and either A's transport is
-	 * {@link PluginConfig#getTransportPreferences() preferred} to B's, or
-	 * they use the same transport and A has higher {@link Priority priority}
-	 * than B.
-	 * <p>
-	 * For backward compatibility, connections without priorities are not
-	 * considered better or worse than other connections.
-	 */
-	void registerOutgoingConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, Priority priority);
-
-	/**
-	 * Unregisters a connection with the given contact over the given transport.
-	 * <p>
-	 * Broadcasts {@link ConnectionClosedEvent}. Also broadcasts
-	 * {@link ContactDisconnectedEvent} if this is the only connection with
-	 * the contact.
-	 */
-	void unregisterConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming, boolean exception);
-
-	/**
-	 * Sets the {@link Priority priority} of a connection that was previously
-	 * registered via {@link #registerIncomingConnection(ContactId, TransportId,
-	 * InterruptibleConnection)}.
-	 * <p>
-	 * If the registry has any "better" connections with the given contact, the
-	 * given connection will be interrupted. If the registry has any "worse"
-	 * connections with the given contact, those connections will be
-	 * interrupted.
-	 * <p>
-	 * Connection A is considered "better" than connection B if both
-	 * connections have had their priorities set, and either A's transport is
-	 * {@link PluginConfig#getTransportPreferences() preferred} to B's, or
-	 * they use the same transport and A has higher {@link Priority priority}
-	 * than B.
-	 * <p>
-	 * For backward compatibility, connections without priorities are not
-	 * considered better or worse than other connections.
-	 */
-	void setPriority(ContactId c, TransportId t, InterruptibleConnection conn,
-			Priority priority);
-
-	/**
-	 * Returns any contacts that are connected via the given transport.
-	 */
-	Collection<ContactId> getConnectedContacts(TransportId t);
-
-	/**
-	 * Returns any contacts that are connected via the given transport or any
-	 * {@link PluginConfig#getTransportPreferences() better} transport.
-	 */
-	Collection<ContactId> getConnectedOrBetterContacts(TransportId t);
-
-	/**
-	 * Returns true if the given contact is connected via the given transport.
-	 */
-	boolean isConnected(ContactId c, TransportId t);
-
-	/**
-	 * Returns true if the given contact is connected via any transport.
-	 */
-	boolean isConnected(ContactId c);
-
-	/**
-	 * Registers a connection with the given pending contact. Broadcasts
-	 * {@link RendezvousConnectionOpenedEvent} if this is the only connection
-	 * with the pending contact.
-	 *
-	 * @return True if this is the only connection with the pending contact,
-	 * false if it is redundant and should be closed
-	 */
-	boolean registerConnection(PendingContactId p);
-
-	/**
-	 * Unregisters a connection with the given pending contact. Broadcasts
-	 * {@link RendezvousConnectionClosedEvent}.
-	 */
-	void unregisterConnection(PendingContactId p, boolean success);
-}

bramble-api/src/main/java/org/briarproject/bramble/api/connection/InterruptibleConnection.java

@@ -1,19 +0,0 @@
-package org.briarproject.bramble.api.connection;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * A duplex sync connection that can be closed by interrupting its outgoing
- * sync session.
- */
-@NotNullByDefault
-public interface InterruptibleConnection {
-
-	/**
-	 * Interrupts the connection's outgoing sync session. If the underlying
-	 * transport connection is alive and the remote peer is cooperative, this
-	 * should result in both sync sessions ending and the connection being
-	 * cleanly closed.
-	 */
-	void interruptOutgoingSession();
-}

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

@@ -1,11 +1,8 @@
-package org.briarproject.bramble.api.connection;
+package org.briarproject.bramble.api.plugin;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 
 @NotNullByDefault

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

@@ -0,0 +1,67 @@
+package org.briarproject.bramble.api.plugin;
+
+import org.briarproject.bramble.api.contact.ContactId;
+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.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 java.util.Collection;
+
+/**
+ * Keeps track of which contacts are currently connected by which transports.
+ */
+@NotNullByDefault
+public interface ConnectionRegistry {
+
+	/**
+	 * Registers a connection with the given contact over the given transport.
+	 * Broadcasts {@link ConnectionOpenedEvent}. Also broadcasts
+	 * {@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 ContactDisconnectedEvent} if this is the only connection with
+	 * the contact.
+	 */
+	void unregisterConnection(ContactId c, TransportId t, boolean incoming);
+
+	/**
+	 * Returns any contacts that are connected via the given transport.
+	 */
+	Collection<ContactId> getConnectedContacts(TransportId t);
+
+	/**
+	 * Returns true if the given contact is connected via the given transport.
+	 */
+	boolean isConnected(ContactId c, TransportId t);
+
+	/**
+	 * Returns true if the given contact is connected via any transport.
+	 */
+	boolean isConnected(ContactId c);
+
+	/**
+	 * Registers a connection with the given pending contact. Broadcasts
+	 * {@link RendezvousConnectionOpenedEvent} if this is the only connection
+	 * with the pending contact.
+	 *
+	 * @return True if this is the only connection with the pending contact,
+	 * false if it is redundant and should be closed
+	 */
+	boolean registerConnection(PendingContactId p);
+
+	/**
+	 * Unregisters a connection with the given pending contact. Broadcasts
+	 * {@link RendezvousConnectionClosedEvent}.
+	 */
+	void unregisterConnection(PendingContactId p, boolean success);
+}

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

@@ -5,8 +5,6 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 
 import java.util.Collection;
-import java.util.List;
-import java.util.Map;
 
 @NotNullByDefault
 public interface PluginConfig {
@@ -16,11 +14,4 @@ public interface PluginConfig {
 	Collection<SimplexPluginFactory> getSimplexFactories();
 
 	boolean shouldPoll();
-
-	/**
-	 * Returns a map representing transport preferences. For each entry in the
-	 * map, connections via the transports identified by the value are
-	 * preferred to connections via the transport identified by the key.
-	 */
-	Map<TransportId, List<TransportId>> getTransportPreferences();
 }

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

@@ -13,14 +13,13 @@ public class ConnectionClosedEvent extends Event {
 
 	private final ContactId contactId;
 	private final TransportId transportId;
-	private final boolean incoming, exception;
+	private final boolean incoming;
 
 	public ConnectionClosedEvent(ContactId contactId, TransportId transportId,
-			boolean incoming, boolean exception) {
+			boolean incoming) {
 		this.contactId = contactId;
 		this.transportId = transportId;
 		this.incoming = incoming;
-		this.exception = exception;
 	}
 
 	public ContactId getContactId() {
@@ -34,8 +33,4 @@ public class ConnectionClosedEvent extends Event {
 	public boolean isIncoming() {
 		return incoming;
 	}
-
-	public boolean isException() {
-		return exception;
-	}
 }

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

@@ -1,23 +0,0 @@
-package org.briarproject.bramble.api.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A record containing a nonce for choosing between redundant sessions.
- */
-@Immutable
-@NotNullByDefault
-public class Priority {
-
-	private final byte[] nonce;
-
-	public Priority(byte[] nonce) {
-		this.nonce = nonce;
-	}
-
-	public byte[] getNonce() {
-		return nonce;
-	}
-}

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

@@ -1,13 +0,0 @@
-package org.briarproject.bramble.api.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * An interface for handling a {@link Priority} record received by an
- * incoming {@link SyncSession}.
- */
-@NotNullByDefault
-public interface PriorityHandler {
-
-	void handle(Priority p);
-}

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

@@ -10,5 +10,4 @@ public interface RecordTypes {
 	byte OFFER = 2;
 	byte REQUEST = 3;
 	byte VERSIONS = 4;
-	byte PRIORITY = 5;
 }

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

@@ -49,10 +49,4 @@ public interface SyncConstants {
 	 * simultaneously.
 	 */
 	int MAX_SUPPORTED_VERSIONS = 10;
-
-	/**
-	 * The length of the priority nonce used for choosing between redundant
-	 * connections.
-	 */
-	int PRIORITY_NONCE_BYTES = 16;
 }

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

@@ -28,8 +28,4 @@ public interface SyncRecordReader {
 	boolean hasVersions() throws IOException;
 
 	Versions readVersions() throws IOException;
-
-	boolean hasPriority() throws IOException;
-
-	Priority readPriority() throws IOException;
 }

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

@@ -17,7 +17,5 @@ public interface SyncRecordWriter {
 
 	void writeVersions(Versions v) throws IOException;
 
-	void writePriority(Priority p) throws IOException;
-
 	void flush() throws IOException;
 }

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

@@ -7,18 +7,14 @@ import org.briarproject.bramble.api.transport.StreamWriter;
 
 import java.io.InputStream;
 
-import javax.annotation.Nullable;
-
 @NotNullByDefault
 public interface SyncSessionFactory {
 
-	SyncSession createIncomingSession(ContactId c, InputStream in,
+	SyncSession createIncomingSession(ContactId c, InputStream in);
-			PriorityHandler handler);
 
 	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
 			int maxLatency, StreamWriter streamWriter);
 
 	SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
-			int maxLatency, int maxIdleTime, StreamWriter streamWriter,
+			int maxLatency, int maxIdleTime, StreamWriter streamWriter);
-			@Nullable Priority priority);
 }

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble;
 
 import org.briarproject.bramble.client.ClientModule;
-import org.briarproject.bramble.connection.ConnectionModule;
 import org.briarproject.bramble.contact.ContactModule;
 import org.briarproject.bramble.crypto.CryptoExecutorModule;
 import org.briarproject.bramble.crypto.CryptoModule;
@@ -29,7 +28,6 @@ import dagger.Module;
 
 @Module(includes = {
 		ClientModule.class,
-		ConnectionModule.class,
 		ContactModule.class,
 		CryptoModule.class,
 		CryptoExecutorModule.class,

bramble-core/src/main/java/org/briarproject/bramble/connection/Connection.java

@@ -1,79 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
-import static org.briarproject.bramble.util.IoUtils.read;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-abstract class Connection {
-
-	protected static final Logger LOG = getLogger(Connection.class.getName());
-
-	final KeyManager keyManager;
-	final ConnectionRegistry connectionRegistry;
-	final StreamReaderFactory streamReaderFactory;
-	final StreamWriterFactory streamWriterFactory;
-
-	Connection(KeyManager keyManager, ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory) {
-		this.keyManager = keyManager;
-		this.connectionRegistry = connectionRegistry;
-		this.streamReaderFactory = streamReaderFactory;
-		this.streamWriterFactory = streamWriterFactory;
-	}
-
-	@Nullable
-	StreamContext recogniseTag(TransportConnectionReader reader,
-			TransportId transportId) {
-		StreamContext ctx;
-		try {
-			byte[] tag = readTag(reader.getInputStream());
-			return keyManager.getStreamContext(transportId, tag);
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			return null;
-		}
-	}
-
-	private byte[] readTag(InputStream in) throws IOException {
-		byte[] tag = new byte[TAG_LENGTH];
-		read(in, tag);
-		return tag;
-	}
-
-	void disposeOnError(TransportConnectionReader reader, boolean recognised) {
-		try {
-			reader.dispose(true, recognised);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	void disposeOnError(TransportConnectionWriter writer) {
-		try {
-			writer.dispose(true);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-}

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

@@ -1,114 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.security.SecureRandom;
-import java.util.concurrent.Executor;
-
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-@Immutable
-@NotNullByDefault
-class ConnectionManagerImpl implements ConnectionManager {
-
-	private final Executor ioExecutor;
-	private final KeyManager keyManager;
-	private final StreamReaderFactory streamReaderFactory;
-	private final StreamWriterFactory streamWriterFactory;
-	private final SyncSessionFactory syncSessionFactory;
-	private final HandshakeManager handshakeManager;
-	private final ContactExchangeManager contactExchangeManager;
-	private final ConnectionRegistry connectionRegistry;
-	private final TransportPropertyManager transportPropertyManager;
-	private final SecureRandom secureRandom;
-
-	@Inject
-	ConnectionManagerImpl(@IoExecutor Executor ioExecutor,
-			KeyManager keyManager, StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionRegistry connectionRegistry,
-			TransportPropertyManager transportPropertyManager,
-			SecureRandom secureRandom) {
-		this.ioExecutor = ioExecutor;
-		this.keyManager = keyManager;
-		this.streamReaderFactory = streamReaderFactory;
-		this.streamWriterFactory = streamWriterFactory;
-		this.syncSessionFactory = syncSessionFactory;
-		this.handshakeManager = handshakeManager;
-		this.contactExchangeManager = contactExchangeManager;
-		this.connectionRegistry = connectionRegistry;
-		this.transportPropertyManager = transportPropertyManager;
-		this.secureRandom = secureRandom;
-	}
-
-
-	@Override
-	public void manageIncomingConnection(TransportId t,
-			TransportConnectionReader r) {
-		ioExecutor.execute(new IncomingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, t, r));
-	}
-
-	@Override
-	public void manageIncomingConnection(TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new IncomingDuplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, ioExecutor,
-				t, d));
-	}
-
-	@Override
-	public void manageIncomingConnection(PendingContactId p, TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new IncomingHandshakeConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				handshakeManager, contactExchangeManager, this, p, t, d));
-	}
-
-	@Override
-	public void manageOutgoingConnection(ContactId c, TransportId t,
-			TransportConnectionWriter w) {
-		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w));
-	}
-
-	@Override
-	public void manageOutgoingConnection(ContactId c, TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new OutgoingDuplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, ioExecutor,
-				secureRandom, c, t, d));
-	}
-
-	@Override
-	public void manageOutgoingConnection(PendingContactId p, TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new OutgoingHandshakeConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				handshakeManager, contactExchangeManager, this, p, t, d));
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/ConnectionModule.java

@@ -1,26 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class ConnectionModule {
-
-	@Provides
-	ConnectionManager provideConnectionManager(
-			ConnectionManagerImpl connectionManager) {
-		return connectionManager;
-	}
-
-	@Provides
-	@Singleton
-	ConnectionRegistry provideConnectionRegistry(
-			ConnectionRegistryImpl connectionRegistry) {
-		return connectionRegistry;
-	}
-}

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

@@ -1,289 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.Bytes;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.connection.InterruptibleConnection;
-import org.briarproject.bramble.api.contact.ContactId;
-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.PluginConfig;
-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.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.sync.Priority;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.util.Collections.emptyList;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
-
-@ThreadSafe
-@NotNullByDefault
-class ConnectionRegistryImpl implements ConnectionRegistry {
-
-	private static final Logger LOG =
-			getLogger(ConnectionRegistryImpl.class.getName());
-
-	private final EventBus eventBus;
-	private final Map<TransportId, List<TransportId>> transportPrefs;
-
-	private final Object lock = new Object();
-	@GuardedBy("lock")
-	private final Map<ContactId, List<ConnectionRecord>> contactConnections;
-	@GuardedBy("lock")
-	private final Set<PendingContactId> connectedPendingContacts;
-
-	@Inject
-	ConnectionRegistryImpl(EventBus eventBus, PluginConfig pluginConfig) {
-		this.eventBus = eventBus;
-		transportPrefs = pluginConfig.getTransportPreferences();
-		contactConnections = new HashMap<>();
-		connectedPendingContacts = new HashSet<>();
-	}
-
-	@Override
-	public void registerIncomingConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn) {
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Incoming connection registered: " + t);
-		}
-		registerConnection(c, t, conn, true);
-	}
-
-	@Override
-	public void registerOutgoingConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, Priority priority) {
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Outgoing connection registered: " + t);
-		}
-		registerConnection(c, t, conn, false);
-		setPriority(c, t, conn, priority);
-	}
-
-	private void registerConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming) {
-		if (LOG.isLoggable(INFO)) {
-			if (incoming) LOG.info("Incoming connection registered: " + t);
-			else LOG.info("Outgoing connection registered: " + t);
-		}
-		boolean firstConnection;
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null) {
-				recs = new ArrayList<>();
-				contactConnections.put(c, recs);
-			}
-			firstConnection = recs.isEmpty();
-			recs.add(new ConnectionRecord(t, conn));
-		}
-		eventBus.broadcast(new ConnectionOpenedEvent(c, t, incoming));
-		if (firstConnection) {
-			LOG.info("Contact connected");
-			eventBus.broadcast(new ContactConnectedEvent(c));
-		}
-	}
-
-	@Override
-	public void setPriority(ContactId c, TransportId t,
-			InterruptibleConnection conn, Priority priority) {
-		if (LOG.isLoggable(INFO)) LOG.info("Setting connection priority: " + t);
-		List<InterruptibleConnection> toInterrupt;
-		boolean interruptNewConnection = false;
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null) throw new IllegalArgumentException();
-			toInterrupt = new ArrayList<>(recs.size());
-			for (ConnectionRecord rec : recs) {
-				if (rec.conn == conn) {
-					// Store the priority of this connection
-					rec.priority = priority;
-				} else if (rec.priority != null) {
-					int compare = compareConnections(t, priority,
-							rec.transportId, rec.priority);
-					if (compare == -1) {
-						// The old connection is better than the new one
-						interruptNewConnection = true;
-					} else if (compare == 1 && !rec.interrupted) {
-						// The new connection is better than the old one
-						toInterrupt.add(rec.conn);
-						rec.interrupted = true;
-					}
-				}
-			}
-		}
-		if (interruptNewConnection) {
-			LOG.info("Interrupting new connection");
-			conn.interruptOutgoingSession();
-		}
-		for (InterruptibleConnection old : toInterrupt) {
-			LOG.info("Interrupting old connection");
-			old.interruptOutgoingSession();
-		}
-	}
-
-	private int compareConnections(TransportId tA, Priority pA, TransportId tB,
-			Priority pB) {
-		if (getBetterTransports(tA).contains(tB)) return -1;
-		if (getBetterTransports(tB).contains(tA)) return 1;
-		return tA.equals(tB) ? Bytes.compare(pA.getNonce(), pB.getNonce()) : 0;
-	}
-
-	private List<TransportId> getBetterTransports(TransportId t) {
-		List<TransportId> better = transportPrefs.get(t);
-		return better == null ? emptyList() : better;
-	}
-
-	@Override
-	public void unregisterConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming, boolean exception) {
-		if (LOG.isLoggable(INFO)) {
-			if (incoming) LOG.info("Incoming connection unregistered: " + t);
-			else LOG.info("Outgoing connection unregistered: " + t);
-		}
-		boolean lastConnection;
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null || !recs.remove(new ConnectionRecord(t, conn)))
-				throw new IllegalArgumentException();
-			lastConnection = recs.isEmpty();
-		}
-		eventBus.broadcast(
-				new ConnectionClosedEvent(c, t, incoming, exception));
-		if (lastConnection) {
-			LOG.info("Contact disconnected");
-			eventBus.broadcast(new ContactDisconnectedEvent(c));
-		}
-	}
-
-	@Override
-	public Collection<ContactId> getConnectedContacts(TransportId t) {
-		synchronized (lock) {
-			List<ContactId> contactIds = new ArrayList<>();
-			for (Entry<ContactId, List<ConnectionRecord>> e :
-					contactConnections.entrySet()) {
-				for (ConnectionRecord rec : e.getValue()) {
-					if (rec.transportId.equals(t)) {
-						contactIds.add(e.getKey());
-						break;
-					}
-				}
-			}
-			if (LOG.isLoggable(INFO)) {
-				LOG.info(contactIds.size() + " contacts connected: " + t);
-			}
-			return contactIds;
-		}
-	}
-
-	@Override
-	public Collection<ContactId> getConnectedOrBetterContacts(TransportId t) {
-		synchronized (lock) {
-			List<TransportId> better = getBetterTransports(t);
-			List<ContactId> contactIds = new ArrayList<>();
-			for (Entry<ContactId, List<ConnectionRecord>> e :
-					contactConnections.entrySet()) {
-				for (ConnectionRecord rec : e.getValue()) {
-					if (rec.transportId.equals(t) ||
-							better.contains(rec.transportId)) {
-						contactIds.add(e.getKey());
-						break;
-					}
-				}
-			}
-			if (LOG.isLoggable(INFO)) {
-				LOG.info(contactIds.size()
-						+ " contacts connected or better: " + t);
-			}
-			return contactIds;
-		}
-	}
-
-	@Override
-	public boolean isConnected(ContactId c, TransportId t) {
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null) return false;
-			for (ConnectionRecord rec : recs) {
-				if (rec.transportId.equals(t)) return true;
-			}
-			return false;
-		}
-	}
-
-	@Override
-	public boolean isConnected(ContactId c) {
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			return recs != null && !recs.isEmpty();
-		}
-	}
-
-	@Override
-	public boolean registerConnection(PendingContactId p) {
-		boolean added;
-		synchronized (lock) {
-			added = connectedPendingContacts.add(p);
-		}
-		if (added) eventBus.broadcast(new RendezvousConnectionOpenedEvent(p));
-		return added;
-	}
-
-	@Override
-	public void unregisterConnection(PendingContactId p, boolean success) {
-		synchronized (lock) {
-			if (!connectedPendingContacts.remove(p))
-				throw new IllegalArgumentException();
-		}
-		eventBus.broadcast(new RendezvousConnectionClosedEvent(p, success));
-	}
-
-	private static class ConnectionRecord {
-
-		private final TransportId transportId;
-		private final InterruptibleConnection conn;
-		@GuardedBy("lock")
-		@Nullable
-		private Priority priority = null;
-		@GuardedBy("lock")
-		private boolean interrupted = false;
-
-		private ConnectionRecord(TransportId transportId,
-				InterruptibleConnection conn) {
-			this.transportId = transportId;
-			this.conn = conn;
-		}
-
-		@Override
-		public boolean equals(Object o) {
-			if (o instanceof ConnectionRecord) {
-				return conn == ((ConnectionRecord) o).conn;
-			} else {
-				return false;
-			}
-		}
-
-		@Override
-		public int hashCode() {
-			return conn.hashCode();
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/DuplexSyncConnection.java

@@ -1,109 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.connection.InterruptibleConnection;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportProperties;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.util.concurrent.Executor;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-
-@NotNullByDefault
-abstract class DuplexSyncConnection extends SyncConnection
-		implements InterruptibleConnection {
-
-	final Executor ioExecutor;
-	final TransportId transportId;
-	final TransportConnectionReader reader;
-	final TransportConnectionWriter writer;
-	final TransportProperties remote;
-
-	private final Object interruptLock = new Object();
-
-	@GuardedBy("interruptLock")
-	@Nullable
-	private SyncSession outgoingSession = null;
-	@GuardedBy("interruptLock")
-	private boolean interruptWaiting = false;
-
-	@Override
-	public void interruptOutgoingSession() {
-		SyncSession out = null;
-		synchronized (interruptLock) {
-			if (outgoingSession == null) interruptWaiting = true;
-			else out = outgoingSession;
-		}
-		if (out != null) out.interrupt();
-	}
-
-	void setOutgoingSession(SyncSession outgoingSession) {
-		boolean interruptWasWaiting = false;
-		synchronized (interruptLock) {
-			this.outgoingSession = outgoingSession;
-			if (interruptWaiting) {
-				interruptWasWaiting = true;
-				interruptWaiting = false;
-			}
-		}
-		if (interruptWasWaiting) outgoingSession.interrupt();
-	}
-
-	DuplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, TransportId transportId,
-			DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager);
-		this.ioExecutor = ioExecutor;
-		this.transportId = transportId;
-		reader = connection.getReader();
-		writer = connection.getWriter();
-		remote = connection.getRemoteProperties();
-	}
-
-	void onReadError(boolean recognised) {
-		disposeOnError(reader, recognised);
-		disposeOnError(writer);
-		interruptOutgoingSession();
-	}
-
-	void onWriteError() {
-		disposeOnError(reader, true);
-		disposeOnError(writer);
-	}
-
-	SyncSession createDuplexOutgoingSession(StreamContext ctx,
-			TransportConnectionWriter w, @Nullable Priority priority)
-			throws IOException {
-		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
-				w.getOutputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory.createDuplexOutgoingSession(c,
-				ctx.getTransportId(), w.getMaxLatency(), w.getMaxIdleTime(),
-				streamWriter, priority);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/HandshakeConnection.java

@@ -1,72 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-abstract class HandshakeConnection extends Connection {
-
-	final HandshakeManager handshakeManager;
-	final ContactExchangeManager contactExchangeManager;
-	final ConnectionManager connectionManager;
-	final PendingContactId pendingContactId;
-	final TransportId transportId;
-	final DuplexTransportConnection connection;
-	final TransportConnectionReader reader;
-	final TransportConnectionWriter writer;
-
-	HandshakeConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionManager connectionManager,
-			PendingContactId pendingContactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory);
-		this.handshakeManager = handshakeManager;
-		this.contactExchangeManager = contactExchangeManager;
-		this.connectionManager = connectionManager;
-		this.pendingContactId = pendingContactId;
-		this.transportId = transportId;
-		this.connection = connection;
-		reader = connection.getReader();
-		writer = connection.getWriter();
-	}
-
-	@Nullable
-	StreamContext allocateStreamContext(PendingContactId pendingContactId,
-			TransportId transportId) {
-		try {
-			return keyManager.getStreamContext(pendingContactId, transportId);
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-			return null;
-		}
-	}
-
-	void onError(boolean recognised) {
-		disposeOnError(reader, recognised);
-		disposeOnError(writer);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingDuplexSyncConnection.java

@@ -1,107 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.util.concurrent.Executor;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class IncomingDuplexSyncConnection extends DuplexSyncConnection
-		implements Runnable {
-
-	IncomingDuplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, TransportId transportId,
-			DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager, ioExecutor, transportId, connection);
-	}
-
-	@Override
-	public void run() {
-		// Read and recognise the tag
-		StreamContext ctx = recogniseTag(reader, transportId);
-		if (ctx == null) {
-			LOG.info("Unrecognised tag");
-			onReadError(false);
-			return;
-		}
-		ContactId contactId = ctx.getContactId();
-		if (contactId == null) {
-			LOG.warning("Expected contact tag, got rendezvous tag");
-			onReadError(true);
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onReadError(true);
-			return;
-		}
-		connectionRegistry.registerIncomingConnection(contactId, transportId,
-				this);
-		// Start the outgoing session on another thread
-		ioExecutor.execute(() -> runOutgoingSession(contactId));
-		try {
-			// Store any transport properties discovered from the connection
-			transportPropertyManager.addRemotePropertiesFromConnection(
-					contactId, transportId, remote);
-			// Update the connection registry when we receive our priority
-			PriorityHandler handler = p -> connectionRegistry.setPriority(
-					contactId, transportId, this, p);
-			// Create and run the incoming session
-			createIncomingSession(ctx, reader, handler).run();
-			reader.dispose(false, true);
-			interruptOutgoingSession();
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, true, false);
-		} catch (DbException | IOException e) {
-			logException(LOG, WARNING, e);
-			onReadError(true);
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, true, true);
-		}
-	}
-
-	private void runOutgoingSession(ContactId contactId) {
-		// Allocate a stream context
-		StreamContext ctx = allocateStreamContext(contactId, transportId);
-		if (ctx == null) {
-			LOG.warning("Could not allocate stream context");
-			onWriteError();
-			return;
-		}
-		try {
-			// Create and run the outgoing session
-			SyncSession out = createDuplexOutgoingSession(ctx, writer, null);
-			setOutgoingSession(out);
-			out.run();
-			writer.dispose(false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onWriteError();
-		}
-	}
-}
-

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingHandshakeConnection.java

@@ -1,93 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class IncomingHandshakeConnection extends HandshakeConnection
-		implements Runnable {
-
-	IncomingHandshakeConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionManager connectionManager,
-			PendingContactId pendingContactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, handshakeManager, contactExchangeManager,
-				connectionManager, pendingContactId, transportId, connection);
-	}
-
-	@Override
-	public void run() {
-		// Read and recognise the tag
-		StreamContext ctxIn = recogniseTag(reader, transportId);
-		if (ctxIn == null) {
-			LOG.info("Unrecognised tag");
-			onError(false);
-			return;
-		}
-		PendingContactId inPendingContactId = ctxIn.getPendingContactId();
-		if (inPendingContactId == null) {
-			LOG.warning("Expected rendezvous tag, got contact tag");
-			onError(true);
-			return;
-		}
-		// Allocate the outgoing stream context
-		StreamContext ctxOut =
-				allocateStreamContext(pendingContactId, transportId);
-		if (ctxOut == null) {
-			LOG.warning("Could not allocate stream context");
-			onError(true);
-			return;
-		}
-		// Close the connection if it's redundant
-		if (!connectionRegistry.registerConnection(pendingContactId)) {
-			LOG.info("Redundant rendezvous connection");
-			onError(true);
-			return;
-		}
-		// Handshake and exchange contacts
-		try {
-			InputStream in = streamReaderFactory.createStreamReader(
-					reader.getInputStream(), ctxIn);
-			// Flush the output stream to send the outgoing stream header
-			StreamWriter out = streamWriterFactory.createStreamWriter(
-					writer.getOutputStream(), ctxOut);
-			out.getOutputStream().flush();
-			HandshakeResult result =
-					handshakeManager.handshake(pendingContactId, in, out);
-			contactExchangeManager.exchangeContacts(pendingContactId,
-					connection, result.getMasterKey(), result.isAlice(), false);
-			connectionRegistry.unregisterConnection(pendingContactId, true);
-			// Reuse the connection as a transport connection
-			connectionManager.manageIncomingConnection(transportId, connection);
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onError(true);
-			connectionRegistry.unregisterConnection(pendingContactId, false);
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingSimplexSyncConnection.java

@@ -1,79 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
-
-	private final TransportId transportId;
-	private final TransportConnectionReader reader;
-
-	IncomingSimplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			TransportId transportId, TransportConnectionReader reader) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager);
-		this.transportId = transportId;
-		this.reader = reader;
-	}
-
-	@Override
-	public void run() {
-		// Read and recognise the tag
-		StreamContext ctx = recogniseTag(reader, transportId);
-		if (ctx == null) {
-			LOG.info("Unrecognised tag");
-			onError(false);
-			return;
-		}
-		ContactId contactId = ctx.getContactId();
-		if (contactId == null) {
-			LOG.warning("Received rendezvous stream, expected contact");
-			onError(true);
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onError(true);
-			return;
-		}
-		try {
-			// We don't expect to receive a priority for this connection
-			PriorityHandler handler = p ->
-					LOG.info("Ignoring priority for simplex connection");
-			// Create and run the incoming session
-			createIncomingSession(ctx, reader, handler).run();
-			reader.dispose(false, true);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onError(true);
-		}
-	}
-
-	private void onError(boolean recognised) {
-		disposeOnError(reader, recognised);
-	}
-}
-

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingDuplexSyncConnection.java

@@ -1,140 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.security.SecureRandom;
-import java.util.concurrent.Executor;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.sync.SyncConstants.PRIORITY_NONCE_BYTES;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class OutgoingDuplexSyncConnection extends DuplexSyncConnection
-		implements Runnable {
-
-	private final SecureRandom secureRandom;
-	private final ContactId contactId;
-
-	OutgoingDuplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, SecureRandom secureRandom, ContactId contactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager, ioExecutor, transportId, connection);
-		this.secureRandom = secureRandom;
-		this.contactId = contactId;
-	}
-
-	@Override
-	public void run() {
-		// Allocate a stream context
-		StreamContext ctx = allocateStreamContext(contactId, transportId);
-		if (ctx == null) {
-			LOG.warning("Could not allocate stream context");
-			onWriteError();
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Cannot use handshake mode stream context");
-			onWriteError();
-			return;
-		}
-		// Start the incoming session on another thread
-		Priority priority = generatePriority();
-		ioExecutor.execute(() -> runIncomingSession(priority));
-		try {
-			// Create and run the outgoing session
-			SyncSession out =
-					createDuplexOutgoingSession(ctx, writer, priority);
-			setOutgoingSession(out);
-			out.run();
-			writer.dispose(false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onWriteError();
-		}
-	}
-
-	private void runIncomingSession(Priority priority) {
-		// Read and recognise the tag
-		StreamContext ctx = recogniseTag(reader, transportId);
-		// Unrecognised tags are suspicious in this case
-		if (ctx == null) {
-			LOG.warning("Unrecognised tag for returning stream");
-			onReadError();
-			return;
-		}
-		// Check that the stream comes from the expected contact
-		ContactId inContactId = ctx.getContactId();
-		if (inContactId == null) {
-			LOG.warning("Expected contact tag, got rendezvous tag");
-			onReadError();
-			return;
-		}
-		if (!contactId.equals(inContactId)) {
-			LOG.warning("Wrong contact ID for returning stream");
-			onReadError();
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onReadError();
-			return;
-		}
-		connectionRegistry.registerOutgoingConnection(contactId, transportId,
-				this, priority);
-		try {
-			// Store any transport properties discovered from the connection
-			transportPropertyManager.addRemotePropertiesFromConnection(
-					contactId, transportId, remote);
-			// We don't expect to receive a priority for this connection
-			PriorityHandler handler = p ->
-					LOG.info("Ignoring priority for outgoing connection");
-			// Create and run the incoming session
-			createIncomingSession(ctx, reader, handler).run();
-			reader.dispose(false, true);
-			interruptOutgoingSession();
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, false, false);
-		} catch (DbException | IOException e) {
-			logException(LOG, WARNING, e);
-			onReadError();
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, false, true);
-		}
-	}
-
-	private void onReadError() {
-		// 'Recognised' is always true for outgoing connections
-		onReadError(true);
-	}
-
-	private Priority generatePriority() {
-		byte[] nonce = new byte[PRIORITY_NONCE_BYTES];
-		secureRandom.nextBytes(nonce);
-		return new Priority(nonce);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingHandshakeConnection.java

@@ -1,115 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class OutgoingHandshakeConnection extends HandshakeConnection
-		implements Runnable {
-
-	OutgoingHandshakeConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionManager connectionManager,
-			PendingContactId pendingContactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, handshakeManager, contactExchangeManager,
-				connectionManager, pendingContactId, transportId, connection);
-	}
-
-	@Override
-	public void run() {
-		// Allocate the outgoing stream context
-		StreamContext ctxOut =
-				allocateStreamContext(pendingContactId, transportId);
-		if (ctxOut == null) {
-			LOG.warning("Could not allocate stream context");
-			onError();
-			return;
-		}
-		// Flush the output stream to send the outgoing stream header
-		StreamWriter out;
-		try {
-			out = streamWriterFactory.createStreamWriter(
-					writer.getOutputStream(), ctxOut);
-			out.getOutputStream().flush();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onError();
-			return;
-		}
-		// Read and recognise the tag
-		StreamContext ctxIn = recogniseTag(reader, transportId);
-		// Unrecognised tags are suspicious in this case
-		if (ctxIn == null) {
-			LOG.warning("Unrecognised tag for returning stream");
-			onError();
-			return;
-		}
-		// Check that the stream comes from the expected pending contact
-		PendingContactId inPendingContactId = ctxIn.getPendingContactId();
-		if (inPendingContactId == null) {
-			LOG.warning("Expected rendezvous tag, got contact tag");
-			onError();
-			return;
-		}
-		if (!inPendingContactId.equals(pendingContactId)) {
-			LOG.warning("Wrong pending contact ID for returning stream");
-			onError();
-			return;
-		}
-		// Close the connection if it's redundant
-		if (!connectionRegistry.registerConnection(pendingContactId)) {
-			LOG.info("Redundant rendezvous connection");
-			onError();
-			return;
-		}
-		// Handshake and exchange contacts
-		try {
-			InputStream in = streamReaderFactory.createStreamReader(
-					reader.getInputStream(), ctxIn);
-			HandshakeResult result =
-					handshakeManager.handshake(pendingContactId, in, out);
-			Contact contact = contactExchangeManager.exchangeContacts(
-					pendingContactId, connection, result.getMasterKey(),
-					result.isAlice(), false);
-			connectionRegistry.unregisterConnection(pendingContactId, true);
-			// Reuse the connection as a transport connection
-			connectionManager.manageOutgoingConnection(contact.getId(),
-					transportId, connection);
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onError();
-			connectionRegistry.unregisterConnection(pendingContactId, false);
-		}
-	}
-
-	private void onError() {
-		// 'Recognised' is always true for outgoing connections
-		onError(true);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingSimplexSyncConnection.java

@@ -1,78 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
-
-	private final ContactId contactId;
-	private final TransportId transportId;
-	private final TransportConnectionWriter writer;
-
-	OutgoingSimplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			ContactId contactId, TransportId transportId,
-			TransportConnectionWriter writer) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager);
-		this.contactId = contactId;
-		this.transportId = transportId;
-		this.writer = writer;
-	}
-
-	@Override
-	public void run() {
-		// Allocate a stream context
-		StreamContext ctx = allocateStreamContext(contactId, transportId);
-		if (ctx == null) {
-			LOG.warning("Could not allocate stream context");
-			onError();
-			return;
-		}
-		try {
-			// Create and run the outgoing session
-			createSimplexOutgoingSession(ctx, writer).run();
-			writer.dispose(false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onError();
-		}
-	}
-
-	private void onError() {
-		disposeOnError(writer);
-	}
-
-	private SyncSession createSimplexOutgoingSession(StreamContext ctx,
-			TransportConnectionWriter w) throws IOException {
-		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
-				w.getOutputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory.createSimplexOutgoingSession(c,
-				ctx.getTransportId(), w.getMaxLatency(), streamWriter);
-	}
-}
-

bramble-core/src/main/java/org/briarproject/bramble/connection/SyncConnection.java

@@ -1,64 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class SyncConnection extends Connection {
-
-	final SyncSessionFactory syncSessionFactory;
-	final TransportPropertyManager transportPropertyManager;
-
-	SyncConnection(KeyManager keyManager, ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory);
-		this.syncSessionFactory = syncSessionFactory;
-		this.transportPropertyManager = transportPropertyManager;
-	}
-
-	@Nullable
-	StreamContext allocateStreamContext(ContactId contactId,
-			TransportId transportId) {
-		try {
-			return keyManager.getStreamContext(contactId, transportId);
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-			return null;
-		}
-	}
-
-	SyncSession createIncomingSession(StreamContext ctx,
-			TransportConnectionReader r, PriorityHandler handler)
-			throws IOException {
-		InputStream streamReader = streamReaderFactory.createStreamReader(
-				r.getInputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory
-				.createIncomingSession(c, streamReader, handler);
-	}
-}

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

@@ -0,0 +1,709 @@
+package org.briarproject.bramble.plugin;
+
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactExchangeManager;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.HandshakeManager;
+import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
+import org.briarproject.bramble.api.plugin.TransportConnectionReader;
+import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.properties.TransportPropertyManager;
+import org.briarproject.bramble.api.sync.SyncSession;
+import org.briarproject.bramble.api.sync.SyncSessionFactory;
+import org.briarproject.bramble.api.transport.KeyManager;
+import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.StreamReaderFactory;
+import org.briarproject.bramble.api.transport.StreamWriter;
+import org.briarproject.bramble.api.transport.StreamWriterFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
+import static org.briarproject.bramble.util.IoUtils.read;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@NotNullByDefault
+class ConnectionManagerImpl implements ConnectionManager {
+
+	private static final Logger LOG =
+			getLogger(ConnectionManagerImpl.class.getName());
+
+	private final Executor ioExecutor;
+	private final KeyManager keyManager;
+	private final StreamReaderFactory streamReaderFactory;
+	private final StreamWriterFactory streamWriterFactory;
+	private final SyncSessionFactory syncSessionFactory;
+	private final HandshakeManager handshakeManager;
+	private final ContactExchangeManager contactExchangeManager;
+	private final ConnectionRegistry connectionRegistry;
+	private final TransportPropertyManager transportPropertyManager;
+
+	@Inject
+	ConnectionManagerImpl(@IoExecutor Executor ioExecutor,
+			KeyManager keyManager, StreamReaderFactory streamReaderFactory,
+			StreamWriterFactory streamWriterFactory,
+			SyncSessionFactory syncSessionFactory,
+			HandshakeManager handshakeManager,
+			ContactExchangeManager contactExchangeManager,
+			ConnectionRegistry connectionRegistry,
+			TransportPropertyManager transportPropertyManager) {
+		this.ioExecutor = ioExecutor;
+		this.keyManager = keyManager;
+		this.streamReaderFactory = streamReaderFactory;
+		this.streamWriterFactory = streamWriterFactory;
+		this.syncSessionFactory = syncSessionFactory;
+		this.handshakeManager = handshakeManager;
+		this.contactExchangeManager = contactExchangeManager;
+		this.connectionRegistry = connectionRegistry;
+		this.transportPropertyManager = transportPropertyManager;
+	}
+
+	@Override
+	public void manageIncomingConnection(TransportId t,
+			TransportConnectionReader r) {
+		ioExecutor.execute(new ManageIncomingSimplexConnection(t, r));
+	}
+
+	@Override
+	public void manageIncomingConnection(TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageIncomingDuplexConnection(t, d));
+	}
+
+	@Override
+	public void manageIncomingConnection(PendingContactId p, TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageIncomingHandshakeConnection(p, t, d));
+	}
+
+	@Override
+	public void manageOutgoingConnection(ContactId c, TransportId t,
+			TransportConnectionWriter w) {
+		ioExecutor.execute(new ManageOutgoingSimplexConnection(c, t, w));
+	}
+
+	@Override
+	public void manageOutgoingConnection(ContactId c, TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageOutgoingDuplexConnection(c, t, d));
+	}
+
+	@Override
+	public void manageOutgoingConnection(PendingContactId p, TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageOutgoingHandshakeConnection(p, t, d));
+	}
+
+	private byte[] readTag(InputStream in) throws IOException {
+		byte[] tag = new byte[TAG_LENGTH];
+		read(in, tag);
+		return tag;
+	}
+
+	private SyncSession createIncomingSession(StreamContext ctx,
+			TransportConnectionReader r) throws IOException {
+		InputStream streamReader = streamReaderFactory.createStreamReader(
+				r.getInputStream(), ctx);
+		ContactId c = requireNonNull(ctx.getContactId());
+		return syncSessionFactory.createIncomingSession(c, streamReader);
+	}
+
+	private SyncSession createSimplexOutgoingSession(StreamContext ctx,
+			TransportConnectionWriter w) throws IOException {
+		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
+				w.getOutputStream(), ctx);
+		return syncSessionFactory.createSimplexOutgoingSession(
+				requireNonNull(ctx.getContactId()), ctx.getTransportId(),
+				w.getMaxLatency(), streamWriter);
+	}
+
+	private SyncSession createDuplexOutgoingSession(StreamContext ctx,
+			TransportConnectionWriter w) throws IOException {
+		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
+				w.getOutputStream(), ctx);
+		return syncSessionFactory.createDuplexOutgoingSession(
+				requireNonNull(ctx.getContactId()), ctx.getTransportId(),
+				w.getMaxLatency(), w.getMaxIdleTime(), streamWriter);
+	}
+
+	private void disposeOnError(TransportConnectionReader reader,
+			boolean recognised) {
+		try {
+			reader.dispose(true, recognised);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private void disposeOnError(TransportConnectionWriter writer) {
+		try {
+			writer.dispose(true);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private class ManageIncomingSimplexConnection implements Runnable {
+
+		private final TransportId transportId;
+		private final TransportConnectionReader reader;
+
+		private ManageIncomingSimplexConnection(TransportId transportId,
+				TransportConnectionReader reader) {
+			this.transportId = transportId;
+			this.reader = reader;
+		}
+
+		@Override
+		public void run() {
+			// Read and recognise the tag
+			StreamContext ctx;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctx = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError(false);
+				return;
+			}
+			if (ctx == null) {
+				LOG.info("Unrecognised tag");
+				onError(false);
+				return;
+			}
+			ContactId contactId = ctx.getContactId();
+			if (contactId == null) {
+				LOG.warning("Received rendezvous stream, expected contact");
+				onError(true);
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Received handshake tag, expected rotation mode");
+				onError(true);
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId, true);
+			try {
+				// Create and run the incoming session
+				createIncomingSession(ctx, reader).run();
+				reader.dispose(false, true);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onError(true);
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						true);
+			}
+		}
+
+		private void onError(boolean recognised) {
+			disposeOnError(reader, recognised);
+		}
+	}
+
+	private class ManageOutgoingSimplexConnection implements Runnable {
+
+		private final ContactId contactId;
+		private final TransportId transportId;
+		private final TransportConnectionWriter writer;
+
+		private ManageOutgoingSimplexConnection(ContactId contactId,
+				TransportId transportId, TransportConnectionWriter writer) {
+			this.contactId = contactId;
+			this.transportId = transportId;
+			this.writer = writer;
+		}
+
+		@Override
+		public void run() {
+			// Allocate a stream context
+			StreamContext ctx;
+			try {
+				ctx = keyManager.getStreamContext(contactId, transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			if (ctx == null) {
+				LOG.warning("Could not allocate stream context");
+				onError();
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId,
+					false);
+			try {
+				// Create and run the outgoing session
+				createSimplexOutgoingSession(ctx, writer).run();
+				writer.dispose(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onError();
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						false);
+			}
+		}
+
+		private void onError() {
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageIncomingDuplexConnection implements Runnable {
+
+		private final TransportId transportId;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+		private final TransportProperties remote;
+
+		@Nullable
+		private volatile SyncSession outgoingSession = null;
+
+		private ManageIncomingDuplexConnection(TransportId transportId,
+				DuplexTransportConnection connection) {
+			this.transportId = transportId;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+			remote = connection.getRemoteProperties();
+		}
+
+		@Override
+		public void run() {
+			// Read and recognise the tag
+			StreamContext ctx;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctx = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onReadError(false);
+				return;
+			}
+			if (ctx == null) {
+				LOG.info("Unrecognised tag");
+				onReadError(false);
+				return;
+			}
+			ContactId contactId = ctx.getContactId();
+			if (contactId == null) {
+				LOG.warning("Expected contact tag, got rendezvous tag");
+				onReadError(true);
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Received handshake tag, expected rotation mode");
+				onReadError(true);
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId, true);
+			// Start the outgoing session on another thread
+			ioExecutor.execute(() -> runOutgoingSession(contactId));
+			try {
+				// Store any transport properties discovered from the connection
+				transportPropertyManager.addRemotePropertiesFromConnection(
+						contactId, transportId, remote);
+				// Create and run the incoming session
+				createIncomingSession(ctx, reader).run();
+				reader.dispose(false, true);
+				// Interrupt the outgoing session so it finishes cleanly
+				SyncSession out = outgoingSession;
+				if (out != null) out.interrupt();
+			} catch (DbException | IOException e) {
+				logException(LOG, WARNING, e);
+				onReadError(true);
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						true);
+			}
+		}
+
+		private void runOutgoingSession(ContactId contactId) {
+			// Allocate a stream context
+			StreamContext ctx;
+			try {
+				ctx = keyManager.getStreamContext(contactId, transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+				return;
+			}
+			if (ctx == null) {
+				LOG.warning("Could not allocate stream context");
+				onWriteError();
+				return;
+			}
+			try {
+				// Create and run the outgoing session
+				SyncSession out = createDuplexOutgoingSession(ctx, writer);
+				outgoingSession = out;
+				out.run();
+				writer.dispose(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+			}
+		}
+
+		private void onReadError(boolean recognised) {
+			disposeOnError(reader, recognised);
+			disposeOnError(writer);
+			// Interrupt the outgoing session so it finishes
+			SyncSession out = outgoingSession;
+			if (out != null) out.interrupt();
+		}
+
+		private void onWriteError() {
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageOutgoingDuplexConnection implements Runnable {
+
+		private final ContactId contactId;
+		private final TransportId transportId;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+		private final TransportProperties remote;
+
+		@Nullable
+		private volatile SyncSession outgoingSession = null;
+
+		private ManageOutgoingDuplexConnection(ContactId contactId,
+				TransportId transportId, DuplexTransportConnection connection) {
+			this.contactId = contactId;
+			this.transportId = transportId;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+			remote = connection.getRemoteProperties();
+		}
+
+		@Override
+		public void run() {
+			// Allocate a stream context
+			StreamContext ctx;
+			try {
+				ctx = keyManager.getStreamContext(contactId, transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+				return;
+			}
+			if (ctx == null) {
+				LOG.warning("Could not allocate stream context");
+				onWriteError();
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Cannot use handshake mode stream context");
+				onWriteError();
+				return;
+			}
+			// Start the incoming session on another thread
+			ioExecutor.execute(this::runIncomingSession);
+			try {
+				// Create and run the outgoing session
+				SyncSession out = createDuplexOutgoingSession(ctx, writer);
+				outgoingSession = out;
+				out.run();
+				writer.dispose(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+			}
+		}
+
+		private void runIncomingSession() {
+			// Read and recognise the tag
+			StreamContext ctx;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctx = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onReadError();
+				return;
+			}
+			// Unrecognised tags are suspicious in this case
+			if (ctx == null) {
+				LOG.warning("Unrecognised tag for returning stream");
+				onReadError();
+				return;
+			}
+			// Check that the stream comes from the expected contact
+			ContactId inContactId = ctx.getContactId();
+			if (inContactId == null) {
+				LOG.warning("Expected contact tag, got rendezvous tag");
+				onReadError();
+				return;
+			}
+			if (!contactId.equals(inContactId)) {
+				LOG.warning("Wrong contact ID for returning stream");
+				onReadError();
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Received handshake tag, expected rotation mode");
+				onReadError();
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId,
+					false);
+			try {
+				// Store any transport properties discovered from the connection
+				transportPropertyManager.addRemotePropertiesFromConnection(
+						contactId, transportId, remote);
+				// Create and run the incoming session
+				createIncomingSession(ctx, reader).run();
+				reader.dispose(false, true);
+				// Interrupt the outgoing session so it finishes cleanly
+				SyncSession out = outgoingSession;
+				if (out != null) out.interrupt();
+			} catch (DbException | IOException e) {
+				logException(LOG, WARNING, e);
+				onReadError();
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						false);
+			}
+		}
+
+		private void onReadError() {
+			// 'Recognised' is always true for outgoing connections
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+			// Interrupt the outgoing session so it finishes
+			SyncSession out = outgoingSession;
+			if (out != null) out.interrupt();
+		}
+
+		private void onWriteError() {
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageIncomingHandshakeConnection implements Runnable {
+
+		private final PendingContactId pendingContactId;
+		private final TransportId transportId;
+		private final DuplexTransportConnection connection;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+
+		private ManageIncomingHandshakeConnection(
+				PendingContactId pendingContactId, TransportId transportId,
+				DuplexTransportConnection connection) {
+			this.pendingContactId = pendingContactId;
+			this.transportId = transportId;
+			this.connection = connection;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+		}
+
+		@Override
+		public void run() {
+			// Read and recognise the tag
+			StreamContext ctxIn;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctxIn = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError(false);
+				return;
+			}
+			if (ctxIn == null) {
+				LOG.info("Unrecognised tag");
+				onError(false);
+				return;
+			}
+			PendingContactId inPendingContactId = ctxIn.getPendingContactId();
+			if (inPendingContactId == null) {
+				LOG.warning("Expected rendezvous tag, got contact tag");
+				onError(true);
+				return;
+			}
+			// Allocate the outgoing stream context
+			StreamContext ctxOut;
+			try {
+				ctxOut = keyManager.getStreamContext(pendingContactId,
+						transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onError(true);
+				return;
+			}
+			if (ctxOut == null) {
+				LOG.warning("Could not allocate stream context");
+				onError(true);
+				return;
+			}
+			// Close the connection if it's redundant
+			if (!connectionRegistry.registerConnection(pendingContactId)) {
+				LOG.info("Redundant rendezvous connection");
+				onError(true);
+				return;
+			}
+			// Handshake and exchange contacts
+			try {
+				InputStream in = streamReaderFactory.createStreamReader(
+						reader.getInputStream(), ctxIn);
+				// Flush the output stream to send the outgoing stream header
+				StreamWriter out = streamWriterFactory.createStreamWriter(
+						writer.getOutputStream(), ctxOut);
+				out.getOutputStream().flush();
+				HandshakeResult result = handshakeManager.handshake(
+						pendingContactId, in, out);
+				Contact contact = contactExchangeManager.exchangeContacts(
+						pendingContactId, connection, result.getMasterKey(),
+						result.isAlice(), false);
+				connectionRegistry.unregisterConnection(pendingContactId, true);
+				// Reuse the connection as a transport connection
+				manageOutgoingConnection(contact.getId(), transportId,
+						connection);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError(true);
+				connectionRegistry.unregisterConnection(pendingContactId,
+						false);
+			}
+		}
+
+		private void onError(boolean recognised) {
+			disposeOnError(reader, recognised);
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageOutgoingHandshakeConnection implements Runnable {
+
+		private final PendingContactId pendingContactId;
+		private final TransportId transportId;
+		private final DuplexTransportConnection connection;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+
+		private ManageOutgoingHandshakeConnection(
+				PendingContactId pendingContactId, TransportId transportId,
+				DuplexTransportConnection connection) {
+			this.pendingContactId = pendingContactId;
+			this.transportId = transportId;
+			this.connection = connection;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+		}
+
+		@Override
+		public void run() {
+			// Allocate the outgoing stream context
+			StreamContext ctxOut;
+			try {
+				ctxOut = keyManager.getStreamContext(pendingContactId,
+						transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			if (ctxOut == null) {
+				LOG.warning("Could not allocate stream context");
+				onError();
+				return;
+			}
+			// Flush the output stream to send the outgoing stream header
+			StreamWriter out;
+			try {
+				out = streamWriterFactory.createStreamWriter(
+						writer.getOutputStream(), ctxOut);
+				out.getOutputStream().flush();
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			// Read and recognise the tag
+			StreamContext ctxIn;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctxIn = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			// Unrecognised tags are suspicious in this case
+			if (ctxIn == null) {
+				LOG.warning("Unrecognised tag for returning stream");
+				onError();
+				return;
+			}
+			// Check that the stream comes from the expected pending contact
+			PendingContactId inPendingContactId = ctxIn.getPendingContactId();
+			if (inPendingContactId == null) {
+				LOG.warning("Expected rendezvous tag, got contact tag");
+				onError();
+				return;
+			}
+			if (!inPendingContactId.equals(pendingContactId)) {
+				LOG.warning("Wrong pending contact ID for returning stream");
+				onError();
+				return;
+			}
+			// Close the connection if it's redundant
+			if (!connectionRegistry.registerConnection(pendingContactId)) {
+				LOG.info("Redundant rendezvous connection");
+				onError();
+				return;
+			}
+			// Handshake and exchange contacts
+			try {
+				InputStream in = streamReaderFactory.createStreamReader(
+						reader.getInputStream(), ctxIn);
+				HandshakeResult result = handshakeManager.handshake(
+						pendingContactId, in, out);
+				Contact contact = contactExchangeManager.exchangeContacts(
+						pendingContactId, connection, result.getMasterKey(),
+						result.isAlice(), false);
+				connectionRegistry.unregisterConnection(pendingContactId, true);
+				// Reuse the connection as a transport connection
+				manageOutgoingConnection(contact.getId(), transportId,
+						connection);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				connectionRegistry.unregisterConnection(pendingContactId,
+						false);
+			}
+		}
+
+		private void onError() {
+			// 'Recognised' is always true for outgoing connections
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+		}
+	}
+}

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

@@ -0,0 +1,150 @@
+package org.briarproject.bramble.plugin;
+
+import org.briarproject.bramble.api.Multiset;
+import org.briarproject.bramble.api.contact.ContactId;
+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.TransportId;
+import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
+import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
+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 java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+import javax.inject.Inject;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+
+@ThreadSafe
+@NotNullByDefault
+class ConnectionRegistryImpl implements ConnectionRegistry {
+
+	private static final Logger LOG =
+			getLogger(ConnectionRegistryImpl.class.getName());
+
+	private final EventBus eventBus;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private final Map<TransportId, Multiset<ContactId>> contactConnections;
+	@GuardedBy("lock")
+	private final Multiset<ContactId> contactCounts;
+	@GuardedBy("lock")
+	private final Set<PendingContactId> connectedPendingContacts;
+
+	@Inject
+	ConnectionRegistryImpl(EventBus eventBus) {
+		this.eventBus = eventBus;
+		contactConnections = new HashMap<>();
+		contactCounts = new Multiset<>();
+		connectedPendingContacts = new HashSet<>();
+	}
+
+	@Override
+	public void registerConnection(ContactId c, TransportId t,
+			boolean incoming) {
+		if (LOG.isLoggable(INFO)) {
+			if (incoming) LOG.info("Incoming connection registered: " + t);
+			else LOG.info("Outgoing connection registered: " + t);
+		}
+		boolean firstConnection = false;
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			if (m == null) {
+				m = new Multiset<>();
+				contactConnections.put(t, m);
+			}
+			m.add(c);
+			if (contactCounts.add(c) == 1) firstConnection = true;
+		}
+		eventBus.broadcast(new ConnectionOpenedEvent(c, t, incoming));
+		if (firstConnection) {
+			LOG.info("Contact connected");
+			eventBus.broadcast(new ContactConnectedEvent(c));
+		}
+	}
+
+	@Override
+	public void unregisterConnection(ContactId c, TransportId t,
+			boolean incoming) {
+		if (LOG.isLoggable(INFO)) {
+			if (incoming) LOG.info("Incoming connection unregistered: " + t);
+			else LOG.info("Outgoing connection unregistered: " + t);
+		}
+		boolean lastConnection = false;
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			if (m == null || !m.contains(c))
+				throw new IllegalArgumentException();
+			m.remove(c);
+			if (contactCounts.remove(c) == 0) lastConnection = true;
+		}
+		eventBus.broadcast(new ConnectionClosedEvent(c, t, incoming));
+		if (lastConnection) {
+			LOG.info("Contact disconnected");
+			eventBus.broadcast(new ContactDisconnectedEvent(c));
+		}
+	}
+
+	@Override
+	public Collection<ContactId> getConnectedContacts(TransportId t) {
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			if (m == null) return Collections.emptyList();
+			List<ContactId> ids = new ArrayList<>(m.keySet());
+			if (LOG.isLoggable(INFO))
+				LOG.info(ids.size() + " contacts connected: " + t);
+			return ids;
+		}
+	}
+
+	@Override
+	public boolean isConnected(ContactId c, TransportId t) {
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			return m != null && m.contains(c);
+		}
+	}
+
+	@Override
+	public boolean isConnected(ContactId c) {
+		synchronized (lock) {
+			return contactCounts.contains(c);
+		}
+	}
+
+	@Override
+	public boolean registerConnection(PendingContactId p) {
+		boolean added;
+		synchronized (lock) {
+			added = connectedPendingContacts.add(p);
+		}
+		if (added) eventBus.broadcast(new RendezvousConnectionOpenedEvent(p));
+		return added;
+	}
+
+	@Override
+	public void unregisterConnection(PendingContactId p, boolean success) {
+		synchronized (lock) {
+			if (!connectedPendingContacts.remove(p))
+				throw new IllegalArgumentException();
+		}
+		eventBus.broadcast(new RendezvousConnectionClosedEvent(p, success));
+	}
+}

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

@@ -1,12 +1,12 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginConfig;

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

@@ -3,6 +3,8 @@ package org.briarproject.bramble.plugin;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.PluginManager;
 
@@ -27,6 +29,20 @@ public class PluginModule {
 		return new BackoffFactoryImpl();
 	}
 
+	@Provides
+	@Singleton
+	ConnectionManager provideConnectionManager(
+			ConnectionManagerImpl connectionManager) {
+		return connectionManager;
+	}
+
+	@Provides
+	@Singleton
+	ConnectionRegistry provideConnectionRegistry(
+			ConnectionRegistryImpl connectionRegistry) {
+		return connectionRegistry;
+	}
+
 	@Provides
 	@Singleton
 	PluginManager providePluginManager(LifecycleManager lifecycleManager,

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

@@ -1,8 +1,6 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.db.DbException;
@@ -11,6 +9,8 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
@@ -98,8 +98,8 @@ class PollerImpl implements Poller, EventListener {
 			ConnectionClosedEvent c = (ConnectionClosedEvent) e;
 			// Reschedule polling, the polling interval may have decreased
 			reschedule(c.getTransportId());
-			// If an outgoing connection failed, try to reconnect
+			if (!c.isIncoming()) {
-			if (!c.isIncoming() && c.isException()) {
+				// Connect to the disconnected contact
 				connectToContact(c.getContactId(), c.getTransportId());
 			}
 		} else if (e instanceof ConnectionOpenedEvent) {
@@ -215,7 +215,7 @@ class PollerImpl implements Poller, EventListener {
 			Map<ContactId, TransportProperties> remote =
 					transportPropertyManager.getRemoteProperties(t);
 			Collection<ContactId> connected =
-					connectionRegistry.getConnectedOrBetterContacts(t);
+					connectionRegistry.getConnectedContacts(t);
 			Collection<Pair<TransportProperties, ConnectionHandler>>
 					properties = new ArrayList<>();
 			for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {

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

@@ -3,6 +3,8 @@ 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
@@ -13,6 +15,18 @@ interface BluetoothConnectionLimiter {
 	 */
 	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.
 	 */
@@ -30,17 +44,27 @@ interface BluetoothConnectionLimiter {
 	boolean canOpenContactConnection();
 
 	/**
-	 * Informs the limiter that the given connection has been opened.
+	 * Informs the limiter that a contact connection has been opened.
+	 * <p/>
+	 * Returns true if the connection is allowed.
 	 */
-	void connectionOpened(DuplexTransportConnection conn);
+	boolean contactConnectionOpened(DuplexTransportConnection conn,
+			boolean incoming);
+
+	/**
+	 * Informs the limiter that a key agreement connection has been opened.
+	 */
+	void keyAgreementConnectionOpened(DuplexTransportConnection conn);
 
 	/**
 	 * 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

@@ -13,7 +13,9 @@ 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.Logger.getLogger;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
@@ -34,8 +36,12 @@ class BluetoothConnectionLimiterImpl implements BluetoothConnectionLimiter {
 	@GuardedBy("lock")
 	private boolean keyAgreementInProgress = false;
 	@GuardedBy("lock")
-	private int connectionLimit = 2;
+	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;
@@ -62,82 +68,127 @@ 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;
-			}
-			long now = clock.currentTimeMillis();
-			countStableConnections(now);
-			if (connections.size() < connectionLimit) {
-				LOG.info("Can open contact connection");
-				return true;
 			} else {
-				LOG.info("Can't open contact connection due to limit");
+				long now = clock.currentTimeMillis();
+				return isContactConnectionAllowedByLimit(now);
+			}
+		}
+	}
+
+	@Override
+	public boolean contactConnectionOpened(DuplexTransportConnection conn,
+			boolean incoming) {
+		synchronized (lock) {
+			if (keyAgreementInProgress) {
+				LOG.info("Refusing contact connection during key agreement");
 				return false;
+			} else {
+				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;
+				}
 			}
 		}
 	}
 
 	@Override
-	public void connectionOpened(DuplexTransportConnection conn) {
+	public void keyAgreementConnectionOpened(DuplexTransportConnection conn) {
 		synchronized (lock) {
-			long now = clock.currentTimeMillis();
+			LOG.info("Accepting key agreement connection");
-			countStableConnections(now);
+			connections.add(
-			connections.add(new ConnectionRecord(conn, now));
+					new ConnectionRecord(conn, clock.currentTimeMillis()));
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("Connection opened, " + connections.size() + " open");
-			}
 		}
 	}
 
 	@Override
-	public void connectionClosed(DuplexTransportConnection conn) {
+	public void connectionClosed(DuplexTransportConnection conn,
+			boolean exception) {
 		synchronized (lock) {
-			countStableConnections(clock.currentTimeMillis());
 			Iterator<ConnectionRecord> it = connections.iterator();
 			while (it.hasNext()) {
-				if (it.next().conn == conn) {
+				if (it.next().connection == conn) {
+					long now = clock.currentTimeMillis();
+					if (exception) connectionFailed(now);
+					else considerRaisingConnectionLimit(now);
 					it.remove();
 					break;
 				}
 			}
-			if (LOG.isLoggable(INFO)) {
+			if (LOG.isLoggable(INFO))
 				LOG.info("Connection closed, " + connections.size() + " open");
-			}
 		}
 	}
 
 	@Override
-	public void allConnectionsClosed() {
+	public void bluetoothDisabled() {
 		synchronized (lock) {
-			long now = clock.currentTimeMillis();
+			LOG.info("Bluetooth disabled");
-			countStableConnections(now);
+			considerRaisingConnectionLimit(clock.currentTimeMillis());
 			connections.clear();
-			LOG.info("All connections closed");
 		}
 	}
 
 	@GuardedBy("lock")
-	private void countStableConnections(long now) {
+	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;
-			if (LOG.isLoggable(INFO)) {
+			attemptInterval = MIN_ATTEMPT_INTERVAL_MS;
-				LOG.info("Raising connection limit to " + connectionLimit);
+		}
-			}
+		if (LOG.isLoggable(INFO)) {
+			LOG.info(stable + " connections are stable, limit is "
+					+ connectionLimit);
 		}
 	}
 
-	private static class ConnectionRecord {
+	@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 final DuplexTransportConnection conn;
+	private static final class ConnectionRecord {
+
+		private final DuplexTransportConnection connection;
 		private final long timeOpened;
 
-		private ConnectionRecord(DuplexTransportConnection conn,
+		private ConnectionRecord(DuplexTransportConnection connection,
 				long timeOpened) {
-			this.conn = conn;
+			this.connection = connection;
 			this.timeOpened = timeOpened;
 		}
 	}

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

@@ -130,7 +130,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	void onAdapterDisabled() {
 		LOG.info("Bluetooth disabled");
 		tryToClose(socket);
-		connectionLimiter.allConnectionsClosed();
+		connectionLimiter.bluetoothDisabled();
 		callback.transportDisabled();
 	}
 
@@ -232,13 +232,25 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				return;
 			}
 			LOG.info("Connection received");
-			connectionLimiter.connectionOpened(conn);
+			if (connectionLimiter.contactConnectionOpened(conn, true)) {
-			backoff.reset();
+				backoff.reset();
-			callback.handleConnection(conn);
+				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;
@@ -326,8 +338,13 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		String uuid = p.get(PROP_UUID);
 		if (isNullOrEmpty(uuid)) return null;
 		DuplexTransportConnection conn = connect(address, uuid);
-		if (conn != null) connectionLimiter.connectionOpened(conn);
+		if (conn == null) return null;
-		return conn;
+		if (connectionLimiter.contactConnectionOpened(conn, false)) {
+			return conn;
+		} else {
+			tryToClose(conn);
+			return null;
+		}
 	}
 
 	@Override
@@ -383,7 +400,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				LOG.info("Connecting to key agreement UUID " + uuid);
 			conn = connect(address, uuid);
 		}
-		if (conn != null) connectionLimiter.connectionOpened(conn);
+		if (conn != null) connectionLimiter.keyAgreementConnectionOpened(conn);
 		return conn;
 	}
 
@@ -452,7 +469,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		public KeyAgreementConnection accept() throws IOException {
 			DuplexTransportConnection conn = acceptConnection(ss);
 			if (LOG.isLoggable(INFO)) LOG.info(ID + ": Incoming connection");
-			connectionLimiter.connectionOpened(conn);
+			connectionLimiter.keyAgreementConnectionOpened(conn);
 			return new KeyAgreementConnection(conn, ID);
 		}
 

bramble-core/src/main/java/org/briarproject/bramble/rendezvous/RendezvousPollerImpl.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.rendezvous;
 
 import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.PendingContactState;
@@ -24,6 +23,7 @@ import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;

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

@@ -15,7 +15,6 @@ 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;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
@@ -38,7 +37,6 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
@@ -79,8 +77,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	private final int maxLatency, maxIdleTime;
 	private final StreamWriter streamWriter;
 	private final SyncRecordWriter recordWriter;
-	@Nullable
-	private final Priority priority;
 	private final BlockingQueue<ThrowingRunnable<IOException>> writerTasks;
 
 	private final AtomicBoolean generateAckQueued = new AtomicBoolean(false);
@@ -95,8 +91,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	DuplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, Clock clock, ContactId contactId,
 			TransportId transportId, int maxLatency, int maxIdleTime,
-			StreamWriter streamWriter, SyncRecordWriter recordWriter,
+			StreamWriter streamWriter, SyncRecordWriter recordWriter) {
-			@Nullable Priority priority) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
@@ -107,7 +102,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		this.maxIdleTime = maxIdleTime;
 		this.streamWriter = streamWriter;
 		this.recordWriter = recordWriter;
-		this.priority = priority;
 		writerTasks = new LinkedBlockingQueue<>();
 	}
 
@@ -118,8 +112,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		try {
 			// Send our supported protocol versions
 			recordWriter.writeVersions(new Versions(SUPPORTED_VERSIONS));
-			// Send our connection priority, if this is an outgoing connection
-			if (priority != null) recordWriter.writePriority(priority);
 			// Start a query for each type of record
 			generateAck();
 			generateBatch();

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

@@ -15,8 +15,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.PriorityHandler;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.SyncSession;
@@ -49,19 +47,17 @@ class IncomingSession implements SyncSession, EventListener {
 	private final EventBus eventBus;
 	private final ContactId contactId;
 	private final SyncRecordReader recordReader;
-	private final PriorityHandler priorityHandler;
 
 	private volatile boolean interrupted = false;
 
 	IncomingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, ContactId contactId,
-			SyncRecordReader recordReader, PriorityHandler priorityHandler) {
+			SyncRecordReader recordReader) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.contactId = contactId;
 		this.recordReader = recordReader;
-		this.priorityHandler = priorityHandler;
 	}
 
 	@IoExecutor
@@ -90,9 +86,6 @@ class IncomingSession implements SyncSession, EventListener {
 				} else if (recordReader.hasVersions()) {
 					Versions v = recordReader.readVersions();
 					dbExecutor.execute(new ReceiveVersions(v));
-				} else if (recordReader.hasPriority()) {
-					Priority p = recordReader.readPriority();
-					priorityHandler.handle(p);
 				} else {
 					// unknown records are ignored in RecordReader#eof()
 					throw new FormatException();

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

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.Versions;
@@ -27,12 +26,10 @@ import javax.annotation.concurrent.NotThreadSafe;
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
-import static org.briarproject.bramble.api.sync.RecordTypes.PRIORITY;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
 import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_SUPPORTED_VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.PRIORITY_NONCE_BYTES;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 
 @NotThreadSafe
@@ -51,7 +48,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 
 	private static boolean isKnownRecordType(byte type) {
 		return type == ACK || type == MESSAGE || type == OFFER ||
-				type == REQUEST || type == VERSIONS || type == PRIORITY;
+				type == REQUEST || type == VERSIONS;
 	}
 
 	private final MessageFactory messageFactory;
@@ -177,23 +174,4 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 		nextRecord = null;
 		return supported;
 	}
-
-	@Override
-	public boolean hasPriority() throws IOException {
-		return !eof() && getNextRecordType() == PRIORITY;
-	}
-
-	@Override
-	public Priority readPriority() throws IOException {
-		if (!hasPriority()) throw new FormatException();
-		return new Priority(readNonce());
-	}
-
-	private byte[] readNonce() throws IOException {
-		if (nextRecord == null) throw new AssertionError();
-		byte[] payload = nextRecord.getPayload();
-		if (payload.length != PRIORITY_NONCE_BYTES) throw new FormatException();
-		nextRecord = null;
-		return payload;
-	}
 }

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

@@ -8,7 +8,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.Versions;
@@ -21,7 +20,6 @@ import javax.annotation.concurrent.NotThreadSafe;
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
-import static org.briarproject.bramble.api.sync.RecordTypes.PRIORITY;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
 import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
@@ -75,12 +73,6 @@ class SyncRecordWriterImpl implements SyncRecordWriter {
 		writeRecord(VERSIONS);
 	}
 
-	@Override
-	public void writePriority(Priority p) throws IOException {
-		writer.writeRecord(
-				new Record(PROTOCOL_VERSION, PRIORITY, p.getNonce()));
-	}
-
 	@Override
 	public void flush() throws IOException {
 		writer.flush();

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

@@ -6,8 +6,6 @@ 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.Priority;
-import org.briarproject.bramble.api.sync.PriorityHandler;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.SyncRecordReaderFactory;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
@@ -21,7 +19,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.concurrent.Executor;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
@@ -50,12 +47,10 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 	}
 
 	@Override
-	public SyncSession createIncomingSession(ContactId c, InputStream in,
+	public SyncSession createIncomingSession(ContactId c, InputStream in) {
-			PriorityHandler handler) {
 		SyncRecordReader recordReader =
 				recordReaderFactory.createRecordReader(in);
-		return new IncomingSession(db, dbExecutor, eventBus, c, recordReader,
+		return new IncomingSession(db, dbExecutor, eventBus, c, recordReader);
-				handler);
 	}
 
 	@Override
@@ -69,13 +64,13 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 	}
 
 	@Override
-	public SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
+	public SyncSession createDuplexOutgoingSession(ContactId c,
-			int maxLatency, int maxIdleTime, StreamWriter streamWriter,
+			TransportId t, int maxLatency, int maxIdleTime,
-			@Nullable Priority priority) {
+			StreamWriter streamWriter) {
 		OutputStream out = streamWriter.getOutputStream();
 		SyncRecordWriter recordWriter =
 				recordWriterFactory.createRecordWriter(out);
 		return new DuplexOutgoingSession(db, dbExecutor, eventBus, clock, c, t,
-				maxLatency, maxIdleTime, streamWriter, recordWriter, priority);
+				maxLatency, maxIdleTime, streamWriter, recordWriter);
 	}
 }

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

@@ -1,611 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.connection.InterruptibleConnection;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.plugin.PluginConfig;
-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.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.sync.Priority;
-import org.briarproject.bramble.test.BrambleMockTestCase;
-import org.jmock.Expectations;
-import org.junit.Test;
-
-import java.util.Collection;
-
-import static java.util.Collections.emptyList;
-import static java.util.Collections.emptyMap;
-import static java.util.Collections.singletonList;
-import static java.util.Collections.singletonMap;
-import static org.briarproject.bramble.test.TestUtils.getContactId;
-import static org.briarproject.bramble.test.TestUtils.getRandomId;
-import static org.briarproject.bramble.test.TestUtils.getTransportId;
-import static org.briarproject.bramble.util.StringUtils.fromHexString;
-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 ConnectionRegistryImplTest extends BrambleMockTestCase {
-
-	private final EventBus eventBus = context.mock(EventBus.class);
-	private final PluginConfig pluginConfig = context.mock(PluginConfig.class);
-	private final InterruptibleConnection conn1 =
-			context.mock(InterruptibleConnection.class, "conn1");
-	private final InterruptibleConnection conn2 =
-			context.mock(InterruptibleConnection.class, "conn2");
-	private final InterruptibleConnection conn3 =
-			context.mock(InterruptibleConnection.class, "conn3");
-
-	private final ContactId contactId1 = getContactId();
-	private final ContactId contactId2 = getContactId();
-	private final TransportId transportId1 = getTransportId();
-	private final TransportId transportId2 = getTransportId();
-	private final TransportId transportId3 = getTransportId();
-	private final PendingContactId pendingContactId =
-			new PendingContactId(getRandomId());
-
-	private final Priority low =
-			new Priority(fromHexString("00000000000000000000000000000000"));
-	private final Priority high =
-			new Priority(fromHexString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"));
-
-	@Test
-	public void testRegisterMultipleConnections() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// The registry should be empty
-		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId1));
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedContacts(transportId3));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId3));
-		assertFalse(c.isConnected(contactId1));
-		assertFalse(c.isConnected(contactId1, transportId1));
-		assertFalse(c.isConnected(contactId1, transportId2));
-		assertFalse(c.isConnected(contactId1, transportId3));
-
-		// Check that a registered connection shows up - this should
-		// broadcast a ConnectionOpenedEvent and a ContactConnectedEvent
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerIncomingConnection(contactId1, transportId1, conn1);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-		assertTrue(c.isConnected(contactId1));
-		assertTrue(c.isConnected(contactId1, transportId1));
-
-		// Register another connection with the same contact and transport -
-		// this should broadcast a ConnectionOpenedEvent and lookup should be
-		// unaffected
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerIncomingConnection(contactId1, transportId1, conn2);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-		assertTrue(c.isConnected(contactId1));
-		assertTrue(c.isConnected(contactId1, transportId1));
-
-		// Unregister one of the connections - this should broadcast a
-		// ConnectionClosedEvent and lookup should be unaffected
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId1, conn1, true, false);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-		assertTrue(c.isConnected(contactId1));
-		assertTrue(c.isConnected(contactId1, transportId1));
-
-		// Unregister the other connection - this should broadcast a
-		// ConnectionClosedEvent and a ContactDisconnectedEvent
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(
-					ContactDisconnectedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId1, conn2, true, false);
-		context.assertIsSatisfied();
-
-		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId1));
-		assertFalse(c.isConnected(contactId1));
-		assertFalse(c.isConnected(contactId1, transportId1));
-
-		// Try to unregister the connection again - exception should be thrown
-		try {
-			c.unregisterConnection(contactId1, transportId1, conn2,
-					true, false);
-			fail();
-		} catch (IllegalArgumentException expected) {
-			// Expected
-		}
-	}
-
-	@Test
-	public void testRegisterMultipleContacts() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Register two contacts with one transport, then one of the contacts
-		// with a second transport - this should broadcast three
-		// ConnectionOpenedEvents and two ContactConnectedEvents
-		context.checking(new Expectations() {{
-			exactly(3).of(eventBus).broadcast(with(any(
-					ConnectionOpenedEvent.class)));
-			exactly(2).of(eventBus).broadcast(with(any(
-					ContactConnectedEvent.class)));
-		}});
-		c.registerIncomingConnection(contactId1, transportId1, conn1);
-		c.registerIncomingConnection(contactId2, transportId1, conn2);
-		c.registerIncomingConnection(contactId2, transportId2, conn3);
-		context.assertIsSatisfied();
-
-		assertTrue(c.isConnected(contactId1));
-		assertTrue(c.isConnected(contactId2));
-
-		assertTrue(c.isConnected(contactId1, transportId1));
-		assertFalse(c.isConnected(contactId1, transportId2));
-
-		assertTrue(c.isConnected(contactId2, transportId1));
-		assertTrue(c.isConnected(contactId2, transportId2));
-
-		Collection<ContactId> connected = c.getConnectedContacts(transportId1);
-		assertEquals(2, connected.size());
-		assertTrue(connected.contains(contactId1));
-		assertTrue(connected.contains(contactId2));
-
-		connected = c.getConnectedOrBetterContacts(transportId1);
-		assertEquals(2, connected.size());
-		assertTrue(connected.contains(contactId1));
-		assertTrue(connected.contains(contactId2));
-
-		assertEquals(singletonList(contactId2),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId2),
-				c.getConnectedOrBetterContacts(transportId2));
-	}
-
-	@Test
-	public void testConnectionsAreNotInterruptedUnlessPriorityIsSet() {
-		// Prefer transport 2 to transport 1
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(
-					singletonMap(transportId1, singletonList(transportId2))));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Connect via transport 1 (worse than 2) with no priority set
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerIncomingConnection(contactId1, transportId1, conn1);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 2 (better than 1) and set priority to high -
-		// the old connection should not be interrupted, despite using a worse
-		// transport, to remain compatible with old peers
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId2, conn2, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 3 (no preference) and set priority to high -
-		// again, no interruptions are expected
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId3, conn3, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-	}
-
-	@Test
-	public void testNewConnectionIsInterruptedIfOldConnectionUsesBetterTransport() {
-		// Prefer transport 1 to transport 2
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(
-					singletonMap(transportId2, singletonList(transportId1))));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Connect via transport 1 (better than 2) and set priority to low
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId1, conn1, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// The contact is not connected via transport 2 but is connected via a
-		// better transport
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 2 (worse than 1) and set priority to high -
-		// the new connection should be interrupted because it uses a worse
-		// transport
-		context.checking(new Expectations() {{
-			oneOf(conn2).interruptOutgoingSession();
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId2, conn2, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 3 (no preference) and set priority to low -
-		// no further interruptions
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId3, conn3, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-
-		// Unregister the interrupted connection (transport 2)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId2, conn2, true, false);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// The contact is not connected via transport 2 but is connected via a
-		// better transport
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-	}
-
-	@Test
-	public void testOldConnectionIsInterruptedIfNewConnectionUsesBetterTransport() {
-		// Prefer transport 2 to transport 1
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(
-					singletonMap(transportId1, singletonList(transportId2))));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Connect via transport 1 (worse than 2) and set priority to high
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId1, conn1, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 2 (better than 1) and set priority to low -
-		// the old connection should be interrupted because it uses a worse
-		// transport
-		context.checking(new Expectations() {{
-			oneOf(conn1).interruptOutgoingSession();
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId2, conn2, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 3 (no preference) and set priority to high -
-		// no further interruptions
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId3, conn3, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-
-		// Unregister the interrupted connection (transport 1)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId1, conn1, true, false);
-		context.assertIsSatisfied();
-
-		// The contact is not connected via transport 1 but is connected via a
-		// better transport
-		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-	}
-
-	@Test
-	public void testNewConnectionIsInterruptedIfOldConnectionHasHigherPriority() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Register a connection with high priority
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId1, conn1, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register another connection via the same transport (no priority yet)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerIncomingConnection(contactId1, transportId1, conn2);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Set the priority of the second connection to low - the second
-		// connection should be interrupted
-		context.checking(new Expectations() {{
-			oneOf(conn2).interruptOutgoingSession();
-		}});
-		c.setPriority(contactId1, transportId1, conn2, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register a third connection with low priority - it should also be
-		// interrupted
-		context.checking(new Expectations() {{
-			oneOf(conn3).interruptOutgoingSession();
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId1, conn3, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-	}
-
-	@Test
-	public void testOldConnectionIsInterruptedIfNewConnectionHasHigherPriority() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Register a connection with low priority
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerOutgoingConnection(contactId1, transportId1, conn1, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register another connection via the same transport (no priority yet)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerIncomingConnection(contactId1, transportId1, conn2);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Set the priority of the second connection to high - the first
-		// connection should be interrupted
-		context.checking(new Expectations() {{
-			oneOf(conn1).interruptOutgoingSession();
-		}});
-		c.setPriority(contactId1, transportId1, conn2, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-	}
-
-	@Test
-	public void testRegisterAndUnregisterPendingContacts() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(
-					RendezvousConnectionOpenedEvent.class)));
-		}});
-		assertTrue(c.registerConnection(pendingContactId));
-		assertFalse(c.registerConnection(pendingContactId)); // Redundant
-		context.assertIsSatisfied();
-
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(
-					RendezvousConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(pendingContactId, true);
-		context.assertIsSatisfied();
-
-		try {
-			c.unregisterConnection(pendingContactId, true);
-			fail();
-		} catch (IllegalArgumentException expected) {
-			// Expected
-		}
-	}
-}

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactExchangeIntegrationTestComponent.java

@@ -2,13 +2,13 @@ package org.briarproject.bramble.contact;
 
 import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.test.BrambleCoreIntegrationTestModule;
 
 import java.util.concurrent.Executor;

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

@@ -0,0 +1,149 @@
+package org.briarproject.bramble.plugin;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.event.EventBus;
+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.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.test.BrambleMockTestCase;
+import org.jmock.Expectations;
+import org.junit.Test;
+
+import java.util.Collection;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
+import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.bramble.test.TestUtils.getTransportId;
+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 ConnectionRegistryImplTest extends BrambleMockTestCase {
+
+	private final EventBus eventBus = context.mock(EventBus.class);
+
+	private final ContactId contactId = getContactId();
+	private final ContactId contactId1 = getContactId();
+	private final TransportId transportId = getTransportId();
+	private final TransportId transportId1 = getTransportId();
+	private final PendingContactId pendingContactId =
+			new PendingContactId(getRandomId());
+
+	@Test
+	public void testRegisterAndUnregister() {
+		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 ContactConnectedEvent
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
+			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
+		}});
+		c.registerConnection(contactId, transportId, true);
+		assertEquals(singletonList(contactId),
+				c.getConnectedContacts(transportId));
+		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
+		context.assertIsSatisfied();
+
+		// Register an identical connection - this should broadcast a
+		// ConnectionOpenedEvent and lookup should be unaffected
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
+		}});
+		c.registerConnection(contactId, transportId, true);
+		assertEquals(singletonList(contactId),
+				c.getConnectedContacts(transportId));
+		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
+		context.assertIsSatisfied();
+
+		// Unregister one of the connections - this should broadcast a
+		// ConnectionClosedEvent and lookup should be unaffected
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
+		}});
+		c.unregisterConnection(contactId, transportId, true);
+		assertEquals(singletonList(contactId),
+				c.getConnectedContacts(transportId));
+		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
+		context.assertIsSatisfied();
+
+		// Unregister the other connection - this should broadcast a
+		// ConnectionClosedEvent and a ContactDisconnectedEvent
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
+			oneOf(eventBus).broadcast(with(any(
+					ContactDisconnectedEvent.class)));
+		}});
+		c.unregisterConnection(contactId, transportId, true);
+		assertEquals(emptyList(), c.getConnectedContacts(transportId));
+		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
+		context.assertIsSatisfied();
+
+		// Try to unregister the connection again - exception should be thrown
+		try {
+			c.unregisterConnection(contactId, transportId, true);
+			fail();
+		} catch (IllegalArgumentException expected) {
+			// Expected
+		}
+
+		// Register both contacts with one transport, one contact with both -
+		// this should broadcast three ConnectionOpenedEvents and two
+		// ContactConnectedEvents
+		context.checking(new Expectations() {{
+			exactly(3).of(eventBus).broadcast(with(any(
+					ConnectionOpenedEvent.class)));
+			exactly(2).of(eventBus).broadcast(with(any(
+					ContactConnectedEvent.class)));
+		}});
+		c.registerConnection(contactId, transportId, true);
+		c.registerConnection(contactId1, transportId, true);
+		c.registerConnection(contactId1, transportId1, true);
+		Collection<ContactId> connected = c.getConnectedContacts(transportId);
+		assertEquals(2, connected.size());
+		assertTrue(connected.contains(contactId));
+		assertTrue(connected.contains(contactId1));
+		assertEquals(singletonList(contactId1),
+				c.getConnectedContacts(transportId1));
+	}
+
+	@Test
+	public void testRegisterAndUnregisterPendingContacts() {
+		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus);
+
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(
+					RendezvousConnectionOpenedEvent.class)));
+		}});
+		assertTrue(c.registerConnection(pendingContactId));
+		assertFalse(c.registerConnection(pendingContactId)); // Redundant
+		context.assertIsSatisfied();
+
+		context.checking(new Expectations() {{
+			oneOf(eventBus).broadcast(with(any(
+					RendezvousConnectionClosedEvent.class)));
+		}});
+		c.unregisterConnection(pendingContactId, true);
+		context.assertIsSatisfied();
+
+		try {
+			c.unregisterConnection(pendingContactId, true);
+			fail();
+		} catch (IllegalArgumentException expected) {
+			// Expected
+		}
+	}
+}

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

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.PluginException;

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

@@ -1,10 +1,10 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
@@ -157,21 +157,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testRescheduleOnOutgoingConnectionClosed() {
+	public void testRescheduleAndReconnectOnConnectionClosed()
-		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
-
-		context.checking(new Expectations() {{
-			allowing(plugin).getId();
-			will(returnValue(transportId));
-		}});
-		expectReschedule(plugin);
-
-		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
-				false, false));
-	}
-
-	@Test
-	public void testRescheduleAndReconnectOnOutgoingConnectionFailed()
 			throws Exception {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
 		DuplexTransportConnection duplexConnection =
@@ -180,40 +166,45 @@ public class PollerImplTest extends BrambleMockTestCase {
 		context.checking(new Expectations() {{
 			allowing(plugin).getId();
 			will(returnValue(transportId));
+			// reschedule()
+			// Get the plugin
+			oneOf(pluginManager).getPlugin(transportId);
+			will(returnValue(plugin));
+			// The plugin supports polling
+			oneOf(plugin).shouldPoll();
+			will(returnValue(true));
+			// Get the plugin
+			oneOf(pluginManager).getPlugin(transportId);
+			will(returnValue(plugin));
+			// The plugin supports polling
+			oneOf(plugin).shouldPoll();
+			will(returnValue(true));
+			// Schedule the next poll
+			oneOf(plugin).getPollingInterval();
+			will(returnValue(pollingInterval));
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(scheduler).schedule(with(any(Runnable.class)),
+					with((long) pollingInterval), with(MILLISECONDS));
+			will(returnValue(future));
+			// connectToContact()
+			// Check whether the contact is already connected
+			oneOf(connectionRegistry).isConnected(contactId, transportId);
+			will(returnValue(false));
+			// Get the transport properties
+			oneOf(transportPropertyManager).getRemoteProperties(contactId,
+					transportId);
+			will(returnValue(properties));
+			// Connect to the contact
+			oneOf(plugin).createConnection(properties);
+			will(returnValue(duplexConnection));
+			// Pass the connection to the connection manager
+			oneOf(connectionManager).manageOutgoingConnection(contactId,
+					transportId, duplexConnection);
 		}});
-		expectReschedule(plugin);
-		expectReconnect(plugin, duplexConnection);
 
 		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
-				false, true));
+				false));
-	}
-
-	@Test
-	public void testRescheduleOnIncomingConnectionClosed() {
-		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
-
-		context.checking(new Expectations() {{
-			allowing(plugin).getId();
-			will(returnValue(transportId));
-		}});
-		expectReschedule(plugin);
-
-		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
-				true, false));
-	}
-
-	@Test
-	public void testRescheduleOnIncomingConnectionFailed() {
-		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
-
-		context.checking(new Expectations() {{
-			allowing(plugin).getId();
-			will(returnValue(transportId));
-		}});
-		expectReschedule(plugin);
-
-		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
-				true, false));
 	}
 
 	@Test
@@ -363,7 +354,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 			// Get the transport properties and connected contacts
 			oneOf(transportPropertyManager).getRemoteProperties(transportId);
 			will(returnValue(singletonMap(contactId, properties)));
-			oneOf(connectionRegistry).getConnectedOrBetterContacts(transportId);
+			oneOf(connectionRegistry).getConnectedContacts(transportId);
 			will(returnValue(emptyList()));
 			// Poll the plugin
 			oneOf(plugin).poll(with(collectionOf(
@@ -406,7 +397,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 			// Get the transport properties and connected contacts
 			oneOf(transportPropertyManager).getRemoteProperties(transportId);
 			will(returnValue(singletonMap(contactId, properties)));
-			oneOf(connectionRegistry).getConnectedOrBetterContacts(transportId);
+			oneOf(connectionRegistry).getConnectedContacts(transportId);
 			will(returnValue(singletonList(contactId)));
 			// All contacts are connected, so don't poll the plugin
 		}});
@@ -440,48 +431,4 @@ public class PollerImplTest extends BrambleMockTestCase {
 		poller.eventOccurred(new TransportEnabledEvent(transportId));
 		poller.eventOccurred(new TransportDisabledEvent(transportId));
 	}
-
-	private void expectReschedule(Plugin plugin) {
-		context.checking(new Expectations() {{
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Schedule the next poll
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
-			will(returnValue(future));
-		}});
-	}
-
-	private void expectReconnect(DuplexPlugin plugin,
-			DuplexTransportConnection duplexConnection) throws Exception {
-		context.checking(new Expectations() {{
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Check whether the contact is already connected
-			oneOf(connectionRegistry).isConnected(contactId, transportId);
-			will(returnValue(false));
-			// Get the transport properties
-			oneOf(transportPropertyManager).getRemoteProperties(contactId,
-					transportId);
-			will(returnValue(properties));
-			// Connect to the contact
-			oneOf(plugin).createConnection(properties);
-			will(returnValue(duplexConnection));
-			// Pass the connection to the connection manager
-			oneOf(connectionManager).manageOutgoingConnection(contactId,
-					transportId, duplexConnection);
-		}});
-	}
 }

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/rendezvous/RendezvousPollerImplTest.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.rendezvous;
 
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.contact.event.PendingContactAddedEvent;
@@ -14,6 +13,7 @@ import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;

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

@@ -8,7 +8,6 @@ import org.briarproject.bramble.api.record.RecordReader;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.Versions;
@@ -25,14 +24,11 @@ import javax.annotation.Nullable;
 import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTES;
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
-import static org.briarproject.bramble.api.sync.RecordTypes.PRIORITY;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
 import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_SUPPORTED_VERSIONS;
-import static org.briarproject.bramble.api.sync.SyncConstants.PRIORITY_NONCE_BYTES;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -123,31 +119,6 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 		reader.readVersions();
 	}
 
-	@Test(expected = FormatException.class)
-	public void testFormatExceptionIfPriorityNonceIsTooSmall()
-			throws Exception {
-		expectReadRecord(createPriority(PRIORITY_NONCE_BYTES - 1));
-
-		reader.readPriority();
-	}
-
-	@Test(expected = FormatException.class)
-	public void testFormatExceptionIfPriorityNonceIsTooLarge()
-			throws Exception {
-		expectReadRecord(createPriority(PRIORITY_NONCE_BYTES + 1));
-
-		reader.readPriority();
-	}
-
-	@Test
-	public void testNoFormatExceptionIfPriorityNonceIsCorrectSize()
-			throws Exception {
-		expectReadRecord(createPriority(PRIORITY_NONCE_BYTES));
-
-		Priority priority = reader.readPriority();
-		assertEquals(PRIORITY_NONCE_BYTES, priority.getNonce().length);
-	}
-
 	@Test
 	public void testEofReturnsTrueWhenAtEndOfStream() throws Exception {
 		expectReadRecord(createAck());
@@ -202,11 +173,6 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 		return new Record(PROTOCOL_VERSION, VERSIONS, payload);
 	}
 
-	private Record createPriority(int nonceBytes) {
-		byte[] payload = getRandomBytes(nonceBytes);
-		return new Record(PROTOCOL_VERSION, PRIORITY, payload);
-	}
-
 	private byte[] createPayload() throws Exception {
 		ByteArrayOutputStream payload = new ByteArrayOutputStream();
 		while (payload.size() + UniqueId.LENGTH <= MAX_RECORD_PAYLOAD_BYTES) {

bramble-core/src/test/java/org/briarproject/bramble/test/TestPluginConfigModule.java

@@ -10,15 +10,12 @@ import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 
 import java.util.Collection;
-import java.util.List;
-import java.util.Map;
 
 import javax.annotation.Nullable;
 
 import dagger.Module;
 import dagger.Provides;
 
-import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
 
@@ -88,12 +85,6 @@ public class TestPluginConfigModule {
 			public boolean shouldPoll() {
 				return false;
 			}
-
-			@Override
-			public Map<TransportId, List<TransportId>> getTransportPreferences() {
-				return emptyMap();
-			}
-
 		};
 		return pluginConfig;
 	}

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

@@ -6,10 +6,7 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
-import org.briarproject.bramble.api.plugin.BluetoothConstants;
-import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.PluginConfig;
-import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.reliability.ReliabilityLayerFactory;
@@ -21,8 +18,6 @@ import org.briarproject.bramble.plugin.tcp.WanTcpPluginFactory;
 
 import java.security.SecureRandom;
 import java.util.Collection;
-import java.util.List;
-import java.util.Map;
 import java.util.concurrent.Executor;
 
 import dagger.Module;
@@ -30,8 +25,6 @@ import dagger.Provides;
 
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
-import static java.util.Collections.singletonList;
-import static java.util.Collections.singletonMap;
 
 @Module
 public class DesktopPluginModule extends PluginModule {
@@ -70,13 +63,6 @@ public class DesktopPluginModule extends PluginModule {
 			public boolean shouldPoll() {
 				return true;
 			}
-
-			@Override
-			public Map<TransportId, List<TransportId>> getTransportPreferences() {
-				// Prefer LAN to Bluetooth
-				return singletonMap(BluetoothConstants.ID,
-						singletonList(LanTcpConstants.ID));
-			}
 		};
 		return pluginConfig;
 	}

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

@@ -45,7 +45,7 @@ class JavaBluetoothTransportConnection
 		try {
 			stream.close();
 		} finally {
-			connectionLimiter.connectionClosed(this);
+			connectionLimiter.connectionClosed(this, exception);
 		}
 	}
 }

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/ScreenshotTest.java

@@ -3,7 +3,7 @@ package org.briarproject.briar.android;
 import android.app.Activity;
 import android.util.Log;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.briar.api.test.TestDataCreator;
 import org.junit.ClassRule;

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/SetupDataTest.java

@@ -120,8 +120,7 @@ public class SetupDataTest extends ScreenshotTest {
 
 		// TODO add messages
 
-		connectionRegistry.registerIncomingConnection(bob.getId(), ID, () -> {
+		connectionRegistry.registerConnection(bob.getId(), ID, true);
-		});
 	}
 
 }

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

@@ -7,7 +7,6 @@ import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.api.account.AccountManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
@@ -20,6 +19,7 @@ import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
 import org.briarproject.bramble.api.keyagreement.PayloadParser;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.system.AndroidExecutor;

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

@@ -20,10 +20,7 @@ import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
-import org.briarproject.bramble.api.plugin.BluetoothConstants;
-import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.PluginConfig;
-import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.reporting.DevConfig;
@@ -51,8 +48,6 @@ import java.io.File;
 import java.security.GeneralSecurityException;
 import java.security.SecureRandom;
 import java.util.Collection;
-import java.util.List;
-import java.util.Map;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ScheduledExecutorService;
 
@@ -67,8 +62,6 @@ import static android.content.Context.MODE_PRIVATE;
 import static android.os.Build.VERSION.SDK_INT;
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
-import static java.util.Collections.singletonList;
-import static java.util.Collections.singletonMap;
 import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_ONION_ADDRESS;
 import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_PUBLIC_KEY_HEX;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
@@ -160,13 +153,6 @@ public class AppModule {
 			public boolean shouldPoll() {
 				return true;
 			}
-
-			@Override
-			public Map<TransportId, List<TransportId>> getTransportPreferences() {
-				// Prefer LAN to Bluetooth
-				return singletonMap(BluetoothConstants.ID,
-						singletonList(LanTcpConstants.ID));
-			}
 		};
 		return pluginConfig;
 	}

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

@@ -10,7 +10,6 @@ import android.widget.TextView;
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.google.android.material.snackbar.Snackbar;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -25,6 +24,7 @@ import org.briarproject.bramble.api.event.EventBus;
 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.event.ContactConnectedEvent;
 import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.briar.R;

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

@@ -1,11 +1,11 @@
 package org.briarproject.briar.android.controller;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 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.ContactConnectedEvent;
 import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 

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

@@ -21,7 +21,6 @@ import com.google.android.material.snackbar.Snackbar;
 
 import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
@@ -34,6 +33,7 @@ import org.briarproject.bramble.api.event.EventBus;
 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.event.ContactConnectedEvent;
 import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.sync.ClientId;

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

@@ -5,13 +5,13 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 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.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;

briar-android/src/main/java/org/briarproject/briar/android/keyagreement/ContactExchangeViewModel.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.keyagreement;
 
 import android.app.Application;
 
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.crypto.SecretKey;
@@ -11,6 +10,7 @@ import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 

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

@@ -1,10 +1,10 @@
 package org.briarproject.briar.android.privategroup.memberlist;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
 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.sync.GroupId;
 import org.briarproject.briar.android.controller.DbControllerImpl;
 import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;

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

@@ -5,7 +5,6 @@ import android.os.Bundle;
 import android.view.MenuItem;
 import android.widget.TextView;
 
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
@@ -14,6 +13,7 @@ import org.briarproject.bramble.api.event.EventBus;
 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.sync.GroupId;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.briar.R;

briar-core/src/test/java/org/briarproject/briar/messaging/SimplexMessagingIntegrationTestComponent.java

@@ -2,11 +2,11 @@ package org.briarproject.briar.messaging;
 
 import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.test.BrambleCoreIntegrationTestModule;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessageFactory;

briar-core/src/test/java/org/briarproject/briar/test/BriarIntegrationTestComponent.java

@@ -3,13 +3,13 @@ package org.briarproject.briar.test;
 import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.api.client.ClientHelper;
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.AuthorFactory;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.test.BrambleCoreIntegrationTestModule;
 import org.briarproject.briar.api.blog.BlogFactory;

briar-headless/src/main/java/org/briarproject/briar/headless/HeadlessModule.kt

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor
 import org.briarproject.bramble.api.network.NetworkManager
 import org.briarproject.bramble.api.plugin.BackoffFactory
 import org.briarproject.bramble.api.plugin.PluginConfig
-import org.briarproject.bramble.api.plugin.TransportId
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory
 import org.briarproject.bramble.api.system.Clock
@@ -89,7 +88,6 @@ internal class HeadlessModule(private val appDir: File) {
             override fun getDuplexFactories(): Collection<DuplexPluginFactory> = duplex
             override fun getSimplexFactories(): Collection<SimplexPluginFactory> = emptyList()
             override fun shouldPoll(): Boolean = true
-            override fun getTransportPreferences(): Map<TransportId, List<TransportId>> = emptyMap()
         }
     }
 

briar-headless/src/test/java/org/briarproject/briar/headless/HeadlessTestModule.kt

@@ -6,7 +6,6 @@ import dagger.Provides
 import org.briarproject.bramble.api.FeatureFlags
 import org.briarproject.bramble.api.db.DatabaseConfig
 import org.briarproject.bramble.api.plugin.PluginConfig
-import org.briarproject.bramble.api.plugin.TransportId
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory
 import org.briarproject.bramble.network.JavaNetworkModule
@@ -56,7 +55,6 @@ internal class HeadlessTestModule(private val appDir: File) {
             override fun getDuplexFactories(): Collection<DuplexPluginFactory> = emptyList()
             override fun getSimplexFactories(): Collection<SimplexPluginFactory> = emptyList()
             override fun shouldPoll(): Boolean = false
-            override fun getTransportPreferences(): Map<TransportId, List<TransportId>> = emptyMap()
         }
     }