remove force disable

.gitlab-ci.yml

@@ -6,18 +6,8 @@ cache:
     - .gradle/caches
 
 before_script:
-  - set -e
   - export GRADLE_USER_HOME=$PWD/.gradle
-  # Accept the license for the Android build tools
+  - echo y | /opt/android-sdk/tools/bin/sdkmanager "build-tools;23.0.3"
-  - echo y | /opt/android-sdk/tools/bin/sdkmanager "build-tools;26.0.2"
-  # Download OpenJDK 6 so we can compile against its standard library
-  - JDK_FILE=openjdk-6-jre-headless_6b38-1.13.10-1~deb7u1_amd64.deb
-  - if [ ! -d openjdk ]
-  - then
-  - wget -q http://ftp.uk.debian.org/debian/pool/main/o/openjdk-6/$JDK_FILE
-  - dpkg-deb -x $JDK_FILE openjdk
-  - fi
-  - export JAVA_6_HOME=$PWD/openjdk/usr/lib/jvm/java-6-openjdk-amd64
 
 test:
   script:

bramble-android/build.gradle

@@ -6,90 +6,99 @@ apply plugin: 'witness'
 apply plugin: 'de.undercouch.download'
 
 android {
-	compileSdkVersion 27
+	compileSdkVersion 23
-	buildToolsVersion '26.0.2'
+	buildToolsVersion '25.0.0'
 
 	defaultConfig {
 		minSdkVersion 14
-		targetSdkVersion 26
+		targetSdkVersion 22
-		versionCode 1620
+		versionCode 1611
-		versionName "0.16.20"
+		versionName "0.16.11"
 		consumerProguardFiles 'proguard-rules.txt'
 	}
 
 	compileOptions {
-		sourceCompatibility JavaVersion.VERSION_1_8
+		sourceCompatibility JavaVersion.VERSION_1_7
-		targetCompatibility JavaVersion.VERSION_1_8
+		targetCompatibility JavaVersion.VERSION_1_7
 	}
 }
 
 dependencies {
-	implementation project(path: ':bramble-core', configuration: 'default')
+	compile project(path: ':bramble-core', configuration: 'default')
-	implementation fileTree(dir: 'libs', include: '*.jar')
+	compile fileTree(dir: 'libs', include: '*.jar')
-
+	provided 'javax.annotation:jsr250-api:1.0'
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.0.2'
-
-	compileOnly 'javax.annotation:jsr250-api:1.0'
 }
 
-dependencyVerification {
+def torBinaryDir = 'src/main/res/raw'
-	verify = [
+
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+task downloadTorGeoIp(type: Download) {
-			'com.google.dagger:dagger-compiler:2.0.2:dagger-compiler-2.0.2.jar:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
+	src 'https://briarproject.org/build/geoip-2017-09-06.zip'
-			'com.google.dagger:dagger-producers:2.0-beta:dagger-producers-2.0-beta.jar:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
+	dest "$torBinaryDir/geoip.zip"
-			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+	onlyIfNewer true
-			'com.google.guava:guava:18.0:guava-18.0.jar:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
-			'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-			'com.madgag.spongycastle:core:1.58.0.0:core-1.58.0.0.jar:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
-			'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
-			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-			'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
-			'org.jacoco:org.jacoco.agent:0.7.4.201502262128:org.jacoco.agent-0.7.4.201502262128-runtime.jar:e357a0f1d573c2f702a273992b1b6cb661734f66311854efb3778a888515c5b5',
-			'org.jacoco:org.jacoco.agent:0.7.4.201502262128:org.jacoco.agent-0.7.4.201502262128.jar:47b4bec6df11a1118da3953da8b9fa1e7079d6fec857faa1a3cf912e53a6fd4e',
-			'org.jacoco:org.jacoco.ant:0.7.4.201502262128:org.jacoco.ant-0.7.4.201502262128.jar:013ce2a68ba57a3c59215ae0dec4df3498c078062a38c3b94c841fc14450f283',
-			'org.jacoco:org.jacoco.core:0.7.4.201502262128:org.jacoco.core-0.7.4.201502262128.jar:ec4c74554312fac5116350164786f91b35c9e082fa4ea598bfa42b5db05d7abb',
-			'org.jacoco:org.jacoco.report:0.7.4.201502262128:org.jacoco.report-0.7.4.201502262128.jar:7a3554c605e088e7e323b1084656243f0444fa353e2f2dee1f1a4204eb64ff09',
-			'org.ow2.asm:asm-debug-all:5.0.1:asm-debug-all-5.0.1.jar:4734de5b515a454b0096db6971fb068e5f70e6f10bbee2b3bd2fdfe5d978ed57',
-	]
 }
 
-ext.torBinaryDir = 'src/main/res/raw'
+task downloadTorBinaryArm(type: Download) {
-ext.torVersion = '0.2.9.14'
+	src 'https://briarproject.org/build/tor-0.2.9.12-arm.zip'
-ext.geoipVersion = '2017-11-06'
+	dest "$torBinaryDir/tor_arm.zip"
-ext.torDownloadUrl = 'https://briarproject.org/build/'
+	onlyIfNewer true
-
-def torBinaries = [
-		"tor_arm"    : '1710ea6c47b7f4c1a88bdf4858c7893837635db10e8866854eed8d61629f50e8',
-		"tor_arm_pie": '974e6949507db8fa2ea45231817c2c3677ed4ccf5488a2252317d744b0be1917',
-		"tor_x86"    : '3a5e45b3f051fcda9353b098b7086e762ffe7ba9242f7d7c8bf6523faaa8b1e9',
-		"tor_x86_pie": 'd1d96d8ce1a4b68accf04850185780d10cd5563d3552f7e1f040f8ca32cb4e51',
-		"geoip"      : '8239b98374493529a29096e45fc5877d4d6fdad0146ad8380b291f90d61484ea'
-]
-
-def downloadBinary(name) {
-	return tasks.create("downloadBinary${name}", Download) {
-		src "${torDownloadUrl}${name}.zip"
-				.replace('tor_', "tor-${torVersion}-")
-				.replace('geoip', "geoip-${geoipVersion}")
-				.replaceAll('_', '-')
-		dest "${torBinaryDir}/${name}.zip"
-		onlyIfNewer true
-	}
 }
 
-def verifyBinary(name, chksum) {
+task downloadTorBinaryArmPie(type: Download) {
-	return tasks.create([
+	src 'https://briarproject.org/build/tor-0.2.9.12-arm-pie.zip'
-			name     : "verifyBinary${name}",
+	dest "$torBinaryDir/tor_arm_pie.zip"
-			type     : Verify,
+	onlyIfNewer true
-			dependsOn: downloadBinary(name)]) {
+}
-		src "${torBinaryDir}/${name}.zip"
+
-		algorithm 'SHA-256'
+task downloadTorBinaryX86(type: Download) {
-		checksum chksum
+	src 'https://briarproject.org/build/tor-0.2.9.12-x86.zip'
-	}
+	dest "$torBinaryDir/tor_x86.zip"
+	onlyIfNewer true
+}
+
+task downloadTorBinaryX86Pie(type: Download) {
+	src 'https://briarproject.org/build/tor-0.2.9.12-x86-pie.zip'
+	dest "$torBinaryDir/tor_x86_pie.zip"
+	onlyIfNewer true
+}
+
+task verifyTorGeoIp(type: Verify, dependsOn: 'downloadTorGeoIp') {
+	src "$torBinaryDir/geoip.zip"
+	algorithm 'SHA-256'
+	checksum 'fe49d3adb86d3c512373101422a017dbb86c85a570524663f09dd8ce143a24f3'
+}
+
+task verifyTorBinaryArm(type: Verify, dependsOn: 'downloadTorBinaryArm') {
+	src "$torBinaryDir/tor_arm.zip"
+	algorithm 'SHA-256'
+	checksum '8ed0b347ffed1d6a4d2fd14495118eb92be83e9cc06e057e15220dc288b31688'
+}
+
+task verifyTorBinaryArmPie(type: Verify, dependsOn: 'downloadTorBinaryArmPie') {
+	src "$torBinaryDir/tor_arm_pie.zip"
+	algorithm 'SHA-256'
+	checksum '64403262511c29f462ca5e7c7621bfc3c944898364d1d5ad35a016bb8a034283'
+}
+
+task verifyTorBinaryX86(type: Verify, dependsOn: 'downloadTorBinaryX86') {
+	src "$torBinaryDir/tor_x86.zip"
+	algorithm 'SHA-256'
+	checksum '61e014607a2079bcf1646289c67bff6372b1aded6e1d8d83d7791efda9a4d5ab'
+}
+
+task verifyTorBinaryX86Pie(type: Verify, dependsOn: 'downloadTorBinaryX86Pie') {
+	src "$torBinaryDir/tor_x86_pie.zip"
+	algorithm 'SHA-256'
+	checksum '18fbc98356697dd0895836ab46d5c9877d1c539193464f7db1e82a65adaaf288'
 }
 
 project.afterEvaluate {
-	torBinaries.every { key, value ->
+	preBuild.dependsOn {
-		preBuild.dependsOn.add(verifyBinary(key, value))
+		[
+				'verifyTorGeoIp',
+				'verifyTorBinaryArm',
+				'verifyTorBinaryArmPie',
+				'verifyTorBinaryX86',
+				'verifyTorBinaryX86Pie'
+		]
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/AndroidPluginModule.java

@@ -13,8 +13,7 @@ import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 import org.briarproject.bramble.api.reporting.DevReporter;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.bramble.api.system.Scheduler;
+import org.briarproject.bramble.plugin.droidtooth.DroidtoothPluginFactory;
-import org.briarproject.bramble.plugin.bluetooth.AndroidBluetoothPluginFactory;
 import org.briarproject.bramble.plugin.tcp.AndroidLanTcpPluginFactory;
 import org.briarproject.bramble.plugin.tor.TorPluginFactory;
 
@@ -23,7 +22,6 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 
 import javax.net.SocketFactory;
 
@@ -35,21 +33,19 @@ public class AndroidPluginModule {
 
 	@Provides
 	PluginConfig providePluginConfig(@IoExecutor Executor ioExecutor,
-			@Scheduler ScheduledExecutorService scheduler,
 			AndroidExecutor androidExecutor, SecureRandom random,
 			SocketFactory torSocketFactory, BackoffFactory backoffFactory,
 			Application app, LocationUtils locationUtils, DevReporter reporter,
 			EventBus eventBus) {
 		Context appContext = app.getApplicationContext();
-		DuplexPluginFactory bluetooth =
+		DuplexPluginFactory bluetooth = new DroidtoothPluginFactory(ioExecutor,
-				new AndroidBluetoothPluginFactory(ioExecutor, androidExecutor,
+				androidExecutor, appContext, random, eventBus, backoffFactory);
-						appContext, random, eventBus, backoffFactory);
+		DuplexPluginFactory tor = new TorPluginFactory(ioExecutor, appContext,
-		DuplexPluginFactory tor = new TorPluginFactory(ioExecutor, scheduler,
+				locationUtils, reporter, eventBus, torSocketFactory,
-				appContext, locationUtils, reporter, eventBus,
+				backoffFactory);
-				torSocketFactory, backoffFactory);
 		DuplexPluginFactory lan = new AndroidLanTcpPluginFactory(ioExecutor,
-				scheduler, backoffFactory, appContext);
+				backoffFactory, appContext);
-		Collection<DuplexPluginFactory> duplex =
+		final Collection<DuplexPluginFactory> duplex =
 				Arrays.asList(bluetooth, tor, lan);
 		@NotNullByDefault
 		PluginConfig pluginConfig = new PluginConfig() {

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

@@ -1,206 +0,0 @@
-package org.briarproject.bramble.plugin.bluetooth;
-
-import android.bluetooth.BluetoothAdapter;
-import android.bluetooth.BluetoothDevice;
-import android.bluetooth.BluetoothServerSocket;
-import android.bluetooth.BluetoothSocket;
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.IntentFilter;
-
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.PluginException;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.system.AndroidExecutor;
-import org.briarproject.bramble.util.AndroidUtils;
-
-import java.io.Closeable;
-import java.io.IOException;
-import java.security.SecureRandom;
-import java.util.UUID;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
-import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
-import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
-import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
-import static android.bluetooth.BluetoothAdapter.STATE_OFF;
-import static android.bluetooth.BluetoothAdapter.STATE_ON;
-import static java.util.logging.Level.WARNING;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
-
-	private static final Logger LOG =
-			Logger.getLogger(AndroidBluetoothPlugin.class.getName());
-
-	private final AndroidExecutor androidExecutor;
-	private final Context appContext;
-
-	private volatile boolean wasEnabledByUs = false;
-	private volatile BluetoothStateReceiver receiver = null;
-
-	// Non-null if the plugin started successfully
-	private volatile BluetoothAdapter adapter = null;
-
-	AndroidBluetoothPlugin(Executor ioExecutor, AndroidExecutor androidExecutor,
-			Context appContext, SecureRandom secureRandom, Backoff backoff,
-			DuplexPluginCallback callback, int maxLatency) {
-		super(ioExecutor, secureRandom, backoff, callback, maxLatency);
-		this.androidExecutor = androidExecutor;
-		this.appContext = appContext;
-	}
-
-	@Override
-	public void start() throws PluginException {
-		super.start();
-		// Listen for changes to the Bluetooth state
-		IntentFilter filter = new IntentFilter();
-		filter.addAction(ACTION_STATE_CHANGED);
-		filter.addAction(ACTION_SCAN_MODE_CHANGED);
-		receiver = new BluetoothStateReceiver();
-		appContext.registerReceiver(receiver, filter);
-	}
-
-	@Override
-	public void stop() {
-		super.stop();
-		if (receiver != null) appContext.unregisterReceiver(receiver);
-	}
-
-	@Override
-	void initialiseAdapter() throws IOException {
-		// BluetoothAdapter.getDefaultAdapter() must be called on a thread
-		// with a message queue, so submit it to the AndroidExecutor
-		try {
-			adapter = androidExecutor.runOnBackgroundThread(
-					BluetoothAdapter::getDefaultAdapter).get();
-		} catch (InterruptedException | ExecutionException e) {
-			throw new IOException(e);
-		}
-		if (adapter == null)
-			throw new IOException("Bluetooth is not supported");
-	}
-
-	@Override
-	boolean isAdapterEnabled() {
-		return adapter != null && adapter.isEnabled();
-	}
-
-	@Override
-	void enableAdapter() {
-		if (adapter != null && !adapter.isEnabled()) {
-			if (adapter.enable()) {
-				LOG.info("Enabling Bluetooth");
-				wasEnabledByUs = true;
-			} else {
-				LOG.info("Could not enable Bluetooth");
-			}
-		}
-	}
-
-	@Override
-	void disableAdapterIfEnabledByUs() {
-		if (isAdapterEnabled() && wasEnabledByUs) {
-			if (adapter.disable()) LOG.info("Disabling Bluetooth");
-			else LOG.info("Could not disable Bluetooth");
-			wasEnabledByUs = false;
-		}
-	}
-
-	@Override
-	void setEnabledByUs() {
-		wasEnabledByUs = true;
-	}
-
-	@Override
-	@Nullable
-	String getBluetoothAddress() {
-		String address = AndroidUtils.getBluetoothAddress(appContext, adapter);
-		return address.isEmpty() ? null : address;
-	}
-
-	@Override
-	BluetoothServerSocket openServerSocket(String uuid) throws IOException {
-		return adapter.listenUsingInsecureRfcommWithServiceRecord(
-				"RFCOMM", UUID.fromString(uuid));
-	}
-
-	@Override
-	void tryToClose(@Nullable BluetoothServerSocket ss) {
-		try {
-			if (ss != null) ss.close();
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		}
-	}
-
-	@Override
-	DuplexTransportConnection acceptConnection(BluetoothServerSocket ss)
-			throws IOException {
-		return wrapSocket(ss.accept());
-	}
-
-	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
-		return new AndroidBluetoothTransportConnection(this, s);
-	}
-
-	@Override
-	boolean isValidAddress(String address) {
-		return BluetoothAdapter.checkBluetoothAddress(address);
-	}
-
-	@Override
-	DuplexTransportConnection connectTo(String address, String uuid)
-			throws IOException {
-		BluetoothDevice d = adapter.getRemoteDevice(address);
-		UUID u = UUID.fromString(uuid);
-		BluetoothSocket s = null;
-		try {
-			s = d.createInsecureRfcommSocketToServiceRecord(u);
-			s.connect();
-			return wrapSocket(s);
-		} catch (IOException e) {
-			tryToClose(s);
-			throw e;
-		}
-	}
-
-	private void tryToClose(@Nullable Closeable c) {
-		try {
-			if (c != null) c.close();
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		}
-	}
-
-	private class BluetoothStateReceiver extends BroadcastReceiver {
-
-		@Override
-		public void onReceive(Context ctx, Intent intent) {
-			int state = intent.getIntExtra(EXTRA_STATE, 0);
-			if (state == STATE_ON) onAdapterEnabled();
-			else if (state == STATE_OFF) onAdapterDisabled();
-			int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
-			if (scanMode == SCAN_MODE_NONE) {
-				LOG.info("Scan mode: None");
-			} else if (scanMode == SCAN_MODE_CONNECTABLE) {
-				LOG.info("Scan mode: Connectable");
-			} else if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
-				LOG.info("Scan mode: Discoverable");
-			}
-		}
-	}
-}

bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPlugin.java

@@ -0,0 +1,537 @@
+package org.briarproject.bramble.plugin.droidtooth;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothServerSocket;
+import android.bluetooth.BluetoothSocket;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.widget.ArrayAdapter;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.data.BdfList;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventListener;
+import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
+import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BluetoothEnableDisableReason;
+import org.briarproject.bramble.api.plugin.PluginException;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.plugin.event.DisableBluetoothEvent;
+import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
+import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.util.AndroidUtils;
+import org.briarproject.bramble.util.StringUtils;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.security.SecureRandom;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.UUID;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
+import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
+import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
+import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
+import static android.bluetooth.BluetoothAdapter.STATE_OFF;
+import static android.bluetooth.BluetoothAdapter.STATE_ON;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
+import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class DroidtoothPlugin implements DuplexPlugin, EventListener {
+
+	private static final Logger LOG =
+			Logger.getLogger(DroidtoothPlugin.class.getName());
+
+	private final Executor ioExecutor;
+	private final AndroidExecutor androidExecutor;
+	private final Context appContext;
+	private final SecureRandom secureRandom;
+	private final Backoff backoff;
+	private final DuplexPluginCallback callback;
+	private final int maxLatency;
+	private final AtomicBoolean used = new AtomicBoolean(false);
+
+	private volatile boolean running = false;
+	private volatile boolean wasEnabledByUs = false;
+	private volatile ArrayList<BluetoothEnableDisableReason>
+			enableDisableReasons = new ArrayList<>();
+	private volatile BluetoothStateReceiver receiver = null;
+	private volatile BluetoothServerSocket socket = null;
+
+	// Non-null if the plugin started successfully
+	private volatile BluetoothAdapter adapter = null;
+
+	DroidtoothPlugin(Executor ioExecutor, AndroidExecutor androidExecutor,
+			Context appContext, SecureRandom secureRandom, Backoff backoff,
+			DuplexPluginCallback callback, int maxLatency) {
+		this.ioExecutor = ioExecutor;
+		this.androidExecutor = androidExecutor;
+		this.appContext = appContext;
+		this.secureRandom = secureRandom;
+		this.backoff = backoff;
+		this.callback = callback;
+		this.maxLatency = maxLatency;
+	}
+
+	@Override
+	public TransportId getId() {
+		return ID;
+	}
+
+	@Override
+	public int getMaxLatency() {
+		return maxLatency;
+	}
+
+	@Override
+	public int getMaxIdleTime() {
+		// Bluetooth detects dead connections so we don't need keepalives
+		return Integer.MAX_VALUE;
+	}
+
+	@Override
+	public void start() throws PluginException {
+		if (used.getAndSet(true)) throw new IllegalStateException();
+		// BluetoothAdapter.getDefaultAdapter() must be called on a thread
+		// with a message queue, so submit it to the AndroidExecutor
+		try {
+			adapter = androidExecutor.runOnBackgroundThread(
+					new Callable<BluetoothAdapter>() {
+						@Override
+						public BluetoothAdapter call() throws Exception {
+							return BluetoothAdapter.getDefaultAdapter();
+						}
+					}).get();
+		} catch (InterruptedException e) {
+			Thread.currentThread().interrupt();
+			LOG.warning("Interrupted while getting BluetoothAdapter");
+			throw new PluginException(e);
+		} catch (ExecutionException e) {
+			throw new PluginException(e);
+		}
+		if (adapter == null) {
+			LOG.info("Bluetooth is not supported");
+			throw new PluginException();
+		}
+		running = true;
+		// Listen for changes to the Bluetooth state
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(ACTION_STATE_CHANGED);
+		filter.addAction(ACTION_SCAN_MODE_CHANGED);
+		receiver = new BluetoothStateReceiver();
+		appContext.registerReceiver(receiver, filter);
+		// If Bluetooth is enabled, bind a socket
+		if (adapter.isEnabled()) {
+			bind();
+		} else {
+			// Enable Bluetooth if settings allow
+			if (callback.getSettings().getBoolean(PREF_BT_ENABLE, true)) {
+				enableAdapter(BluetoothEnableDisableReason.COMMUNICATION);
+			} else {
+				LOG.info("Not enabling Bluetooth");
+			}
+		}
+	}
+
+	private void bind() {
+		ioExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				if (!isRunning()) return;
+				String address = AndroidUtils.getBluetoothAddress(appContext,
+						adapter);
+				if (LOG.isLoggable(INFO))
+					LOG.info("Local address " + scrubMacAddress(address));
+				if (!StringUtils.isNullOrEmpty(address)) {
+					// Advertise the Bluetooth address to contacts
+					TransportProperties p = new TransportProperties();
+					p.put(PROP_ADDRESS, address);
+					callback.mergeLocalProperties(p);
+				}
+				// Bind a server socket to accept connections from contacts
+				BluetoothServerSocket ss;
+				try {
+					ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
+							"RFCOMM", getUuid());
+				} catch (IOException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+					return;
+				}
+				if (!isRunning()) {
+					tryToClose(ss);
+					return;
+				}
+				LOG.info("Socket bound");
+				socket = ss;
+				backoff.reset();
+				callback.transportEnabled();
+				acceptContactConnections();
+			}
+		});
+	}
+
+	private UUID getUuid() {
+		String uuid = callback.getLocalProperties().get(PROP_UUID);
+		if (uuid == null) {
+			byte[] random = new byte[UUID_BYTES];
+			secureRandom.nextBytes(random);
+			uuid = UUID.nameUUIDFromBytes(random).toString();
+			TransportProperties p = new TransportProperties();
+			p.put(PROP_UUID, uuid);
+			callback.mergeLocalProperties(p);
+		}
+		return UUID.fromString(uuid);
+	}
+
+	private void tryToClose(@Nullable BluetoothServerSocket ss) {
+		try {
+			if (ss != null) ss.close();
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} finally {
+			callback.transportDisabled();
+		}
+	}
+
+	private void acceptContactConnections() {
+		while (isRunning()) {
+			BluetoothSocket s;
+			try {
+				s = socket.accept();
+			} catch (IOException e) {
+				// This is expected when the socket is closed
+				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+				return;
+			}
+			if (LOG.isLoggable(INFO)) {
+				String address = s.getRemoteDevice().getAddress();
+				LOG.info("Connection from " + scrubMacAddress(address));
+			}
+			backoff.reset();
+			callback.incomingConnectionCreated(wrapSocket(s));
+		}
+	}
+
+	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
+		return new DroidtoothTransportConnection(this, s);
+	}
+
+	private void enableAdapter(BluetoothEnableDisableReason reason) {
+		if (adapter != null && !adapter.isEnabled()) {
+			if (adapter.enable()) {
+				LOG.info("Enabling Bluetooth");
+				wasEnabledByUs = true;
+
+				if(!enableDisableReasons.contains(reason)) {
+					enableDisableReasons.add(reason);
+				}
+			} else {
+				LOG.info("Could not enable Bluetooth");
+			}
+		}
+	}
+
+	@Override
+	public void stop() {
+		running = false;
+		if (receiver != null) appContext.unregisterReceiver(receiver);
+		tryToClose(socket);
+		disableAdapter(true);
+	}
+
+	private void disableAdapter(boolean force){
+		disableAdapter(null, force);
+	}
+
+	private void disableAdapter(BluetoothEnableDisableReason reason,
+			boolean force) {
+		if (adapter != null && adapter.isEnabled() && wasEnabledByUs
+				&& (enableDisableReasons.contains(reason) || force)) {
+
+			if(enableDisableReasons.contains(reason)){
+				enableDisableReasons.remove(reason);
+			}
+
+			if (adapter.disable()) LOG.info("Disabling Bluetooth");
+			else LOG.info("Could not disable Bluetooth");
+		}
+	}
+
+	@Override
+	public boolean isRunning() {
+		return running && adapter != null && adapter.isEnabled();
+	}
+
+	@Override
+	public boolean shouldPoll() {
+		return true;
+	}
+
+	@Override
+	public int getPollingInterval() {
+		return backoff.getPollingInterval();
+	}
+
+	@Override
+	public void poll(Collection<ContactId> connected) {
+		if (!isRunning()) return;
+		backoff.increment();
+		// Try to connect to known devices in parallel
+		Map<ContactId, TransportProperties> remote =
+				callback.getRemoteProperties();
+		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
+			final ContactId c = e.getKey();
+			if (connected.contains(c)) continue;
+			final String address = e.getValue().get(PROP_ADDRESS);
+			if (StringUtils.isNullOrEmpty(address)) continue;
+			final String uuid = e.getValue().get(PROP_UUID);
+			if (StringUtils.isNullOrEmpty(uuid)) continue;
+			ioExecutor.execute(new Runnable() {
+				@Override
+				public void run() {
+					if (!running) return;
+					BluetoothSocket s = connect(address, uuid);
+					if (s != null) {
+						backoff.reset();
+						callback.outgoingConnectionCreated(c, wrapSocket(s));
+					}
+				}
+			});
+		}
+	}
+
+	@Nullable
+	private BluetoothSocket connect(String address, String uuid) {
+		// Validate the address
+		if (!BluetoothAdapter.checkBluetoothAddress(address)) {
+			if (LOG.isLoggable(WARNING))
+				// not scrubbing here to be able to figure out the problem
+				LOG.warning("Invalid address " + address);
+			return null;
+		}
+		// Validate the UUID
+		UUID u;
+		try {
+			u = UUID.fromString(uuid);
+		} catch (IllegalArgumentException e) {
+			if (LOG.isLoggable(WARNING)) LOG.warning("Invalid UUID " + uuid);
+			return null;
+		}
+		// Try to connect
+		BluetoothDevice d = adapter.getRemoteDevice(address);
+		BluetoothSocket s = null;
+		try {
+			s = d.createInsecureRfcommSocketToServiceRecord(u);
+			if (LOG.isLoggable(INFO))
+				LOG.info("Connecting to " + scrubMacAddress(address));
+			s.connect();
+			if (LOG.isLoggable(INFO))
+				LOG.info("Connected to " + scrubMacAddress(address));
+			return s;
+		} catch (IOException e) {
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Failed to connect to " + scrubMacAddress(address)
+						+ ": " + e);
+			}
+			tryToClose(s);
+			return null;
+		}
+	}
+
+	private void tryToClose(@Nullable Closeable c) {
+		try {
+			if (c != null) c.close();
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+	}
+
+	@Override
+	public DuplexTransportConnection createConnection(ContactId c) {
+		if (!isRunning()) return null;
+		TransportProperties p = callback.getRemoteProperties(c);
+		String address = p.get(PROP_ADDRESS);
+		if (StringUtils.isNullOrEmpty(address)) return null;
+		String uuid = p.get(PROP_UUID);
+		if (StringUtils.isNullOrEmpty(uuid)) return null;
+		BluetoothSocket s = connect(address, uuid);
+		if (s == null) return null;
+		return new DroidtoothTransportConnection(this, s);
+	}
+
+	@Override
+	public boolean supportsKeyAgreement() {
+		return true;
+	}
+
+	@Override
+	public KeyAgreementListener createKeyAgreementListener(byte[] commitment) {
+		if (!isRunning()) return null;
+		// There's no point listening if we can't discover our own address
+		String address = AndroidUtils.getBluetoothAddress(appContext, adapter);
+		if (address.isEmpty()) return null;
+		// No truncation necessary because COMMIT_LENGTH = 16
+		UUID uuid = UUID.nameUUIDFromBytes(commitment);
+		if (LOG.isLoggable(INFO)) LOG.info("Key agreement UUID " + uuid);
+		// Bind a server socket for receiving key agreement connections
+		BluetoothServerSocket ss;
+		try {
+			ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
+					"RFCOMM", uuid);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return null;
+		}
+		BdfList descriptor = new BdfList();
+		descriptor.add(TRANSPORT_ID_BLUETOOTH);
+		descriptor.add(StringUtils.macToBytes(address));
+		return new BluetoothKeyAgreementListener(descriptor, ss);
+	}
+
+	@Override
+	public DuplexTransportConnection createKeyAgreementConnection(
+			byte[] commitment, BdfList descriptor, long timeout) {
+		if (!isRunning()) return null;
+		String address;
+		try {
+			address = parseAddress(descriptor);
+		} catch (FormatException e) {
+			LOG.info("Invalid address in key agreement descriptor");
+			return null;
+		}
+		// No truncation necessary because COMMIT_LENGTH = 16
+		UUID uuid = UUID.nameUUIDFromBytes(commitment);
+		if (LOG.isLoggable(INFO))
+			LOG.info("Connecting to key agreement UUID " + uuid);
+		BluetoothSocket s = connect(address, uuid.toString());
+		if (s == null) return null;
+		return new DroidtoothTransportConnection(this, s);
+	}
+
+	private String parseAddress(BdfList descriptor) throws FormatException {
+		byte[] mac = descriptor.getRaw(1);
+		if (mac.length != 6) throw new FormatException();
+		return StringUtils.macToString(mac);
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof EnableBluetoothEvent) {
+			EnableBluetoothEvent enable = (EnableBluetoothEvent) e;
+			enableAdapterAsync(enable.getReason());
+		} else if (e instanceof DisableBluetoothEvent) {
+			DisableBluetoothEvent disable = (DisableBluetoothEvent) e;
+			disableAdapterAsync(disable.getReason());
+		}
+	}
+
+	private void enableAdapterAsync(final BluetoothEnableDisableReason reason) {
+		ioExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				enableAdapter(reason);
+			}
+		});
+	}
+
+	private void disableAdapterAsync(final BluetoothEnableDisableReason reason) {
+		ioExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				disableAdapter(reason, false);
+			}
+		});
+	}
+
+	private class BluetoothStateReceiver extends BroadcastReceiver {
+
+		@Override
+		public void onReceive(Context ctx, Intent intent) {
+			int state = intent.getIntExtra(EXTRA_STATE, 0);
+			if (state == STATE_ON) {
+				LOG.info("Bluetooth enabled");
+				bind();
+			} else if (state == STATE_OFF) {
+				LOG.info("Bluetooth disabled");
+				tryToClose(socket);
+			}
+			int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
+			if (scanMode == SCAN_MODE_NONE) {
+				LOG.info("Scan mode: None");
+			} else if (scanMode == SCAN_MODE_CONNECTABLE) {
+				LOG.info("Scan mode: Connectable");
+			} else if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
+				LOG.info("Scan mode: Discoverable");
+			}
+		}
+	}
+
+	private class BluetoothKeyAgreementListener extends KeyAgreementListener {
+
+		private final BluetoothServerSocket ss;
+
+		private BluetoothKeyAgreementListener(BdfList descriptor,
+				BluetoothServerSocket ss) {
+			super(descriptor);
+			this.ss = ss;
+		}
+
+		@Override
+		public Callable<KeyAgreementConnection> listen() {
+			return new Callable<KeyAgreementConnection>() {
+				@Override
+				public KeyAgreementConnection call() throws IOException {
+					BluetoothSocket s = ss.accept();
+					if (LOG.isLoggable(INFO))
+						LOG.info(ID.getString() + ": Incoming connection");
+					return new KeyAgreementConnection(
+							new DroidtoothTransportConnection(
+									DroidtoothPlugin.this, s), ID);
+				}
+			};
+		}
+
+		@Override
+		public void close() {
+			try {
+				ss.close();
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			}
+		}
+	}
+}

bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPluginFactory.java

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.plugin.bluetooth;
+package org.briarproject.bramble.plugin.droidtooth;
 
 import android.content.Context;
 
@@ -21,7 +21,7 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 
 @Immutable
 @NotNullByDefault
-public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
+public class DroidtoothPluginFactory implements DuplexPluginFactory {
 
 	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
 	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
@@ -35,7 +35,7 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
 
-	public AndroidBluetoothPluginFactory(Executor ioExecutor,
+	public DroidtoothPluginFactory(Executor ioExecutor,
 			AndroidExecutor androidExecutor, Context appContext,
 			SecureRandom secureRandom, EventBus eventBus,
 			BackoffFactory backoffFactory) {
@@ -61,7 +61,7 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(DuplexPluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(ioExecutor,
+		DroidtoothPlugin plugin = new DroidtoothPlugin(ioExecutor,
 				androidExecutor, appContext, secureRandom, backoff, callback,
 				MAX_LATENCY);
 		eventBus.addListener(plugin);

bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothTransportConnection.java

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.plugin.bluetooth;
+package org.briarproject.bramble.plugin.droidtooth;
 
 import android.bluetooth.BluetoothSocket;
 
@@ -11,12 +11,11 @@ import java.io.InputStream;
 import java.io.OutputStream;
 
 @NotNullByDefault
-class AndroidBluetoothTransportConnection
+class DroidtoothTransportConnection extends AbstractDuplexTransportConnection {
-		extends AbstractDuplexTransportConnection {
 
 	private final BluetoothSocket socket;
 
-	AndroidBluetoothTransportConnection(Plugin plugin, BluetoothSocket socket) {
+	DroidtoothTransportConnection(Plugin plugin, BluetoothSocket socket) {
 		super(plugin);
 		this.socket = socket;
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -5,84 +5,37 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
-import android.net.Network;
 import android.net.NetworkInfo;
-import android.net.wifi.WifiInfo;
-import android.net.wifi.WifiManager;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 
-import java.io.IOException;
-import java.net.InetAddress;
-import java.net.Socket;
-import java.net.UnknownHostException;
-import java.util.Collection;
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
-import javax.net.SocketFactory;
 
 import static android.content.Context.CONNECTIVITY_SERVICE;
-import static android.content.Context.WIFI_SERVICE;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
-import static android.net.wifi.WifiManager.EXTRA_WIFI_STATE;
-import static android.os.Build.VERSION.SDK_INT;
-import static java.util.Collections.emptyList;
-import static java.util.Collections.singletonList;
-import static java.util.concurrent.TimeUnit.SECONDS;
 
 @NotNullByDefault
 class AndroidLanTcpPlugin extends LanTcpPlugin {
 
-	// See android.net.wifi.WifiManager
-	private static final String WIFI_AP_STATE_CHANGED_ACTION =
-			"android.net.wifi.WIFI_AP_STATE_CHANGED";
-	private static final int WIFI_AP_STATE_ENABLED = 13;
-
-	private static final byte[] WIFI_AP_ADDRESS_BYTES =
-			{(byte) 192, (byte) 168, 43, 1};
-	private static final InetAddress WIFI_AP_ADDRESS;
-
 	private static final Logger LOG =
 			Logger.getLogger(AndroidLanTcpPlugin.class.getName());
 
-	static {
-		try {
-			WIFI_AP_ADDRESS = InetAddress.getByAddress(WIFI_AP_ADDRESS_BYTES);
-		} catch (UnknownHostException e) {
-			// Should only be thrown if the address has an illegal length
-			throw new AssertionError(e);
-		}
-	}
-
-	private final ScheduledExecutorService scheduler;
 	private final Context appContext;
-	private final ConnectivityManager connectivityManager;
-	@Nullable
-	private final WifiManager wifiManager;
 
 	@Nullable
 	private volatile BroadcastReceiver networkStateReceiver = null;
-	private volatile SocketFactory socketFactory;
 
-	AndroidLanTcpPlugin(Executor ioExecutor, ScheduledExecutorService scheduler,
+	AndroidLanTcpPlugin(Executor ioExecutor, Backoff backoff,
-			Backoff backoff, Context appContext, DuplexPluginCallback callback,
+			Context appContext, DuplexPluginCallback callback, int maxLatency,
-			int maxLatency, int maxIdleTime) {
+			int maxIdleTime) {
 		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
-		this.scheduler = scheduler;
 		this.appContext = appContext;
-		ConnectivityManager connectivityManager = (ConnectivityManager)
-				appContext.getSystemService(CONNECTIVITY_SERVICE);
-		if (connectivityManager == null) throw new AssertionError();
-		this.connectivityManager = connectivityManager;
-		wifiManager = (WifiManager) appContext.getApplicationContext()
-				.getSystemService(WIFI_SERVICE);
-		socketFactory = SocketFactory.getDefault();
 	}
 
 	@Override
@@ -91,9 +44,7 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		running = true;
 		// Register to receive network status events
 		networkStateReceiver = new NetworkStateReceiver();
-		IntentFilter filter = new IntentFilter();
+		IntentFilter filter = new IntentFilter(CONNECTIVITY_ACTION);
-		filter.addAction(CONNECTIVITY_ACTION);
-		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
 		appContext.registerReceiver(networkStateReceiver, filter);
 	}
 
@@ -105,92 +56,21 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		tryToClose(socket);
 	}
 
-	@Override
-	protected Socket createSocket() throws IOException {
-		return socketFactory.createSocket();
-	}
-
-	@Override
-	protected Collection<InetAddress> getLocalIpAddresses() {
-		// If the device doesn't have wifi, don't open any sockets
-		if (wifiManager == null) return emptyList();
-		// If we're connected to a wifi network, use that network
-		WifiInfo info = wifiManager.getConnectionInfo();
-		if (info != null && info.getIpAddress() != 0)
-			return singletonList(intToInetAddress(info.getIpAddress()));
-		// If we're running an access point, return its address
-		if (super.getLocalIpAddresses().contains(WIFI_AP_ADDRESS))
-				return singletonList(WIFI_AP_ADDRESS);
-		// No suitable addresses
-		return emptyList();
-	}
-
-	private InetAddress intToInetAddress(int ip) {
-		byte[] ipBytes = new byte[4];
-		ipBytes[0] = (byte) (ip & 0xFF);
-		ipBytes[1] = (byte) ((ip >> 8) & 0xFF);
-		ipBytes[2] = (byte) ((ip >> 16) & 0xFF);
-		ipBytes[3] = (byte) ((ip >> 24) & 0xFF);
-		try {
-			return InetAddress.getByAddress(ipBytes);
-		} catch (UnknownHostException e) {
-			// Should only be thrown if address has illegal length
-			throw new AssertionError(e);
-		}
-	}
-
-	// On API 21 and later, a socket that is not created with the wifi
-	// network's socket factory may try to connect via another network
-	private SocketFactory getSocketFactory() {
-		if (SDK_INT < 21) return SocketFactory.getDefault();
-		for (Network net : connectivityManager.getAllNetworks()) {
-			NetworkInfo info = connectivityManager.getNetworkInfo(net);
-			if (info != null && info.getType() == TYPE_WIFI)
-				return net.getSocketFactory();
-		}
-		LOG.warning("Could not find suitable socket factory");
-		return SocketFactory.getDefault();
-	}
-
 	private class NetworkStateReceiver extends BroadcastReceiver {
 
 		@Override
 		public void onReceive(Context ctx, Intent i) {
 			if (!running) return;
-			if (isApEnabledEvent(i)) {
+			Object o = ctx.getSystemService(CONNECTIVITY_SERVICE);
-				// The state change may be broadcast before the AP address is
+			ConnectivityManager cm = (ConnectivityManager) o;
-				// visible, so delay handling the event
+			NetworkInfo net = cm.getActiveNetworkInfo();
-				scheduler.schedule(this::handleConnectivityChange, 1, SECONDS);
+			if (net != null && net.getType() == TYPE_WIFI && net.isConnected()) {
-			} else {
+				LOG.info("Connected to Wi-Fi");
-				handleConnectivityChange();
-			}
-		}
-
-		private void handleConnectivityChange() {
-			if (!running) return;
-			Collection<InetAddress> addrs = getLocalIpAddresses();
-			if (addrs.contains(WIFI_AP_ADDRESS)) {
-				LOG.info("Providing wifi hotspot");
-				// There's no corresponding Network object and thus no way
-				// to get a suitable socket factory, so we won't be able to
-				// make outgoing connections on API 21+ if another network
-				// has internet access
-				socketFactory = SocketFactory.getDefault();
 				if (socket == null || socket.isClosed()) bind();
-			} else if (addrs.isEmpty()) {
+			} else {
-				LOG.info("Not connected to wifi");
+				LOG.info("Not connected to Wi-Fi");
-				socketFactory = SocketFactory.getDefault();
 				tryToClose(socket);
-			} else {
-				LOG.info("Connected to wifi");
-				socketFactory = getSocketFactory();
-				if (socket == null || socket.isClosed()) bind();
 			}
 		}
-
-		private boolean isApEnabledEvent(Intent i) {
-			return WIFI_AP_STATE_CHANGED_ACTION.equals(i.getAction()) &&
-					i.getIntExtra(EXTRA_WIFI_STATE, 0) == WIFI_AP_STATE_ENABLED;
-		}
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPluginFactory.java

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 
 import javax.annotation.concurrent.Immutable;
 
@@ -28,15 +27,12 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
-	private final ScheduledExecutorService scheduler;
 	private final BackoffFactory backoffFactory;
 	private final Context appContext;
 
 	public AndroidLanTcpPluginFactory(Executor ioExecutor,
-			ScheduledExecutorService scheduler, BackoffFactory backoffFactory,
+			BackoffFactory backoffFactory, Context appContext) {
-			Context appContext) {
 		this.ioExecutor = ioExecutor;
-		this.scheduler = scheduler;
 		this.backoffFactory = backoffFactory;
 		this.appContext = appContext;
 	}
@@ -55,7 +51,7 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(DuplexPluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		return new AndroidLanTcpPlugin(ioExecutor, scheduler, backoff,
+		return new AndroidLanTcpPlugin(ioExecutor, backoff, appContext,
-				appContext, callback, MAX_LATENCY, MAX_IDLE_TIME);
+				callback, MAX_LATENCY, MAX_IDLE_TIME);
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java

@@ -16,7 +16,6 @@ import android.os.PowerManager;
 import net.freehaven.tor.control.EventHandler;
 import net.freehaven.tor.control.TorControlConnection;
 
-import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.event.Event;
@@ -60,10 +59,7 @@ import java.util.Map.Entry;
 import java.util.Scanner;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
 import java.util.zip.ZipInputStream;
@@ -74,15 +70,10 @@ import javax.net.SocketFactory;
 import static android.content.Context.CONNECTIVITY_SERVICE;
 import static android.content.Context.MODE_PRIVATE;
 import static android.content.Context.POWER_SERVICE;
-import static android.content.Intent.ACTION_SCREEN_OFF;
-import static android.content.Intent.ACTION_SCREEN_ON;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
-import static android.os.Build.VERSION.SDK_INT;
-import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
 import static android.os.PowerManager.PARTIAL_WAKE_LOCK;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static net.freehaven.tor.control.TorControlCommands.HS_ADDRESS;
@@ -110,8 +101,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private static final Logger LOG =
 			Logger.getLogger(TorPlugin.class.getName());
 
-	private final Executor ioExecutor, connectionStatusExecutor;
+	private final Executor ioExecutor;
-	private final ScheduledExecutorService scheduler;
 	private final Context appContext;
 	private final LocationUtils locationUtils;
 	private final DevReporter reporter;
@@ -124,8 +114,6 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private final File torDirectory, torFile, geoIpFile, configFile;
 	private final File doneFile, cookieFile;
 	private final PowerManager.WakeLock wakeLock;
-	private final AtomicReference<Future<?>> connectivityCheck =
-			new AtomicReference<>();
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	private volatile boolean running = false;
@@ -134,13 +122,12 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private volatile TorControlConnection controlConnection = null;
 	private volatile BroadcastReceiver networkStateReceiver = null;
 
-	TorPlugin(Executor ioExecutor, ScheduledExecutorService scheduler,
+	TorPlugin(Executor ioExecutor, Context appContext,
-			Context appContext, LocationUtils locationUtils,
+			LocationUtils locationUtils, DevReporter reporter,
-			DevReporter reporter, SocketFactory torSocketFactory,
+			SocketFactory torSocketFactory, Backoff backoff,
-			Backoff backoff, DuplexPluginCallback callback,
+			DuplexPluginCallback callback, String architecture, int maxLatency,
-			String architecture, int maxLatency, int maxIdleTime) {
+			int maxIdleTime) {
 		this.ioExecutor = ioExecutor;
-		this.scheduler = scheduler;
 		this.appContext = appContext;
 		this.locationUtils = locationUtils;
 		this.reporter = reporter;
@@ -165,9 +152,6 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		// This tag will prevent Huawei's powermanager from killing us.
 		wakeLock = pm.newWakeLock(PARTIAL_WAKE_LOCK, "LocationManagerService");
 		wakeLock.setReferenceCounted(false);
-		// Don't execute more than one connection status check at a time
-		connectionStatusExecutor = new PoliteExecutor("TorPlugin",
-				ioExecutor, 1);
 	}
 
 	@Override
@@ -220,11 +204,11 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (LOG.isLoggable(INFO)) {
 			Scanner stdout = new Scanner(torProcess.getInputStream());
 			Scanner stderr = new Scanner(torProcess.getErrorStream());
-			while (stdout.hasNextLine() || stderr.hasNextLine()) {
+			while (stdout.hasNextLine() || stderr.hasNextLine()){
-				if (stdout.hasNextLine()) {
+				if(stdout.hasNextLine()) {
 					LOG.info(stdout.nextLine());
 				}
-				if (stderr.hasNextLine()) {
+				if(stderr.hasNextLine()){
 					LOG.info(stderr.nextLine());
 				}
 			}
@@ -273,11 +257,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 		// Register to receive network status events
 		networkStateReceiver = new NetworkStateReceiver();
-		IntentFilter filter = new IntentFilter();
+		IntentFilter filter = new IntentFilter(CONNECTIVITY_ACTION);
-		filter.addAction(CONNECTIVITY_ACTION);
-		filter.addAction(ACTION_SCREEN_ON);
-		filter.addAction(ACTION_SCREEN_OFF);
-		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
 		appContext.registerReceiver(networkStateReceiver, filter);
 		// Bind a server socket to receive incoming hidden service connections
 		bind();
@@ -390,45 +370,57 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void sendDevReports() {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			// TODO: Trigger this with a TransportEnabledEvent
+			@Override
-			File reportDir = AndroidUtils.getReportDir(appContext);
+			public void run() {
-			reporter.sendReports(reportDir);
+				// TODO: Trigger this with a TransportEnabledEvent
+				File reportDir = AndroidUtils.getReportDir(appContext);
+				reporter.sendReports(reportDir);
+			}
 		});
 	}
 
 	private void bind() {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			// If there's already a port number stored in config, reuse it
+			@Override
-			String portString = callback.getSettings().get(PREF_TOR_PORT);
+			public void run() {
-			int port;
+				// If there's already a port number stored in config, reuse it
-			if (StringUtils.isNullOrEmpty(portString)) port = 0;
+				String portString = callback.getSettings().get(PREF_TOR_PORT);
-			else port = Integer.parseInt(portString);
+				int port;
-			// Bind a server socket to receive connections from Tor
+				if (StringUtils.isNullOrEmpty(portString)) port = 0;
-			ServerSocket ss = null;
+				else port = Integer.parseInt(portString);
-			try {
+				// Bind a server socket to receive connections from Tor
-				ss = new ServerSocket();
+				ServerSocket ss = null;
-				ss.bind(new InetSocketAddress("127.0.0.1", port));
+				try {
-			} catch (IOException e) {
+					ss = new ServerSocket();
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+					ss.bind(new InetSocketAddress("127.0.0.1", port));
-				tryToClose(ss);
+				} catch (IOException e) {
-				return;
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+					tryToClose(ss);
+					return;
+				}
+				if (!running) {
+					tryToClose(ss);
+					return;
+				}
+				socket = ss;
+				// Store the port number
+				final String localPort = String.valueOf(ss.getLocalPort());
+				Settings s = new Settings();
+				s.put(PREF_TOR_PORT, localPort);
+				callback.mergeSettings(s);
+				// Create a hidden service if necessary
+				ioExecutor.execute(new Runnable() {
+					@Override
+					public void run() {
+						publishHiddenService(localPort);
+					}
+				});
+				backoff.reset();
+				// Accept incoming hidden service connections from Tor
+				acceptContactConnections(ss);
 			}
-			if (!running) {
-				tryToClose(ss);
-				return;
-			}
-			socket = ss;
-			// Store the port number
-			String localPort = String.valueOf(ss.getLocalPort());
-			Settings s = new Settings();
-			s.put(PREF_TOR_PORT, localPort);
-			callback.mergeSettings(s);
-			// Create a hidden service if necessary
-			ioExecutor.execute(() -> publishHiddenService(localPort));
-			backoff.reset();
-			// Accept incoming hidden service connections from Tor
-			acceptContactConnections(ss);
 		});
 	}
 
@@ -556,13 +548,17 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 	}
 
-	private void connectAndCallBack(ContactId c, TransportProperties p) {
+	private void connectAndCallBack(final ContactId c,
-		ioExecutor.execute(() -> {
+			final TransportProperties p) {
-			if (!isRunning()) return;
+		ioExecutor.execute(new Runnable() {
-			DuplexTransportConnection d = createConnection(p);
+			@Override
-			if (d != null) {
+			public void run() {
-				backoff.reset();
+				if (!isRunning()) return;
-				callback.outgoingConnectionCreated(c, d);
+				DuplexTransportConnection d = createConnection(p);
+				if (d != null) {
+					backoff.reset();
+					callback.outgoingConnectionCreated(c, d);
+				}
 			}
 		});
 	}
@@ -614,7 +610,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor) {
+			byte[] commitment, BdfList descriptor, long timeout) {
 		throw new UnsupportedOperationException();
 	}
 
@@ -638,8 +634,6 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void orConnStatus(String status, String orName) {
 		if (LOG.isLoggable(INFO)) LOG.info("OR connection " + status);
-		if (status.equals("CLOSED") || status.equals("FAILED"))
-			updateConnectionStatus(); // Check whether we've lost connectivity
 	}
 
 	@Override
@@ -679,7 +673,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 
 		@Override
-		public void onEvent(int event, @Nullable String path) {
+		public void onEvent(int event, String path) {
 			stopWatching();
 			latch.countDown();
 		}
@@ -697,65 +691,60 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void updateConnectionStatus() {
-		connectionStatusExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			if (!running) return;
+			@Override
-			Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
+			public void run() {
-			ConnectivityManager cm = (ConnectivityManager) o;
+				if (!running) return;
-			NetworkInfo net = cm.getActiveNetworkInfo();
-			boolean online = net != null && net.isConnected();
-			boolean wifi = online && net.getType() == TYPE_WIFI;
-			String country = locationUtils.getCurrentCountry();
-			boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
-					country);
-			Settings s = callback.getSettings();
-			int network = s.getInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_ALWAYS);
 
-			if (LOG.isLoggable(INFO)) {
+				Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
-				LOG.info("Online: " + online + ", wifi: " + wifi);
+				ConnectivityManager cm = (ConnectivityManager) o;
-				if ("".equals(country)) LOG.info("Country code unknown");
+				NetworkInfo net = cm.getActiveNetworkInfo();
-				else LOG.info("Country code: " + country);
+				boolean online = net != null && net.isConnected();
-			}
+				boolean wifi = online && net.getType() == TYPE_WIFI;
+				String country = locationUtils.getCurrentCountry();
+				boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
+						country);
+				Settings s = callback.getSettings();
+				int network = s.getInt(PREF_TOR_NETWORK,
+						PREF_TOR_NETWORK_ALWAYS);
 
-			try {
+				if (LOG.isLoggable(INFO)) {
-				if (!online) {
+					LOG.info("Online: " + online + ", wifi: " + wifi);
-					LOG.info("Disabling network, device is offline");
+					if ("".equals(country)) LOG.info("Country code unknown");
-					enableNetwork(false);
+					else LOG.info("Country code: " + country);
-				} else if (blocked) {
+				}
-					LOG.info("Disabling network, country is blocked");
+
-					enableNetwork(false);
+				try {
-				} else if (network == PREF_TOR_NETWORK_NEVER
+					if (!online) {
-						|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
+						LOG.info("Disabling network, device is offline");
-					LOG.info("Disabling network due to data setting");
+						enableNetwork(false);
-					enableNetwork(false);
+					} else if (blocked) {
-				} else {
+						LOG.info("Disabling network, country is blocked");
-					LOG.info("Enabling network");
+						enableNetwork(false);
-					enableNetwork(true);
+					} else if (network == PREF_TOR_NETWORK_NEVER
+							|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
+						LOG.info("Disabling network due to data setting");
+						enableNetwork(false);
+					} else {
+						LOG.info("Enabling network");
+						enableNetwork(true);
+					}
+				} catch (IOException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
 				}
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			}
 		});
 	}
 
-	private void scheduleConnectionStatusUpdate() {
-		Future<?> newConnectivityCheck =
-				scheduler.schedule(this::updateConnectionStatus, 1, MINUTES);
-		Future<?> oldConnectivityCheck =
-				connectivityCheck.getAndSet(newConnectivityCheck);
-		if (oldConnectivityCheck != null) oldConnectivityCheck.cancel(false);
-	}
-
 	private class NetworkStateReceiver extends BroadcastReceiver {
 
 		@Override
 		public void onReceive(Context ctx, Intent i) {
 			if (!running) return;
-			String action = i.getAction();
+			if (CONNECTIVITY_ACTION.equals(i.getAction())) {
-			if (LOG.isLoggable(INFO)) LOG.info("Received broadcast " + action);
+				LOG.info("Detected connectivity change");
-			updateConnectionStatus();
+				updateConnectionStatus();
-			if (ACTION_SCREEN_ON.equals(action)
-					|| ACTION_SCREEN_OFF.equals(action)) {
-				scheduleConnectionStatusUpdate();
 			}
 		}
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPluginFactory.java

@@ -17,7 +17,6 @@ import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.util.AndroidUtils;
 
 import java.util.concurrent.Executor;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.Immutable;
@@ -37,7 +36,6 @@ public class TorPluginFactory implements DuplexPluginFactory {
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
-	private final ScheduledExecutorService scheduler;
 	private final Context appContext;
 	private final LocationUtils locationUtils;
 	private final DevReporter reporter;
@@ -45,13 +43,11 @@ public class TorPluginFactory implements DuplexPluginFactory {
 	private final SocketFactory torSocketFactory;
 	private final BackoffFactory backoffFactory;
 
-	public TorPluginFactory(Executor ioExecutor,
+	public TorPluginFactory(Executor ioExecutor, Context appContext,
-			ScheduledExecutorService scheduler, Context appContext,
 			LocationUtils locationUtils, DevReporter reporter,
 			EventBus eventBus, SocketFactory torSocketFactory,
 			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
-		this.scheduler = scheduler;
 		this.appContext = appContext;
 		this.locationUtils = locationUtils;
 		this.reporter = reporter;
@@ -93,9 +89,9 @@ public class TorPluginFactory implements DuplexPluginFactory {
 
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		TorPlugin plugin = new TorPlugin(ioExecutor, scheduler, appContext,
+		TorPlugin plugin = new TorPlugin(ioExecutor, appContext, locationUtils,
-				locationUtils, reporter, torSocketFactory, backoff, callback,
+				reporter, torSocketFactory, backoff, callback, architecture,
-				architecture, MAX_LATENCY, MAX_IDLE_TIME);
+				MAX_LATENCY, MAX_IDLE_TIME);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidExecutorImpl.java

@@ -27,11 +27,14 @@ class AndroidExecutorImpl implements AndroidExecutor {
 	@Inject
 	AndroidExecutorImpl(Application app) {
 		uiHandler = new Handler(app.getApplicationContext().getMainLooper());
-		loop = () -> {
+		loop = new Runnable() {
-			Looper.prepare();
+			@Override
-			backgroundHandler = new Handler();
+			public void run() {
-			startLatch.countDown();
+				Looper.prepare();
-			Looper.loop();
+				backgroundHandler = new Handler();
+				startLatch.countDown();
+				Looper.loop();
+			}
 		};
 	}
 

bramble-api/build.gradle

@@ -1,39 +1,30 @@
-apply plugin: 'java-library'
+apply plugin: 'java'
-sourceCompatibility = 1.8
+sourceCompatibility = 1.6
-targetCompatibility = 1.8
+targetCompatibility = 1.6
 
 apply plugin: 'witness'
 
 dependencies {
-	implementation "com.google.dagger:dagger:2.0.2"
+	compile "com.google.dagger:dagger:2.0.2"
-	implementation 'com.google.code.findbugs:jsr305:3.0.2'
+	compile 'com.google.dagger:dagger-compiler:2.0.2'
+	compile 'com.google.code.findbugs:jsr305:3.0.2'
 
-	testImplementation 'junit:junit:4.12'
+	testCompile 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
+	testCompile "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testCompile "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testCompile "org.jmock:jmock-legacy:2.8.2"
-	testImplementation "org.hamcrest:hamcrest-library:1.3"
+	testCompile "org.hamcrest:hamcrest-library:1.3"
-	testImplementation "org.hamcrest:hamcrest-core:1.3"
+	testCompile "org.hamcrest:hamcrest-core:1.3"
 }
 
 dependencyVerification {
 	verify = [
-			'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+			'com.google.dagger:dagger:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.google.dagger:dagger-compiler:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
-			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+			'com.google.code.findbugs:jsr305:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
+			'javax.inject:javax.inject:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-			'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+			'com.google.dagger:dagger-producers:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
-			'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
+			'com.google.guava:guava:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
-			'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
-			'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
-			'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-			'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-			'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-			'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-			'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-			'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-			'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
-			'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
 	]
 }
 
@@ -48,8 +39,3 @@ task jarTest(type: Jar, dependsOn: testClasses) {
 artifacts {
 	testOutput jarTest
 }
-
-// If a Java 6 JRE is available, check we're not using any Java 7 or 8 APIs
-tasks.withType(JavaCompile) {
-	useJava6StandardLibrary(it)
-}

bramble-api/src/main/java/org/briarproject/bramble/api/client/BdfMessageContext.java

@@ -23,7 +23,7 @@ public class BdfMessageContext {
 	}
 
 	public BdfMessageContext(BdfDictionary dictionary) {
-		this(dictionary, Collections.emptyList());
+		this(dictionary, Collections.<MessageId>emptyList());
 	}
 
 	public BdfDictionary getDictionary() {

bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java

@@ -4,14 +4,11 @@ import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.api.FormatException;
 
 import java.util.Map;
-import java.util.Map.Entry;
+import java.util.concurrent.ConcurrentSkipListMap;
-import java.util.TreeMap;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.NotThreadSafe;
 
-@NotThreadSafe
+public class BdfDictionary extends ConcurrentSkipListMap<String, Object> {
-public class BdfDictionary extends TreeMap<String, Object> {
 
 	public static final Object NULL_VALUE = new Object();
 

bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfList.java

@@ -3,17 +3,15 @@ package org.briarproject.bramble.api.data;
 import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.api.FormatException;
 
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Vector;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.NotThreadSafe;
 
 import static org.briarproject.bramble.api.data.BdfDictionary.NULL_VALUE;
 
-@NotThreadSafe
+public class BdfList extends Vector<Object> {
-public class BdfList extends ArrayList<Object> {
 
 	/**
 	 * Factory method for constructing lists inline.

bramble-api/src/main/java/org/briarproject/bramble/api/db/DataTooNewException.java

@@ -1,7 +0,0 @@
-package org.briarproject.bramble.api.db;
-
-/**
- * Thrown when the database uses a newer schema than the current code.
- */
-public class DataTooNewException extends DbException {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/db/DataTooOldException.java

@@ -1,8 +0,0 @@
-package org.briarproject.bramble.api.db;
-
-/**
- * Thrown when the database uses an older schema than the current code and
- * cannot be migrated.
- */
-public class DataTooOldException extends DbException {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java

@@ -37,13 +37,8 @@ public interface DatabaseComponent {
 
 	/**
 	 * Opens the database and returns true if the database already existed.
-	 *
-	 * @throws DataTooNewException if the data uses a newer schema than the
-	 * current code
-	 * @throws DataTooOldException if the data uses an older schema than the
-	 * current code and cannot be migrated
 	 */
-	boolean open(@Nullable MigrationListener listener) throws DbException;
+	boolean open() throws DbException;
 
 	/**
 	 * Waits for any open transactions to finish and closes the database.
@@ -127,9 +122,8 @@ public interface DatabaseComponent {
 			throws DbException;
 
 	/**
-	 * Deletes the message with the given ID. Unlike
+	 * Deletes the message with the given ID. The message ID and any other
-	 * {@link #removeMessage(Transaction, MessageId)}, the message ID and any
+	 * associated data are not deleted.
-	 * other associated data are not deleted.
 	 */
 	void deleteMessage(Transaction txn, MessageId m) throws DbException;
 
@@ -259,30 +253,31 @@ public interface DatabaseComponent {
 	Collection<LocalAuthor> getLocalAuthors(Transaction txn) throws DbException;
 
 	/**
-	 * Returns the IDs of any messages that need to be validated.
+	 * Returns the IDs of any messages that need to be validated by the given
+	 * client.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToValidate(Transaction txn)
+	Collection<MessageId> getMessagesToValidate(Transaction txn, ClientId c)
 			throws DbException;
 
 	/**
-	 * Returns the IDs of any messages that are pending delivery due to
+	 * Returns the IDs of any messages that are valid but pending delivery due
-	 * dependencies on other messages.
+	 * to dependencies on other messages for the given client.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getPendingMessages(Transaction txn)
+	Collection<MessageId> getPendingMessages(Transaction txn, ClientId c)
 			throws DbException;
 
 	/**
-	 * Returns the IDs of any messages that have shared dependents but have
+	 * Returns the IDs of any messages from the given client
-	 * not yet been shared themselves.
+	 * that have a shared dependent, but are still not shared themselves.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToShare(Transaction txn)
+	Collection<MessageId> getMessagesToShare(Transaction txn,
-			throws DbException;
+			ClientId c) throws DbException;
 
 	/**
 	 * Returns the message with the given ID, in serialised form, or null if
@@ -377,16 +372,6 @@ public interface DatabaseComponent {
 	MessageStatus getMessageStatus(Transaction txn, ContactId c, MessageId m)
 			throws DbException;
 
-	/*
-	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be sent to the given contact. The returned value may
-	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE if
-	 * no messages are scheduled to be sent.
-	 * <p/>
-	 * Read-only.
-	 */
-	long getNextSendTime(Transaction txn, ContactId c) throws DbException;
-
 	/**
 	 * Returns all settings in the given namespace.
 	 * <p/>
@@ -467,11 +452,6 @@ public interface DatabaseComponent {
 	 */
 	void removeLocalAuthor(Transaction txn, AuthorId a) throws DbException;
 
-	/**
-	 * Removes a message (and all associated state) from the database.
-	 */
-	void removeMessage(Transaction txn, MessageId m) throws DbException;
-
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/db/Metadata.java

@@ -1,11 +1,11 @@
 package org.briarproject.bramble.api.db;
 
-import java.util.TreeMap;
+import java.util.Hashtable;
 
-import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
-@NotThreadSafe
+@ThreadSafe
-public class Metadata extends TreeMap<String, byte[]> {
+public class Metadata extends Hashtable<String, byte[]> {
 
 	/**
 	 * Special value to indicate that a key is being removed.

bramble-api/src/main/java/org/briarproject/bramble/api/db/MigrationListener.java

@@ -1,11 +0,0 @@
-package org.briarproject.bramble.api.db;
-
-public interface MigrationListener {
-
-	/**
-	 * This is called when a migration is started while opening the database.
-	 * It will be called once for each migration being applied.
-	 */
-	void onMigrationRun();
-
-}

bramble-api/src/main/java/org/briarproject/bramble/api/db/Transaction.java

@@ -45,7 +45,7 @@ public class Transaction {
 	 * committed.
 	 */
 	public void attach(Event e) {
-		if (events == null) events = new ArrayList<>();
+		if (events == null) events = new ArrayList<Event>();
 		events.add(e);
 	}
 

bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementListener.java

@@ -2,7 +2,7 @@ package org.briarproject.bramble.api.keyagreement;
 
 import org.briarproject.bramble.api.data.BdfList;
 
-import java.io.IOException;
+import java.util.concurrent.Callable;
 
 /**
  * An class for managing a particular key agreement listener.
@@ -24,11 +24,11 @@ public abstract class KeyAgreementListener {
 	}
 
 	/**
-	 * Blocks until an incoming connection is received and returns it.
+	 * Starts listening for incoming connections, and returns a Callable that
-	 *
+	 * will return a KeyAgreementConnection when an incoming connection is
-	 * @throws IOException if an error occurs or {@link #close()} is called.
+	 * received.
 	 */
-	public abstract KeyAgreementConnection accept() throws IOException;
+	public abstract Callable<KeyAgreementConnection> listen();
 
 	/**
 	 * Closes the underlying server socket.

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/LifecycleManager.java

@@ -21,25 +21,7 @@ public interface LifecycleManager {
 	 * The result of calling {@link #startServices(String)}.
 	 */
 	enum StartResult {
-		ALREADY_RUNNING,
+		ALREADY_RUNNING, DB_ERROR, SERVICE_ERROR, SUCCESS
-		DB_ERROR,
-		DATA_TOO_OLD_ERROR,
-		DATA_TOO_NEW_ERROR,
-		SERVICE_ERROR,
-		SUCCESS
-	}
-
-	/**
-	 * The state the lifecycle can be in.
-	 * Returned by {@link #getLifecycleState()}
-	 */
-	enum LifecycleState {
-
-		STARTING, MIGRATING_DATABASE, STARTING_SERVICES, RUNNING, STOPPING;
-
-		public boolean isAfter(LifecycleState state) {
-			return ordinal() > state.ordinal();
-		}
 	}
 
 	/**
@@ -89,10 +71,4 @@ public interface LifecycleManager {
 	 * the {@link DatabaseComponent} to be closed before returning.
 	 */
 	void waitForShutdown() throws InterruptedException;
-
-	/**
-	 * Returns the current state of the lifecycle.
-	 */
-	LifecycleState getLifecycleState();
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/event/LifecycleEvent.java

@@ -1,20 +0,0 @@
-package org.briarproject.bramble.api.lifecycle.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState;
-
-/**
- * An event that is broadcast when the app enters a new lifecycle state.
- */
-public class LifecycleEvent extends Event {
-
-	private final LifecycleState state;
-
-	public LifecycleEvent(LifecycleState state) {
-		this.state = state;
-	}
-
-	public LifecycleState getLifecycleState() {
-		return state;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/event/ShutdownEvent.java

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.lifecycle.event;
+
+import org.briarproject.bramble.api.event.Event;
+
+/**
+ * An event that is broadcast when the app is shutting down.
+ */
+public class ShutdownEvent extends Event {
+}

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

@@ -0,0 +1,6 @@
+package org.briarproject.bramble.api.plugin;
+
+public enum BluetoothEnableDisableReason {
+	COMMUNICATION,
+	ADD_CONTACT
+}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPlugin.java

@@ -36,9 +36,9 @@ public interface DuplexPlugin extends Plugin {
 
 	/**
 	 * Attempts to connect to the remote peer specified in the given descriptor.
-	 * Returns null if no connection can be established.
+	 * Returns null if no connection can be established within the given time.
 	 */
 	@Nullable
 	DuplexTransportConnection createKeyAgreementConnection(
-			byte[] remoteCommitment, BdfList descriptor);
+			byte[] remoteCommitment, BdfList descriptor, long timeout);
 }

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

@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.plugin.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that informs the Bluetooth plugin that we have enabled the
- * Bluetooth adapter.
- */
-@Immutable
-@NotNullByDefault
-public class BluetoothEnabledEvent extends Event {
-}

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

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.api.plugin.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.plugin.BluetoothEnableDisableReason;
+
+abstract class BluetoothEvent extends Event {
+	private BluetoothEnableDisableReason selectedReason;
+
+	BluetoothEvent(BluetoothEnableDisableReason reason){
+		selectedReason = reason;
+	}
+
+	public BluetoothEnableDisableReason getReason(){
+		return selectedReason;
+	}
+}

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

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.api.plugin.event;
 
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.BluetoothEnableDisableReason;
 
 import javax.annotation.concurrent.Immutable;
 
@@ -11,5 +11,8 @@ import javax.annotation.concurrent.Immutable;
  */
 @Immutable
 @NotNullByDefault
-public class DisableBluetoothEvent extends Event {
+public class DisableBluetoothEvent extends BluetoothEvent {
+	public DisableBluetoothEvent(BluetoothEnableDisableReason reason) {
+		super(reason);
+	}
 }

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

@@ -2,13 +2,17 @@ package org.briarproject.bramble.api.plugin.event;
 
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.BluetoothEnableDisableReason;
 
 import javax.annotation.concurrent.Immutable;
 
 /**
- * An event that asks the Bluetooth plugin to enable the Bluetooth adapter.
+ * An event asks the Bluetooth plugin to enable the Bluetooth adapter.
  */
 @Immutable
 @NotNullByDefault
-public class EnableBluetoothEvent extends Event {
+public class EnableBluetoothEvent extends BluetoothEvent {
+	public EnableBluetoothEvent(BluetoothEnableDisableReason reason){
+		super(reason);
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyManager.java

@@ -33,7 +33,7 @@ public interface TransportPropertyManager {
 	/**
 	 * Returns the local transport properties for all transports.
 	 * <br/>
-	 * TODO: Transaction can be read-only when code is simplified
+	 * Read-Only
 	 */
 	Map<TransportId, TransportProperties> getLocalProperties(Transaction txn)
 			throws DbException;

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

@@ -22,7 +22,7 @@ public class MessageContext {
 	}
 
 	public MessageContext(Metadata metadata) {
-		this(metadata, Collections.emptyList());
+		this(metadata, Collections.<MessageId>emptyList());
 	}
 
 	public Metadata getMetadata() {

bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java

@@ -126,10 +126,6 @@ public class StringUtils {
 		return toUtf8(s).length > maxLength;
 	}
 
-	public static boolean isValidMac(String mac) {
-		return MAC.matcher(mac).matches();
-	}
-
 	public static byte[] macToBytes(String mac) {
 		if (!MAC.matcher(mac).matches()) throw new IllegalArgumentException();
 		return fromHexString(mac.replaceAll(":", ""));

bramble-api/src/test/java/org/briarproject/bramble/test/BrambleMockTestCase.java

@@ -3,7 +3,8 @@ package org.briarproject.bramble.test;
 import org.jmock.Mockery;
 import org.junit.After;
 
-public abstract class BrambleMockTestCase extends BrambleTestCase {
+public abstract class BrambleMockTestCase extends
+		BrambleTestCase {
 
 	protected final Mockery context = new Mockery();
 

bramble-api/src/test/java/org/briarproject/bramble/test/BrambleTestCase.java

@@ -8,9 +8,12 @@ public abstract class BrambleTestCase {
 
 	public BrambleTestCase() {
 		// Ensure exceptions thrown on worker threads cause tests to fail
-		UncaughtExceptionHandler fail = (thread, throwable) -> {
+		UncaughtExceptionHandler fail = new UncaughtExceptionHandler() {
-			throwable.printStackTrace();
+			@Override
-			fail();
+			public void uncaughtException(Thread thread, Throwable throwable) {
+				throwable.printStackTrace();
+				fail();
+			}
 		};
 		Thread.setDefaultUncaughtExceptionHandler(fail);
 	}

bramble-api/src/test/java/org/briarproject/bramble/test/TestUtils.java

@@ -2,27 +2,12 @@ package org.briarproject.bramble.test;
 
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorId;
-import org.briarproject.bramble.api.identity.LocalAuthor;
-import org.briarproject.bramble.api.sync.ClientId;
-import org.briarproject.bramble.api.sync.Group;
-import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.Message;
-import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.util.IoUtils;
 
 import java.io.File;
 import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
-import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
-import static org.briarproject.bramble.util.StringUtils.getRandomString;
-
 public class TestUtils {
 
 	private static final AtomicInteger nextTestDir =
@@ -53,50 +38,4 @@ public class TestUtils {
 		return new SecretKey(getRandomBytes(SecretKey.LENGTH));
 	}
 
-	public static LocalAuthor getLocalAuthor() {
-		return getLocalAuthor(1 + random.nextInt(MAX_AUTHOR_NAME_LENGTH));
-	}
-
-	public static LocalAuthor getLocalAuthor(int nameLength) {
-		AuthorId id = new AuthorId(getRandomId());
-		String name = getRandomString(nameLength);
-		byte[] publicKey = getRandomBytes(MAX_PUBLIC_KEY_LENGTH);
-		byte[] privateKey = getRandomBytes(MAX_PUBLIC_KEY_LENGTH);
-		long created = System.currentTimeMillis();
-		return new LocalAuthor(id, name, publicKey, privateKey, created);
-	}
-
-	public static Author getAuthor() {
-		return getAuthor(1 + random.nextInt(MAX_AUTHOR_NAME_LENGTH));
-	}
-
-	public static Author getAuthor(int nameLength) {
-		AuthorId id = new AuthorId(getRandomId());
-		String name = getRandomString(nameLength);
-		byte[] publicKey = getRandomBytes(MAX_PUBLIC_KEY_LENGTH);
-		return new Author(id, name, publicKey);
-	}
-
-	public static Group getGroup(ClientId clientId) {
-		int descriptorLength = 1 + random.nextInt(MAX_GROUP_DESCRIPTOR_LENGTH);
-		return getGroup(clientId, descriptorLength);
-	}
-
-	public static Group getGroup(ClientId clientId, int descriptorLength) {
-		GroupId groupId = new GroupId(getRandomId());
-		byte[] descriptor = getRandomBytes(descriptorLength);
-		return new Group(groupId, clientId, descriptor);
-	}
-
-	public static Message getMessage(GroupId groupId) {
-		int bodyLength = 1 + random.nextInt(MAX_MESSAGE_BODY_LENGTH);
-		return getMessage(groupId, MESSAGE_HEADER_LENGTH + bodyLength);
-	}
-
-	public static Message getMessage(GroupId groupId, int rawLength) {
-		MessageId id = new MessageId(getRandomId());
-		byte[] raw = getRandomBytes(rawLength);
-		long timestamp = System.currentTimeMillis();
-		return new Message(id, groupId, timestamp, raw);
-	}
 }

bramble-core/build.gradle

@@ -1,54 +1,28 @@
-apply plugin: 'java-library'
+plugins {
-sourceCompatibility = 1.8
+	id 'java'
-targetCompatibility = 1.8
+	id 'net.ltgt.apt' version '0.9'
+	id 'idea'
+}
+
+sourceCompatibility = 1.6
+targetCompatibility = 1.6
 
-apply plugin: 'net.ltgt.apt'
-apply plugin: 'idea'
 apply plugin: 'witness'
 
 dependencies {
-	implementation project(path: ':bramble-api', configuration: 'default')
+	compile project(path: ':bramble-api', configuration: 'default')
-	implementation 'com.madgag.spongycastle:core:1.58.0.0'
+	compile 'com.madgag.spongycastle:core:1.58.0.0'
-	implementation 'com.h2database:h2:1.4.192' // This is the last version that supports Java 1.6
+	compile 'com.h2database:h2:1.4.192' // This is the last version that supports Java 1.6
-	implementation 'org.bitlet:weupnp:0.1.4'
+	compile 'org.bitlet:weupnp:0.1.4'
 
-	apt 'com.google.dagger:dagger-compiler:2.0.2'
+	testCompile project(path: ':bramble-api', configuration: 'testOutput')
-
-	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
-	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
-	testImplementation "org.hamcrest:hamcrest-library:1.3"
-	testImplementation "org.hamcrest:hamcrest-core:1.3"
-
-	testApt 'com.google.dagger:dagger-compiler:2.0.2'
 }
 
 dependencyVerification {
 	verify = [
-			'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+			'com.madgag.spongycastle:core:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.h2database:h2:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-			'com.google.dagger:dagger-compiler:2.0.2:dagger-compiler-2.0.2.jar:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
+			'org.bitlet:weupnp:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
-			'com.google.dagger:dagger-producers:2.0-beta:dagger-producers-2.0-beta.jar:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
-			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
-			'com.google.guava:guava:18.0:guava-18.0.jar:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
-			'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-			'com.madgag.spongycastle:core:1.58.0.0:core-1.58.0.0.jar:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
-			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-			'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
-			'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
-			'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
-			'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
-			'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
-			'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-			'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-			'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-			'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-			'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-			'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-			'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
-			'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
 	]
 }
 
@@ -63,8 +37,3 @@ task jarTest(type: Jar, dependsOn: testClasses) {
 artifacts {
 	testOutput jarTest
 }
-
-// If a Java 6 JRE is available, check we're not using any Java 7 or 8 APIs
-tasks.withType(JavaCompile) {
-	useJava6StandardLibrary(it)
-}

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

@@ -24,7 +24,7 @@ public class PoliteExecutor implements Executor {
 
 	private final Object lock = new Object();
 	@GuardedBy("lock")
-	private final Queue<Runnable> queue = new LinkedList<>();
+	private final Queue<Runnable> queue = new LinkedList<Runnable>();
 	private final Executor delegate;
 	private final int maxConcurrentTasks;
 	private final Logger log;
@@ -48,17 +48,20 @@ public class PoliteExecutor implements Executor {
 	}
 
 	@Override
-	public void execute(Runnable r) {
+	public void execute(final Runnable r) {
-		long submitted = System.currentTimeMillis();
+		final long submitted = System.currentTimeMillis();
-		Runnable wrapped = () -> {
+		Runnable wrapped = new Runnable() {
-			if (log.isLoggable(LOG_LEVEL)) {
+			@Override
-				long queued = System.currentTimeMillis() - submitted;
+			public void run() {
-				log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+				if (log.isLoggable(LOG_LEVEL)) {
-			}
+					long queued = System.currentTimeMillis() - submitted;
-			try {
+					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
-				r.run();
+				}
-			} finally {
+				try {
-				scheduleNext();
+					r.run();
+				} finally {
+					scheduleNext();
+				}
 			}
 		};
 		synchronized (lock) {

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

@@ -28,16 +28,19 @@ public class TimeLoggingExecutor extends ThreadPoolExecutor {
 	}
 
 	@Override
-	public void execute(Runnable r) {
+	public void execute(final Runnable r) {
 		if (log.isLoggable(LOG_LEVEL)) {
-			long submitted = System.currentTimeMillis();
+			final long submitted = System.currentTimeMillis();
-			super.execute(() -> {
+			super.execute(new Runnable() {
-				long started = System.currentTimeMillis();
+				@Override
-				long queued = started - submitted;
+				public void run() {
-				log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+					long started = System.currentTimeMillis();
-				r.run();
+					long queued = started - submitted;
-				long executing = System.currentTimeMillis() - started;
+					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
-				log.log(LOG_LEVEL, "Execution time " + executing + " ms");
+					r.run();
+					long executing = System.currentTimeMillis() - started;
+					log.log(LOG_LEVEL, "Execution time " + executing + " ms");
+				}
 			});
 		} else {
 			super.execute(r);

bramble-core/src/main/java/org/briarproject/bramble/client/ClientHelperImpl.java

@@ -201,7 +201,8 @@ class ClientHelperImpl implements ClientHelper {
 	public Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(
 			Transaction txn, GroupId g) throws DbException, FormatException {
 		Map<MessageId, Metadata> raw = db.getMessageMetadata(txn, g);
-		Map<MessageId, BdfDictionary> parsed = new HashMap<>(raw.size());
+		Map<MessageId, BdfDictionary> parsed =
+				new HashMap<MessageId, BdfDictionary>(raw.size());
 		for (Entry<MessageId, Metadata> e : raw.entrySet())
 			parsed.put(e.getKey(), metadataParser.parse(e.getValue()));
 		return parsed;
@@ -228,7 +229,8 @@ class ClientHelperImpl implements ClientHelper {
 			FormatException {
 		Metadata metadata = metadataEncoder.encode(query);
 		Map<MessageId, Metadata> raw = db.getMessageMetadata(txn, g, metadata);
-		Map<MessageId, BdfDictionary> parsed = new HashMap<>(raw.size());
+		Map<MessageId, BdfDictionary> parsed =
+				new HashMap<MessageId, BdfDictionary>(raw.size());
 		for (Entry<MessageId, Metadata> e : raw.entrySet())
 			parsed.put(e.getKey(), metadataParser.parse(e.getValue()));
 		return parsed;

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactExchangeTaskImpl.java

@@ -184,7 +184,12 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			// Close the outgoing stream and expect EOF on the incoming stream
 			w.close();
 			if (!r.eof()) LOG.warning("Unexpected data at end of connection");
-		} catch (GeneralSecurityException | IOException e) {
+		} catch (GeneralSecurityException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			listener.contactExchangeFailed();
+			tryToClose(conn, true);
+			return;
+		} catch (IOException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			listener.contactExchangeFailed();
 			tryToClose(conn, true);
@@ -271,7 +276,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 
 	private Map<TransportId, TransportProperties> receiveTransportProperties(
 			BdfReader r) throws IOException {
-		Map<TransportId, TransportProperties> remote = new HashMap<>();
+		Map<TransportId, TransportProperties> remote =
+				new HashMap<TransportId, TransportProperties>();
 		r.readListStart();
 		while (!r.hasListEnd()) {
 			r.readListStart();

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactManagerImpl.java

@@ -34,8 +34,8 @@ class ContactManagerImpl implements ContactManager {
 	ContactManagerImpl(DatabaseComponent db, KeyManager keyManager) {
 		this.db = db;
 		this.keyManager = keyManager;
-		addHooks = new CopyOnWriteArrayList<>();
+		addHooks = new CopyOnWriteArrayList<AddContactHook>();
-		removeHooks = new CopyOnWriteArrayList<>();
+		removeHooks = new CopyOnWriteArrayList<RemoveContactHook>();
 	}
 
 	@Override
@@ -125,7 +125,7 @@ class ContactManagerImpl implements ContactManager {
 		} finally {
 			db.endTransaction(txn);
 		}
-		List<Contact> active = new ArrayList<>(contacts.size());
+		List<Contact> active = new ArrayList<Contact>(contacts.size());
 		for (Contact c : contacts) if (c.isActive()) active.add(c);
 		return active;
 	}

bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoComponentImpl.java

@@ -602,8 +602,8 @@ class CryptoComponentImpl implements CryptoComponent {
 
 	// Package access for testing
 	int chooseIterationCount(int targetMillis) {
-		List<Long> quickSamples = new ArrayList<>(PBKDF_SAMPLES);
+		List<Long> quickSamples = new ArrayList<Long>(PBKDF_SAMPLES);
-		List<Long> slowSamples = new ArrayList<>(PBKDF_SAMPLES);
+		List<Long> slowSamples = new ArrayList<Long>(PBKDF_SAMPLES);
 		long iterationNanos = 0, initNanos = 0;
 		while (iterationNanos <= 0 || initNanos <= 0) {
 			// Sample the running time with one iteration and two iterations

bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoModule.java

@@ -48,7 +48,7 @@ public class CryptoModule {
 
 	public CryptoModule() {
 		// Use an unbounded queue
-		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<>();
+		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<Runnable>();
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();

bramble-core/src/main/java/org/briarproject/bramble/crypto/PasswordStrengthEstimatorImpl.java

@@ -16,7 +16,7 @@ class PasswordStrengthEstimatorImpl implements PasswordStrengthEstimator {
 
 	@Override
 	public float estimateStrength(String password) {
-		HashSet<Character> unique = new HashSet<>();
+		HashSet<Character> unique = new HashSet<Character>();
 		int length = password.length();
 		for (int i = 0; i < length; i++) unique.add(password.charAt(i));
 		return Math.min(1, (float) unique.size() / STRONG_UNIQUE_CHARS);

bramble-core/src/main/java/org/briarproject/bramble/db/Database.java

@@ -2,11 +2,8 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DataTooNewException;
-import org.briarproject.bramble.api.db.DataTooOldException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
-import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -40,13 +37,8 @@ interface Database<T> {
 
 	/**
 	 * Opens the database and returns true if the database already existed.
-	 *
-	 * @throws DataTooNewException if the data uses a newer schema than the
-	 * current code
-	 * @throws DataTooOldException if the data uses an older schema than the
-	 * current code and cannot be migrated
 	 */
-	boolean open(@Nullable MigrationListener listener) throws DbException;
+	boolean open() throws DbException;
 
 	/**
 	 * Prevents new transactions from starting, waits for all current
@@ -97,12 +89,9 @@ interface Database<T> {
 
 	/**
 	 * Stores a message.
-	 *
-	 * @param sender the contact from whom the message was received, or null
-	 * if the message was created locally.
 	 */
-	void addMessage(T txn, Message m, State state, boolean shared,
+	void addMessage(T txn, Message m, State state, boolean shared)
-			@Nullable ContactId sender) throws DbException;
+			throws DbException;
 
 	/**
 	 * Adds a dependency between two messages in the given group.
@@ -115,6 +104,16 @@ interface Database<T> {
 	 */
 	void addOfferedMessage(T txn, ContactId c, MessageId m) throws DbException;
 
+	/**
+	 * Initialises the status of the given message with respect to the given
+	 * contact.
+	 *
+	 * @param ack whether the message needs to be acknowledged.
+	 * @param seen whether the contact has seen the message.
+	 */
+	void addStatus(T txn, ContactId c, MessageId m, boolean ack, boolean seen)
+			throws DbException;
+
 	/**
 	 * Stores a transport.
 	 */
@@ -273,7 +272,7 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	Map<ContactId, Boolean> getGroupVisibility(T txn, GroupId g)
+	Collection<ContactId> getGroupVisibility(T txn, GroupId g)
 			throws DbException;
 
 	/**
@@ -424,37 +423,31 @@ interface Database<T> {
 			throws DbException;
 
 	/**
-	 * Returns the IDs of any messages that need to be validated.
+	 * Returns the IDs of any messages that need to be validated by the given
+	 * client.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToValidate(T txn) throws DbException;
+	Collection<MessageId> getMessagesToValidate(T txn, ClientId c)
+			throws DbException;
 
 	/**
-	 * Returns the IDs of any messages that are pending delivery due to
+	 * Returns the IDs of any messages that are still pending due to
-	 * dependencies on other messages.
+	 * dependencies to other messages for the given client.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getPendingMessages(T txn) throws DbException;
+	Collection<MessageId> getPendingMessages(T txn, ClientId c)
+			throws DbException;
 
 	/**
-	 * Returns the IDs of any messages that have a shared dependent but have
+	 * Returns the IDs of any messages from the given client
-	 * not yet been shared themselves.
+	 * that have a shared dependent, but are still not shared themselves.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToShare(T txn) throws DbException;
+	Collection<MessageId> getMessagesToShare(T txn, ClientId c)
-
+			throws DbException;
-	/**
-	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be sent to the given contact. The returned value may
-	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE
-	 * if no messages are scheduled to be sent.
-	 * <p/>
-	 * Read-only.
-	 */
-	long getNextSendTime(T txn, ContactId c) throws DbException;
 
 	/**
 	 * Returns the message with the given ID, in serialised form, or null if
@@ -573,6 +566,13 @@ interface Database<T> {
 	 */
 	void removeMessage(T txn, MessageId m) throws DbException;
 
+	/**
+	 * Removes an offered message that was offered by the given contact, or
+	 * returns false if there is no such message.
+	 */
+	boolean removeOfferedMessage(T txn, ContactId c, MessageId m)
+			throws DbException;
+
 	/**
 	 * Removes the given offered messages that were offered by the given
 	 * contact.
@@ -580,6 +580,12 @@ interface Database<T> {
 	void removeOfferedMessages(T txn, ContactId c,
 			Collection<MessageId> requested) throws DbException;
 
+	/**
+	 * Removes the status of the given message with respect to the given
+	 * contact.
+	 */
+	void removeStatus(T txn, ContactId c, MessageId m) throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -10,7 +10,6 @@ import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Metadata;
-import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.db.NoSuchContactException;
 import org.briarproject.bramble.api.db.NoSuchGroupException;
 import org.briarproject.bramble.api.db.NoSuchLocalAuthorException;
@@ -91,6 +90,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	private final ReentrantReadWriteLock lock =
 			new ReentrantReadWriteLock(true);
 
+	private volatile int shutdownHandle = -1;
+
 	@Inject
 	DatabaseComponentImpl(Database<T> db, Class<T> txnClass, EventBus eventBus,
 			ShutdownManager shutdown) {
@@ -101,22 +102,27 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public boolean open(@Nullable MigrationListener listener)
+	public boolean open() throws DbException {
-			throws DbException {
+		Runnable shutdownHook = new Runnable() {
-		boolean reopened = db.open(listener);
+			@Override
-		shutdown.addShutdownHook(() -> {
+			public void run() {
-			try {
+				try {
-				close();
+					close();
-			} catch (DbException e) {
+				} catch (DbException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+				}
 			}
-		});
+		};
+		boolean reopened = db.open();
+		shutdownHandle = shutdown.addShutdownHook(shutdownHook);
 		return reopened;
 	}
 
 	@Override
 	public void close() throws DbException {
 		if (closed.getAndSet(true)) return;
+		shutdown.removeShutdownHook(shutdownHandle);
 		db.close();
 	}
 
@@ -135,7 +141,11 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 		try {
 			return new Transaction(db.startTransaction(), readOnly);
-		} catch (DbException | RuntimeException e) {
+		} catch (DbException e) {
+			if (readOnly) lock.readLock().unlock();
+			else lock.writeLock().unlock();
+			throw e;
+		} catch (RuntimeException e) {
 			if (readOnly) lock.readLock().unlock();
 			else lock.writeLock().unlock();
 			throw e;
@@ -215,7 +225,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (!db.containsGroup(txn, m.getGroupId()))
 			throw new NoSuchGroupException();
 		if (!db.containsMessage(txn, m.getId())) {
-			db.addMessage(txn, m, DELIVERED, shared, null);
+			addMessage(txn, m, DELIVERED, shared, null);
 			transaction.attach(new MessageAddedEvent(m, null));
 			transaction.attach(new MessageStateChangedEvent(m.getId(), true,
 					DELIVERED));
@@ -224,6 +234,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.mergeMessageMetadata(txn, m.getId(), meta);
 	}
 
+	private void addMessage(T txn, Message m, State state, boolean shared,
+			@Nullable ContactId sender) throws DbException {
+		db.addMessage(txn, m, state, shared);
+		for (ContactId c : db.getGroupVisibility(txn, m.getGroupId())) {
+			boolean offered = db.removeOfferedMessage(txn, c, m.getId());
+			boolean seen = offered || (sender != null && c.equals(sender));
+			db.addStatus(txn, c, m.getId(), seen, seen);
+		}
+	}
+
 	@Override
 	public void addTransport(Transaction transaction, TransportId t,
 			int maxLatency) throws DbException {
@@ -311,7 +331,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
 		Collection<MessageId> ids = db.getMessagesToSend(txn, c, maxLength);
-		List<byte[]> messages = new ArrayList<>(ids.size());
+		List<byte[]> messages = new ArrayList<byte[]>(ids.size());
 		for (MessageId m : ids) {
 			messages.add(db.getRawMessage(txn, m));
 			db.updateExpiryTime(txn, c, m, maxLatency);
@@ -361,7 +381,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			throw new NoSuchContactException();
 		Collection<MessageId> ids = db.getRequestedMessagesToSend(txn, c,
 				maxLength);
-		List<byte[]> messages = new ArrayList<>(ids.size());
+		List<byte[]> messages = new ArrayList<byte[]>(ids.size());
 		for (MessageId m : ids) {
 			messages.add(db.getRawMessage(txn, m));
 			db.updateExpiryTime(txn, c, m, maxLatency);
@@ -455,24 +475,24 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public Collection<MessageId> getMessagesToValidate(Transaction transaction)
+	public Collection<MessageId> getMessagesToValidate(Transaction transaction,
-			throws DbException {
+			ClientId c) throws DbException {
 		T txn = unbox(transaction);
-		return db.getMessagesToValidate(txn);
+		return db.getMessagesToValidate(txn, c);
 	}
 
 	@Override
-	public Collection<MessageId> getPendingMessages(Transaction transaction)
+	public Collection<MessageId> getPendingMessages(Transaction transaction,
-			throws DbException {
+			ClientId c) throws DbException {
 		T txn = unbox(transaction);
-		return db.getPendingMessages(txn);
+		return db.getPendingMessages(txn, c);
 	}
 
 	@Override
-	public Collection<MessageId> getMessagesToShare(Transaction transaction)
+	public Collection<MessageId> getMessagesToShare(
-			throws DbException {
+			Transaction transaction, ClientId c) throws DbException {
 		T txn = unbox(transaction);
-		return db.getMessagesToShare(txn);
+		return db.getMessagesToShare(txn, c);
 	}
 
 	@Nullable
@@ -571,13 +591,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessageDependents(txn, m);
 	}
 
-	@Override
-	public long getNextSendTime(Transaction transaction, ContactId c)
-			throws DbException {
-		T txn = unbox(transaction);
-		return db.getNextSendTime(txn, c);
-	}
-
 	@Override
 	public Settings getSettings(Transaction transaction, String namespace)
 			throws DbException {
@@ -648,7 +661,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		Collection<MessageId> acked = new ArrayList<>();
+		Collection<MessageId> acked = new ArrayList<MessageId>();
 		for (MessageId m : a.getMessageIds()) {
 			if (db.containsVisibleMessage(txn, c, m)) {
 				db.raiseSeenFlag(txn, c, m);
@@ -672,7 +685,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.raiseSeenFlag(txn, c, m.getId());
 				db.raiseAckFlag(txn, c, m.getId());
 			} else {
-				db.addMessage(txn, m, UNKNOWN, false, c);
+				addMessage(txn, m, UNKNOWN, false, c);
 				transaction.attach(new MessageAddedEvent(m, c));
 			}
 			transaction.attach(new MessageToAckEvent(c));
@@ -740,8 +753,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		GroupId id = g.getId();
 		if (!db.containsGroup(txn, id))
 			throw new NoSuchGroupException();
-		Collection<ContactId> affected =
+		Collection<ContactId> affected = db.getGroupVisibility(txn, id);
-				db.getGroupVisibility(txn, id).keySet();
 		db.removeGroup(txn, id);
 		transaction.attach(new GroupRemovedEvent(g));
 		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
@@ -758,16 +770,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new LocalAuthorRemovedEvent(a));
 	}
 
-	@Override
-	public void removeMessage(Transaction transaction, MessageId m)
-			throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsMessage(txn, m))
-			throw new NoSuchMessageException();
-		db.removeMessage(txn, m);
-	}
-
 	@Override
 	public void removeTransport(Transaction transaction, TransportId t)
 			throws DbException {
@@ -811,9 +813,19 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			throw new NoSuchGroupException();
 		Visibility old = db.getGroupVisibility(txn, c, g);
 		if (old == v) return;
-		if (old == INVISIBLE) db.addGroupVisibility(txn, c, g, v == SHARED);
+		if (old == INVISIBLE) {
-		else if (v == INVISIBLE) db.removeGroupVisibility(txn, c, g);
+			db.addGroupVisibility(txn, c, g, v == SHARED);
-		else db.setGroupVisibility(txn, c, g, v == SHARED);
+			for (MessageId m : db.getMessageIds(txn, g)) {
+				boolean seen = db.removeOfferedMessage(txn, c, m);
+				db.addStatus(txn, c, m, seen, seen);
+			}
+		} else if (v == INVISIBLE) {
+			db.removeGroupVisibility(txn, c, g);
+			for (MessageId m : db.getMessageIds(txn, g))
+				db.removeStatus(txn, c, m);
+		} else {
+			db.setGroupVisibility(txn, c, g, v == SHARED);
+		}
 		List<ContactId> affected = Collections.singletonList(c);
 		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
@@ -874,7 +886,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			Map<ContactId, TransportKeys> keys) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		Map<ContactId, TransportKeys> filtered = new HashMap<>();
+		Map<ContactId, TransportKeys> filtered =
+				new HashMap<ContactId, TransportKeys>();
 		for (Entry<ContactId, TransportKeys> e : keys.entrySet()) {
 			ContactId c = e.getKey();
 			TransportKeys k = e.getValue();

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseConstants.java

@@ -23,4 +23,10 @@ interface DatabaseConstants {
 	 */
 	String SCHEMA_VERSION_KEY = "schemaVersion";
 
+	/**
+	 * The {@link Settings} key under which the minimum supported database
+	 * schema version is stored.
+	 */
+	String MIN_SCHEMA_VERSION_KEY = "minSchemaVersion";
+
 }

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseExecutorModule.java

@@ -32,7 +32,7 @@ public class DatabaseExecutorModule {
 
 	public DatabaseExecutorModule() {
 		// Use an unbounded queue
-		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<>();
+		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<Runnable>();
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java

@@ -26,7 +26,7 @@ public class DatabaseModule {
 	@Singleton
 	DatabaseComponent provideDatabaseComponent(Database<Connection> db,
 			EventBus eventBus, ShutdownManager shutdown) {
-		return new DatabaseComponentImpl<>(db, Connection.class, eventBus,
+		return new DatabaseComponentImpl<Connection>(db, Connection.class,
-				shutdown);
+				eventBus, shutdown);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.db;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
@@ -14,7 +13,6 @@ import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.util.Properties;
 
-import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 /**
@@ -42,11 +40,10 @@ class H2Database extends JdbcDatabase {
 	}
 
 	@Override
-	public boolean open(@Nullable MigrationListener listener)
+	public boolean open() throws DbException {
-			throws DbException {
 		boolean reopen = config.databaseExists();
 		if (!reopen) config.getDatabaseDirectory().mkdirs();
-		super.open("org.h2.Driver", reopen, listener);
+		super.open("org.h2.Driver", reopen);
 		return reopen;
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/db/Migration.java

@@ -1,18 +0,0 @@
-package org.briarproject.bramble.db;
-
-import org.briarproject.bramble.api.db.DbException;
-
-interface Migration<T> {
-
-	/**
-	 * Returns the schema version from which this migration starts.
-	 */
-	int getStartVersion();
-
-	/**
-	 * Returns the schema version at which this migration ends.
-	 */
-	int getEndVersion();
-
-	void migrate(T txn) throws DbException;
-}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration30_31.java

@@ -1,75 +0,0 @@
-package org.briarproject.bramble.db;
-
-import org.briarproject.bramble.api.db.DbException;
-
-import java.sql.Connection;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-
-class Migration30_31 implements Migration<Connection> {
-
-	private static final Logger LOG =
-			Logger.getLogger(Migration30_31.class.getName());
-
-	@Override
-	public int getStartVersion() {
-		return 30;
-	}
-
-	@Override
-	public int getEndVersion() {
-		return 31;
-	}
-
-	@Override
-	public void migrate(Connection txn) throws DbException {
-		Statement s = null;
-		try {
-			s = txn.createStatement();
-			// Add groupId column
-			s.execute("ALTER TABLE messageMetadata"
-					+ " ADD COLUMN groupId BINARY(32) AFTER messageId");
-			// Populate groupId column
-			s.execute("UPDATE messageMetadata AS mm SET groupId ="
-					+ " (SELECT groupId FROM messages AS m"
-					+ " WHERE mm.messageId = m.messageId)");
-			// Add not null constraint now column has been populated
-			s.execute("ALTER TABLE messageMetadata"
-					+ " ALTER COLUMN groupId"
-					+ " SET NOT NULL");
-			// Add foreign key constraint
-			s.execute("ALTER TABLE messageMetadata"
-					+ " ADD CONSTRAINT groupIdForeignKey"
-					+ " FOREIGN KEY (groupId)"
-					+ " REFERENCES groups (groupId)"
-					+ " ON DELETE CASCADE");
-			// Add state column
-			s.execute("ALTER TABLE messageMetadata"
-					+ " ADD COLUMN state INT AFTER groupId");
-			// Populate state column
-			s.execute("UPDATE messageMetadata AS mm SET state ="
-					+ " (SELECT state FROM messages AS m"
-					+ " WHERE mm.messageId = m.messageId)");
-			// Add not null constraint now column has been populated
-			s.execute("ALTER TABLE messageMetadata"
-					+ " ALTER COLUMN state"
-					+ " SET NOT NULL");
-		} catch (SQLException e) {
-			tryToClose(s);
-			throw new DbException(e);
-		}
-	}
-
-	private void tryToClose(@Nullable Statement s) {
-		try {
-			if (s != null) s.close();
-		} catch (SQLException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration31_32.java

@@ -1,84 +0,0 @@
-package org.briarproject.bramble.db;
-
-import org.briarproject.bramble.api.db.DbException;
-
-import java.sql.Connection;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-
-class Migration31_32 implements Migration<Connection> {
-
-	private static final Logger LOG =
-			Logger.getLogger(Migration31_32.class.getName());
-
-	@Override
-	public int getStartVersion() {
-		return 31;
-	}
-
-	@Override
-	public int getEndVersion() {
-		return 32;
-	}
-
-	@Override
-	public void migrate(Connection txn) throws DbException {
-		Statement s = null;
-		try {
-			s = txn.createStatement();
-			// Add denormalised columns
-			s.execute("ALTER TABLE statuses ADD COLUMN"
-					+ " (groupId BINARY(32),"
-					+ " timestamp BIGINT,"
-					+ " length INT,"
-					+ " state INT,"
-					+ " groupShared BOOLEAN,"
-					+ " messageShared BOOLEAN,"
-					+ " deleted BOOLEAN)");
-			// Populate columns from messages table
-			s.execute("UPDATE statuses AS s SET (groupId, timestamp, length,"
-					+ " state, messageShared, deleted) ="
-					+ " (SELECT groupId, timestamp, length, state, shared,"
-					+ " raw IS NULL FROM messages AS m"
-					+ " WHERE s.messageId = m.messageId)");
-			// Populate column from groupVisibilities table
-			s.execute("UPDATE statuses AS s SET groupShared ="
-					+ " (SELECT shared FROM groupVisibilities AS gv"
-					+ " WHERE s.contactId = gv.contactId"
-					+ " AND s.groupId = gv.groupId)");
-			// Add not null constraints now columns have been populated
-			s.execute("ALTER TABLE statuses ALTER COLUMN groupId SET NOT NULL");
-			s.execute("ALTER TABLE statuses ALTER COLUMN timestamp"
-					+ " SET NOT NULL");
-			s.execute("ALTER TABLE statuses ALTER COLUMN length SET NOT NULL");
-			s.execute("ALTER TABLE statuses ALTER COLUMN state SET NOT NULL");
-			s.execute("ALTER TABLE statuses ALTER COLUMN groupShared"
-					+ " SET NOT NULL");
-			s.execute("ALTER TABLE statuses ALTER COLUMN messageShared"
-					+ " SET NOT NULL");
-			s.execute("ALTER TABLE statuses ALTER COLUMN deleted SET NOT NULL");
-			// Add foreign key constraint
-			s.execute("ALTER TABLE statuses"
-					+ " ADD CONSTRAINT statusesForeignKeyGroupId"
-					+ " FOREIGN KEY (groupId)"
-					+ " REFERENCES groups (groupId)"
-					+ " ON DELETE CASCADE");
-		} catch (SQLException e) {
-			tryToClose(s);
-			throw new DbException(e);
-		}
-	}
-
-	private void tryToClose(@Nullable Statement s) {
-		try {
-			if (s != null) s.close();
-		} catch (SQLException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/event/EventBusImpl.java

@@ -15,7 +15,7 @@ import javax.annotation.concurrent.ThreadSafe;
 class EventBusImpl implements EventBus {
 
 	private final Collection<EventListener> listeners =
-			new CopyOnWriteArrayList<>();
+			new CopyOnWriteArrayList<EventListener>();
 
 	@Override
 	public void addListener(EventListener l) {

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/ConnectionChooser.java

@@ -1,36 +0,0 @@
-package org.briarproject.bramble.keyagreement;
-
-import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
-
-import java.util.concurrent.Callable;
-
-import javax.annotation.Nullable;
-
-interface ConnectionChooser {
-
-	/**
-	 * Submits a connection task to the chooser.
-	 */
-	void submit(Callable<KeyAgreementConnection> task);
-
-	/**
-	 * Returns a connection returned by any of the tasks submitted to the
-	 * chooser, waiting up to the given amount of time for a connection if
-	 * necessary. Returns null if the time elapses without a connection
-	 * becoming available.
-	 *
-	 * @param timeout the timeout in milliseconds
-	 * @throws InterruptedException if the thread is interrupted while waiting
-	 * for a connection to become available
-	 */
-	@Nullable
-	KeyAgreementConnection poll(long timeout) throws InterruptedException;
-
-	/**
-	 * Stops the chooser. Any connections already returned to the chooser are
-	 * closed unless they have been removed from the chooser by calling
-	 * {@link #poll(long)}. Any connections subsequently returned to the
-	 * chooser will also be closed.
-	 */
-	void stop();
-}

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/ConnectionChooserImpl.java

@@ -1,112 +0,0 @@
-package org.briarproject.bramble.keyagreement;
-
-import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.system.Clock;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.Callable;
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.util.logging.Level.INFO;
-
-@NotNullByDefault
-@ThreadSafe
-class ConnectionChooserImpl implements ConnectionChooser {
-
-	private static final Logger LOG =
-			Logger.getLogger(ConnectionChooserImpl.class.getName());
-
-	private final Clock clock;
-	private final Executor ioExecutor;
-	private final Object lock = new Object();
-
-	// The following are locking: lock
-	private boolean stopped = false;
-	private final Queue<KeyAgreementConnection> results = new LinkedList<>();
-
-	@Inject
-	ConnectionChooserImpl(Clock clock, @IoExecutor Executor ioExecutor) {
-		this.clock = clock;
-		this.ioExecutor = ioExecutor;
-	}
-
-	@Override
-	public void submit(Callable<KeyAgreementConnection> task) {
-		ioExecutor.execute(() -> {
-			try {
-				KeyAgreementConnection c = task.call();
-				if (c != null) addResult(c);
-			} catch (Exception e) {
-				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
-			}
-		});
-	}
-
-	@Nullable
-	@Override
-	public KeyAgreementConnection poll(long timeout)
-			throws InterruptedException {
-		long now = clock.currentTimeMillis();
-		long end = now + timeout;
-		synchronized (lock) {
-			while (!stopped && results.isEmpty() && now < end) {
-				lock.wait(end - now);
-				now = clock.currentTimeMillis();
-			}
-			return results.poll();
-		}
-	}
-
-	@Override
-	public void stop() {
-		List<KeyAgreementConnection> unused;
-		synchronized (lock) {
-			unused = new ArrayList<>(results);
-			results.clear();
-			stopped = true;
-			lock.notifyAll();
-		}
-		if (LOG.isLoggable(INFO))
-			LOG.info("Closing " + unused.size() + " unused connections");
-		for (KeyAgreementConnection c : unused) tryToClose(c.getConnection());
-	}
-
-	private void addResult(KeyAgreementConnection c) {
-		if (LOG.isLoggable(INFO))
-			LOG.info("Got connection for " + c.getTransportId());
-		boolean close = false;
-		synchronized (lock) {
-			if (stopped) {
-				close = true;
-			} else {
-				results.add(c);
-				lock.notifyAll();
-			}
-		}
-		if (close) {
-			LOG.info("Already stopped");
-			tryToClose(c.getConnection());
-		}
-	}
-
-	private void tryToClose(DuplexTransportConnection conn) {
-		try {
-			conn.getReader().dispose(false, true);
-			conn.getWriter().dispose(false);
-		} catch (IOException e) {
-			if (LOG.isLoggable(INFO)) LOG.info(e.toString());
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementConnector.java

@@ -13,19 +13,23 @@ import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.system.Clock;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.Callable;
-import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CompletionService;
-import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorCompletionService;
+import java.util.concurrent.Future;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.CONNECTION_TIMEOUT;
@@ -41,42 +45,46 @@ class KeyAgreementConnector {
 			Logger.getLogger(KeyAgreementConnector.class.getName());
 
 	private final Callbacks callbacks;
+	private final Clock clock;
 	private final CryptoComponent crypto;
 	private final PluginManager pluginManager;
-	private final ConnectionChooser connectionChooser;
+	private final CompletionService<KeyAgreementConnection> connect;
 
 	private final List<KeyAgreementListener> listeners =
-			new CopyOnWriteArrayList<>();
+			new ArrayList<KeyAgreementListener>();
-	private final CountDownLatch aliceLatch = new CountDownLatch(1);
+	private final List<Future<KeyAgreementConnection>> pending =
-	private final AtomicBoolean waitingSent = new AtomicBoolean(false);
+			new ArrayList<Future<KeyAgreementConnection>>();
 
-	private volatile boolean alice = false, stopped = false;
+	private volatile boolean connecting = false;
+	private volatile boolean alice = false;
 
-	KeyAgreementConnector(Callbacks callbacks,
+	KeyAgreementConnector(Callbacks callbacks, Clock clock,
 			CryptoComponent crypto, PluginManager pluginManager,
-			ConnectionChooser connectionChooser) {
+			Executor ioExecutor) {
 		this.callbacks = callbacks;
+		this.clock = clock;
 		this.crypto = crypto;
 		this.pluginManager = pluginManager;
-		this.connectionChooser = connectionChooser;
+		connect = new ExecutorCompletionService<KeyAgreementConnection>(
+				ioExecutor);
 	}
 
-	Payload listen(KeyPair localKeyPair) {
+	public Payload listen(KeyPair localKeyPair) {
 		LOG.info("Starting BQP listeners");
 		// Derive commitment
 		byte[] commitment = crypto.deriveKeyCommitment(
 				localKeyPair.getPublic().getEncoded());
 		// Start all listeners and collect their descriptors
-		List<TransportDescriptor> descriptors = new ArrayList<>();
+		List<TransportDescriptor> descriptors =
+				new ArrayList<TransportDescriptor>();
 		for (DuplexPlugin plugin : pluginManager.getKeyAgreementPlugins()) {
 			KeyAgreementListener l =
 					plugin.createKeyAgreementListener(commitment);
 			if (l != null) {
 				TransportId id = plugin.getId();
 				descriptors.add(new TransportDescriptor(id, l.getDescriptor()));
-				if (LOG.isLoggable(INFO)) LOG.info("Listening via " + id);
+				pending.add(connect.submit(new ReadableTask(l.listen())));
 				listeners.add(l);
-				connectionChooser.submit(new ReadableTask(l::accept));
 			}
 		}
 		return new Payload(commitment, descriptors);
@@ -84,92 +92,128 @@ class KeyAgreementConnector {
 
 	void stopListening() {
 		LOG.info("Stopping BQP listeners");
-		stopped = true;
+		for (KeyAgreementListener l : listeners) {
-		aliceLatch.countDown();
+			l.close();
-		for (KeyAgreementListener l : listeners) l.close();
+		}
-		connectionChooser.stop();
+		listeners.clear();
 	}
 
 	@Nullable
-	public KeyAgreementTransport connect(Payload remotePayload, boolean alice) {
+	public KeyAgreementTransport connect(Payload remotePayload,
-		// Let the ReadableTasks know if we are Alice
+			boolean alice) {
+		// Let the listeners know if we are Alice
+		this.connecting = true;
 		this.alice = alice;
-		aliceLatch.countDown();
+		long end = clock.currentTimeMillis() + CONNECTION_TIMEOUT;
 
 		// Start connecting over supported transports
-		if (LOG.isLoggable(INFO)) {
+		LOG.info("Starting outgoing BQP connections");
-			LOG.info("Starting outgoing BQP connections as "
-					+ (alice ? "Alice" : "Bob"));
-		}
 		for (TransportDescriptor d : remotePayload.getTransportDescriptors()) {
 			Plugin p = pluginManager.getPlugin(d.getId());
 			if (p instanceof DuplexPlugin) {
-				if (LOG.isLoggable(INFO))
-					LOG.info("Connecting via " + d.getId());
 				DuplexPlugin plugin = (DuplexPlugin) p;
-				byte[] commitment = remotePayload.getCommitment();
+				pending.add(connect.submit(new ReadableTask(
-				BdfList descriptor = d.getDescriptor();
+						new ConnectorTask(plugin, remotePayload.getCommitment(),
-				connectionChooser.submit(new ReadableTask(
+								d.getDescriptor(), end))));
-						new ConnectorTask(plugin, commitment, descriptor)));
 			}
 		}
 
 		// Get chosen connection
+		KeyAgreementConnection chosen = null;
 		try {
-			KeyAgreementConnection chosen =
+			long now = clock.currentTimeMillis();
-					connectionChooser.poll(CONNECTION_TIMEOUT);
+			Future<KeyAgreementConnection> f =
-			if (chosen == null) return null;
+					connect.poll(end - now, MILLISECONDS);
+			if (f == null)
+				return null; // No task completed within the timeout.
+			chosen = f.get();
 			return new KeyAgreementTransport(chosen);
 		} catch (InterruptedException e) {
 			LOG.info("Interrupted while waiting for connection");
 			Thread.currentThread().interrupt();
 			return null;
+		} catch (ExecutionException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return null;
 		} catch (IOException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			return null;
 		} finally {
 			stopListening();
+			// Close all other connections
+			closePending(chosen);
 		}
 	}
 
-	private void waitingForAlice() {
+	private void closePending(@Nullable KeyAgreementConnection chosen) {
-		if (!waitingSent.getAndSet(true)) callbacks.connectionWaiting();
+		for (Future<KeyAgreementConnection> f : pending) {
+			try {
+				if (f.cancel(true)) {
+					LOG.info("Cancelled task");
+				} else if (!f.isCancelled()) {
+					KeyAgreementConnection c = f.get();
+					if (c != null && c != chosen)
+						tryToClose(c.getConnection(), false);
+				}
+			} catch (InterruptedException e) {
+				LOG.info("Interrupted while closing sockets");
+				Thread.currentThread().interrupt();
+				return;
+			} catch (ExecutionException e) {
+				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+			}
+		}
+	}
+
+	private void tryToClose(DuplexTransportConnection conn, boolean exception) {
+		try {
+			if (LOG.isLoggable(INFO))
+				LOG.info("Closing connection, exception: " + exception);
+			conn.getReader().dispose(exception, true);
+			conn.getWriter().dispose(exception);
+		} catch (IOException e) {
+			if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+		}
 	}
 
 	private class ConnectorTask implements Callable<KeyAgreementConnection> {
 
 		private final byte[] commitment;
 		private final BdfList descriptor;
+		private final long end;
 		private final DuplexPlugin plugin;
 
 		private ConnectorTask(DuplexPlugin plugin, byte[] commitment,
-				BdfList descriptor) {
+				BdfList descriptor, long end) {
 			this.plugin = plugin;
 			this.commitment = commitment;
 			this.descriptor = descriptor;
+			this.end = end;
 		}
 
-		@Nullable
 		@Override
 		public KeyAgreementConnection call() throws Exception {
-			// Repeat attempts until we connect, get stopped, or get interrupted
+			// Repeat attempts until we connect, get interrupted, or time out
-			while (!stopped) {
+			while (true) {
+				long now = clock.currentTimeMillis();
+				if (now > end) throw new IOException();
 				DuplexTransportConnection conn =
 						plugin.createKeyAgreementConnection(commitment,
-								descriptor);
+								descriptor, end - now);
 				if (conn != null) {
 					if (LOG.isLoggable(INFO))
-						LOG.info(plugin.getId() + ": Outgoing connection");
+						LOG.info(plugin.getId().getString() +
+								": Outgoing connection");
 					return new KeyAgreementConnection(conn, plugin.getId());
 				}
 				// Wait 2s before retry (to circumvent transient failures)
 				Thread.sleep(2000);
 			}
-			return null;
 		}
 	}
 
-	private class ReadableTask implements Callable<KeyAgreementConnection> {
+	private class ReadableTask
+			implements Callable<KeyAgreementConnection> {
 
 		private final Callable<KeyAgreementConnection> connectionTask;
 
@@ -177,23 +221,24 @@ class KeyAgreementConnector {
 			this.connectionTask = connectionTask;
 		}
 
-		@Nullable
 		@Override
 		public KeyAgreementConnection call() throws Exception {
 			KeyAgreementConnection c = connectionTask.call();
-			if (c == null) return null;
-			aliceLatch.await();
-			if (alice || stopped) return c;
-			// Bob waits here for Alice to scan his QR code, determine her
-			// role, and send her key
 			InputStream in = c.getConnection().getReader().getInputStream();
-			while (!stopped && in.available() == 0) {
+			boolean waitingSent = false;
-				if (LOG.isLoggable(INFO))
+			while (!alice && in.available() == 0) {
-					LOG.info(c.getTransportId() + ": Waiting for data");
+				if (!waitingSent && connecting && !alice) {
-				waitingForAlice();
+					// Bob waits here until Alice obtains his payload.
-				Thread.sleep(500);
+					callbacks.connectionWaiting();
+					waitingSent = true;
+				}
+				if (LOG.isLoggable(INFO)) {
+					LOG.info(c.getTransportId().getString() +
+							": Waiting for connection");
+				}
+				Thread.sleep(1000);
 			}
-			if (!stopped && LOG.isLoggable(INFO))
+			if (!alice && LOG.isLoggable(INFO))
 				LOG.info(c.getTransportId().getString() + ": Data available");
 			return c;
 		}

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementModule.java

@@ -1,10 +1,19 @@
 package org.briarproject.bramble.keyagreement;
 
+import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.data.BdfReaderFactory;
 import org.briarproject.bramble.api.data.BdfWriterFactory;
+import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementTaskFactory;
 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.plugin.PluginManager;
+import org.briarproject.bramble.api.system.Clock;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Singleton;
 
 import dagger.Module;
 import dagger.Provides;
@@ -13,9 +22,13 @@ import dagger.Provides;
 public class KeyAgreementModule {
 
 	@Provides
-	KeyAgreementTaskFactory provideKeyAgreementTaskFactory(
+	@Singleton
-			KeyAgreementTaskFactoryImpl keyAgreementTaskFactory) {
+	KeyAgreementTaskFactory provideKeyAgreementTaskFactory(Clock clock,
-		return keyAgreementTaskFactory;
+			CryptoComponent crypto, EventBus eventBus,
+			@IoExecutor Executor ioExecutor, PayloadEncoder payloadEncoder,
+			PluginManager pluginManager) {
+		return new KeyAgreementTaskFactoryImpl(clock, crypto, eventBus,
+				ioExecutor, payloadEncoder, pluginManager);
 	}
 
 	@Provides
@@ -27,10 +40,4 @@ public class KeyAgreementModule {
 	PayloadParser providePayloadParser(BdfReaderFactory bdfReaderFactory) {
 		return new PayloadParserImpl(bdfReaderFactory);
 	}
-
-	@Provides
-	ConnectionChooser provideConnectionChooser(
-			ConnectionChooserImpl connectionChooser) {
-		return connectionChooser;
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocol.java

@@ -89,8 +89,7 @@ class KeyAgreementProtocol {
 			byte[] theirPublicKey;
 			if (alice) {
 				sendKey();
-				// Alice waits here for Bob to scan her QR code, determine his
+				// Alice waits here until Bob obtains her payload.
-				// role, receive her key and respond with his key
 				callbacks.connectionWaiting();
 				theirPublicKey = receiveKey();
 			} else {

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskFactoryImpl.java

@@ -5,37 +5,42 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementTask;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementTaskFactory;
 import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.PluginManager;
+import org.briarproject.bramble.api.system.Clock;
+
+import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
-import javax.inject.Provider;
 
 @Immutable
 @NotNullByDefault
 class KeyAgreementTaskFactoryImpl implements KeyAgreementTaskFactory {
 
+	private final Clock clock;
 	private final CryptoComponent crypto;
 	private final EventBus eventBus;
+	private final Executor ioExecutor;
 	private final PayloadEncoder payloadEncoder;
 	private final PluginManager pluginManager;
-	private final Provider<ConnectionChooser> connectionChooserProvider;
 
 	@Inject
-	KeyAgreementTaskFactoryImpl(CryptoComponent crypto, EventBus eventBus,
+	KeyAgreementTaskFactoryImpl(Clock clock, CryptoComponent crypto,
-			PayloadEncoder payloadEncoder, PluginManager pluginManager,
+			EventBus eventBus, @IoExecutor Executor ioExecutor,
-			Provider<ConnectionChooser> connectionChooserProvider) {
+			PayloadEncoder payloadEncoder, PluginManager pluginManager) {
+		this.clock = clock;
 		this.crypto = crypto;
 		this.eventBus = eventBus;
+		this.ioExecutor = ioExecutor;
 		this.payloadEncoder = payloadEncoder;
 		this.pluginManager = pluginManager;
-		this.connectionChooserProvider = connectionChooserProvider;
 	}
 
 	@Override
 	public KeyAgreementTask createTask() {
-		return new KeyAgreementTaskImpl(crypto, eventBus, payloadEncoder,
+		return new KeyAgreementTaskImpl(clock, crypto, eventBus, payloadEncoder,
-				pluginManager, connectionChooserProvider.get());
+				pluginManager, ioExecutor);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskImpl.java

@@ -17,16 +17,19 @@ import org.briarproject.bramble.api.keyagreement.event.KeyAgreementWaitingEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.PluginManager;
+import org.briarproject.bramble.api.system.Clock;
 
 import java.io.IOException;
+import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import static java.util.logging.Level.WARNING;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class KeyAgreementTaskImpl extends Thread implements KeyAgreementTask,
+class KeyAgreementTaskImpl extends Thread implements
-		KeyAgreementProtocol.Callbacks, KeyAgreementConnector.Callbacks {
+		KeyAgreementTask, KeyAgreementConnector.Callbacks,
+		KeyAgreementProtocol.Callbacks {
 
 	private static final Logger LOG =
 			Logger.getLogger(KeyAgreementTaskImpl.class.getName());
@@ -40,15 +43,15 @@ class KeyAgreementTaskImpl extends Thread implements KeyAgreementTask,
 	private Payload localPayload;
 	private Payload remotePayload;
 
-	KeyAgreementTaskImpl(CryptoComponent crypto, EventBus eventBus,
+	KeyAgreementTaskImpl(Clock clock, CryptoComponent crypto,
-			PayloadEncoder payloadEncoder, PluginManager pluginManager,
+			EventBus eventBus, PayloadEncoder payloadEncoder,
-			ConnectionChooser connectionChooser) {
+			PluginManager pluginManager, Executor ioExecutor) {
 		this.crypto = crypto;
 		this.eventBus = eventBus;
 		this.payloadEncoder = payloadEncoder;
 		localKeyPair = crypto.generateAgreementKeyPair();
-		connector = new KeyAgreementConnector(this, crypto, pluginManager,
+		connector = new KeyAgreementConnector(this, clock, crypto,
-				connectionChooser);
+				pluginManager, ioExecutor);
 	}
 
 	@Override
@@ -62,8 +65,10 @@ class KeyAgreementTaskImpl extends Thread implements KeyAgreementTask,
 	@Override
 	public synchronized void stopListening() {
 		if (localPayload != null) {
-			if (remotePayload == null) connector.stopListening();
+			if (remotePayload == null)
-			else interrupt();
+				connector.stopListening();
+			else
+				interrupt();
 		}
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/PayloadParserImpl.java

@@ -51,7 +51,8 @@ class PayloadParserImpl implements PayloadParser {
 		byte[] commitment = payload.getRaw(1);
 		if (commitment.length != COMMIT_LENGTH) throw new FormatException();
 		// Remaining elements: transport descriptors
-		List<TransportDescriptor> recognised = new ArrayList<>();
+		List<TransportDescriptor> recognised =
+				new ArrayList<TransportDescriptor>();
 		for (int i = 2; i < payload.size(); i++) {
 			BdfList descriptor = payload.getList(i);
 			long transportId = descriptor.getLong(0);

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/LifecycleManagerImpl.java

@@ -2,11 +2,8 @@ package org.briarproject.bramble.lifecycle;
 
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyPair;
-import org.briarproject.bramble.api.db.DataTooNewException;
-import org.briarproject.bramble.api.db.DataTooOldException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.AuthorFactory;
@@ -15,7 +12,7 @@ import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
-import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
+import org.briarproject.bramble.api.lifecycle.event.ShutdownEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Client;
 
@@ -32,21 +29,14 @@ import javax.inject.Inject;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.MIGRATING_DATABASE;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING_SERVICES;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.DATA_TOO_NEW_ERROR;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.DATA_TOO_OLD_ERROR;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.DB_ERROR;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.SERVICE_ERROR;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.SUCCESS;
 
 @ThreadSafe
 @NotNullByDefault
-class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
+class LifecycleManagerImpl implements LifecycleManager {
 
 	private static final Logger LOG =
 			Logger.getLogger(LifecycleManagerImpl.class.getName());
@@ -64,8 +54,6 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 	private final CountDownLatch startupLatch = new CountDownLatch(1);
 	private final CountDownLatch shutdownLatch = new CountDownLatch(1);
 
-	private volatile LifecycleState state = STARTING;
-
 	@Inject
 	LifecycleManagerImpl(DatabaseComponent db, EventBus eventBus,
 			CryptoComponent crypto, AuthorFactory authorFactory,
@@ -75,9 +63,9 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		this.crypto = crypto;
 		this.authorFactory = authorFactory;
 		this.identityManager = identityManager;
-		services = new CopyOnWriteArrayList<>();
+		services = new CopyOnWriteArrayList<Service>();
-		clients = new CopyOnWriteArrayList<>();
+		clients = new CopyOnWriteArrayList<Client>();
-		executors = new CopyOnWriteArrayList<>();
+		executors = new CopyOnWriteArrayList<ExecutorService>();
 	}
 
 	@Override
@@ -100,7 +88,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		executors.add(e);
 	}
 
-	private LocalAuthor createLocalAuthor(String nickname) {
+	private LocalAuthor createLocalAuthor(final String nickname) {
 		long now = System.currentTimeMillis();
 		KeyPair keyPair = crypto.generateSignatureKeyPair();
 		byte[] publicKey = keyPair.getPublic().getEncoded();
@@ -131,7 +119,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 			LOG.info("Starting services");
 			long start = System.currentTimeMillis();
 
-			boolean reopened = db.open(this);
+			boolean reopened = db.open();
 			long duration = System.currentTimeMillis() - start;
 			if (LOG.isLoggable(INFO)) {
 				if (reopened)
@@ -143,10 +131,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 				registerLocalAuthor(createLocalAuthor(nickname));
 			}
 
-			state = STARTING_SERVICES;
 			dbLatch.countDown();
-			eventBus.broadcast(new LifecycleEvent(STARTING_SERVICES));
-
 			Transaction txn = db.startTransaction(false);
 			try {
 				for (Client c : clients) {
@@ -172,17 +157,8 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 							+ " took " + duration + " ms");
 				}
 			}
-
-			state = RUNNING;
 			startupLatch.countDown();
-			eventBus.broadcast(new LifecycleEvent(RUNNING));
 			return SUCCESS;
-		} catch (DataTooOldException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			return DATA_TOO_OLD_ERROR;
-		} catch (DataTooNewException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			return DATA_TOO_NEW_ERROR;
 		} catch (DbException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			return DB_ERROR;
@@ -194,12 +170,6 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		}
 	}
 
-	@Override
-	public void onMigrationRun() {
-		state = MIGRATING_DATABASE;
-		eventBus.broadcast(new LifecycleEvent(MIGRATING_DATABASE));
-	}
-
 	@Override
 	public void stopServices() {
 		try {
@@ -210,8 +180,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		}
 		try {
 			LOG.info("Stopping services");
-			state = STOPPING;
+			eventBus.broadcast(new ShutdownEvent());
-			eventBus.broadcast(new LifecycleEvent(STOPPING));
 			for (Service s : services) {
 				long start = System.currentTimeMillis();
 				s.stopService();
@@ -234,7 +203,9 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Closing database took " + duration + " ms");
 			shutdownLatch.countDown();
-		} catch (DbException | ServiceException e) {
+		} catch (DbException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} catch (ServiceException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		} finally {
 			startStopSemaphore.release();
@@ -256,8 +227,4 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		shutdownLatch.await();
 	}
 
-	@Override
-	public LifecycleState getLifecycleState() {
-		return state;
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/LifecycleModule.java

@@ -37,7 +37,7 @@ public class LifecycleModule {
 
 	public LifecycleModule() {
 		// The thread pool is unbounded, so use direct handoff
-		BlockingQueue<Runnable> queue = new SynchronousQueue<>();
+		BlockingQueue<Runnable> queue = new SynchronousQueue<Runnable>();
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/ShutdownManagerImpl.java

@@ -21,7 +21,7 @@ class ShutdownManagerImpl implements ShutdownManager {
 	private int nextHandle = 0;
 
 	ShutdownManagerImpl() {
-		hooks = new HashMap<>();
+		hooks = new HashMap<Integer, Thread>();
 	}
 
 	@Override

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

@@ -134,7 +134,11 @@ class ConnectionManagerImpl implements ConnectionManager {
 			try {
 				byte[] tag = readTag(reader);
 				ctx = keyManager.getStreamContext(transportId, tag);
-			} catch (IOException | DbException e) {
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				disposeReader(true, false);
+				return;
+			} catch (DbException e) {
 				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 				disposeReader(true, false);
 				return;
@@ -245,7 +249,11 @@ class ConnectionManagerImpl implements ConnectionManager {
 			try {
 				byte[] tag = readTag(reader);
 				ctx = keyManager.getStreamContext(transportId, tag);
-			} catch (IOException | DbException e) {
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				disposeReader(true, false);
+				return;
+			} catch (DbException e) {
 				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 				disposeReader(true, false);
 				return;
@@ -258,7 +266,12 @@ class ConnectionManagerImpl implements ConnectionManager {
 			contactId = ctx.getContactId();
 			connectionRegistry.registerConnection(contactId, transportId, true);
 			// Start the outgoing session on another thread
-			ioExecutor.execute(this::runOutgoingSession);
+			ioExecutor.execute(new Runnable() {
+				@Override
+				public void run() {
+					runOutgoingSession();
+				}
+			});
 			try {
 				// Create and run the incoming session
 				incomingSession = createIncomingSession(ctx, reader);
@@ -355,7 +368,12 @@ class ConnectionManagerImpl implements ConnectionManager {
 				return;
 			}
 			// Start the incoming session on another thread
-			ioExecutor.execute(this::runIncomingSession);
+			ioExecutor.execute(new Runnable() {
+				@Override
+				public void run() {
+					runIncomingSession();
+				}
+			});
 			try {
 				// Create and run the outgoing session
 				outgoingSession = createDuplexOutgoingSession(ctx, writer);
@@ -373,7 +391,11 @@ class ConnectionManagerImpl implements ConnectionManager {
 			try {
 				byte[] tag = readTag(reader);
 				ctx = keyManager.getStreamContext(transportId, tag);
-			} catch (IOException | DbException e) {
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				disposeReader(true, false);
+				return;
+			} catch (DbException e) {
 				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 				disposeReader(true, false);
 				return;

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

@@ -42,8 +42,8 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	@Inject
 	ConnectionRegistryImpl(EventBus eventBus) {
 		this.eventBus = eventBus;
-		connections = new HashMap<>();
+		connections = new HashMap<TransportId, Map<ContactId, Integer>>();
-		contactCounts = new HashMap<>();
+		contactCounts = new HashMap<ContactId, Integer>();
 	}
 
 	@Override
@@ -58,7 +58,7 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 		try {
 			Map<ContactId, Integer> m = connections.get(t);
 			if (m == null) {
-				m = new HashMap<>();
+				m = new HashMap<ContactId, Integer>();
 				connections.put(t, m);
 			}
 			Integer count = m.get(c);
@@ -124,7 +124,7 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 		try {
 			Map<ContactId, Integer> m = connections.get(t);
 			if (m == null) return Collections.emptyList();
-			List<ContactId> ids = new ArrayList<>(m.keySet());
+			List<ContactId> ids = new ArrayList<ContactId>(m.keySet());
 			if (LOG.isLoggable(INFO))
 				LOG.info(ids.size() + " contacts connected");
 			return ids;

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

@@ -82,10 +82,10 @@ class PluginManagerImpl implements PluginManager, Service {
 		this.settingsManager = settingsManager;
 		this.transportPropertyManager = transportPropertyManager;
 		this.uiCallback = uiCallback;
-		plugins = new ConcurrentHashMap<>();
+		plugins = new ConcurrentHashMap<TransportId, Plugin>();
-		simplexPlugins = new CopyOnWriteArrayList<>();
+		simplexPlugins = new CopyOnWriteArrayList<SimplexPlugin>();
-		duplexPlugins = new CopyOnWriteArrayList<>();
+		duplexPlugins = new CopyOnWriteArrayList<DuplexPlugin>();
-		startLatches = new ConcurrentHashMap<>();
+		startLatches = new ConcurrentHashMap<TransportId, CountDownLatch>();
 	}
 
 	@Override
@@ -156,17 +156,17 @@ class PluginManagerImpl implements PluginManager, Service {
 
 	@Override
 	public Collection<SimplexPlugin> getSimplexPlugins() {
-		return new ArrayList<>(simplexPlugins);
+		return new ArrayList<SimplexPlugin>(simplexPlugins);
 	}
 
 	@Override
 	public Collection<DuplexPlugin> getDuplexPlugins() {
-		return new ArrayList<>(duplexPlugins);
+		return new ArrayList<DuplexPlugin>(duplexPlugins);
 	}
 
 	@Override
 	public Collection<DuplexPlugin> getKeyAgreementPlugins() {
-		List<DuplexPlugin> supported = new ArrayList<>();
+		List<DuplexPlugin> supported = new ArrayList<DuplexPlugin>();
 		for (DuplexPlugin d : duplexPlugins)
 			if (d.supportsKeyAgreement()) supported.add(d);
 		return supported;

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

@@ -16,7 +16,6 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.TransportDisabledEvent;
 import org.briarproject.bramble.api.plugin.event.TransportEnabledEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
 import org.briarproject.bramble.api.system.Clock;
@@ -26,7 +25,6 @@ import java.security.SecureRandom;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
@@ -52,7 +50,7 @@ class Poller implements EventListener {
 	private final SecureRandom random;
 	private final Clock clock;
 	private final Lock lock;
-	private final Map<TransportId, ScheduledPollTask> tasks; // Locking: lock
+	private final Map<TransportId, PollTask> tasks; // Locking: lock
 
 	@Inject
 	Poller(@IoExecutor Executor ioExecutor,
@@ -68,7 +66,7 @@ class Poller implements EventListener {
 		this.random = random;
 		this.clock = clock;
 		lock = new ReentrantLock();
-		tasks = new HashMap<>();
+		tasks = new HashMap<TransportId, PollTask>();
 	}
 
 	@Override
@@ -95,10 +93,6 @@ class Poller implements EventListener {
 			TransportEnabledEvent t = (TransportEnabledEvent) e;
 			// Poll the newly enabled transport
 			pollNow(t.getTransportId());
-		} else if (e instanceof TransportDisabledEvent) {
-			TransportDisabledEvent t = (TransportDisabledEvent) e;
-			// Cancel polling for the disabled transport
-			cancel(t.getTransportId());
 		}
 	}
 
@@ -117,24 +111,30 @@ class Poller implements EventListener {
 			connectToContact(c, (DuplexPlugin) p);
 	}
 
-	private void connectToContact(ContactId c, SimplexPlugin p) {
+	private void connectToContact(final ContactId c, final SimplexPlugin p) {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			TransportId t = p.getId();
+			@Override
-			if (!connectionRegistry.isConnected(c, t)) {
+			public void run() {
-				TransportConnectionWriter w = p.createWriter(c);
+				TransportId t = p.getId();
-				if (w != null)
+				if (!connectionRegistry.isConnected(c, t)) {
-					connectionManager.manageOutgoingConnection(c, t, w);
+					TransportConnectionWriter w = p.createWriter(c);
+					if (w != null)
+						connectionManager.manageOutgoingConnection(c, t, w);
+				}
 			}
 		});
 	}
 
-	private void connectToContact(ContactId c, DuplexPlugin p) {
+	private void connectToContact(final ContactId c, final DuplexPlugin p) {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			TransportId t = p.getId();
+			@Override
-			if (!connectionRegistry.isConnected(c, t)) {
+			public void run() {
-				DuplexTransportConnection d = p.createConnection(c);
+				TransportId t = p.getId();
-				if (d != null)
+				if (!connectionRegistry.isConnected(c, t)) {
-					connectionManager.manageOutgoingConnection(c, t, d);
+					DuplexTransportConnection d = p.createConnection(c);
+					if (d != null)
+						connectionManager.manageOutgoingConnection(c, t, d);
+				}
 			}
 		});
 	}
@@ -157,49 +157,29 @@ class Poller implements EventListener {
 		TransportId t = p.getId();
 		lock.lock();
 		try {
-			ScheduledPollTask scheduled = tasks.get(t);
+			PollTask scheduled = tasks.get(t);
-			if (scheduled == null || due < scheduled.task.due) {
+			if (scheduled == null || due < scheduled.due) {
-				// If a later task exists, cancel it. If it's already started
+				final PollTask task = new PollTask(p, due, randomiseNext);
-				// it will abort safely when it finds it's been replaced
+				tasks.put(t, task);
-				if (scheduled != null) scheduled.future.cancel(false);
+				scheduler.schedule(new Runnable() {
-				PollTask task = new PollTask(p, due, randomiseNext);
+					@Override
-				Future future = scheduler.schedule(
+					public void run() {
-						() -> ioExecutor.execute(task), delay, MILLISECONDS);
+						ioExecutor.execute(task);
-				tasks.put(t, new ScheduledPollTask(task, future));
+					}
+				}, delay, MILLISECONDS);
 			}
 		} finally {
 			lock.unlock();
 		}
 	}
 
-	private void cancel(TransportId t) {
-		lock.lock();
-		try {
-			ScheduledPollTask scheduled = tasks.remove(t);
-			if (scheduled != null) scheduled.future.cancel(false);
-		} finally {
-			lock.unlock();
-		}
-	}
-
 	@IoExecutor
-	private void poll(Plugin p) {
+	private void poll(final Plugin p) {
 		TransportId t = p.getId();
 		if (LOG.isLoggable(INFO)) LOG.info("Polling plugin " + t);
 		p.poll(connectionRegistry.getConnectedContacts(t));
 	}
 
-	private class ScheduledPollTask {
-
-		private final PollTask task;
-		private final Future future;
-
-		private ScheduledPollTask(PollTask task, Future future) {
-			this.task = task;
-			this.future = future;
-		}
-	}
-
 	private class PollTask implements Runnable {
 
 		private final Plugin plugin;
@@ -218,9 +198,7 @@ class Poller implements EventListener {
 			lock.lock();
 			try {
 				TransportId t = plugin.getId();
-				ScheduledPollTask scheduled = tasks.get(t);
+				if (tasks.get(t) != this) return; // Replaced by another task
-				if (scheduled != null && scheduled.task != this)
-					return; // Replaced by another task
 				tasks.remove(t);
 			} finally {
 				lock.unlock();

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

@@ -1,419 +0,0 @@
-package org.briarproject.bramble.plugin.bluetooth;
-
-import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.data.BdfList;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.PluginException;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.BluetoothEnabledEvent;
-import org.briarproject.bramble.api.plugin.event.DisableBluetoothEvent;
-import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
-import org.briarproject.bramble.api.properties.TransportProperties;
-import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
-import org.briarproject.bramble.util.StringUtils;
-
-import java.io.IOException;
-import java.security.SecureRandom;
-import java.util.Collection;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.UUID;
-import java.util.concurrent.Executor;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
-import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
-
-	private static final Logger LOG =
-			Logger.getLogger(BluetoothPlugin.class.getName());
-
-	private final Executor ioExecutor;
-	private final SecureRandom secureRandom;
-	private final Backoff backoff;
-	private final DuplexPluginCallback callback;
-	private final int maxLatency;
-	private final AtomicBoolean used = new AtomicBoolean(false);
-
-	private volatile boolean running = false, contactConnections = false;
-	private volatile String contactConnectionsUuid = null;
-	private volatile SS socket = null;
-
-	abstract void initialiseAdapter() throws IOException;
-
-	abstract boolean isAdapterEnabled();
-
-	abstract void enableAdapter();
-
-	abstract void disableAdapterIfEnabledByUs();
-
-	abstract void setEnabledByUs();
-
-	/**
-	 * Returns the local Bluetooth address, or null if no valid address can
-	 * be found.
-	 */
-	@Nullable
-	abstract String getBluetoothAddress();
-
-	abstract SS openServerSocket(String uuid) throws IOException;
-
-	abstract void tryToClose(@Nullable SS ss);
-
-	abstract DuplexTransportConnection acceptConnection(SS ss)
-			throws IOException;
-
-	abstract boolean isValidAddress(String address);
-
-	abstract DuplexTransportConnection connectTo(String address, String uuid)
-			throws IOException;
-
-	BluetoothPlugin(Executor ioExecutor, SecureRandom secureRandom,
-			Backoff backoff, DuplexPluginCallback callback, int maxLatency) {
-		this.ioExecutor = ioExecutor;
-		this.secureRandom = secureRandom;
-		this.backoff = backoff;
-		this.callback = callback;
-		this.maxLatency = maxLatency;
-	}
-
-	void onAdapterEnabled() {
-		LOG.info("Bluetooth enabled");
-		// We may not have been able to get the local address before
-		ioExecutor.execute(this::updateProperties);
-		if (shouldAllowContactConnections()) bind();
-	}
-
-	void onAdapterDisabled() {
-		LOG.info("Bluetooth disabled");
-		tryToClose(socket);
-		callback.transportDisabled();
-	}
-
-	@Override
-	public TransportId getId() {
-		return ID;
-	}
-
-	@Override
-	public int getMaxLatency() {
-		return maxLatency;
-	}
-
-	@Override
-	public int getMaxIdleTime() {
-		// Bluetooth detects dead connections so we don't need keepalives
-		return Integer.MAX_VALUE;
-	}
-
-	@Override
-	public void start() throws PluginException {
-		if (used.getAndSet(true)) throw new IllegalStateException();
-		try {
-			initialiseAdapter();
-		} catch (IOException e) {
-			throw new PluginException(e);
-		}
-		updateProperties();
-		running = true;
-		loadSettings();
-		if (shouldAllowContactConnections()) {
-			if (isAdapterEnabled()) bind();
-			else enableAdapter();
-		}
-	}
-
-	private void loadSettings() {
-		contactConnections =
-				callback.getSettings().getBoolean(PREF_BT_ENABLE, false);
-	}
-
-	private boolean shouldAllowContactConnections() {
-		return contactConnections;
-	}
-
-	private void bind() {
-		ioExecutor.execute(() -> {
-			if (!isRunning() || !shouldAllowContactConnections()) return;
-			// Bind a server socket to accept connections from contacts
-			SS ss;
-			try {
-				ss = openServerSocket(contactConnectionsUuid);
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				return;
-			}
-			if (!isRunning() || !shouldAllowContactConnections()) {
-				tryToClose(ss);
-				return;
-			}
-			socket = ss;
-			backoff.reset();
-			callback.transportEnabled();
-			acceptContactConnections();
-		});
-	}
-
-	private void updateProperties() {
-		TransportProperties p = callback.getLocalProperties();
-		String address = p.get(PROP_ADDRESS);
-		String uuid = p.get(PROP_UUID);
-		boolean changed = false;
-		if (address == null) {
-			address = getBluetoothAddress();
-			if (LOG.isLoggable(INFO))
-				LOG.info("Local address " + scrubMacAddress(address));
-			if (!StringUtils.isNullOrEmpty(address)) {
-				p.put(PROP_ADDRESS, address);
-				changed = true;
-			}
-		}
-		if (uuid == null) {
-			byte[] random = new byte[UUID_BYTES];
-			secureRandom.nextBytes(random);
-			uuid = UUID.nameUUIDFromBytes(random).toString();
-			p.put(PROP_UUID, uuid);
-			changed = true;
-		}
-		contactConnectionsUuid = uuid;
-		if (changed) callback.mergeLocalProperties(p);
-	}
-
-	private void acceptContactConnections() {
-		while (true) {
-			DuplexTransportConnection conn;
-			try {
-				conn = acceptConnection(socket);
-			} catch (IOException e) {
-				// This is expected when the socket is closed
-				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
-				return;
-			}
-			backoff.reset();
-			callback.incomingConnectionCreated(conn);
-			if (!running) return;
-		}
-	}
-
-	@Override
-	public void stop() {
-		running = false;
-		tryToClose(socket);
-		callback.transportDisabled();
-		disableAdapterIfEnabledByUs();
-	}
-
-	@Override
-	public boolean isRunning() {
-		return running && isAdapterEnabled();
-	}
-
-	@Override
-	public boolean shouldPoll() {
-		return true;
-	}
-
-	@Override
-	public int getPollingInterval() {
-		return backoff.getPollingInterval();
-	}
-
-	@Override
-	public void poll(Collection<ContactId> connected) {
-		if (!isRunning() || !shouldAllowContactConnections()) return;
-		backoff.increment();
-		// Try to connect to known devices in parallel
-		Map<ContactId, TransportProperties> remote =
-				callback.getRemoteProperties();
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			ContactId c = e.getKey();
-			if (connected.contains(c)) continue;
-			String address = e.getValue().get(PROP_ADDRESS);
-			if (StringUtils.isNullOrEmpty(address)) continue;
-			String uuid = e.getValue().get(PROP_UUID);
-			if (StringUtils.isNullOrEmpty(uuid)) continue;
-			ioExecutor.execute(() -> {
-				if (!isRunning() || !shouldAllowContactConnections()) return;
-				DuplexTransportConnection conn = connect(address, uuid);
-				if (conn != null) {
-					backoff.reset();
-					callback.outgoingConnectionCreated(c, conn);
-				}
-			});
-		}
-	}
-
-	@Nullable
-	private DuplexTransportConnection connect(String address, String uuid) {
-		// Validate the address
-		if (!isValidAddress(address)) {
-			if (LOG.isLoggable(WARNING))
-				// Not scrubbing here to be able to figure out the problem
-				LOG.warning("Invalid address " + address);
-			return null;
-		}
-		// Validate the UUID
-		try {
-			//noinspection ResultOfMethodCallIgnored
-			UUID.fromString(uuid);
-		} catch (IllegalArgumentException e) {
-			if (LOG.isLoggable(WARNING)) LOG.warning("Invalid UUID " + uuid);
-			return null;
-		}
-		if (LOG.isLoggable(INFO))
-			LOG.info("Connecting to " + scrubMacAddress(address));
-		try {
-			DuplexTransportConnection conn = connectTo(address, uuid);
-			if (LOG.isLoggable(INFO))
-				LOG.info("Connected to " + scrubMacAddress(address));
-			return conn;
-		} catch (IOException e) {
-			if (LOG.isLoggable(INFO))
-				LOG.info("Could not connect to " + scrubMacAddress(address));
-			return null;
-		}
-	}
-
-	@Override
-	public DuplexTransportConnection createConnection(ContactId c) {
-		if (!isRunning() || !shouldAllowContactConnections()) return null;
-		TransportProperties p = callback.getRemoteProperties(c);
-		String address = p.get(PROP_ADDRESS);
-		if (StringUtils.isNullOrEmpty(address)) return null;
-		String uuid = p.get(PROP_UUID);
-		if (StringUtils.isNullOrEmpty(uuid)) return null;
-		return connect(address, uuid);
-	}
-
-	@Override
-	public boolean supportsKeyAgreement() {
-		return true;
-	}
-
-	@Override
-	public KeyAgreementListener createKeyAgreementListener(byte[] commitment) {
-		if (!isRunning()) return null;
-		// There's no point listening if we can't discover our own address
-		String address = getBluetoothAddress();
-		if (address == null) return null;
-		// No truncation necessary because COMMIT_LENGTH = 16
-		String uuid = UUID.nameUUIDFromBytes(commitment).toString();
-		if (LOG.isLoggable(INFO)) LOG.info("Key agreement UUID " + uuid);
-		// Bind a server socket for receiving key agreement connections
-		SS ss;
-		try {
-			ss = openServerSocket(uuid);
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			return null;
-		}
-		if (!isRunning()) {
-			tryToClose(ss);
-			return null;
-		}
-		BdfList descriptor = new BdfList();
-		descriptor.add(TRANSPORT_ID_BLUETOOTH);
-		descriptor.add(StringUtils.macToBytes(address));
-		return new BluetoothKeyAgreementListener(descriptor, ss);
-	}
-
-	@Override
-	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor) {
-		if (!isRunning()) return null;
-		String address;
-		try {
-			address = parseAddress(descriptor);
-		} catch (FormatException e) {
-			LOG.info("Invalid address in key agreement descriptor");
-			return null;
-		}
-		// No truncation necessary because COMMIT_LENGTH = 16
-		String uuid = UUID.nameUUIDFromBytes(commitment).toString();
-		if (LOG.isLoggable(INFO))
-			LOG.info("Connecting to key agreement UUID " + uuid);
-		return connect(address, uuid);
-	}
-
-	private String parseAddress(BdfList descriptor) throws FormatException {
-		byte[] mac = descriptor.getRaw(1);
-		if (mac.length != 6) throw new FormatException();
-		return StringUtils.macToString(mac);
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof EnableBluetoothEvent) {
-			ioExecutor.execute(this::enableAdapter);
-		} else if (e instanceof DisableBluetoothEvent) {
-			ioExecutor.execute(this::disableAdapterIfEnabledByUs);
-		} else if (e instanceof BluetoothEnabledEvent) {
-			setEnabledByUs();
-		} else if (e instanceof SettingsUpdatedEvent) {
-			SettingsUpdatedEvent s = (SettingsUpdatedEvent) e;
-			if (s.getNamespace().equals(ID.getString()))
-				ioExecutor.execute(this::onSettingsUpdated);
-		}
-	}
-
-	private void onSettingsUpdated() {
-		boolean wasAllowed = shouldAllowContactConnections();
-		loadSettings();
-		boolean isAllowed = shouldAllowContactConnections();
-		if (wasAllowed && !isAllowed) {
-			LOG.info("Contact connections disabled");
-			tryToClose(socket);
-			callback.transportDisabled();
-			disableAdapterIfEnabledByUs();
-		} else if (!wasAllowed && isAllowed) {
-			LOG.info("Contact connections enabled");
-			if (isAdapterEnabled()) bind();
-			else enableAdapter();
-		}
-	}
-
-	private class BluetoothKeyAgreementListener extends KeyAgreementListener {
-
-		private final SS ss;
-
-		private BluetoothKeyAgreementListener(BdfList descriptor, SS ss) {
-			super(descriptor);
-			this.ss = ss;
-		}
-
-		@Override
-		public KeyAgreementConnection accept() throws IOException {
-			DuplexTransportConnection conn = acceptConnection(ss);
-			if (LOG.isLoggable(INFO)) LOG.info(ID + ": Incoming connection");
-			return new KeyAgreementConnection(conn, ID);
-		}
-
-		@Override
-		public void close() {
-			tryToClose(ss);
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/plugin/file/FilePlugin.java

@@ -108,7 +108,7 @@ abstract class FilePlugin implements SimplexPlugin {
 		}
 	}
 
-	protected void createReaderFromFile(File f) {
+	protected void createReaderFromFile(final File f) {
 		if (!running) return;
 		ioExecutor.execute(new ReaderCreator(f));
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -23,8 +23,9 @@ import java.net.SocketAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Comparator;
+import java.util.LinkedList;
 import java.util.List;
+import java.util.concurrent.Callable;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
@@ -43,9 +44,6 @@ class LanTcpPlugin extends TcpPlugin {
 	private static final Logger LOG =
 			Logger.getLogger(LanTcpPlugin.class.getName());
 
-	private static final LanAddressComparator ADDRESS_COMPARATOR =
-			new LanAddressComparator();
-
 	private static final int MAX_ADDRESSES = 4;
 	private static final String SEPARATOR = ",";
 
@@ -65,25 +63,26 @@ class LanTcpPlugin extends TcpPlugin {
 		TransportProperties p = callback.getLocalProperties();
 		String oldIpPorts = p.get(PROP_IP_PORTS);
 		List<InetSocketAddress> olds = parseSocketAddresses(oldIpPorts);
-		List<InetSocketAddress> locals = new ArrayList<>();
+		List<InetSocketAddress> locals = new LinkedList<InetSocketAddress>();
 		for (InetAddress local : getLocalIpAddresses()) {
 			if (isAcceptableAddress(local)) {
 				// If this is the old address, try to use the same port
 				for (InetSocketAddress old : olds) {
-					if (old.getAddress().equals(local))
+					if (old.getAddress().equals(local)) {
-						locals.add(new InetSocketAddress(local, old.getPort()));
+						int port = old.getPort();
+						locals.add(0, new InetSocketAddress(local, port));
+					}
 				}
 				locals.add(new InetSocketAddress(local, 0));
 			}
 		}
-		Collections.sort(locals, ADDRESS_COMPARATOR);
 		return locals;
 	}
 
 	private List<InetSocketAddress> parseSocketAddresses(String ipPorts) {
 		if (StringUtils.isNullOrEmpty(ipPorts)) return Collections.emptyList();
 		String[] split = ipPorts.split(SEPARATOR);
-		List<InetSocketAddress> addresses = new ArrayList<>();
+		List<InetSocketAddress> addresses = new ArrayList<InetSocketAddress>();
 		for (String ipPort : split) {
 			InetSocketAddress a = parseSocketAddress(ipPort);
 			if (a != null) addresses.add(a);
@@ -96,7 +95,7 @@ class LanTcpPlugin extends TcpPlugin {
 		String ipPort = getIpPortString(a);
 		// Get the list of recently used addresses
 		String setting = callback.getSettings().get(PREF_LAN_IP_PORTS);
-		List<String> recent = new ArrayList<>();
+		List<String> recent = new ArrayList<String>();
 		if (!StringUtils.isNullOrEmpty(setting))
 			Collections.addAll(recent, setting.split(SEPARATOR));
 		// Is the address already in the list?
@@ -112,7 +111,7 @@ class LanTcpPlugin extends TcpPlugin {
 				recent = recent.subList(0, MAX_ADDRESSES);
 			setting = StringUtils.join(recent, SEPARATOR);
 			// Update the list of addresses shared with contacts
-			List<String> shared = new ArrayList<>(recent);
+			List<String> shared = new ArrayList<String>(recent);
 			Collections.sort(shared);
 			String property = StringUtils.join(shared, SEPARATOR);
 			TransportProperties properties = new TransportProperties();
@@ -154,39 +153,17 @@ class LanTcpPlugin extends TcpPlugin {
 	// Package access for testing
 	boolean addressesAreOnSameLan(byte[] localIp, byte[] remoteIp) {
 		// 10.0.0.0/8
-		if (isPrefix10(localIp)) return isPrefix10(remoteIp);
+		if (localIp[0] == 10) return remoteIp[0] == 10;
 		// 172.16.0.0/12
-		if (isPrefix172(localIp)) return isPrefix172(remoteIp);
+		if (localIp[0] == (byte) 172 && (localIp[1] & 0xF0) == 16)
+			return remoteIp[0] == (byte) 172 && (remoteIp[1] & 0xF0) == 16;
 		// 192.168.0.0/16
-		if (isPrefix192(localIp)) return isPrefix192(remoteIp);
+		if (localIp[0] == (byte) 192 && localIp[1] == (byte) 168)
+			return remoteIp[0] == (byte) 192 && remoteIp[1] == (byte) 168;
 		// Unrecognised prefix - may be compatible
 		return true;
 	}
 
-	private static boolean isPrefix10(byte[] ipv4) {
-		return ipv4[0] == 10;
-	}
-
-	private static boolean isPrefix172(byte[] ipv4) {
-		return ipv4[0] == (byte) 172 && (ipv4[1] & 0xF0) == 16;
-	}
-
-	private static boolean isPrefix192(byte[] ipv4) {
-		return ipv4[0] == (byte) 192 && ipv4[1] == (byte) 168;
-	}
-
-	// Returns the prefix length for an RFC 1918 address, or 0 for any other
-	// address
-	private static int getRfc1918PrefixLength(InetAddress addr) {
-		if (!(addr instanceof Inet4Address)) return 0;
-		if (!addr.isSiteLocalAddress()) return 0;
-		byte[] ipv4 = addr.getAddress();
-		if (isPrefix10(ipv4)) return 8;
-		if (isPrefix172(ipv4)) return 12;
-		if (isPrefix192(ipv4)) return 16;
-		return 0;
-	}
-
 	@Override
 	public boolean supportsKeyAgreement() {
 		return true;
@@ -223,7 +200,7 @@ class LanTcpPlugin extends TcpPlugin {
 
 	@Override
 	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor) {
+			byte[] commitment, BdfList descriptor, long timeout) {
 		if (!isRunning()) return null;
 		InetSocketAddress remote;
 		try {
@@ -241,11 +218,10 @@ class LanTcpPlugin extends TcpPlugin {
 			}
 			return null;
 		}
+		Socket s = new Socket();
 		try {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Connecting to " + scrubSocketAddress(remote));
-			Socket s = createSocket();
-			s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
 			s.connect(remote);
 			s.setSoTimeout(socketTimeout);
 			if (LOG.isLoggable(INFO))
@@ -283,11 +259,18 @@ class LanTcpPlugin extends TcpPlugin {
 		}
 
 		@Override
-		public KeyAgreementConnection accept() throws IOException {
+		public Callable<KeyAgreementConnection> listen() {
-			Socket s = ss.accept();
+			return new Callable<KeyAgreementConnection>() {
-			if (LOG.isLoggable(INFO)) LOG.info(ID + ": Incoming connection");
+				@Override
-			return new KeyAgreementConnection(new TcpTransportConnection(
+				public KeyAgreementConnection call() throws IOException {
-					LanTcpPlugin.this, s), ID);
+					Socket s = ss.accept();
+					if (LOG.isLoggable(INFO))
+						LOG.info(ID.getString() + ": Incoming connection");
+					return new KeyAgreementConnection(
+							new TcpTransportConnection(LanTcpPlugin.this, s),
+							ID);
+				}
+			};
 		}
 
 		@Override
@@ -299,19 +282,4 @@ class LanTcpPlugin extends TcpPlugin {
 			}
 		}
 	}
-
-	static class LanAddressComparator implements Comparator<InetSocketAddress> {
-
-		@Override
-		public int compare(InetSocketAddress a, InetSocketAddress b) {
-			// Prefer addresses with non-zero ports
-			int aPort = a.getPort(), bPort = b.getPort();
-			if (aPort > 0 && bPort == 0) return -1;
-			if (aPort == 0 && bPort > 0) return 1;
-			// Prefer addresses with longer RFC 1918 prefixes
-			int aPrefix = getRfc1918PrefixLength(a.getAddress());
-			int bPrefix = getRfc1918PrefixLength(b.getAddress());
-			return bPrefix - aPrefix;
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/PortMapperImpl.java

@@ -37,7 +37,7 @@ class PortMapperImpl implements PortMapper {
 	}
 
 	@Override
-	public MappingResult map(int port) {
+	public MappingResult map(final int port) {
 		if (!started.getAndSet(true)) start();
 		if (gateway == null) return null;
 		InetAddress internal = gateway.getLocalAddress();
@@ -50,7 +50,12 @@ class PortMapperImpl implements PortMapper {
 			succeeded = gateway.addPortMapping(port, port,
 					getHostAddress(internal), "TCP", "TCP");
 			if (succeeded) {
-				shutdownManager.addShutdownHook(() -> deleteMapping(port));
+				shutdownManager.addShutdownHook(new Runnable() {
+					@Override
+					public void run() {
+						deleteMapping(port);
+					}
+				});
 			}
 			String externalString = gateway.getExternalIPAddress();
 			if (LOG.isLoggable(INFO))
@@ -58,7 +63,9 @@ class PortMapperImpl implements PortMapper {
 						"External address " + scrubInetAddress(externalString));
 			if (externalString != null)
 				external = InetAddress.getByName(externalString);
-		} catch (IOException | SAXException e) {
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} catch (SAXException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		}
 		return new MappingResult(internal, external, port, succeeded);
@@ -75,7 +82,11 @@ class PortMapperImpl implements PortMapper {
 		GatewayDiscover d = new GatewayDiscover();
 		try {
 			d.discover();
-		} catch (IOException | SAXException | ParserConfigurationException e) {
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} catch (SAXException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} catch (ParserConfigurationException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		}
 		gateway = d.getValidGateway();
@@ -86,7 +97,9 @@ class PortMapperImpl implements PortMapper {
 			gateway.deletePortMapping(port, "TCP");
 			if (LOG.isLoggable(INFO))
 				LOG.info("Deleted mapping for port " + port);
-		} catch (IOException | SAXException e) {
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} catch (SAXException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		}
 	}

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/TcpPlugin.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.plugin.tcp;
 
-import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
@@ -48,7 +47,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	private static final Logger LOG =
 			Logger.getLogger(TcpPlugin.class.getName());
 
-	protected final Executor ioExecutor, bindExecutor;
+	protected final Executor ioExecutor;
 	protected final Backoff backoff;
 	protected final DuplexPluginCallback callback;
 	protected final int maxLatency, maxIdleTime, socketTimeout;
@@ -91,8 +90,6 @@ abstract class TcpPlugin implements DuplexPlugin {
 		if (maxIdleTime > Integer.MAX_VALUE / 2)
 			socketTimeout = Integer.MAX_VALUE;
 		else socketTimeout = maxIdleTime * 2;
-		// Don't execute more than one bind operation at a time
-		bindExecutor = new PoliteExecutor("TcpPlugin", ioExecutor, 1);
 	}
 
 	@Override
@@ -113,38 +110,41 @@ abstract class TcpPlugin implements DuplexPlugin {
 	}
 
 	protected void bind() {
-		bindExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			if (!running) return;
+			@Override
-			if (socket != null && !socket.isClosed()) return;
+			public void run() {
-			ServerSocket ss = null;
+				if (!running) return;
-			for (InetSocketAddress addr : getLocalSocketAddresses()) {
+				ServerSocket ss = null;
-				try {
+				for (InetSocketAddress addr : getLocalSocketAddresses()) {
-					ss = new ServerSocket();
+					try {
-					ss.bind(addr);
+						ss = new ServerSocket();
-					break;
+						ss.bind(addr);
-				} catch (IOException e) {
+						break;
-					if (LOG.isLoggable(INFO))
+					} catch (IOException e) {
-						LOG.info("Failed to bind " + scrubSocketAddress(addr));
+						if (LOG.isLoggable(INFO))
-					tryToClose(ss);
+							LOG.info("Failed to bind " +
+									scrubSocketAddress(addr));
+						tryToClose(ss);
+					}
 				}
+				if (ss == null || !ss.isBound()) {
+					LOG.info("Could not bind server socket");
+					return;
+				}
+				if (!running) {
+					tryToClose(ss);
+					return;
+				}
+				socket = ss;
+				backoff.reset();
+				InetSocketAddress local =
+						(InetSocketAddress) ss.getLocalSocketAddress();
+				setLocalSocketAddress(local);
+				if (LOG.isLoggable(INFO))
+					LOG.info("Listening on " + scrubSocketAddress(local));
+				callback.transportEnabled();
+				acceptContactConnections();
 			}
-			if (ss == null || !ss.isBound()) {
-				LOG.info("Could not bind server socket");
-				return;
-			}
-			if (!running) {
-				tryToClose(ss);
-				return;
-			}
-			socket = ss;
-			backoff.reset();
-			InetSocketAddress local =
-					(InetSocketAddress) ss.getLocalSocketAddress();
-			setLocalSocketAddress(local);
-			if (LOG.isLoggable(INFO))
-				LOG.info("Listening on " + scrubSocketAddress(local));
-			callback.transportEnabled();
-			acceptContactConnections();
 		});
 	}
 
@@ -218,13 +218,17 @@ abstract class TcpPlugin implements DuplexPlugin {
 		}
 	}
 
-	private void connectAndCallBack(ContactId c, TransportProperties p) {
+	private void connectAndCallBack(final ContactId c,
-		ioExecutor.execute(() -> {
+			final TransportProperties p) {
-			if (!isRunning()) return;
+		ioExecutor.execute(new Runnable() {
-			DuplexTransportConnection d = createConnection(p);
+			@Override
-			if (d != null) {
+			public void run() {
-				backoff.reset();
+				if (!isRunning()) return;
-				callback.outgoingConnectionCreated(c, d);
+				DuplexTransportConnection d = createConnection(p);
+				if (d != null) {
+					backoff.reset();
+					callback.outgoingConnectionCreated(c, d);
+				}
 			}
 		});
 	}
@@ -247,11 +251,10 @@ abstract class TcpPlugin implements DuplexPlugin {
 				}
 				continue;
 			}
+			Socket s = new Socket();
 			try {
 				if (LOG.isLoggable(INFO))
 					LOG.info("Connecting to " + scrubSocketAddress(remote));
-				Socket s = createSocket();
-				s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
 				s.connect(remote);
 				s.setSoTimeout(socketTimeout);
 				if (LOG.isLoggable(INFO))
@@ -266,10 +269,6 @@ abstract class TcpPlugin implements DuplexPlugin {
 		return null;
 	}
 
-	protected Socket createSocket() throws IOException {
-		return new Socket();
-	}
-
 	@Nullable
 	InetSocketAddress parseSocketAddress(String ipPort) {
 		if (StringUtils.isNullOrEmpty(ipPort)) return null;
@@ -306,7 +305,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 
 	@Override
 	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor) {
+			byte[] commitment, BdfList descriptor, long timeout) {
 		throw new UnsupportedOperationException();
 	}
 
@@ -318,7 +317,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			return Collections.emptyList();
 		}
-		List<InetAddress> addrs = new ArrayList<>();
+		List<InetAddress> addrs = new ArrayList<InetAddress>();
 		for (NetworkInterface iface : ifaces)
 			addrs.addAll(Collections.list(iface.getInetAddresses()));
 		return addrs;

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/WanTcpPlugin.java

@@ -43,7 +43,7 @@ class WanTcpPlugin extends TcpPlugin {
 		// Use the same address and port as last time if available
 		TransportProperties p = callback.getLocalProperties();
 		InetSocketAddress old = parseSocketAddress(p.get(PROP_IP_PORT));
-		List<InetSocketAddress> addrs = new LinkedList<>();
+		List<InetSocketAddress> addrs = new LinkedList<InetSocketAddress>();
 		for (InetAddress a : getLocalIpAddresses()) {
 			if (isAcceptableAddress(a)) {
 				// If this is the old address, try to use the same port

bramble-core/src/main/java/org/briarproject/bramble/properties/PropertiesModule.java

@@ -40,12 +40,9 @@ public class PropertiesModule {
 	@Provides
 	@Singleton
 	TransportPropertyManager getTransportPropertyManager(
-			LifecycleManager lifecycleManager,
+			LifecycleManager lifecycleManager, ContactManager contactManager,
-			ValidationManager validationManager, ContactManager contactManager,
 			TransportPropertyManagerImpl transportPropertyManager) {
 		lifecycleManager.registerClient(transportPropertyManager);
-		validationManager.registerIncomingMessageHook(CLIENT_ID,
-				transportPropertyManager);
 		contactManager.registerAddContactHook(transportPropertyManager);
 		contactManager.registerRemoveContactHook(transportPropertyManager);
 		return transportPropertyManager;

bramble-core/src/main/java/org/briarproject/bramble/properties/TransportPropertyManagerImpl.java

@@ -9,10 +9,8 @@ import org.briarproject.bramble.api.contact.ContactManager.AddContactHook;
 import org.briarproject.bramble.api.contact.ContactManager.RemoveContactHook;
 import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.data.BdfList;
-import org.briarproject.bramble.api.data.MetadataParser;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -21,10 +19,8 @@ import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.sync.Client;
 import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.InvalidMessageException;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.ValidationManager.IncomingMessageHook;
 import org.briarproject.bramble.api.system.Clock;
 
 import java.util.HashMap;
@@ -40,22 +36,20 @@ import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 @Immutable
 @NotNullByDefault
 class TransportPropertyManagerImpl implements TransportPropertyManager,
-		Client, AddContactHook, RemoveContactHook, IncomingMessageHook {
+		Client, AddContactHook, RemoveContactHook {
 
 	private final DatabaseComponent db;
 	private final ClientHelper clientHelper;
-	private final MetadataParser metadataParser;
 	private final ContactGroupFactory contactGroupFactory;
 	private final Clock clock;
 	private final Group localGroup;
 
 	@Inject
 	TransportPropertyManagerImpl(DatabaseComponent db,
-			ClientHelper clientHelper, MetadataParser metadataParser,
+			ClientHelper clientHelper, ContactGroupFactory contactGroupFactory,
-			ContactGroupFactory contactGroupFactory, Clock clock) {
+			Clock clock) {
 		this.db = db;
 		this.clientHelper = clientHelper;
-		this.metadataParser = metadataParser;
 		this.contactGroupFactory = contactGroupFactory;
 		this.clock = clock;
 		localGroup = contactGroupFactory.createLocalGroup(CLIENT_ID);
@@ -63,7 +57,6 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 
 	@Override
 	public void createLocalState(Transaction txn) throws DbException {
-		if (db.containsGroup(txn, localGroup.getId())) return;
 		db.addGroup(txn, localGroup);
 		// Ensure we've set things up for any pre-existing contacts
 		for (Contact c : db.getContacts(txn)) addingContact(txn, c);
@@ -91,31 +84,6 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		db.removeGroup(txn, getContactGroup(c));
 	}
 
-	@Override
-	public boolean incomingMessage(Transaction txn, Message m, Metadata meta)
-			throws DbException, InvalidMessageException {
-		try {
-			// Find the latest update for this transport, if any
-			BdfDictionary d = metadataParser.parse(meta);
-			TransportId t = new TransportId(d.getString("transportId"));
-			LatestUpdate latest = findLatest(txn, m.getGroupId(), t, false);
-			if (latest != null) {
-				if (d.getLong("version") > latest.version) {
-					// This update is newer - delete the previous update
-					db.deleteMessage(txn, latest.messageId);
-					db.deleteMessageMetadata(txn, latest.messageId);
-				} else {
-					// We've already received a newer update - delete this one
-					db.deleteMessage(txn, m.getId());
-					db.deleteMessageMetadata(txn, m.getId());
-				}
-			}
-		} catch (FormatException e) {
-			throw new InvalidMessageException(e);
-		}
-		return false;
-	}
-
 	@Override
 	public void addRemoteProperties(Transaction txn, ContactId c,
 			Map<TransportId, TransportProperties> props) throws DbException {
@@ -130,8 +98,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	public Map<TransportId, TransportProperties> getLocalProperties()
 			throws DbException {
 		Map<TransportId, TransportProperties> local;
-		// TODO: Transaction can be read-only when code is simplified
+		Transaction txn = db.startTransaction(true);
-		Transaction txn = db.startTransaction(false);
 		try {
 			local = getLocalProperties(txn);
 			db.commitTransaction(txn);
@@ -145,9 +112,11 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	public Map<TransportId, TransportProperties> getLocalProperties(
 			Transaction txn) throws DbException {
 		try {
-			Map<TransportId, TransportProperties> local = new HashMap<>();
+			Map<TransportId, TransportProperties> local =
+					new HashMap<TransportId, TransportProperties>();
 			// Find the latest local update for each transport
-			Map<TransportId, LatestUpdate> latest = findLatestLocal(txn);
+			Map<TransportId, LatestUpdate> latest = findLatest(txn,
+					localGroup.getId(), true);
 			// Retrieve and parse the latest local properties
 			for (Entry<TransportId, LatestUpdate> e : latest.entrySet()) {
 				BdfList message = clientHelper.getMessageAsList(txn,
@@ -166,8 +135,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 			throws DbException {
 		try {
 			TransportProperties p = null;
-			// TODO: Transaction can be read-only when code is simplified
+			Transaction txn = db.startTransaction(true);
-			Transaction txn = db.startTransaction(false);
 			try {
 				// Find the latest local update
 				LatestUpdate latest = findLatest(txn, localGroup.getId(), t,
@@ -192,9 +160,9 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Override
 	public Map<ContactId, TransportProperties> getRemoteProperties(
 			TransportId t) throws DbException {
-		Map<ContactId, TransportProperties> remote = new HashMap<>();
+		Map<ContactId, TransportProperties> remote =
-		// TODO: Transaction can be read-only when code is simplified
+				new HashMap<ContactId, TransportProperties>();
-		Transaction txn = db.startTransaction(false);
+		Transaction txn = db.startTransaction(true);
 		try {
 			for (Contact c : db.getContacts(txn))
 				remote.put(c.getId(), getRemoteProperties(txn, c, t));
@@ -228,8 +196,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	public TransportProperties getRemoteProperties(ContactId c, TransportId t)
 			throws DbException {
 		TransportProperties p;
-		// TODO: Transaction can be read-only when code is simplified
+		Transaction txn = db.startTransaction(true);
-		Transaction txn = db.startTransaction(false);
 		try {
 			p = getRemoteProperties(txn, db.getContact(txn, c), t);
 			db.commitTransaction(txn);
@@ -267,9 +234,6 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 					long version = latest == null ? 1 : latest.version + 1;
 					storeMessage(txn, localGroup.getId(), t, merged, version,
 							true, false);
-					// Delete the previous update, if any
-					if (latest != null)
-						db.removeMessage(txn, latest.messageId);
 					// Store the merged properties in each contact's group
 					for (Contact c : db.getContacts(txn)) {
 						Group g = getContactGroup(c);
@@ -277,9 +241,6 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 						version = latest == null ? 1 : latest.version + 1;
 						storeMessage(txn, g.getId(), t, merged, version,
 								true, true);
-						// Delete the previous update, if any
-						if (latest != null)
-							db.removeMessage(txn, latest.messageId);
 					}
 				}
 				db.commitTransaction(txn);
@@ -317,26 +278,20 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		return BdfList.of(t.getString(), version, p);
 	}
 
-	private Map<TransportId, LatestUpdate> findLatestLocal(Transaction txn)
+	private Map<TransportId, LatestUpdate> findLatest(Transaction txn,
-			throws DbException, FormatException {
+			GroupId g, boolean local) throws DbException, FormatException {
-		// TODO: This can be simplified before 1.0
+		Map<TransportId, LatestUpdate> latestUpdates =
-		Map<TransportId, LatestUpdate> latestUpdates = new HashMap<>();
+				new HashMap<TransportId, LatestUpdate>();
-		Map<MessageId, BdfDictionary> metadata = clientHelper
+		Map<MessageId, BdfDictionary> metadata =
-				.getMessageMetadataAsDictionary(txn, localGroup.getId());
+				clientHelper.getMessageMetadataAsDictionary(txn, g);
 		for (Entry<MessageId, BdfDictionary> e : metadata.entrySet()) {
 			BdfDictionary meta = e.getValue();
-			TransportId t = new TransportId(meta.getString("transportId"));
+			if (meta.getBoolean("local") == local) {
-			long version = meta.getLong("version");
+				TransportId t = new TransportId(meta.getString("transportId"));
-			LatestUpdate latest = latestUpdates.get(t);
+				long version = meta.getLong("version");
-			if (latest == null) {
+				LatestUpdate latest = latestUpdates.get(t);
-				latestUpdates.put(t, new LatestUpdate(e.getKey(), version));
+				if (latest == null || version > latest.version)
-			} else if (version > latest.version) {
+					latestUpdates.put(t, new LatestUpdate(e.getKey(), version));
-				// This update is newer - delete the previous one
-				db.removeMessage(txn, latest.messageId);
-				latestUpdates.put(t, new LatestUpdate(e.getKey(), version));
-			} else {
-				// We've already found a newer update - delete this one
-				db.removeMessage(txn, e.getKey());
 			}
 		}
 		return latestUpdates;
@@ -345,7 +300,6 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Nullable
 	private LatestUpdate findLatest(Transaction txn, GroupId g, TransportId t,
 			boolean local) throws DbException, FormatException {
-		// TODO: This can be simplified before 1.0
 		LatestUpdate latest = null;
 		Map<MessageId, BdfDictionary> metadata =
 				clientHelper.getMessageMetadataAsDictionary(txn, g);
@@ -354,26 +308,8 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 			if (meta.getString("transportId").equals(t.getString())
 					&& meta.getBoolean("local") == local) {
 				long version = meta.getLong("version");
-				if (latest == null) {
+				if (latest == null || version > latest.version)
 					latest = new LatestUpdate(e.getKey(), version);
-				} else if (version > latest.version) {
-					// This update is newer - delete the previous one
-					if (local) {
-						db.removeMessage(txn, latest.messageId);
-					} else {
-						db.deleteMessage(txn, latest.messageId);
-						db.deleteMessageMetadata(txn, latest.messageId);
-					}
-					latest = new LatestUpdate(e.getKey(), version);
-				} else {
-					// We've already found a newer update - delete this one
-					if (local) {
-						db.removeMessage(txn, e.getKey());
-					} else {
-						db.deleteMessage(txn, e.getKey());
-						db.deleteMessageMetadata(txn, e.getKey());
-					}
-				}
 			}
 		}
 		return latest;

bramble-core/src/main/java/org/briarproject/bramble/reliability/Receiver.java

@@ -41,7 +41,7 @@ class Receiver implements ReadHandler {
 	Receiver(Clock clock, Sender sender) {
 		this.sender = sender;
 		this.clock = clock;
-		dataFrames = new TreeSet<>(new SequenceNumberComparator());
+		dataFrames = new TreeSet<Data>(new SequenceNumberComparator());
 	}
 
 	Data read() throws IOException, InterruptedException {

bramble-core/src/main/java/org/briarproject/bramble/reliability/ReliabilityLayerImpl.java

@@ -42,44 +42,48 @@ class ReliabilityLayerImpl implements ReliabilityLayer, WriteHandler {
 		this.executor = executor;
 		this.clock = clock;
 		this.writeHandler = writeHandler;
-		writes = new LinkedBlockingQueue<>();
+		writes = new LinkedBlockingQueue<byte[]>();
 	}
 
 	@Override
 	public void start() {
 		SlipEncoder encoder = new SlipEncoder(this);
-		Sender sender = new Sender(clock, encoder);
+		final Sender sender = new Sender(clock, encoder);
 		receiver = new Receiver(clock, sender);
 		decoder = new SlipDecoder(receiver, Data.MAX_LENGTH);
 		inputStream = new ReceiverInputStream(receiver);
 		outputStream = new SenderOutputStream(sender);
 		running = true;
-		executor.execute(() -> {
+		executor.execute(new Runnable() {
-			long now = clock.currentTimeMillis();
+			@Override
-			long next = now + TICK_INTERVAL;
+			public void run() {
-			try {
+				long now = clock.currentTimeMillis();
-				while (running) {
+				long next = now + TICK_INTERVAL;
-					byte[] b = null;
+				try {
-					while (now < next && b == null) {
+					while (running) {
-						b = writes.poll(next - now, MILLISECONDS);
+						byte[] b = null;
-						if (!running) return;
+						while (now < next && b == null) {
-						now = clock.currentTimeMillis();
+							b = writes.poll(next - now, MILLISECONDS);
-					}
+							if (!running) return;
-					if (b == null) {
+							now = clock.currentTimeMillis();
-						sender.tick();
+						}
-						while (next <= now) next += TICK_INTERVAL;
+						if (b == null) {
-					} else {
+							sender.tick();
-						if (b.length == 0) return; // Poison pill
+							while (next <= now) next += TICK_INTERVAL;
-						writeHandler.handleWrite(b);
+						} else {
+							if (b.length == 0) return; // Poison pill
+							writeHandler.handleWrite(b);
+						}
 					}
+				} catch (InterruptedException e) {
+					LOG.warning("Interrupted while waiting to write");
+					Thread.currentThread().interrupt();
+					running = false;
+				} catch (IOException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+					running = false;
 				}
-			} catch (InterruptedException e) {
-				LOG.warning("Interrupted while waiting to write");
-				Thread.currentThread().interrupt();
-				running = false;
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				running = false;
 			}
 		});
 	}

bramble-core/src/main/java/org/briarproject/bramble/reliability/Sender.java

@@ -46,7 +46,7 @@ class Sender {
 	Sender(Clock clock, WriteHandler writeHandler) {
 		this.clock = clock;
 		this.writeHandler = writeHandler;
-		outstanding = new LinkedList<>();
+		outstanding = new LinkedList<Outstanding>();
 	}
 
 	void sendAck(long sequenceNumber, int windowSize) throws IOException {
@@ -136,7 +136,7 @@ class Sender {
 					if (now - o.lastTransmitted > rto) {
 						it.remove();
 						if (retransmit == null)
-							retransmit = new ArrayList<>();
+							retransmit = new ArrayList<Outstanding>();
 						retransmit.add(o);
 						// Update the retransmission timeout
 						rto <<= 1;

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

@@ -10,7 +10,7 @@ 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.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
+import org.briarproject.bramble.api.lifecycle.event.ShutdownEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Offer;
@@ -29,8 +29,6 @@ import java.util.Collection;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.Executor;
 import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicLong;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.ThreadSafe;
@@ -38,7 +36,6 @@ import javax.annotation.concurrent.ThreadSafe;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
 
@@ -52,14 +49,17 @@ import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD
 @NotNullByDefault
 class DuplexOutgoingSession implements SyncSession, EventListener {
 
+	// Check for retransmittable records once every 60 seconds
+	private static final int RETX_QUERY_INTERVAL = 60 * 1000;
 	private static final Logger LOG =
 			Logger.getLogger(DuplexOutgoingSession.class.getName());
 
-	private static final ThrowingRunnable<IOException> CLOSE = () -> {
+	private static final ThrowingRunnable<IOException> CLOSE =
-	};
+			new ThrowingRunnable<IOException>() {
-	private static final ThrowingRunnable<IOException>
+				@Override
-			NEXT_SEND_TIME_DECREASED = () -> {
+				public void run() {
-	};
+				}
+			};
 
 	private final DatabaseComponent db;
 	private final Executor dbExecutor;
@@ -70,13 +70,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	private final RecordWriter recordWriter;
 	private final BlockingQueue<ThrowingRunnable<IOException>> writerTasks;
 
-	private final AtomicBoolean generateAckQueued = new AtomicBoolean(false);
-	private final AtomicBoolean generateBatchQueued = new AtomicBoolean(false);
-	private final AtomicBoolean generateOfferQueued = new AtomicBoolean(false);
-	private final AtomicBoolean generateRequestQueued =
-			new AtomicBoolean(false);
-	private final AtomicLong nextSendTime = new AtomicLong(Long.MAX_VALUE);
-
 	private volatile boolean interrupted = false;
 
 	DuplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
@@ -90,7 +83,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
 		this.recordWriter = recordWriter;
-		writerTasks = new LinkedBlockingQueue<>();
+		writerTasks = new LinkedBlockingQueue<ThrowingRunnable<IOException>>();
 	}
 
 	@IoExecutor
@@ -99,21 +92,21 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		eventBus.addListener(this);
 		try {
 			// Start a query for each type of record
-			generateAck();
+			dbExecutor.execute(new GenerateAck());
-			generateBatch();
+			dbExecutor.execute(new GenerateBatch());
-			generateOffer();
+			dbExecutor.execute(new GenerateOffer());
-			generateRequest();
+			dbExecutor.execute(new GenerateRequest());
 			long now = clock.currentTimeMillis();
 			long nextKeepalive = now + maxIdleTime;
+			long nextRetxQuery = now + RETX_QUERY_INTERVAL;
 			boolean dataToFlush = true;
 			// Write records until interrupted
 			try {
 				while (!interrupted) {
 					// Work out how long we should wait for a record
 					now = clock.currentTimeMillis();
-					long keepaliveWait = Math.max(0, nextKeepalive - now);
+					long wait = Math.min(nextKeepalive, nextRetxQuery) - now;
-					long sendWait = Math.max(0, nextSendTime.get() - now);
+					if (wait < 0) wait = 0;
-					long wait = Math.min(keepaliveWait, sendWait);
 					// Flush any unflushed data if we're going to wait
 					if (wait > 0 && dataToFlush && writerTasks.isEmpty()) {
 						recordWriter.flush();
@@ -125,25 +118,20 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 							MILLISECONDS);
 					if (task == null) {
 						now = clock.currentTimeMillis();
-						if (now >= nextSendTime.get()) {
+						if (now >= nextRetxQuery) {
-							// Check for retransmittable messages
+							// Check for retransmittable records
-							LOG.info("Checking for retransmittable messages");
+							dbExecutor.execute(new GenerateBatch());
-							setNextSendTime(Long.MAX_VALUE);
+							dbExecutor.execute(new GenerateOffer());
-							generateBatch();
+							nextRetxQuery = now + RETX_QUERY_INTERVAL;
-							generateOffer();
 						}
 						if (now >= nextKeepalive) {
 							// Flush the stream to keep it alive
-							LOG.info("Sending keepalive");
 							recordWriter.flush();
 							dataToFlush = false;
 							nextKeepalive = now + maxIdleTime;
 						}
 					} else if (task == CLOSE) {
-						LOG.info("Closed");
 						break;
-					} else if (task == NEXT_SEND_TIME_DECREASED) {
-						LOG.info("Next send time decreased");
 					} else {
 						task.run();
 						dataToFlush = true;
@@ -159,31 +147,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		}
 	}
 
-	private void generateAck() {
-		if (generateAckQueued.compareAndSet(false, true))
-			dbExecutor.execute(new GenerateAck());
-	}
-
-	private void generateBatch() {
-		if (generateBatchQueued.compareAndSet(false, true))
-			dbExecutor.execute(new GenerateBatch());
-	}
-
-	private void generateOffer() {
-		if (generateOfferQueued.compareAndSet(false, true))
-			dbExecutor.execute(new GenerateOffer());
-	}
-
-	private void generateRequest() {
-		if (generateRequestQueued.compareAndSet(false, true))
-			dbExecutor.execute(new GenerateRequest());
-	}
-
-	private void setNextSendTime(long time) {
-		long old = nextSendTime.getAndSet(time);
-		if (time < old) writerTasks.add(NEXT_SEND_TIME_DECREASED);
-	}
-
 	@Override
 	public void interrupt() {
 		interrupted = true;
@@ -196,23 +159,22 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 			ContactRemovedEvent c = (ContactRemovedEvent) e;
 			if (c.getContactId().equals(contactId)) interrupt();
 		} else if (e instanceof MessageSharedEvent) {
-			generateOffer();
+			dbExecutor.execute(new GenerateOffer());
 		} else if (e instanceof GroupVisibilityUpdatedEvent) {
 			GroupVisibilityUpdatedEvent g = (GroupVisibilityUpdatedEvent) e;
 			if (g.getAffectedContacts().contains(contactId))
-				generateOffer();
+				dbExecutor.execute(new GenerateOffer());
 		} else if (e instanceof MessageRequestedEvent) {
 			if (((MessageRequestedEvent) e).getContactId().equals(contactId))
-				generateBatch();
+				dbExecutor.execute(new GenerateBatch());
 		} else if (e instanceof MessageToAckEvent) {
 			if (((MessageToAckEvent) e).getContactId().equals(contactId))
-				generateAck();
+				dbExecutor.execute(new GenerateAck());
 		} else if (e instanceof MessageToRequestEvent) {
 			if (((MessageToRequestEvent) e).getContactId().equals(contactId))
-				generateRequest();
+				dbExecutor.execute(new GenerateRequest());
-		} else if (e instanceof LifecycleEvent) {
+		} else if (e instanceof ShutdownEvent) {
-			LifecycleEvent l = (LifecycleEvent) e;
+			interrupt();
-			if (l.getLifecycleState() == STOPPING) interrupt();
 		}
 	}
 
@@ -222,7 +184,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() {
 			if (interrupted) return;
-			if (!generateAckQueued.getAndSet(false)) throw new AssertionError();
 			try {
 				Ack a;
 				Transaction txn = db.startTransaction(false);
@@ -256,7 +217,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 			if (interrupted) return;
 			recordWriter.writeAck(ack);
 			LOG.info("Sent ack");
-			generateAck();
+			dbExecutor.execute(new GenerateAck());
 		}
 	}
 
@@ -266,15 +227,12 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() {
 			if (interrupted) return;
-			if (!generateBatchQueued.getAndSet(false))
-				throw new AssertionError();
 			try {
 				Collection<byte[]> b;
 				Transaction txn = db.startTransaction(false);
 				try {
 					b = db.generateRequestedBatch(txn, contactId,
 							MAX_RECORD_PAYLOAD_LENGTH, maxLatency);
-					setNextSendTime(db.getNextSendTime(txn, contactId));
 					db.commitTransaction(txn);
 				} finally {
 					db.endTransaction(txn);
@@ -303,7 +261,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 			if (interrupted) return;
 			for (byte[] raw : batch) recordWriter.writeMessage(raw);
 			LOG.info("Sent batch");
-			generateBatch();
+			dbExecutor.execute(new GenerateBatch());
 		}
 	}
 
@@ -313,15 +271,12 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() {
 			if (interrupted) return;
-			if (!generateOfferQueued.getAndSet(false))
-				throw new AssertionError();
 			try {
 				Offer o;
 				Transaction txn = db.startTransaction(false);
 				try {
 					o = db.generateOffer(txn, contactId, MAX_MESSAGE_IDS,
 							maxLatency);
-					setNextSendTime(db.getNextSendTime(txn, contactId));
 					db.commitTransaction(txn);
 				} finally {
 					db.endTransaction(txn);
@@ -350,7 +305,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 			if (interrupted) return;
 			recordWriter.writeOffer(offer);
 			LOG.info("Sent offer");
-			generateOffer();
+			dbExecutor.execute(new GenerateOffer());
 		}
 	}
 
@@ -360,8 +315,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		@Override
 		public void run() {
 			if (interrupted) return;
-			if (!generateRequestQueued.getAndSet(false))
-				throw new AssertionError();
 			try {
 				Request r;
 				Transaction txn = db.startTransaction(false);
@@ -395,7 +348,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 			if (interrupted) return;
 			recordWriter.writeRequest(request);
 			LOG.info("Sent request");
-			generateRequest();
+			dbExecutor.execute(new GenerateRequest());
 		}
 	}
 }

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

@@ -11,7 +11,7 @@ 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.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
+import org.briarproject.bramble.api.lifecycle.event.ShutdownEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
@@ -27,7 +27,6 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 
 /**
  * An incoming {@link SyncSession}.
@@ -97,9 +96,8 @@ class IncomingSession implements SyncSession, EventListener {
 		if (e instanceof ContactRemovedEvent) {
 			ContactRemovedEvent c = (ContactRemovedEvent) e;
 			if (c.getContactId().equals(contactId)) interrupt();
-		} else if (e instanceof LifecycleEvent) {
+		} else if (e instanceof ShutdownEvent) {
-			LifecycleEvent l = (LifecycleEvent) e;
+			interrupt();
-			if (l.getLifecycleState() == STOPPING) interrupt();
 		}
 	}
 

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

@@ -116,7 +116,7 @@ class RecordReaderImpl implements RecordReader {
 	private List<MessageId> readMessageIds() throws IOException {
 		if (payloadLength == 0) throw new FormatException();
 		if (payloadLength % UniqueId.LENGTH != 0) throw new FormatException();
-		List<MessageId> ids = new ArrayList<>();
+		List<MessageId> ids = new ArrayList<MessageId>();
 		for (int off = 0; off < payloadLength; off += UniqueId.LENGTH) {
 			byte[] id = new byte[UniqueId.LENGTH];
 			System.arraycopy(payload, off, id, 0, UniqueId.LENGTH);

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

@@ -10,7 +10,7 @@ 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.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
+import org.briarproject.bramble.api.lifecycle.event.ShutdownEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.RecordWriter;
@@ -28,7 +28,6 @@ import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_RECORD_PAYLOAD_LENGTH;
 
@@ -44,7 +43,12 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 	private static final Logger LOG =
 			Logger.getLogger(SimplexOutgoingSession.class.getName());
 
-	private static final ThrowingRunnable<IOException> CLOSE = () -> {};
+	private static final ThrowingRunnable<IOException> CLOSE =
+			new ThrowingRunnable<IOException>() {
+				@Override
+				public void run() {
+				}
+			};
 
 	private final DatabaseComponent db;
 	private final Executor dbExecutor;
@@ -67,7 +71,7 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 		this.maxLatency = maxLatency;
 		this.recordWriter = recordWriter;
 		outstandingQueries = new AtomicInteger(2); // One per type of record
-		writerTasks = new LinkedBlockingQueue<>();
+		writerTasks = new LinkedBlockingQueue<ThrowingRunnable<IOException>>();
 	}
 
 	@IoExecutor
@@ -110,9 +114,8 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 		if (e instanceof ContactRemovedEvent) {
 			ContactRemovedEvent c = (ContactRemovedEvent) e;
 			if (c.getContactId().equals(contactId)) interrupt();
-		} else if (e instanceof LifecycleEvent) {
+		} else if (e instanceof ShutdownEvent) {
-			LifecycleEvent l = (LifecycleEvent) e;
+			interrupt();
-			if (l.getLifecycleState() == STOPPING) interrupt();
 		}
 	}
 

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

@@ -64,16 +64,18 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		this.dbExecutor = dbExecutor;
 		this.validationExecutor = validationExecutor;
 		this.messageFactory = messageFactory;
-		validators = new ConcurrentHashMap<>();
+		validators = new ConcurrentHashMap<ClientId, MessageValidator>();
-		hooks = new ConcurrentHashMap<>();
+		hooks = new ConcurrentHashMap<ClientId, IncomingMessageHook>();
 	}
 
 	@Override
 	public void startService() {
 		if (used.getAndSet(true)) throw new IllegalStateException();
-		validateOutstandingMessagesAsync();
+		for (ClientId c : validators.keySet()) {
-		deliverOutstandingMessagesAsync();
+			validateOutstandingMessagesAsync(c);
-		shareOutstandingMessagesAsync();
+			deliverOutstandingMessagesAsync(c);
+			shareOutstandingMessagesAsync(c);
+		}
 	}
 
 	@Override
@@ -91,17 +93,22 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		hooks.put(c, hook);
 	}
 
-	private void validateOutstandingMessagesAsync() {
+	private void validateOutstandingMessagesAsync(final ClientId c) {
-		dbExecutor.execute(this::validateOutstandingMessages);
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				validateOutstandingMessages(c);
+			}
+		});
 	}
 
 	@DatabaseExecutor
-	private void validateOutstandingMessages() {
+	private void validateOutstandingMessages(ClientId c) {
 		try {
-			Queue<MessageId> unvalidated = new LinkedList<>();
+			Queue<MessageId> unvalidated = new LinkedList<MessageId>();
 			Transaction txn = db.startTransaction(true);
 			try {
-				unvalidated.addAll(db.getMessagesToValidate(txn));
+				unvalidated.addAll(db.getMessagesToValidate(txn, c));
 				db.commitTransaction(txn);
 			} finally {
 				db.endTransaction(txn);
@@ -112,9 +119,14 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
-	private void validateNextMessageAsync(Queue<MessageId> unvalidated) {
+	private void validateNextMessageAsync(final Queue<MessageId> unvalidated) {
 		if (unvalidated.isEmpty()) return;
-		dbExecutor.execute(() -> validateNextMessage(unvalidated));
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				validateNextMessage(unvalidated);
+			}
+		});
 	}
 
 	@DatabaseExecutor
@@ -146,17 +158,22 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
-	private void deliverOutstandingMessagesAsync() {
+	private void deliverOutstandingMessagesAsync(final ClientId c) {
-		dbExecutor.execute(this::deliverOutstandingMessages);
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				deliverOutstandingMessages(c);
+			}
+		});
 	}
 
 	@DatabaseExecutor
-	private void deliverOutstandingMessages() {
+	private void deliverOutstandingMessages(ClientId c) {
 		try {
-			Queue<MessageId> pending = new LinkedList<>();
+			Queue<MessageId> pending = new LinkedList<MessageId>();
 			Transaction txn = db.startTransaction(true);
 			try {
-				pending.addAll(db.getPendingMessages(txn));
+				pending.addAll(db.getPendingMessages(txn, c));
 				db.commitTransaction(txn);
 			} finally {
 				db.endTransaction(txn);
@@ -167,9 +184,15 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
-	private void deliverNextPendingMessageAsync(Queue<MessageId> pending) {
+	private void deliverNextPendingMessageAsync(
+			final Queue<MessageId> pending) {
 		if (pending.isEmpty()) return;
-		dbExecutor.execute(() -> deliverNextPendingMessage(pending));
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				deliverNextPendingMessage(pending);
+			}
+		});
 	}
 
 	@DatabaseExecutor
@@ -206,7 +229,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 							pending.addAll(getPendingDependents(txn, id));
 							if (result.share) {
 								db.setMessageShared(txn, id);
-								toShare = new LinkedList<>(states.keySet());
+								toShare = new LinkedList<MessageId>(
+										states.keySet());
 							}
 						} else {
 							invalidate = getDependentsToInvalidate(txn, id);
@@ -231,8 +255,13 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
-	private void validateMessageAsync(Message m, Group g) {
+	private void validateMessageAsync(final Message m, final Group g) {
-		validationExecutor.execute(() -> validateMessage(m, g));
+		validationExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				validateMessage(m, g);
+			}
+		});
 	}
 
 	@ValidationExecutor
@@ -248,16 +277,21 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			} catch (InvalidMessageException e) {
 				if (LOG.isLoggable(INFO))
 					LOG.log(INFO, e.toString(), e);
-				Queue<MessageId> invalidate = new LinkedList<>();
+				Queue<MessageId> invalidate = new LinkedList<MessageId>();
 				invalidate.add(m.getId());
 				invalidateNextMessageAsync(invalidate);
 			}
 		}
 	}
 
-	private void storeMessageContextAsync(Message m, ClientId c,
+	private void storeMessageContextAsync(final Message m, final ClientId c,
-			MessageContext result) {
+			final MessageContext result) {
-		dbExecutor.execute(() -> storeMessageContext(m, c, result));
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				storeMessageContext(m, c, result);
+			}
+		});
 	}
 
 	@DatabaseExecutor
@@ -297,7 +331,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 							pending = getPendingDependents(txn, id);
 							if (result.share) {
 								db.setMessageShared(txn, id);
-								toShare = new LinkedList<>(dependencies);
+								toShare =
+										new LinkedList<MessageId>(dependencies);
 							}
 						} else {
 							invalidate = getDependentsToInvalidate(txn, id);
@@ -343,7 +378,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	@DatabaseExecutor
 	private Queue<MessageId> getPendingDependents(Transaction txn, MessageId m)
 			throws DbException {
-		Queue<MessageId> pending = new LinkedList<>();
+		Queue<MessageId> pending = new LinkedList<MessageId>();
 		Map<MessageId, State> states = db.getMessageDependents(txn, m);
 		for (Entry<MessageId, State> e : states.entrySet()) {
 			if (e.getValue() == PENDING) pending.add(e.getKey());
@@ -351,17 +386,22 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		return pending;
 	}
 
-	private void shareOutstandingMessagesAsync() {
+	private void shareOutstandingMessagesAsync(final ClientId c) {
-		dbExecutor.execute(this::shareOutstandingMessages);
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				shareOutstandingMessages(c);
+			}
+		});
 	}
 
 	@DatabaseExecutor
-	private void shareOutstandingMessages() {
+	private void shareOutstandingMessages(ClientId c) {
 		try {
-			Queue<MessageId> toShare = new LinkedList<>();
+			Queue<MessageId> toShare = new LinkedList<MessageId>();
 			Transaction txn = db.startTransaction(true);
 			try {
-				toShare.addAll(db.getMessagesToShare(txn));
+				toShare.addAll(db.getMessagesToShare(txn, c));
 				db.commitTransaction(txn);
 			} finally {
 				db.endTransaction(txn);
@@ -378,9 +418,14 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	 * This method should only be called for messages that have all their
 	 * dependencies delivered and have been delivered themselves.
 	 */
-	private void shareNextMessageAsync(Queue<MessageId> toShare) {
+	private void shareNextMessageAsync(final Queue<MessageId> toShare) {
 		if (toShare.isEmpty()) return;
-		dbExecutor.execute(() -> shareNextMessage(toShare));
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				shareNextMessage(toShare);
+			}
+		});
 	}
 
 	@DatabaseExecutor
@@ -407,9 +452,14 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
-	private void invalidateNextMessageAsync(Queue<MessageId> invalidate) {
+	private void invalidateNextMessageAsync(final Queue<MessageId> invalidate) {
 		if (invalidate.isEmpty()) return;
-		dbExecutor.execute(() -> invalidateNextMessage(invalidate));
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				invalidateNextMessage(invalidate);
+			}
+		});
 	}
 
 	@DatabaseExecutor
@@ -446,7 +496,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	@DatabaseExecutor
 	private Queue<MessageId> getDependentsToInvalidate(Transaction txn,
 			MessageId m) throws DbException {
-		Queue<MessageId> invalidate = new LinkedList<>();
+		Queue<MessageId> invalidate = new LinkedList<MessageId>();
 		Map<MessageId, State> states = db.getMessageDependents(txn, m);
 		for (Entry<MessageId, State> e : states.entrySet()) {
 			if (e.getValue() != INVALID) invalidate.add(e.getKey());
@@ -464,12 +514,17 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
-	private void loadGroupAndValidateAsync(Message m) {
+	private void loadGroupAndValidateAsync(final Message m) {
-		dbExecutor.execute(() -> loadGroupAndValidate(m));
+		dbExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				loadGroupAndValidate(m);
+			}
+		});
 	}
 
 	@DatabaseExecutor
-	private void loadGroupAndValidate(Message m) {
+	private void loadGroupAndValidate(final Message m) {
 		try {
 			Group g;
 			Transaction txn = db.startTransaction(true);

bramble-core/src/main/java/org/briarproject/bramble/system/SystemModule.java

@@ -4,9 +4,8 @@ import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.Scheduler;
 
-import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
@@ -26,10 +25,7 @@ public class SystemModule {
 	private final ScheduledExecutorService scheduler;
 
 	public SystemModule() {
-		// Discard tasks that are submitted during shutdown
+		scheduler = Executors.newSingleThreadScheduledExecutor();
-		RejectedExecutionHandler policy =
-				new ScheduledThreadPoolExecutor.DiscardPolicy();
-		scheduler = new ScheduledThreadPoolExecutor(1, policy);
 	}
 
 	@Provides

bramble-core/src/main/java/org/briarproject/bramble/transport/KeyManagerImpl.java

@@ -58,14 +58,15 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 		this.pluginConfig = pluginConfig;
 		this.transportKeyManagerFactory = transportKeyManagerFactory;
 		// Use a ConcurrentHashMap as a thread-safe set
-		activeContacts = new ConcurrentHashMap<>();
+		activeContacts = new ConcurrentHashMap<ContactId, Boolean>();
-		managers = new ConcurrentHashMap<>();
+		managers = new ConcurrentHashMap<TransportId, TransportKeyManager>();
 	}
 
 	@Override
 	public void startService() throws ServiceException {
 		if (used.getAndSet(true)) throw new IllegalStateException();
-		Map<TransportId, Integer> transports = new HashMap<>();
+		Map<TransportId, Integer> transports =
+				new HashMap<TransportId, Integer>();
 		for (SimplexPluginFactory f : pluginConfig.getSimplexFactories())
 			transports.put(f.getId(), f.getMaxLatency());
 		for (DuplexPluginFactory f : pluginConfig.getDuplexFactories())
@@ -155,10 +156,14 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 		}
 	}
 
-	private void removeContact(ContactId c) {
+	private void removeContact(final ContactId c) {
 		activeContacts.remove(c);
-		dbExecutor.execute(() -> {
+		dbExecutor.execute(new Runnable() {
-			for (TransportKeyManager m : managers.values()) m.removeContact(c);
+			@Override
+			public void run() {
+				for (TransportKeyManager m : managers.values())
+					m.removeContact(c);
+			}
 		});
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/transport/ReorderingWindow.java

@@ -45,7 +45,7 @@ class ReorderingWindow {
 	}
 
 	List<Long> getUnseen() {
-		List<Long> unseen = new ArrayList<>(seen.length);
+		List<Long> unseen = new ArrayList<Long>(seen.length);
 		for (int i = 0; i < seen.length; i++)
 			if (!seen[i]) unseen.add(base + i);
 		return unseen;
@@ -69,8 +69,8 @@ class ReorderingWindow {
 			return new Change(added, removed);
 		}
 		// Record the elements that will be added and removed
-		List<Long> added = new ArrayList<>(slide);
+		List<Long> added = new ArrayList<Long>(slide);
-		List<Long> removed = new ArrayList<>(slide);
+		List<Long> removed = new ArrayList<Long>(slide);
 		for (int i = 0; i < slide; i++) {
 			if (!seen[i]) removed.add(base + i);
 			added.add(base + seen.length + i);

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerImpl.java

@@ -65,9 +65,9 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		this.transportId = transportId;
 		rotationPeriodLength = maxLatency + MAX_CLOCK_DIFFERENCE;
 		lock = new ReentrantLock();
-		inContexts = new HashMap<>();
+		inContexts = new HashMap<Bytes, TagContext>();
-		outContexts = new HashMap<>();
+		outContexts = new HashMap<ContactId, MutableOutgoingKeys>();
-		keys = new HashMap<>();
+		keys = new HashMap<ContactId, MutableTransportKeys>();
 	}
 
 	@Override
@@ -134,22 +134,32 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	private void scheduleKeyRotation(long now) {
+		Runnable task = new Runnable() {
+			@Override
+			public void run() {
+				rotateKeys();
+			}
+		};
 		long delay = rotationPeriodLength - now % rotationPeriodLength;
-		scheduler.schedule((Runnable) this::rotateKeys, delay, MILLISECONDS);
+		scheduler.schedule(task, delay, MILLISECONDS);
 	}
 
 	private void rotateKeys() {
-		dbExecutor.execute(() -> {
+		dbExecutor.execute(new Runnable() {
-			try {
+			@Override
-				Transaction txn = db.startTransaction(false);
+			public void run() {
 				try {
-					rotateKeys(txn);
+					Transaction txn = db.startTransaction(false);
-					db.commitTransaction(txn);
+					try {
-				} finally {
+						rotateKeys(txn);
-					db.endTransaction(txn);
+						db.commitTransaction(txn);
+					} finally {
+						db.endTransaction(txn);
+					}
+				} catch (DbException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
 				}
-			} catch (DbException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			}
 		});
 	}
@@ -262,7 +272,8 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		lock.lock();
 		try {
 			// Rotate the keys to the current rotation period
-			Map<ContactId, TransportKeys> snapshot = new HashMap<>();
+			Map<ContactId, TransportKeys> snapshot =
+					new HashMap<ContactId, TransportKeys>();
 			for (Entry<ContactId, MutableTransportKeys> e : keys.entrySet())
 				snapshot.put(e.getKey(), e.getValue().snapshot());
 			RotationResult rotationResult = rotateKeys(snapshot, now);
@@ -300,8 +311,8 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		private final Map<ContactId, TransportKeys> current, rotated;
 
 		private RotationResult() {
-			current = new HashMap<>();
+			current = new HashMap<ContactId, TransportKeys>();
-			rotated = new HashMap<>();
+			rotated = new HashMap<ContactId, TransportKeys>();
 		}
 	}
 }

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

@@ -24,13 +24,16 @@ public class PoliteExecutorTest extends BrambleTestCase {
 		Executor delegate = Executors.newSingleThreadExecutor();
 		// Allow all the tasks to be delegated straight away
 		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, TASKS * 2);
-		List<Integer> list = new Vector<>();
+		final List<Integer> list = new Vector<Integer>();
-		CountDownLatch latch = new CountDownLatch(TASKS);
+		final CountDownLatch latch = new CountDownLatch(TASKS);
 		for (int i = 0; i < TASKS; i++) {
-			int result = i;
+			final int result = i;
-			polite.execute(() -> {
+			polite.execute(new Runnable() {
-				list.add(result);
+				@Override
-				latch.countDown();
+				public void run() {
+					list.add(result);
+					latch.countDown();
+				}
 			});
 		}
 		// Wait for all the tasks to finish
@@ -46,13 +49,16 @@ public class PoliteExecutorTest extends BrambleTestCase {
 		Executor delegate = Executors.newSingleThreadExecutor();
 		// Allow two tasks to be delegated at a time
 		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, 2);
-		List<Integer> list = new Vector<>();
+		final List<Integer> list = new Vector<Integer>();
-		CountDownLatch latch = new CountDownLatch(TASKS);
+		final CountDownLatch latch = new CountDownLatch(TASKS);
 		for (int i = 0; i < TASKS; i++) {
-			int result = i;
+			final int result = i;
-			polite.execute(() -> {
+			polite.execute(new Runnable() {
-				list.add(result);
+				@Override
-				latch.countDown();
+				public void run() {
+					list.add(result);
+					latch.countDown();
+				}
 			});
 		}
 		// Wait for all the tasks to finish
@@ -67,20 +73,23 @@ public class PoliteExecutorTest extends BrambleTestCase {
 		Executor delegate = Executors.newCachedThreadPool();
 		// Allow all the tasks to be delegated straight away
 		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, TASKS * 2);
-		List<Integer> list = new Vector<>();
+		final List<Integer> list = new Vector<Integer>();
-		CountDownLatch[] latches = new CountDownLatch[TASKS];
+		final CountDownLatch[] latches = new CountDownLatch[TASKS];
 		for (int i = 0; i < TASKS; i++) latches[i] = new CountDownLatch(1);
 		for (int i = 0; i < TASKS; i++) {
-			int result = i;
+			final int result = i;
-			polite.execute(() -> {
+			polite.execute(new Runnable() {
-				try {
+				@Override
-					// Each task waits for the next task, if any, to finish
+				public void run() {
-					if (result < TASKS - 1) latches[result + 1].await();
+					try {
-					list.add(result);
+						// Each task waits for the next task, if any, to finish
-				} catch (InterruptedException e) {
+						if (result < TASKS - 1) latches[result + 1].await();
-					fail();
+						list.add(result);
+					} catch (InterruptedException e) {
+						fail();
+					}
+					latches[result].countDown();
 				}
-				latches[result].countDown();
 			});
 		}
 		// Wait for all the tasks to finish
@@ -95,19 +104,22 @@ public class PoliteExecutorTest extends BrambleTestCase {
 		Executor delegate = Executors.newCachedThreadPool();
 		// Allow one task to be delegated at a time
 		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, 1);
-		List<Integer> list = new Vector<>();
+		final List<Integer> list = new Vector<Integer>();
-		CountDownLatch latch = new CountDownLatch(TASKS);
+		final CountDownLatch latch = new CountDownLatch(TASKS);
 		for (int i = 0; i < TASKS; i++) {
-			int result = i;
+			final int result = i;
-			polite.execute(() -> {
+			polite.execute(new Runnable() {
-				try {
+				@Override
-					// Each task runs faster than the previous task
+				public void run() {
-					Thread.sleep(TASKS - result);
+					try {
-					list.add(result);
+						// Each task runs faster than the previous task
-				} catch (InterruptedException e) {
+						Thread.sleep(TASKS - result);
-					fail();
+						list.add(result);
+					} catch (InterruptedException e) {
+						fail();
+					}
+					latch.countDown();
 				}
-				latch.countDown();
 			});
 		}
 		// Wait for all the tasks to finish

bramble-core/src/test/java/org/briarproject/bramble/client/BdfMessageValidatorTest.java

@@ -83,9 +83,9 @@ public class BdfMessageValidatorTest extends ValidatorTestCase {
 
 	@Test(expected = InvalidMessageException.class)
 	public void testRejectsTooShortMessage() throws Exception {
-		byte[] invalidRaw = new byte[MESSAGE_HEADER_LENGTH];
+		final byte[] invalidRaw = new byte[MESSAGE_HEADER_LENGTH];
 		// Use a mock message so the length of the raw message can be invalid
-		Message invalidMessage = context.mock(Message.class);
+		final Message invalidMessage = context.mock(Message.class);
 
 		context.checking(new Expectations() {{
 			oneOf(invalidMessage).getTimestamp();
@@ -101,8 +101,8 @@ public class BdfMessageValidatorTest extends ValidatorTestCase {
 
 	@Test
 	public void testAcceptsMinLengthMessage() throws Exception {
-		byte[] shortRaw = new byte[MESSAGE_HEADER_LENGTH + 1];
+		final byte[] shortRaw = new byte[MESSAGE_HEADER_LENGTH + 1];
-		Message shortMessage =
+		final Message shortMessage =
 				new Message(messageId, groupId, timestamp, shortRaw);
 
 		context.checking(new Expectations() {{

bramble-core/src/test/java/org/briarproject/bramble/client/ClientHelperImplTest.java

@@ -76,8 +76,8 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testAddLocalMessage() throws Exception {
-		boolean shared = true;
+		final boolean shared = true;
-		Transaction txn = new Transaction(null, false);
+		final Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(false);
@@ -95,7 +95,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testCreateMessage() throws Exception {
-		byte[] bytes = expectToByteArray(list);
+		final byte[] bytes = expectToByteArray(list);
 
 		context.checking(new Expectations() {{
 			oneOf(messageFactory).createMessage(groupId, timestamp, bytes);
@@ -107,7 +107,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testGetMessageAsList() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 
 		expectToList(true);
 		context.checking(new Expectations() {{
@@ -125,7 +125,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testGetGroupMetadataAsDictionary() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
@@ -145,7 +145,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testGetMessageMetadataAsDictionary() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
@@ -165,9 +165,10 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testGetMessageMetadataAsDictionaryMap() throws Exception {
-		Map<MessageId, BdfDictionary> map = new HashMap<>();
+		final Map<MessageId, BdfDictionary> map =
+				new HashMap<MessageId, BdfDictionary>();
 		map.put(messageId, dictionary);
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
@@ -187,13 +188,14 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testGetMessageMetadataAsDictionaryQuery() throws Exception {
-		Map<MessageId, BdfDictionary> map = new HashMap<>();
+		final Map<MessageId, BdfDictionary> map =
+				new HashMap<MessageId, BdfDictionary>();
 		map.put(messageId, dictionary);
-		BdfDictionary query =
+		final BdfDictionary query =
 				BdfDictionary.of(new BdfEntry("query", "me"));
-		Metadata queryMetadata = new Metadata();
+		final Metadata queryMetadata = new Metadata();
 		queryMetadata.put("query", getRandomBytes(42));
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
@@ -215,7 +217,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testMergeGroupMetadata() throws Exception {
-		Transaction txn = new Transaction(null, false);
+		final Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(false);
@@ -233,7 +235,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testMergeMessageMetadata() throws Exception {
-		Transaction txn = new Transaction(null, false);
+		final Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(false);
@@ -280,10 +282,10 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testSign() throws Exception {
-		byte[] privateKey = getRandomBytes(42);
+		final byte[] privateKey = getRandomBytes(42);
-		byte[] signed = getRandomBytes(42);
+		final byte[] signed = getRandomBytes(42);
 
-		byte[] bytes = expectToByteArray(list);
+		final byte[] bytes = expectToByteArray(list);
 		context.checking(new Expectations() {{
 			oneOf(cryptoComponent).sign(label, bytes, privateKey);
 			will(returnValue(signed));
@@ -295,8 +297,8 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testVerifySignature() throws Exception {
-		byte[] publicKey = getRandomBytes(42);
+		final byte[] publicKey = getRandomBytes(42);
-		byte[] bytes = expectToByteArray(list);
+		final byte[] bytes = expectToByteArray(list);
 
 		context.checking(new Expectations() {{
 			oneOf(cryptoComponent).verify(label, bytes, publicKey, rawMessage);
@@ -309,8 +311,8 @@ public class ClientHelperImplTest extends BrambleTestCase {
 
 	@Test
 	public void testVerifyWrongSignature() throws Exception {
-		byte[] publicKey = getRandomBytes(42);
+		final byte[] publicKey = getRandomBytes(42);
-		byte[] bytes = expectToByteArray(list);
+		final byte[] bytes = expectToByteArray(list);
 
 		context.checking(new Expectations() {{
 			oneOf(cryptoComponent).verify(label, bytes, publicKey, rawMessage);
@@ -327,8 +329,8 @@ public class ClientHelperImplTest extends BrambleTestCase {
 		}
 	}
 
-	private byte[] expectToByteArray(BdfList list) throws Exception {
+	private byte[] expectToByteArray(final BdfList list) throws Exception {
-		BdfWriter bdfWriter = context.mock(BdfWriter.class);
+		final BdfWriter bdfWriter = context.mock(BdfWriter.class);
 
 		context.checking(new Expectations() {{
 			oneOf(bdfWriterFactory)
@@ -339,8 +341,8 @@ public class ClientHelperImplTest extends BrambleTestCase {
 		return new byte[0];
 	}
 
-	private void expectToList(boolean eof) throws Exception {
+	private void expectToList(final boolean eof) throws Exception {
-		BdfReader bdfReader = context.mock(BdfReader.class);
+		final BdfReader bdfReader = context.mock(BdfReader.class);
 
 		context.checking(new Expectations() {{
 			oneOf(bdfReaderFactory)

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

@@ -46,10 +46,10 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testAddContact() throws Exception {
-		SecretKey master = getSecretKey();
+		final SecretKey master = getSecretKey();
-		long timestamp = 42;
+		final long timestamp = 42;
-		boolean alice = true;
+		final boolean alice = true;
-		Transaction txn = new Transaction(null, false);
+		final Transaction txn = new Transaction(null, false);
 
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(false);
@@ -64,13 +64,14 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).endTransaction(txn);
 		}});
 
-		assertEquals(contactId, contactManager.addContact(remote, local,
+		assertEquals(contactId, contactManager
-				master, timestamp, alice, verified, active));
+				.addContact(remote, local, master, timestamp, alice, verified,
+						active));
 	}
 
 	@Test
 	public void testGetContact() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
 			will(returnValue(txn));
@@ -85,8 +86,8 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testGetContactByAuthor() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
-		Collection<Contact> contacts = Collections.singleton(contact);
+		final Collection<Contact> contacts = Collections.singleton(contact);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
 			will(returnValue(txn));
@@ -101,7 +102,7 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test(expected = NoSuchContactException.class)
 	public void testGetContactByUnknownAuthor() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
 			will(returnValue(txn));
@@ -115,8 +116,8 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test(expected = NoSuchContactException.class)
 	public void testGetContactByUnknownLocalAuthor() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
-		Collection<Contact> contacts = Collections.singleton(contact);
+		final Collection<Contact> contacts = Collections.singleton(contact);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
 			will(returnValue(txn));
@@ -131,9 +132,10 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testActiveContacts() throws Exception {
 		Collection<Contact> activeContacts = Collections.singletonList(contact);
-		Collection<Contact> contacts = new ArrayList<>(activeContacts);
+		final Collection<Contact> contacts =
+				new ArrayList<Contact>(activeContacts);
 		contacts.add(new Contact(new ContactId(3), remote, local, true, false));
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
 			will(returnValue(txn));
@@ -148,7 +150,7 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testRemoveContact() throws Exception {
-		Transaction txn = new Transaction(null, false);
+		final Transaction txn = new Transaction(null, false);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(false);
 			will(returnValue(txn));
@@ -164,7 +166,7 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testSetContactActive() throws Exception {
-		Transaction txn = new Transaction(null, false);
+		final Transaction txn = new Transaction(null, false);
 		context.checking(new Expectations() {{
 			oneOf(db).setContactActive(txn, contactId, active);
 		}});
@@ -174,7 +176,7 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testContactExists() throws Exception {
-		Transaction txn = new Transaction(null, true);
+		final Transaction txn = new Transaction(null, true);
 		context.checking(new Expectations() {{
 			oneOf(db).startTransaction(true);
 			will(returnValue(txn));

bramble-core/src/test/java/org/briarproject/bramble/crypto/EllipticCurvePerformanceTest.java

@@ -69,7 +69,7 @@ public class EllipticCurvePerformanceTest {
 		ECPublicKeyParameters public2 =
 				(ECPublicKeyParameters) keyPair2.getPublic();
 		// Time some ECDH key agreements
-		List<Long> samples = new ArrayList<>();
+		List<Long> samples = new ArrayList<Long>();
 		for (int i = 0; i < SAMPLES; i++) {
 			ECDHCBasicAgreement agreement = new ECDHCBasicAgreement();
 			long start = System.nanoTime();
@@ -79,7 +79,7 @@ public class EllipticCurvePerformanceTest {
 		}
 		long agreementMedian = median(samples);
 		// Time some signatures
-		List<byte[]> signatures = new ArrayList<>();
+		List<byte[]> signatures = new ArrayList<byte[]>();
 		samples.clear();
 		for (int i = 0; i < SAMPLES; i++) {
 			Digest digest = new Blake2sDigest();

bramble-core/src/test/java/org/briarproject/bramble/crypto/KeyDerivationTest.java

@@ -145,7 +145,7 @@ public class KeyDerivationTest extends BrambleTestCase {
 	}
 
 	private void assertAllDifferent(TransportKeys... transportKeys) {
-		List<SecretKey> secretKeys = new ArrayList<>();
+		List<SecretKey> secretKeys = new ArrayList<SecretKey>();
 		for (TransportKeys k : transportKeys) {
 			secretKeys.add(k.getPreviousIncomingKeys().getTagKey());
 			secretKeys.add(k.getPreviousIncomingKeys().getHeaderKey());
@@ -160,7 +160,7 @@ public class KeyDerivationTest extends BrambleTestCase {
 	}
 
 	private void assertAllDifferent(List<SecretKey> keys) {
-		Set<Bytes> set = new HashSet<>();
+		Set<Bytes> set = new HashSet<Bytes>();
 		for (SecretKey k : keys) assertTrue(set.add(new Bytes(k.getBytes())));
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/crypto/TagEncodingTest.java

@@ -28,7 +28,7 @@ public class TagEncodingTest extends BrambleTestCase {
 
 	@Test
 	public void testKeyAffectsTag() throws Exception {
-		Set<Bytes> set = new HashSet<>();
+		Set<Bytes> set = new HashSet<Bytes>();
 		for (int i = 0; i < 100; i++) {
 			byte[] tag = new byte[TAG_LENGTH];
 			SecretKey tagKey = TestUtils.getSecretKey();
@@ -39,7 +39,7 @@ public class TagEncodingTest extends BrambleTestCase {
 
 	@Test
 	public void testProtocolVersionAffectsTag() throws Exception {
-		Set<Bytes> set = new HashSet<>();
+		Set<Bytes> set = new HashSet<Bytes>();
 		for (int i = 0; i < 100; i++) {
 			byte[] tag = new byte[TAG_LENGTH];
 			crypto.encodeTag(tag, tagKey, PROTOCOL_VERSION + i, streamNumber);
@@ -49,7 +49,7 @@ public class TagEncodingTest extends BrambleTestCase {
 
 	@Test
 	public void testStreamNumberAffectsTag() throws Exception {
-		Set<Bytes> set = new HashSet<>();
+		Set<Bytes> set = new HashSet<Bytes>();
 		for (int i = 0; i < 100; i++) {
 			byte[] tag = new byte[TAG_LENGTH];
 			crypto.encodeTag(tag, tagKey, PROTOCOL_VERSION, streamNumber + i);