Log DB table names.

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

@@ -86,8 +86,8 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 		BluetoothConnectionFactory<BluetoothSocket> connectionFactory =
 				new AndroidBluetoothConnectionFactory(connectionLimiter,
 						wakeLockManager, timeoutMonitor);
-		Backoff backoff = backoffFactory.createBackoff(eventBus, ID,
-				MIN_POLLING_INTERVAL, MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
 				connectionLimiter, connectionFactory, ioExecutor,
 				wakefulIoExecutor, secureRandom, androidExecutor, app,

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

@@ -61,8 +61,8 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
-		Backoff backoff = backoffFactory.createBackoff(eventBus, ID,
-				MIN_POLLING_INTERVAL, MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidLanTcpPlugin plugin = new AndroidLanTcpPlugin(ioExecutor,
 				wakefulIoExecutor, app, backoff, callback,
 				MAX_LATENCY, MAX_IDLE_TIME, CONNECTION_TIMEOUT);

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

@@ -9,6 +9,7 @@ import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 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.PluginCallback;
 import org.briarproject.bramble.api.system.AndroidWakeLock;
 import org.briarproject.bramble.api.system.AndroidWakeLockManager;
@@ -63,6 +64,7 @@ class AndroidTorPlugin extends TorPlugin {
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
 			AndroidWakeLockManager wakeLockManager,
+			Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback,
 			String architecture,
@@ -73,7 +75,7 @@ class AndroidTorPlugin extends TorPlugin {
 			int torControlPort) {
 		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
 				torSocketFactory, clock, resourceProvider,
-				circumventionProvider, batteryManager,
+				circumventionProvider, batteryManager, backoff,
 				torRendezvousCrypto, callback, architecture, maxLatency,
 				maxIdleTime, torDirectory, torSocksPort, torControlPort);
 		this.app = app;

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

@@ -8,6 +8,8 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TorControlPort;
 import org.briarproject.bramble.api.plugin.TorDirectory;
@@ -42,6 +44,7 @@ public class AndroidTorPluginFactory extends TorPluginFactory {
 			LocationUtils locationUtils,
 			EventBus eventBus,
 			SocketFactory torSocketFactory,
+			BackoffFactory backoffFactory,
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
@@ -53,7 +56,7 @@ public class AndroidTorPluginFactory extends TorPluginFactory {
 			Application app,
 			AndroidWakeLockManager wakeLockManager) {
 		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
-				eventBus, torSocketFactory, resourceProvider,
+				eventBus, torSocketFactory, backoffFactory, resourceProvider,
 				circumventionProvider, batteryManager, clock, crypto,
 				torDirectory, torSocksPort, torControlPort);
 		this.app = app;
@@ -73,14 +76,14 @@ public class AndroidTorPluginFactory extends TorPluginFactory {
 	}
 
 	@Override
-	TorPlugin createPluginInstance(TorRendezvousCrypto torRendezvousCrypto,
-			PluginCallback callback,
+	TorPlugin createPluginInstance(Backoff backoff,
+			TorRendezvousCrypto torRendezvousCrypto, PluginCallback callback,
 			String architecture) {
 		return new AndroidTorPlugin(ioExecutor,
 				wakefulIoExecutor, app, networkManager, locationUtils,
 				torSocketFactory, clock, resourceProvider,
 				circumventionProvider, batteryManager, wakeLockManager,
-				torRendezvousCrypto, callback, architecture,
+				backoff, torRendezvousCrypto, callback, architecture,
 				MAX_LATENCY, MAX_IDLE_TIME, torDirectory, torSocksPort,
 				torControlPort);
 	}

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

@@ -1,9 +1,7 @@
 package org.briarproject.bramble.api.plugin;
 
-import org.briarproject.bramble.api.event.EventBus;
-
 public interface BackoffFactory {
 
-	Backoff createBackoff(EventBus eventBus, TransportId transportId,
-			int minInterval, int maxInterval, double base);
+	Backoff createBackoff(int minInterval, int maxInterval,
+			double base);
 }

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

@@ -56,9 +56,4 @@ public interface PluginCallback extends ConnectionHandler {
 	 * This method can safely be called while holding a lock.
 	 */
 	void pluginStateChanged(State state);
-
-	/**
-	 * Informs the callback that the plugin's polling interval has decreased.
-	 */
-	void pollingIntervalDecreased();
 }

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

@@ -1,25 +0,0 @@
-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.TransportId;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when a plugin's polling interval decreases.
- */
-@Immutable
-@NotNullByDefault
-public class PollingIntervalDecreasedEvent extends Event {
-
-	private final TransportId transportId;
-
-	public PollingIntervalDecreasedEvent(TransportId transportId) {
-		this.transportId = transportId;
-	}
-
-	public TransportId getTransportId() {
-		return transportId;
-	}
-}

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

@@ -3,15 +3,16 @@ package org.briarproject.bramble.db;
 class DatabaseTypes {
 
 	private final String hashType, secretType, binaryType;
-	private final String counterType, stringType;
+	private final String counterType, stringType, schemaQuery;
 
-	public DatabaseTypes(String hashType, String secretType, String binaryType,
-			String counterType, String stringType) {
+	DatabaseTypes(String hashType, String secretType, String binaryType,
+			String counterType, String stringType, String schemaQuery) {
 		this.hashType = hashType;
 		this.secretType = secretType;
 		this.binaryType = binaryType;
 		this.counterType = counterType;
 		this.stringType = stringType;
+		this.schemaQuery = schemaQuery;
 	}
 
 	/**
@@ -31,4 +32,8 @@ class DatabaseTypes {
 		s = s.replaceAll("_STRING", stringType);
 		return s;
 	}
+
+	String getSchemaQuery() {
+		return schemaQuery;
+	}
 }

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

@@ -41,8 +41,9 @@ class H2Database extends JdbcDatabase {
 	private static final String BINARY_TYPE = "BINARY";
 	private static final String COUNTER_TYPE = "INT NOT NULL AUTO_INCREMENT";
 	private static final String STRING_TYPE = "VARCHAR";
+	private static final String SCHEMA_QUERY = "SHOW TABLES";
 	private static final DatabaseTypes dbTypes = new DatabaseTypes(HASH_TYPE,
-			SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE);
+			SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE, SCHEMA_QUERY);
 
 	private final DatabaseConfig config;
 	private final String url;

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

@@ -41,8 +41,11 @@ class HyperSqlDatabase extends JdbcDatabase {
 	private static final String COUNTER_TYPE =
 			"INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY(START WITH 1)";
 	private static final String STRING_TYPE = "VARCHAR";
+	private static final String SCHEMA_QUERY =
+			"SELECT TABLE_NAME FROM INFORMATION_SCHEMA.SYSTEM_TABLES"
+					+ " WHERE TABLE_TYPE='TABLE'";
 	private static final DatabaseTypes dbTypes = new DatabaseTypes(HASH_TYPE,
-			SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE);
+			SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE, SCHEMA_QUERY);
 
 	private final DatabaseConfig config;
 	private final String url;

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

@@ -405,6 +405,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		boolean compact;
 		Connection txn = startTransaction();
 		try {
+			if (LOG.isLoggable(INFO)) logSchema(txn);
 			if (reopen) {
 				Settings s = getSettings(txn, DB_SETTINGS_NAMESPACE);
 				wasDirtyOnInitialisation = isDirty(s);
@@ -447,6 +448,24 @@ abstract class JdbcDatabase implements Database<Connection> {
 		return wasDirtyOnInitialisation;
 	}
 
+	private void logSchema(Connection txn) throws DbException {
+		Statement s = null;
+		ResultSet rs = null;
+		try {
+			s = txn.createStatement();
+			rs = s.executeQuery(dbTypes.getSchemaQuery());
+			StringBuilder sb = new StringBuilder("Tables:");
+			while (rs.next()) sb.append('\n').append(rs.getString(1));
+			LOG.info(sb.toString());
+			rs.close();
+			s.close();
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	/**
 	 * Compares the schema version stored in the database with the schema
 	 * version used by the current code and applies any suitable migrations to

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ConnectivityChecker.java

@@ -22,21 +22,10 @@ interface ConnectivityChecker {
 	 * the check succeeds. If a check is already running then the observer is
 	 * called when the check succeeds. If a connectivity check has recently
 	 * succeeded then the observer is called immediately.
-	 * <p>
-	 * Observers are removed after being called, or when the checker is
-	 * {@link #destroy() destroyed}.
 	 */
 	void checkConnectivity(MailboxProperties properties,
 			ConnectivityObserver o);
 
-	/**
-	 * Removes an observer that was added via
-	 * {@link #checkConnectivity(MailboxProperties, ConnectivityObserver)}. If
-	 * there are no remaining observers and a connectivity check is running
-	 * then the check will be cancelled.
-	 */
-	void removeObserver(ConnectivityObserver o);
-
 	interface ConnectivityObserver {
 		void onConnectivityCheckSucceeded();
 	}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ConnectivityCheckerImpl.java

@@ -80,7 +80,8 @@ abstract class ConnectivityCheckerImpl implements ConnectivityChecker {
 						> CONNECTIVITY_CHECK_FRESHNESS_MS) {
 					// The last connectivity check is stale, start a new one
 					connectivityObservers.add(o);
-					ApiCall task = createConnectivityCheckTask(properties);
+					ApiCall task =
+							createConnectivityCheckTask(properties);
 					connectivityCheck = mailboxApiCaller.retryWithBackoff(task);
 				} else {
 					// The last connectivity check is fresh
@@ -107,16 +108,4 @@ abstract class ConnectivityCheckerImpl implements ConnectivityChecker {
 			o.onConnectivityCheckSucceeded();
 		}
 	}
-
-	@Override
-	public void removeObserver(ConnectivityObserver o) {
-		synchronized (lock) {
-			if (destroyed) return;
-			connectivityObservers.remove(o);
-			if (connectivityObservers.isEmpty() && connectivityCheck != null) {
-				connectivityCheck.cancel();
-				connectivityCheck = null;
-			}
-		}
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ContactMailboxConnectivityChecker.java

@@ -5,6 +5,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
 
+import java.io.IOException;
+
 import javax.annotation.concurrent.ThreadSafe;
 
 @ThreadSafe
@@ -22,11 +24,16 @@ class ContactMailboxConnectivityChecker extends ConnectivityCheckerImpl {
 	@Override
 	ApiCall createConnectivityCheckTask(MailboxProperties properties) {
 		if (properties.isOwner()) throw new IllegalArgumentException();
-		return new SimpleApiCall(() -> {
-			if (!mailboxApi.checkStatus(properties)) throw new ApiException();
-			// Call the observers and cache the result
-			onConnectivityCheckSucceeded(clock.currentTimeMillis());
-		});
+		return new SimpleApiCall() {
+			@Override
+			void tryToCallApi() throws IOException, ApiException {
+				if (!mailboxApi.checkStatus(properties)) {
+					throw new ApiException();
+				}
+				// Call the observers and cache the result
+				onConnectivityCheckSucceeded(clock.currentTimeMillis());
+			}
+		};
 	}
 
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ContactMailboxDownloadWorker.java

@@ -1,241 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.mailbox.ConnectivityChecker.ConnectivityObserver;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-import org.briarproject.bramble.mailbox.MailboxApi.MailboxFile;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-import org.briarproject.bramble.mailbox.TorReachabilityMonitor.TorReachabilityObserver;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxDownloadWorker implements MailboxWorker,
-		ConnectivityObserver, TorReachabilityObserver {
-
-	/**
-	 * When the worker is started it waits for a connectivity check, then
-	 * starts its first download cycle: checking the inbox, downloading and
-	 * deleting any files, and checking again until the inbox is empty.
-	 * <p>
-	 * The worker then waits for our Tor hidden service to be reachable before
-	 * starting its second download cycle. This ensures that if a contact
-	 * tried and failed to connect to our hidden service before it was
-	 * reachable, and therefore uploaded a file to the mailbox instead, we'll
-	 * find the file in the second download cycle.
-	 */
-	private enum State {
-		CREATED,
-		CONNECTIVITY_CHECK,
-		DOWNLOAD_CYCLE_1,
-		WAITING_FOR_TOR,
-		DOWNLOAD_CYCLE_2,
-		FINISHED,
-		DESTROYED
-	}
-
-	private static final Logger LOG =
-			getLogger(ContactMailboxDownloadWorker.class.getName());
-
-	private final ConnectivityChecker connectivityChecker;
-	private final TorReachabilityMonitor torReachabilityMonitor;
-	private final MailboxApiCaller mailboxApiCaller;
-	private final MailboxApi mailboxApi;
-	private final MailboxFileManager mailboxFileManager;
-	private final MailboxProperties mailboxProperties;
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	private State state = State.CREATED;
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable apiCall = null;
-
-	ContactMailboxDownloadWorker(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor torReachabilityMonitor,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			MailboxFileManager mailboxFileManager,
-			MailboxProperties mailboxProperties) {
-		if (mailboxProperties.isOwner()) throw new IllegalArgumentException();
-		this.connectivityChecker = connectivityChecker;
-		this.torReachabilityMonitor = torReachabilityMonitor;
-		this.mailboxApiCaller = mailboxApiCaller;
-		this.mailboxApi = mailboxApi;
-		this.mailboxFileManager = mailboxFileManager;
-		this.mailboxProperties = mailboxProperties;
-	}
-
-	@Override
-	public void start() {
-		LOG.info("Started");
-		synchronized (lock) {
-			// Don't allow the worker to be reused
-			if (state != State.CREATED) throw new IllegalStateException();
-			state = State.CONNECTIVITY_CHECK;
-		}
-		// Avoid leaking observer in case destroy() is called concurrently
-		// before observer is added
-		connectivityChecker.checkConnectivity(mailboxProperties, this);
-		boolean destroyed;
-		synchronized (lock) {
-			destroyed = state == State.DESTROYED;
-		}
-		if (destroyed) connectivityChecker.removeObserver(this);
-	}
-
-	@Override
-	public void destroy() {
-		LOG.info("Destroyed");
-		Cancellable apiCall;
-		synchronized (lock) {
-			state = State.DESTROYED;
-			apiCall = this.apiCall;
-			this.apiCall = null;
-		}
-		if (apiCall != null) apiCall.cancel();
-		connectivityChecker.removeObserver(this);
-		torReachabilityMonitor.removeObserver(this);
-	}
-
-	@Override
-	public void onConnectivityCheckSucceeded() {
-		LOG.info("Connectivity check succeeded");
-		synchronized (lock) {
-			if (state != State.CONNECTIVITY_CHECK) return;
-			state = State.DOWNLOAD_CYCLE_1;
-			// Start first download cycle
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(this::apiCallListInbox));
-		}
-	}
-
-	private void apiCallListInbox() throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		LOG.info("Listing inbox");
-		List<MailboxFile> files = mailboxApi.getFiles(mailboxProperties,
-				requireNonNull(mailboxProperties.getInboxId()));
-		if (files.isEmpty()) onDownloadCycleFinished();
-		else downloadNextFile(new LinkedList<>(files));
-	}
-
-	private void onDownloadCycleFinished() {
-		boolean addObserver = false;
-		synchronized (lock) {
-			if (state == State.DOWNLOAD_CYCLE_1) {
-				LOG.info("First download cycle finished");
-				state = State.WAITING_FOR_TOR;
-				addObserver = true;
-			} else if (state == State.DOWNLOAD_CYCLE_2) {
-				LOG.info("Second download cycle finished");
-				state = State.FINISHED;
-			}
-		}
-		if (addObserver) {
-			// Avoid leaking observer in case destroy() is called concurrently
-			// before observer is added
-			torReachabilityMonitor.addOneShotObserver(this);
-			boolean destroyed;
-			synchronized (lock) {
-				destroyed = state == State.DESTROYED;
-			}
-			if (destroyed) torReachabilityMonitor.removeObserver(this);
-		}
-	}
-
-	private void downloadNextFile(Queue<MailboxFile> queue) {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-			MailboxFile file = queue.remove();
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(() -> apiCallDownloadFile(file, queue)));
-		}
-	}
-
-	private void apiCallDownloadFile(MailboxFile file,
-			Queue<MailboxFile> queue) throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		LOG.info("Downloading file");
-		File tempFile = mailboxFileManager.createTempFileForDownload();
-		try {
-			mailboxApi.getFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()),
-					file.name, tempFile);
-		} catch (IOException | ApiException e) {
-			if (!tempFile.delete()) {
-				LOG.warning("Failed to delete temporary file");
-			}
-			throw e;
-		}
-		mailboxFileManager.handleDownloadedFile(tempFile);
-		deleteFile(file, queue);
-	}
-
-	private void deleteFile(MailboxFile file, Queue<MailboxFile> queue) {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(() -> apiCallDeleteFile(file, queue)));
-		}
-	}
-
-	private void apiCallDeleteFile(MailboxFile file, Queue<MailboxFile> queue)
-			throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		try {
-			mailboxApi.deleteFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()), file.name);
-		} catch (TolerableFailureException e) {
-			// Catch this so we can continue to the next file
-			logException(LOG, INFO, e);
-		}
-		if (queue.isEmpty()) {
-			// List the inbox again to check for files that may have arrived
-			// while we were downloading
-			synchronized (lock) {
-				if (state == State.DESTROYED) return;
-				apiCall = mailboxApiCaller.retryWithBackoff(
-						new SimpleApiCall(this::apiCallListInbox));
-			}
-		} else {
-			downloadNextFile(queue);
-		}
-	}
-
-	@Override
-	public void onTorReachable() {
-		LOG.info("Our Tor hidden service is reachable");
-		synchronized (lock) {
-			if (state != State.WAITING_FOR_TOR) return;
-			state = State.DOWNLOAD_CYCLE_2;
-			// Start second download cycle
-			apiCall = mailboxApiCaller.retryWithBackoff(
-					new SimpleApiCall(this::apiCallListInbox));
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiCaller.java

@@ -24,8 +24,6 @@ interface MailboxApiCaller {
 	 * Asynchronously calls the given API call on the {@link IoExecutor},
 	 * automatically retrying at increasing intervals until the API call
 	 * returns false or retries are cancelled.
-	 * <p>
-	 * This method is safe to call while holding a lock.
 	 *
 	 * @return A {@link Cancellable} that can be used to cancel any future
 	 * retries.

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxWorker.java

@@ -1,23 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * A worker that downloads files from a contact's mailbox.
- */
-@ThreadSafe
-@NotNullByDefault
-interface MailboxWorker {
-
-	/**
-	 * Asynchronously starts the worker.
-	 */
-	void start();
-
-	/**
-	 * Destroys the worker and cancels any pending tasks or retries.
-	 */
-	void destroy();
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/SimpleApiCall.java

@@ -16,20 +16,17 @@ import static org.briarproject.bramble.util.LogUtils.logException;
  * Convenience class for making simple API calls that don't return values.
  */
 @NotNullByDefault
-class SimpleApiCall implements ApiCall {
+public abstract class SimpleApiCall implements ApiCall {
 
 	private static final Logger LOG = getLogger(SimpleApiCall.class.getName());
 
-	private final Attempt attempt;
-
-	SimpleApiCall(Attempt attempt) {
-		this.attempt = attempt;
-	}
+	abstract void tryToCallApi()
+			throws IOException, ApiException, TolerableFailureException;
 
 	@Override
 	public boolean callApi() {
 		try {
-			attempt.tryToCallApi();
+			tryToCallApi();
 			return false; // Succeeded, don't retry
 		} catch (IOException | ApiException e) {
 			logException(LOG, WARNING, e);
@@ -39,17 +36,4 @@ class SimpleApiCall implements ApiCall {
 			return false; // Failed tolerably, don't retry
 		}
 	}
-
-	interface Attempt {
-
-		/**
-		 * Makes a single attempt to call an API endpoint. If this method
-		 * throws an {@link IOException} or an {@link ApiException}, the call
-		 * will be retried. If it throws a {@link TolerableFailureException}
-		 * or returns without throwing an exception, the call will not be
-		 * retried.
-		 */
-		void tryToCallApi()
-				throws IOException, ApiException, TolerableFailureException;
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/TorReachabilityMonitor.java

@@ -38,12 +38,6 @@ interface TorReachabilityMonitor {
 	 */
 	void addOneShotObserver(TorReachabilityObserver o);
 
-	/**
-	 * Removes an observer that was added via
-	 * {@link #addOneShotObserver(TorReachabilityObserver)}.
-	 */
-	void removeObserver(TorReachabilityObserver o);
-
 	interface TorReachabilityObserver {
 
 		void onTorReachable();

bramble-core/src/main/java/org/briarproject/bramble/mailbox/TorReachabilityMonitorImpl.java

@@ -87,14 +87,6 @@ class TorReachabilityMonitorImpl
 		if (callNow) o.onTorReachable();
 	}
 
-	@Override
-	public void removeObserver(TorReachabilityObserver o) {
-		synchronized (lock) {
-			if (destroyed) return;
-			observers.remove(o);
-		}
-	}
-
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof TransportActiveEvent) {

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

@@ -1,10 +1,8 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
-import org.briarproject.bramble.api.plugin.TransportId;
 
 import javax.annotation.concurrent.Immutable;
 
@@ -13,9 +11,8 @@ import javax.annotation.concurrent.Immutable;
 class BackoffFactoryImpl implements BackoffFactory {
 
 	@Override
-	public Backoff createBackoff(EventBus eventBus, TransportId transportId,
-			int minInterval, int maxInterval, double base) {
-		return new BackoffImpl(eventBus, transportId, minInterval, maxInterval,
-				base);
+	public Backoff createBackoff(int minInterval, int maxInterval,
+			double base) {
+		return new BackoffImpl(minInterval, maxInterval, base);
 	}
 }

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

@@ -1,10 +1,7 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.event.PollingIntervalDecreasedEvent;
 
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -14,16 +11,11 @@ import javax.annotation.concurrent.ThreadSafe;
 @NotNullByDefault
 class BackoffImpl implements Backoff {
 
-	private final EventBus eventBus;
-	private final TransportId transportId;
 	private final int minInterval, maxInterval;
 	private final double base;
 	private final AtomicInteger backoff;
 
-	BackoffImpl(EventBus eventBus, TransportId transportId,
-			int minInterval, int maxInterval, double base) {
-		this.eventBus = eventBus;
-		this.transportId = transportId;
+	BackoffImpl(int minInterval, int maxInterval, double base) {
 		this.minInterval = minInterval;
 		this.maxInterval = maxInterval;
 		this.base = base;
@@ -45,9 +37,6 @@ class BackoffImpl implements Backoff {
 
 	@Override
 	public void reset() {
-		int old = backoff.getAndSet(0);
-		if (old > 0) {
-			eventBus.broadcast(new PollingIntervalDecreasedEvent(transportId));
-		}
+		backoff.set(0);
 	}
 }

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

@@ -20,7 +20,6 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.PollingIntervalDecreasedEvent;
 import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
 import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
@@ -363,11 +362,6 @@ class PluginManagerImpl implements PluginManager, Service {
 			}
 		}
 
-		@Override
-		public void pollingIntervalDecreased() {
-			eventBus.broadcast(new PollingIntervalDecreasedEvent(id));
-		}
-
 		@Override
 		public void handleConnection(DuplexTransportConnection d) {
 			connectionManager.manageIncomingConnection(id, d);

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

@@ -20,7 +20,7 @@ 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.plugin.event.ConnectionClosedEvent;
-import org.briarproject.bramble.api.plugin.event.PollingIntervalDecreasedEvent;
+import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
 import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
 import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
@@ -107,14 +107,10 @@ class PollerImpl implements Poller, EventListener {
 			if (!c.isIncoming() && c.isException()) {
 				connectToContact(c.getContactId(), c.getTransportId());
 			}
-		} else if (e instanceof PollingIntervalDecreasedEvent) {
-			PollingIntervalDecreasedEvent p = (PollingIntervalDecreasedEvent) e;
-			TransportId t = p.getTransportId();
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("Polling interval decreased for " + t);
-			}
-			// Reschedule polling
-			reschedule(t);
+		} else if (e instanceof ConnectionOpenedEvent) {
+			ConnectionOpenedEvent c = (ConnectionOpenedEvent) e;
+			// Reschedule polling, the polling interval may have decreased
+			reschedule(c.getTransportId());
 		} else if (e instanceof TransportActiveEvent) {
 			TransportActiveEvent t = (TransportActiveEvent) e;
 			// Poll the newly activated transport
@@ -232,7 +228,7 @@ class PollerImpl implements Poller, EventListener {
 				if (!connected.contains(c))
 					properties.add(new Pair<>(e.getValue(), new Handler(c, t)));
 			}
-			p.poll(properties);
+			if (!properties.isEmpty()) p.poll(properties);
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
 		}

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

@@ -335,7 +335,7 @@ abstract class AbstractBluetoothPlugin<S, SS> implements BluetoothPlugin,
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
-		if (properties.isEmpty() || getState() != ACTIVE) return;
+		if (getState() != ACTIVE) return;
 		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());

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

@@ -56,8 +56,8 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
-		Backoff backoff = backoffFactory.createBackoff(eventBus, ID,
-				MIN_POLLING_INTERVAL, MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		LanTcpPlugin plugin = new LanTcpPlugin(ioExecutor, wakefulIoExecutor,
 				backoff, callback, MAX_LATENCY, MAX_IDLE_TIME,
 				CONNECTION_TIMEOUT);

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

@@ -246,7 +246,7 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
-		if (properties.isEmpty() || getState() != ACTIVE) return;
+		if (getState() != ACTIVE) return;
 		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());

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

@@ -60,8 +60,8 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
-		Backoff backoff = backoffFactory.createBackoff(eventBus, ID,
-				MIN_POLLING_INTERVAL, MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		PortMapper portMapper = new PortMapperImpl(shutdownManager);
 		WanTcpPlugin plugin = new WanTcpPlugin(ioExecutor, wakefulIoExecutor,
 				backoff, portMapper, callback, MAX_LATENCY, MAX_IDLE_TIME,

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProvider.java

@@ -27,7 +27,7 @@ public interface CircumventionProvider {
 	 * Countries where bridge connections are likely to work.
 	 * Should be a subset of {@link #BLOCKED} and the union of
 	 * {@link #DEFAULT_BRIDGES}, {@link #NON_DEFAULT_BRIDGES} and
-	 * {@link #DPI_BRIDGES}.
+	 * {@link #MEEK_BRIDGES}.
 	 */
 	String[] BRIDGES = {"BY", "CN", "EG", "IR", "RU", "TM", "VE"};
 
@@ -44,10 +44,10 @@ public interface CircumventionProvider {
 	String[] NON_DEFAULT_BRIDGES = {"BY", "RU", "TM"};
 
 	/**
-	 * Countries where vanilla bridges are blocked via DPI but non-default
-	 * obfs4 bridges and meek may work. Should be a subset of {@link #BRIDGES}.
+	 * Countries where obfs4 and vanilla bridges won't work and meek is needed.
+	 * Should be a subset of {@link #BRIDGES}.
 	 */
-	String[] DPI_BRIDGES = {"CN", "IR"};
+	String[] MEEK_BRIDGES = {"CN", "IR"};
 
 	/**
 	 * Returns true if vanilla Tor connections are blocked in the given country.

bramble-core/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProviderImpl.java

@@ -14,6 +14,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.DEFAULT_OBFS4;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.MEEK;
@@ -34,8 +35,8 @@ class CircumventionProviderImpl implements CircumventionProvider {
 			new HashSet<>(asList(DEFAULT_BRIDGES));
 	private static final Set<String> NON_DEFAULT_BRIDGE_COUNTRIES =
 			new HashSet<>(asList(NON_DEFAULT_BRIDGES));
-	private static final Set<String> DPI_COUNTRIES =
-			new HashSet<>(asList(DPI_BRIDGES));
+	private static final Set<String> MEEK_COUNTRIES =
+			new HashSet<>(asList(MEEK_BRIDGES));
 
 	@Inject
 	CircumventionProviderImpl() {
@@ -57,8 +58,8 @@ class CircumventionProviderImpl implements CircumventionProvider {
 			return asList(DEFAULT_OBFS4, VANILLA);
 		} else if (NON_DEFAULT_BRIDGE_COUNTRIES.contains(countryCode)) {
 			return asList(NON_DEFAULT_OBFS4, VANILLA);
-		} else if (DPI_COUNTRIES.contains(countryCode)) {
-			return asList(NON_DEFAULT_OBFS4, MEEK);
+		} else if (MEEK_COUNTRIES.contains(countryCode)) {
+			return singletonList(MEEK);
 		} else {
 			return asList(DEFAULT_OBFS4, VANILLA);
 		}

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

@@ -18,6 +18,7 @@ import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginException;
@@ -25,7 +26,6 @@ import org.briarproject.bramble.api.plugin.TorConstants;
 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.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
@@ -67,7 +67,6 @@ import javax.net.SocketFactory;
 import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
-import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
@@ -108,7 +107,7 @@ import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
 @ParametersNotNullByDefault
 abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
-	protected static final Logger LOG = getLogger(TorPlugin.class.getName());
+	private static final Logger LOG = getLogger(TorPlugin.class.getName());
 
 	private static final String[] EVENTS = {
 			"CIRC",
@@ -125,53 +124,14 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private static final int COOKIE_POLLING_INTERVAL_MS = 200;
 	private static final Pattern ONION_V3 = Pattern.compile("[a-z2-7]{56}");
 
-	/**
-	 * After this many consecutive successful connections to our own hidden
-	 * service we consider the network to be stable.
-	 * <p>
-	 * This constant times {@link #POLLING_INTERVAL_UNSTABLE} should be
-	 * greater than {@link #POLLING_INTERVAL_STABLE}. This ensures that if
-	 * we experience a network outage that isn't detected by the
-	 * {@link NetworkManager}, and if one of our contacts comes online during
-	 * the outage, then either the outage lasts longer than
-	 * {@link #POLLING_INTERVAL_STABLE}, in which case we detect the outage
-	 * by failing to connect to our own hidden service, or the outage ends
-	 * before the contact considers their own network connection to be stable,
-	 * in which case the contact is still trying to connect to us when the
-	 * outage ends. Either way, we don't end up in a situation where both we
-	 * and the contact consider our network connections to be stable and stop
-	 * trying to connect to each other, despite both being online.
-	 */
-	private static final int STABLE_NETWORK_THRESHOLD = 10;
-
-	/**
-	 * After this many consecutive failed connections to our own hidden service
-	 * we consider our connection to the Tor network to be broken.
-	 */
-	private static final int BROKEN_NETWORK_THRESHOLD = 3;
-
-	/**
-	 * How often to poll our own hidden service when the network is considered
-	 * to be stable.
-	 */
-	private static final int POLLING_INTERVAL_STABLE =
-			(int) MINUTES.toMillis(10);
-
-	/**
-	 * How often to poll our own hidden service and our contacts' hidden
-	 * services when the network is considered to be unstable.
-	 */
-	private static final int POLLING_INTERVAL_UNSTABLE =
-			(int) MINUTES.toMillis(2);
-
-	protected final Executor ioExecutor;
-	private final Executor wakefulIoExecutor;
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final Executor connectionStatusExecutor;
 	private final NetworkManager networkManager;
 	private final LocationUtils locationUtils;
 	private final SocketFactory torSocketFactory;
 	private final Clock clock;
 	private final BatteryManager batteryManager;
+	private final Backoff backoff;
 	private final TorRendezvousCrypto torRendezvousCrypto;
 	private final PluginCallback callback;
 	private final String architecture;
@@ -191,7 +151,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private volatile Socket controlSocket = null;
 	private volatile TorControlConnection controlConnection = null;
 	private volatile Settings settings = null;
-	private volatile String ownOnion = null;
 
 	protected abstract int getProcessId();
 
@@ -206,6 +165,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
+			Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback,
 			String architecture,
@@ -223,6 +183,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		this.resourceProvider = resourceProvider;
 		this.circumventionProvider = circumventionProvider;
 		this.batteryManager = batteryManager;
+		this.backoff = backoff;
 		this.torRendezvousCrypto = torRendezvousCrypto;
 		this.callback = callback;
 		this.architecture = architecture;
@@ -293,15 +254,34 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		Map<String, String> env = pb.environment();
 		env.put("HOME", torDirectory.getAbsolutePath());
 		pb.directory(torDirectory);
-		pb.redirectErrorStream(true);
 		try {
 			torProcess = pb.start();
 		} catch (SecurityException | IOException e) {
 			throw new PluginException(e);
 		}
+		// Log the process's standard output until it detaches
+		if (LOG.isLoggable(INFO)) {
+			Scanner stdout = new Scanner(torProcess.getInputStream());
+			Scanner stderr = new Scanner(torProcess.getErrorStream());
+			while (stdout.hasNextLine() || stderr.hasNextLine()) {
+				if (stdout.hasNextLine()) {
+					LOG.info(stdout.nextLine());
+				}
+				if (stderr.hasNextLine()) {
+					LOG.info(stderr.nextLine());
+				}
+			}
+			stdout.close();
+			stderr.close();
+		}
 		try {
-			// Wait for the Tor process to start
-			waitForTorToStart(torProcess);
+			// Wait for the process to detach or exit
+			int exit = torProcess.waitFor();
+			if (exit != 0) {
+				if (LOG.isLoggable(WARNING))
+					LOG.warning("Tor exited with value " + exit);
+				throw new PluginException();
+			}
 			// Wait for the auth cookie file to be created/updated
 			long start = clock.currentTimeMillis();
 			while (cookieFile.length() < 32) {
@@ -417,7 +397,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		return zin;
 	}
 
-	private static void append(StringBuilder strb, String name, Object value) {
+	private static void append(StringBuilder strb, String name, int value) {
 		strb.append(name);
 		strb.append(" ");
 		strb.append(value);
@@ -425,17 +405,13 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private InputStream getConfigInputStream() {
-		File dataDirectory = new File(torDirectory, ".tor");
 		StringBuilder strb = new StringBuilder();
 		append(strb, "ControlPort", torControlPort);
 		append(strb, "CookieAuthentication", 1);
-		append(strb, "DataDirectory", dataDirectory.getAbsolutePath());
 		append(strb, "DisableNetwork", 1);
 		append(strb, "RunAsDaemon", 1);
 		append(strb, "SafeSocks", 1);
 		append(strb, "SocksPort", torSocksPort);
-		strb.append("GeoIPFile\n");
-		strb.append("GeoIPv6File\n");
 		//noinspection CharsetObjectCanBeUsed
 		return new ByteArrayInputStream(
 				strb.toString().getBytes(Charset.forName("UTF-8")));
@@ -466,23 +442,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 	}
 
-	protected void waitForTorToStart(Process torProcess)
-			throws InterruptedException, PluginException {
-		Scanner stdout = new Scanner(torProcess.getInputStream());
-		// Log the first line of stdout (contains Tor and library versions)
-		if (stdout.hasNextLine()) LOG.info(stdout.nextLine());
-		// Read the process's stdout (and redirected stderr) until it detaches
-		while (stdout.hasNextLine()) stdout.nextLine();
-		stdout.close();
-		// Wait for the process to detach or exit
-		int exit = torProcess.waitFor();
-		if (exit != 0) {
-			if (LOG.isLoggable(WARNING))
-				LOG.warning("Tor exited with value " + exit);
-			throw new PluginException();
-		}
-	}
-
 	private void bind() {
 		ioExecutor.execute(() -> {
 			// If there's already a port number stored in config, reuse it
@@ -512,6 +471,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			callback.mergeSettings(s);
 			// Create a hidden service if necessary
 			ioExecutor.execute(() -> publishHiddenService(localPort));
+			backoff.reset();
 			// Accept incoming hidden service connections from Tor
 			acceptContactConnections(ss);
 		});
@@ -550,7 +510,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			return;
 		}
 		String onion3 = response.get(HS_ADDRESS);
-		ownOnion = onion3;
 		if (LOG.isLoggable(INFO)) {
 			LOG.info("V3 hidden service " + scrubOnion(onion3));
 		}
@@ -579,6 +538,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				return;
 			}
 			LOG.info("Connection received");
+			backoff.reset();
 			callback.handleConnection(new TorTransportConnection(this, s));
 		}
 	}
@@ -655,58 +615,14 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public int getPollingInterval() {
-		if (state.isNetworkStable()) {
-			LOG.info("Using stable polling interval");
-			return POLLING_INTERVAL_STABLE;
-		} else {
-			LOG.info("Using unstable polling interval");
-			return POLLING_INTERVAL_UNSTABLE;
-		}
+		return backoff.getPollingInterval();
 	}
 
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
 		if (getState() != ACTIVE) return;
-		String ownOnion = this.ownOnion;
-		if (ownOnion == null) {
-			// Our own hidden service hasn't been created yet
-			pollContacts(properties);
-		} else {
-			// If the network is unstable, poll our contacts
-			boolean stable = state.isNetworkStable();
-			if (!stable) pollContacts(properties);
-			// Poll our own hidden service to check if the network is stable
-			wakefulIoExecutor.execute(() -> {
-				LOG.info("Connecting to own hidden service");
-				TransportProperties p = new TransportProperties();
-				p.put(PROP_ONION_V3, ownOnion);
-				DuplexTransportConnection d = createConnection(p);
-				if (d == null) {
-					LOG.info("Could not connect to own hidden service");
-					state.onStabilityCheckFailed();
-					// If the network was previously considered stable then
-					// we didn't poll our contacts above, so poll them now
-					if (stable) pollContacts(properties);
-				} else {
-					LOG.info("Connected to own hidden service");
-					// Close the connection (this will cause the other end of
-					// the connection to log an EOFException)
-					try {
-						d.getWriter().dispose(false);
-						d.getReader().dispose(false, false);
-					} catch (IOException e) {
-						logException(LOG, WARNING, e);
-					}
-					state.onStabilityCheckSucceeded();
-				}
-			});
-		}
-	}
-
-	private void pollContacts(
-			Collection<Pair<TransportProperties, ConnectionHandler>> properties) {
-		if (properties.isEmpty() || getState() != ACTIVE) return;
+		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
 		}
@@ -715,7 +631,10 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private void connect(TransportProperties p, ConnectionHandler h) {
 		wakefulIoExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
-			if (d != null) h.handleConnection(d);
+			if (d != null) {
+				backoff.reset();
+				h.handleConnection(d);
+			}
 		});
 	}
 
@@ -838,6 +757,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		// DisableNetwork, set our circuitBuilt flag if not already set
 		if (status.equals("BUILT") && !state.getAndSetCircuitBuilt(true)) {
 			LOG.info("Circuit built");
+			backoff.reset();
 		}
 	}
 
@@ -864,9 +784,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void message(String severity, String msg) {
 		if (LOG.isLoggable(INFO)) LOG.info(severity + " " + msg);
-		if (msg.startsWith("Switching to guard context")) {
-			state.resetNetworkStability();
-		}
 	}
 
 	@Override
@@ -893,8 +810,12 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (msg.startsWith("BOOTSTRAP PROGRESS=100")) {
 			LOG.info("Bootstrapped");
 			state.setBootstrapped();
+			backoff.reset();
 		} else if (msg.startsWith("CIRCUIT_ESTABLISHED")) {
-			if (!state.getAndSetCircuitBuilt(true)) LOG.info("Circuit built");
+			if (!state.getAndSetCircuitBuilt(true)) {
+				LOG.info("Circuit built");
+				backoff.reset();
+			}
 		} else if (msg.startsWith("CIRCUIT_NOT_ESTABLISHED")) {
 			if (state.getAndSetCircuitBuilt(false)) {
 				LOG.info("Circuit not built");
@@ -939,15 +860,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof ConnectionClosedEvent) {
-			ConnectionClosedEvent c = (ConnectionClosedEvent) e;
-			if (c.getTransportId().equals(getId())
-					&& !c.isIncoming() && c.isException()) {
-				LOG.info("Outgoing connection closed with exception");
-				// The failure may indicate that the network is unstable
-				state.resetNetworkStability();
-			}
-		} else if (e instanceof SettingsUpdatedEvent) {
+		if (e instanceof SettingsUpdatedEvent) {
 			SettingsUpdatedEvent s = (SettingsUpdatedEvent) e;
 			if (s.getNamespace().equals(ID.getString())) {
 				LOG.info("Tor settings updated");
@@ -964,18 +877,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 	}
 
-	private void disableAndReenableNetwork() {
-		connectionStatusExecutor.execute(() -> {
-			try {
-				if (state.isTorRunning()) enableNetwork(false);
-			} catch (IOException ex) {
-				logException(LOG, WARNING, ex);
-			}
-		});
-		updateConnectionStatus(networkManager.getNetworkStatus(),
-				batteryManager.isCharging());
-	}
-
 	private void updateConnectionStatus(NetworkStatus status,
 			boolean charging) {
 		connectionStatusExecutor.execute(() -> {
@@ -1104,13 +1005,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		@GuardedBy("this")
 		private int reasonsDisabled = 0;
 
-		/**
-		 * The number of consecutive successful (positive) or failed (negative)
-		 * connections to our own hidden service.
-		 */
-		@GuardedBy("this")
-		private int networkStability = 0;
-
 		@GuardedBy("this")
 		@Nullable
 		private ServerSocket serverSocket = null;
@@ -1205,7 +1099,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			}
 			logOrConnections();
 			if (orConnectionsConnected == 0 && oldConnected != 0) {
-				resetNetworkStability();
 				callback.pluginStateChanged(getState());
 			}
 		}
@@ -1216,43 +1109,5 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				LOG.info(orConnectionsConnected + " OR connections connected");
 			}
 		}
-
-		private synchronized boolean isNetworkStable() {
-			return networkStability >= STABLE_NETWORK_THRESHOLD;
-		}
-
-		private synchronized void onStabilityCheckSucceeded() {
-			if (networkStability <= 0) networkStability = 1;
-			else networkStability++;
-			logNetworkStability();
-		}
-
-		private synchronized void onStabilityCheckFailed() {
-			if (networkStability >= 0) networkStability = -1;
-			else networkStability--;
-			if (networkStability <= -BROKEN_NETWORK_THRESHOLD) {
-				LOG.warning("Connection to Tor appears to be broken");
-				resetNetworkStability();
-				disableAndReenableNetwork();
-			} else {
-				logNetworkStability();
-			}
-		}
-
-		private synchronized void resetNetworkStability() {
-			int old = networkStability;
-			networkStability = 0;
-			logNetworkStability();
-			if (old >= STABLE_NETWORK_THRESHOLD) {
-				callback.pollingIntervalDecreased();
-			}
-		}
-
-		@GuardedBy("this")
-		private void logNetworkStability() {
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("Network stability score " + networkStability);
-			}
-		}
 	}
 }

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

@@ -6,6 +6,8 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.plugin.TorControlPort;
@@ -39,12 +41,16 @@ abstract class TorPluginFactory implements DuplexPluginFactory {
 
 	protected static final int MAX_LATENCY = 30 * 1000; // 30 seconds
 	protected static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	private static final double BACKOFF_BASE = 1.2;
 
 	protected final Executor ioExecutor, wakefulIoExecutor;
 	protected final NetworkManager networkManager;
 	protected final LocationUtils locationUtils;
 	protected final EventBus eventBus;
 	protected final SocketFactory torSocketFactory;
+	protected final BackoffFactory backoffFactory;
 	protected final ResourceProvider resourceProvider;
 	protected final CircumventionProvider circumventionProvider;
 	protected final BatteryManager batteryManager;
@@ -60,6 +66,7 @@ abstract class TorPluginFactory implements DuplexPluginFactory {
 			LocationUtils locationUtils,
 			EventBus eventBus,
 			SocketFactory torSocketFactory,
+			BackoffFactory backoffFactory,
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
@@ -74,6 +81,7 @@ abstract class TorPluginFactory implements DuplexPluginFactory {
 		this.locationUtils = locationUtils;
 		this.eventBus = eventBus;
 		this.torSocketFactory = torSocketFactory;
+		this.backoffFactory = backoffFactory;
 		this.resourceProvider = resourceProvider;
 		this.circumventionProvider = circumventionProvider;
 		this.batteryManager = batteryManager;
@@ -87,7 +95,7 @@ abstract class TorPluginFactory implements DuplexPluginFactory {
 	@Nullable
 	abstract String getArchitectureForTorBinary();
 
-	abstract TorPlugin createPluginInstance(
+	abstract TorPlugin createPluginInstance(Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto, PluginCallback callback,
 			String architecture);
 
@@ -114,9 +122,11 @@ abstract class TorPluginFactory implements DuplexPluginFactory {
 			LOG.info("The selected architecture for Tor is " + architecture);
 		}
 
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		TorRendezvousCrypto torRendezvousCrypto =
 				new TorRendezvousCryptoImpl(crypto);
-		TorPlugin plugin = createPluginInstance(torRendezvousCrypto,
+		TorPlugin plugin = createPluginInstance(backoff, torRendezvousCrypto,
 				callback, architecture);
 		eventBus.addListener(plugin);
 		return plugin;

bramble-core/src/main/resources/bridges

@@ -15,6 +15,7 @@ n Bridge obfs4 46.226.107.197:10300 A38FD6BDFD902882F5F5B9B7CCC95602A20B0BC4 cer
 n Bridge obfs4 185.181.11.86:443 A961609729E7FDF520B4E81F1F1B8FA1045285C3 cert=e5faG9Zk4Ni+e7z2YgGfevyKPQlMvkVGi4ublSsHYjaBovKeNXpOhbeFxzbZZoAzxAoGUQ iat-mode=0
 n Bridge obfs4 85.242.211.221:8042 A36A938DD7FDB8BACC846BA326EE0BA0D89A9252 cert=1AN6Pt1eFca3Y/WYD2TGAU3Al9cO4eouXE9SX63s66Z/ks3tVmgQ5GeXi1B5DOvx6Il7Zw iat-mode=0
 n Bridge obfs4 74.104.165.202:9002 EF432018A6AA5D970B2F84E39CD30A147030141C cert=PhppfUusY85dHGvWtGTybZ1fED4DtbHmALkNMIOIYrAz1B4xN7/2a5gyiZe1epju1BOHVg iat-mode=0
+n Bridge obfs4 70.34.242.31:443 7F026956402CDFF4BCBA8E11EE9C50E3FE0A2B72 cert=hP/KU7JATSfWH3HwS5Er/YLT0J+bRO3+s2fWx2yirrgf37EyrWvm/BQshoNje8WfUm6CBw iat-mode=0
 n Bridge obfs4 93.95.226.151:41185 460B0CFFC0CF1D965F3DE064E08BA1915E7C916A cert=inluPzp5Jp5OzZar1eQb4dcQ/YlAj/v0kHAUCoCr3rmLt03+pVuVTjoH4mRy4+acXpn+Gw iat-mode=0
 n Bridge obfs4 120.29.217.52:5223 40FE3DB9800272F9CDC76422F8ED7883280EE96D cert=/71PS4l8c/XJ4DIItlH9xMqNvPFg2RUTrHvPlQWh48u5et8h/yyyjCcYphUadDsfBWpaGQ iat-mode=0
 n Bridge obfs4 83.97.179.29:1199 D83068BFAA28E71DB024B786E1E803BE14257127 cert=IduGtt05tM59Xmvo0oVNWgIRgY4OGPJjFP+y2oa6RMDHQBL/GRyFOOgX70iiazNAIJNkPw iat-mode=0
@@ -23,11 +24,7 @@ n Bridge obfs4 76.255.201.112:8888 96CF36C2ECCFB7376AB6BE905BECD2C2AE8AEFCD cert
 n Bridge obfs4 65.108.159.114:14174 E1AD374BA9F34BD98862D128AC54D40C7DC138AE cert=YMkxMSBN2OOd99AkJpFaEUyKkdqZgJt9oVJEgO1QnT37n/Vc2yR4nhx4k4VkPLfEP1f4eg iat-mode=0
 n Bridge obfs4 185.177.207.138:8443 53716FE26F23C8C6A71A2BC5D9D8DC64747278C7 cert=6jcYVilMEzxdsWghSrQFpYYJlkkir/GPIXw/EnddUK3S8ToVpMG8u1SwMOEdEs735RrMHw iat-mode=0
 n Bridge obfs4 176.123.2.253:1933 B855D141CE6C4DE0F7EA4AAED83EBA8373FA8191 cert=1rOoSaRagc6PPR//paIl+ukv1N+xWKCdBXMFxK0k/moEwH0lk5bURBrUDzIX35fVzaiicQ iat-mode=0
-n Bridge obfs4 5.252.176.61:9418 3E61130100AD827AB9CB33DAC052D9BC49A39509 cert=/aMyBPnKbQFISithD3i1KHUdpWeMpWG3SvUpq1YWCf2EQohFxQfw+646gW1knm4BI/DLRA iat-mode=0
-n Bridge obfs4 70.34.213.156:12345 BC1C79ABBAE085D305346E7A2B0E838953B4B4D3 cert=3Sk4uA3/NiAsn4ObOUzjIzARclGmkiEUrku8o8bkq4ZL+dek9uLj/d5LZ5nAXT6L9S0CZA iat-mode=0
-n Bridge obfs4 202.61.224.111:6902 A4F91299763DB925AE3BD29A0FC1A9821E5D9BAE cert=NBKm2MJ83wMvYShkqpD5RrbDtW5YpIZrFNnMw7Dj1XOM3plU60Bh4eziaQXe8fGtb8ZqKg iat-mode=0
 v Bridge 135.181.113.164:54444 74AF4CCA614C454B7D3E81FF8BACD78CEBC7D7DE
 v Bridge 92.243.15.235:9001 477EAD3C04036B48235F1F27FC91420A286A4B7F
 v Bridge 77.96.91.103:443 ED000A75B79A58F1D83A4D1675C2A9395B71BE8E
-v Bridge 213.108.108.145:17674 A39C0FE47963B6E8CFE9815549864DE544935A31
 m Bridge meek_lite 192.0.2.2:2 97700DFE9F483596DDA6264C4D7DF7641E1E39CE url=https://meek.azureedge.net/ front=ajax.aspnetcdn.com

bramble-core/src/test/java/org/briarproject/bramble/mailbox/ConnectivityCheckerImplTest.java

@@ -187,32 +187,6 @@ public class ConnectivityCheckerImplTest extends BrambleMockTestCase {
 		checker.onConnectivityCheckSucceeded(now);
 	}
 
-	@Test
-	public void testCheckIsCancelledWhenObserverIsRemoved() {
-		ConnectivityCheckerImpl checker = createChecker();
-
-		// When checkConnectivity() is called a check should be started
-		context.checking(new Expectations() {{
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now));
-			oneOf(mailboxApiCaller).retryWithBackoff(apiCall);
-			will(returnValue(task));
-		}});
-
-		checker.checkConnectivity(properties, observer1);
-
-		// When the observer is removed the check should be cancelled
-		context.checking(new Expectations() {{
-			oneOf(task).cancel();
-		}});
-
-		checker.removeObserver(observer1);
-
-		// If the check runs anyway (cancellation came too late) the observer
-		// should not be called
-		checker.onConnectivityCheckSucceeded(now);
-	}
-
 	private ConnectivityCheckerImpl createChecker() {
 
 		return new ConnectivityCheckerImpl(clock, mailboxApiCaller) {

bramble-core/src/test/java/org/briarproject/bramble/mailbox/ContactMailboxDownloadWorkerTest.java

@@ -1,215 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.mailbox.MailboxFileId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.mailbox.MailboxApi.MailboxFile;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-import org.briarproject.bramble.test.BrambleMockTestCase;
-import org.briarproject.bramble.test.CaptureArgumentAction;
-import org.jmock.Expectations;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-
-import java.io.File;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicReference;
-
-import static java.util.Arrays.asList;
-import static java.util.Collections.emptyList;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.CLIENT_SUPPORTS;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
-import static org.briarproject.bramble.test.TestUtils.getMailboxProperties;
-import static org.briarproject.bramble.test.TestUtils.getRandomId;
-import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
-import static org.junit.Assert.assertFalse;
-
-public class ContactMailboxDownloadWorkerTest extends BrambleMockTestCase {
-
-	private final ConnectivityChecker connectivityChecker =
-			context.mock(ConnectivityChecker.class);
-	private final TorReachabilityMonitor torReachabilityMonitor =
-			context.mock(TorReachabilityMonitor.class);
-	private final MailboxApiCaller mailboxApiCaller =
-			context.mock(MailboxApiCaller.class);
-	private final MailboxApi mailboxApi = context.mock(MailboxApi.class);
-	private final MailboxFileManager mailboxFileManager =
-			context.mock(MailboxFileManager.class);
-
-	private final MailboxProperties mailboxProperties =
-			getMailboxProperties(false, CLIENT_SUPPORTS);
-	private final long now = System.currentTimeMillis();
-	private final MailboxFile file1 =
-			new MailboxFile(new MailboxFileId(getRandomId()), now - 1);
-	private final MailboxFile file2 =
-			new MailboxFile(new MailboxFileId(getRandomId()), now);
-	private final List<MailboxFile> files = asList(file1, file2);
-
-	private File testDir, tempFile;
-	private ContactMailboxDownloadWorker worker;
-
-	@Before
-	public void setUp() {
-		testDir = getTestDirectory();
-		tempFile = new File(testDir, "temp");
-		worker = new ContactMailboxDownloadWorker(connectivityChecker,
-				torReachabilityMonitor, mailboxApiCaller, mailboxApi,
-				mailboxFileManager, mailboxProperties);
-	}
-
-	@After
-	public void tearDown() {
-		deleteTestDirectory(testDir);
-	}
-
-	@Test
-	public void testChecksConnectivityWhenStartedAndRemovesObserverWhenDestroyed() {
-		// When the worker is started it should start a connectivity check
-		context.checking(new Expectations() {{
-			oneOf(connectivityChecker).checkConnectivity(
-					with(mailboxProperties), with(worker));
-		}});
-
-		worker.start();
-
-		// When the worker is destroyed it should remove the connectivity
-		// and reachability observers
-		context.checking(new Expectations() {{
-			oneOf(connectivityChecker).removeObserver(worker);
-			oneOf(torReachabilityMonitor).removeObserver(worker);
-		}});
-
-		worker.destroy();
-	}
-
-	@Test
-	public void testDownloadsFilesWhenConnectivityCheckSucceeds()
-			throws Exception {
-		// When the worker is started it should start a connectivity check
-		context.checking(new Expectations() {{
-			oneOf(connectivityChecker).checkConnectivity(
-					with(mailboxProperties), with(worker));
-		}});
-
-		worker.start();
-
-		// When the connectivity check succeeds, a list-inbox task should be
-		// started for the first download cycle
-		AtomicReference<ApiCall> listTask = new AtomicReference<>(null);
-		context.checking(new Expectations() {{
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(listTask, ApiCall.class, 0));
-		}});
-
-		worker.onConnectivityCheckSucceeded();
-
-		// When the list-inbox tasks runs and finds some files to download,
-		// it should start a download task for the first file
-		AtomicReference<ApiCall> downloadTask = new AtomicReference<>(null);
-		context.checking(new Expectations() {{
-			oneOf(mailboxApi).getFiles(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()));
-			will(returnValue(files));
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(downloadTask, ApiCall.class, 0));
-		}});
-
-		assertFalse(listTask.get().callApi());
-
-		// When the first download task runs it should download the file to the
-		// location provided by the file manager and start a delete task
-		AtomicReference<ApiCall> deleteTask = new AtomicReference<>(null);
-		context.checking(new Expectations() {{
-			oneOf(mailboxFileManager).createTempFileForDownload();
-			will(returnValue(tempFile));
-			oneOf(mailboxApi).getFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()),
-					file1.name, tempFile);
-			oneOf(mailboxFileManager).handleDownloadedFile(tempFile);
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(deleteTask, ApiCall.class, 0));
-		}});
-
-		assertFalse(downloadTask.get().callApi());
-
-		// When the first delete task runs it should delete the file, ignore
-		// the tolerable failure, and start a download task for the next file
-		context.checking(new Expectations() {{
-			oneOf(mailboxApi).deleteFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()), file1.name);
-			will(throwException(new TolerableFailureException()));
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(downloadTask, ApiCall.class, 0));
-		}});
-
-		assertFalse(deleteTask.get().callApi());
-
-		// When the second download task runs it should download the file to
-		// the location provided by the file manager and start a delete task
-		context.checking(new Expectations() {{
-			oneOf(mailboxFileManager).createTempFileForDownload();
-			will(returnValue(tempFile));
-			oneOf(mailboxApi).getFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()),
-					file2.name, tempFile);
-			oneOf(mailboxFileManager).handleDownloadedFile(tempFile);
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(deleteTask, ApiCall.class, 0));
-		}});
-
-		assertFalse(downloadTask.get().callApi());
-
-		// When the second delete task runs it should delete the file and
-		// start a list-inbox task to check for files that may have arrived
-		// since the first download cycle started
-		context.checking(new Expectations() {{
-			oneOf(mailboxApi).deleteFile(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()), file2.name);
-			will(throwException(new TolerableFailureException()));
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(listTask, ApiCall.class, 0));
-		}});
-
-		assertFalse(deleteTask.get().callApi());
-
-		// When the list-inbox tasks runs and finds no more files to download,
-		// it should add a Tor reachability observer
-		context.checking(new Expectations() {{
-			oneOf(mailboxApi).getFiles(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()));
-			will(returnValue(emptyList()));
-			oneOf(torReachabilityMonitor).addOneShotObserver(worker);
-		}});
-
-		assertFalse(listTask.get().callApi());
-
-		// When the reachability observer is called, a list-inbox task should
-		// be started for the second download cycle
-		context.checking(new Expectations() {{
-			oneOf(mailboxApiCaller).retryWithBackoff(with(any(ApiCall.class)));
-			will(new CaptureArgumentAction<>(listTask, ApiCall.class, 0));
-		}});
-
-		worker.onTorReachable();
-
-		// When the list-inbox tasks runs and finds no more files to download,
-		// it should finish the second download cycle
-		context.checking(new Expectations() {{
-			oneOf(mailboxApi).getFiles(mailboxProperties,
-					requireNonNull(mailboxProperties.getInboxId()));
-			will(returnValue(emptyList()));
-		}});
-
-		assertFalse(listTask.get().callApi());
-
-		// When the worker is destroyed it should remove the connectivity
-		// and reachability observers
-		context.checking(new Expectations() {{
-			oneOf(connectivityChecker).removeObserver(worker);
-			oneOf(torReachabilityMonitor).removeObserver(worker);
-		}});
-
-		worker.destroy();
-	}
-}

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

@@ -1,69 +1,45 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.event.PollingIntervalDecreasedEvent;
-import org.briarproject.bramble.test.BrambleMockTestCase;
-import org.jmock.Expectations;
+import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
-import static org.briarproject.bramble.test.TestUtils.getTransportId;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
-public class BackoffImplTest extends BrambleMockTestCase {
+public class BackoffImplTest extends BrambleTestCase {
 
-	private final EventBus eventBus = context.mock(EventBus.class);
-
-	private final TransportId transportId = getTransportId();
 	private static final int MIN_INTERVAL = 60 * 1000;
 	private static final int MAX_INTERVAL = 60 * 60 * 1000;
 	private static final double BASE = 1.2;
 
 	@Test
 	public void testPollingIntervalStartsAtMinimum() {
-		BackoffImpl b = new BackoffImpl(eventBus, transportId,
-				MIN_INTERVAL, MAX_INTERVAL, BASE);
+		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
 		assertEquals(MIN_INTERVAL, b.getPollingInterval());
 	}
 
 	@Test
-	public void testIncrementMethodIncreasesPollingInterval() {
-		BackoffImpl b = new BackoffImpl(eventBus, transportId,
-				MIN_INTERVAL, MAX_INTERVAL, BASE);
+	public void testIncrementIncreasesPollingInterval() {
+		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
 		b.increment();
 		assertTrue(b.getPollingInterval() > MIN_INTERVAL);
 	}
 
 	@Test
-	public void testResetMethodResetsPollingInterval() {
-		BackoffImpl b = new BackoffImpl(eventBus, transportId,
-				MIN_INTERVAL, MAX_INTERVAL, BASE);
+	public void testResetResetsPollingInterval() {
+		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
+		b.increment();
 		b.increment();
-		assertTrue(b.getPollingInterval() > MIN_INTERVAL);
-
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(
-					PollingIntervalDecreasedEvent.class)));
-		}});
-
-		b.reset();
-		assertEquals(MIN_INTERVAL, b.getPollingInterval());
-		context.assertIsSatisfied();
-
-		// Resetting again should not broadcast another event
 		b.reset();
 		assertEquals(MIN_INTERVAL, b.getPollingInterval());
 	}
 
 	@Test
 	public void testBaseAffectsBackoffSpeed() {
-		BackoffImpl b = new BackoffImpl(eventBus, transportId,
-				MIN_INTERVAL, MAX_INTERVAL, BASE);
+		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
 		b.increment();
 		int interval = b.getPollingInterval();
-		BackoffImpl b1 = new BackoffImpl(eventBus, transportId, MIN_INTERVAL,
-				MAX_INTERVAL, BASE * 2);
+		BackoffImpl b1 = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE * 2);
 		b1.increment();
 		int interval1 = b1.getPollingInterval();
 		assertTrue(interval < interval1);
@@ -71,16 +47,15 @@ public class BackoffImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testIntervalDoesNotExceedMaxInterval() {
-		BackoffImpl b = new BackoffImpl(eventBus, transportId,
-				MIN_INTERVAL, MAX_INTERVAL, BASE);
+		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
 		for (int i = 0; i < 100; i++) b.increment();
 		assertEquals(MAX_INTERVAL, b.getPollingInterval());
 	}
 
 	@Test
 	public void testIntervalDoesNotExceedMaxIntervalWithInfiniteMultiplier() {
-		BackoffImpl b = new BackoffImpl(eventBus, transportId,
-				MIN_INTERVAL, MAX_INTERVAL, Double.POSITIVE_INFINITY);
+		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL,
+				Double.POSITIVE_INFINITY);
 		b.increment();
 		assertEquals(MAX_INTERVAL, b.getPollingInterval());
 	}

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

@@ -13,7 +13,7 @@ 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.plugin.event.ConnectionClosedEvent;
-import org.briarproject.bramble.api.plugin.event.PollingIntervalDecreasedEvent;
+import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
 import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
 import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
@@ -35,6 +35,7 @@ import java.util.concurrent.Executor;
 
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static org.briarproject.bramble.test.CollectionMatcher.collectionOf;
@@ -216,7 +217,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testRescheduleOnPollingIntervalDecreased() {
+	public void testRescheduleOnConnectionOpened() {
 		Plugin plugin = context.mock(Plugin.class);
 
 		context.checking(new Expectations() {{
@@ -239,7 +240,8 @@ public class PollerImplTest extends BrambleMockTestCase {
 			will(returnValue(cancellable));
 		}});
 
-		poller.eventOccurred(new PollingIntervalDecreasedEvent(transportId));
+		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
+				false));
 	}
 
 	@Test
@@ -279,8 +281,10 @@ public class PollerImplTest extends BrambleMockTestCase {
 			will(returnValue(now + 1));
 		}});
 
-		poller.eventOccurred(new PollingIntervalDecreasedEvent(transportId));
-		poller.eventOccurred(new PollingIntervalDecreasedEvent(transportId));
+		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
+				false));
+		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
+				false));
 	}
 
 	@Test
@@ -324,8 +328,10 @@ public class PollerImplTest extends BrambleMockTestCase {
 					with(MILLISECONDS));
 		}});
 
-		poller.eventOccurred(new PollingIntervalDecreasedEvent(transportId));
-		poller.eventOccurred(new PollingIntervalDecreasedEvent(transportId));
+		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
+				false));
+		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
+				false));
 	}
 
 	@Test
@@ -372,6 +378,48 @@ public class PollerImplTest extends BrambleMockTestCase {
 		poller.eventOccurred(new TransportActiveEvent(transportId));
 	}
 
+	@Test
+	public void testDoesNotPollIfAllContactsAreConnected() throws Exception {
+		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
+
+		context.checking(new Expectations() {{
+			allowing(plugin).getId();
+			will(returnValue(transportId));
+			// Get the plugin
+			oneOf(pluginManager).getPlugin(transportId);
+			will(returnValue(plugin));
+			// The plugin supports polling
+			oneOf(plugin).shouldPoll();
+			will(returnValue(true));
+			// Schedule a polling task immediately
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(scheduler).schedule(with(any(Runnable.class)),
+					with(ioExecutor), with(0L), with(MILLISECONDS));
+			will(returnValue(cancellable));
+			will(new RunAction());
+			// Running the polling task schedules the next polling task
+			oneOf(plugin).getPollingInterval();
+			will(returnValue(pollingInterval));
+			oneOf(random).nextDouble();
+			will(returnValue(0.5));
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(scheduler).schedule(with(any(Runnable.class)),
+					with(ioExecutor), with((long) (pollingInterval * 0.5)),
+					with(MILLISECONDS));
+			will(returnValue(cancellable));
+			// Get the transport properties and connected contacts
+			oneOf(transportPropertyManager).getRemoteProperties(transportId);
+			will(returnValue(singletonMap(contactId, properties)));
+			oneOf(connectionRegistry).getConnectedOrBetterContacts(transportId);
+			will(returnValue(singletonList(contactId)));
+			// All contacts are connected, so don't poll the plugin
+		}});
+
+		poller.eventOccurred(new TransportActiveEvent(transportId));
+	}
+
 	@Test
 	public void testCancelsPollingOnTransportDeactivated() {
 		Plugin plugin = context.mock(Plugin.class);

bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java

@@ -342,10 +342,6 @@ public class LanTcpPluginTest extends BrambleTestCase {
 		public void pluginStateChanged(State newState) {
 		}
 
-		@Override
-		public void pollingIntervalDecreased() {
-		}
-
 		@Override
 		public void handleConnection(DuplexTransportConnection d) {
 			connectionsLatch.countDown();

bramble-core/src/test/java/org/briarproject/bramble/plugin/tor/CircumventionProviderTest.java

@@ -7,6 +7,7 @@ import java.util.HashSet;
 import java.util.Set;
 
 import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BLOCKED;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BRIDGES;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.DEFAULT_OBFS4;
@@ -14,7 +15,7 @@ import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeTy
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.NON_DEFAULT_OBFS4;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.BridgeType.VANILLA;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.DEFAULT_BRIDGES;
-import static org.briarproject.bramble.plugin.tor.CircumventionProvider.DPI_BRIDGES;
+import static org.briarproject.bramble.plugin.tor.CircumventionProvider.MEEK_BRIDGES;
 import static org.briarproject.bramble.plugin.tor.CircumventionProvider.NON_DEFAULT_BRIDGES;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -31,18 +32,18 @@ public class CircumventionProviderTest extends BrambleTestCase {
 		Set<String> defaultBridges = new HashSet<>(asList(DEFAULT_BRIDGES));
 		Set<String> nonDefaultBridges =
 				new HashSet<>(asList(NON_DEFAULT_BRIDGES));
-		Set<String> dpiBridges = new HashSet<>(asList(DPI_BRIDGES));
+		Set<String> meekBridges = new HashSet<>(asList(MEEK_BRIDGES));
 		// BRIDGES should be a subset of BLOCKED
 		assertTrue(blocked.containsAll(bridges));
 		// BRIDGES should be the union of the bridge type sets
 		Set<String> union = new HashSet<>(defaultBridges);
 		union.addAll(nonDefaultBridges);
-		union.addAll(dpiBridges);
+		union.addAll(meekBridges);
 		assertEquals(bridges, union);
 		// The bridge type sets should not overlap
 		assertEmptyIntersection(defaultBridges, nonDefaultBridges);
-		assertEmptyIntersection(defaultBridges, dpiBridges);
-		assertEmptyIntersection(nonDefaultBridges, dpiBridges);
+		assertEmptyIntersection(defaultBridges, meekBridges);
+		assertEmptyIntersection(nonDefaultBridges, meekBridges);
 	}
 
 	@Test
@@ -55,8 +56,8 @@ public class CircumventionProviderTest extends BrambleTestCase {
 			assertEquals(asList(NON_DEFAULT_OBFS4, VANILLA),
 					provider.getSuitableBridgeTypes(country));
 		}
-		for (String country : DPI_BRIDGES) {
-			assertEquals(asList(NON_DEFAULT_OBFS4, MEEK),
+		for (String country : MEEK_BRIDGES) {
+			assertEquals(singletonList(MEEK),
 					provider.getSuitableBridgeTypes(country));
 		}
 		assertEquals(asList(DEFAULT_OBFS4, VANILLA),

bramble-java/build.gradle

@@ -18,9 +18,7 @@ dependencies {
 	implementation "net.java.dev.jna:jna:$jna_version"
 	implementation "net.java.dev.jna:jna-platform:$jna_version"
 	tor "org.briarproject:tor-linux:$tor_version"
-	tor "org.briarproject:tor-windows:$tor_version"
 	tor "org.briarproject:obfs4proxy-linux:$obfs4proxy_version"
-	tor "org.briarproject:obfs4proxy-windows:$obfs4proxy_version"
 
 	annotationProcessor "com.google.dagger:dagger-compiler:$dagger_version"
 

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

@@ -69,8 +69,8 @@ public class JavaBluetoothPluginFactory implements DuplexPluginFactory {
 		BluetoothConnectionFactory<StreamConnection> connectionFactory =
 				new JavaBluetoothConnectionFactory(connectionLimiter,
 						timeoutMonitor);
-		Backoff backoff = backoffFactory.createBackoff(eventBus, ID,
-				MIN_POLLING_INTERVAL, MAX_POLLING_INTERVAL, BACKOFF_BASE);
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		JavaBluetoothPlugin plugin = new JavaBluetoothPlugin(connectionLimiter,
 				connectionFactory, ioExecutor, wakefulIoExecutor, secureRandom,
 				backoff, callback, MAX_LATENCY, MAX_IDLE_TIME);

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/JavaTorPlugin.java

@@ -3,6 +3,7 @@ package org.briarproject.bramble.plugin.tor;
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -28,6 +29,7 @@ abstract class JavaTorPlugin extends TorPlugin {
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
+			Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback,
 			String architecture,
@@ -38,7 +40,7 @@ abstract class JavaTorPlugin extends TorPlugin {
 			int torControlPort) {
 		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
 				torSocketFactory, clock, resourceProvider,
-				circumventionProvider, batteryManager,
+				circumventionProvider, batteryManager, backoff,
 				torRendezvousCrypto, callback, architecture,
 				maxLatency, maxIdleTime, torDirectory, torSocksPort,
 				torControlPort);

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPlugin.java

@@ -6,6 +6,7 @@ import com.sun.jna.Native;
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -28,6 +29,7 @@ class UnixTorPlugin extends JavaTorPlugin {
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
+			Backoff backoff,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback,
 			String architecture,
@@ -38,7 +40,7 @@ class UnixTorPlugin extends JavaTorPlugin {
 			int torControlPort) {
 		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
 				torSocketFactory, clock, resourceProvider,
-				circumventionProvider, batteryManager,
+				circumventionProvider, batteryManager, backoff,
 				torRendezvousCrypto, callback, architecture,
 				maxLatency, maxIdleTime, torDirectory, torSocksPort,
 				torControlPort);

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPluginFactory.java

@@ -6,6 +6,8 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TorControlPort;
 import org.briarproject.bramble.api.plugin.TorDirectory;
@@ -37,6 +39,7 @@ public class UnixTorPluginFactory extends TorPluginFactory {
 			LocationUtils locationUtils,
 			EventBus eventBus,
 			SocketFactory torSocketFactory,
+			BackoffFactory backoffFactory,
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
@@ -46,7 +49,7 @@ public class UnixTorPluginFactory extends TorPluginFactory {
 			@TorSocksPort int torSocksPort,
 			@TorControlPort int torControlPort) {
 		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
-				eventBus, torSocketFactory, resourceProvider,
+				eventBus, torSocketFactory, backoffFactory, resourceProvider,
 				circumventionProvider, batteryManager, clock, crypto,
 				torDirectory, torSocksPort, torControlPort);
 	}
@@ -66,13 +69,13 @@ public class UnixTorPluginFactory extends TorPluginFactory {
 	}
 
 	@Override
-	TorPlugin createPluginInstance(TorRendezvousCrypto torRendezvousCrypto,
-			PluginCallback callback,
+	TorPlugin createPluginInstance(Backoff backoff,
+			TorRendezvousCrypto torRendezvousCrypto, PluginCallback callback,
 			String architecture) {
 		return new UnixTorPlugin(ioExecutor, wakefulIoExecutor,
 				networkManager, locationUtils, torSocketFactory, clock,
 				resourceProvider, circumventionProvider, batteryManager,
-				torRendezvousCrypto, callback, architecture,
+				backoff, torRendezvousCrypto, callback, architecture,
 				MAX_LATENCY, MAX_IDLE_TIME, torDirectory, torSocksPort,
 				torControlPort);
 	}

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/WindowsTorPlugin.java

@@ -1,95 +0,0 @@
-package org.briarproject.bramble.plugin.tor;
-
-import com.sun.jna.platform.win32.Kernel32;
-
-import org.briarproject.bramble.api.battery.BatteryManager;
-import org.briarproject.bramble.api.network.NetworkManager;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginCallback;
-import org.briarproject.bramble.api.plugin.PluginException;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.bramble.api.system.ResourceProvider;
-
-import java.io.File;
-import java.util.Scanner;
-import java.util.concurrent.ArrayBlockingQueue;
-import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.Executor;
-
-import javax.net.SocketFactory;
-
-import static java.util.logging.Level.INFO;
-
-@NotNullByDefault
-class WindowsTorPlugin extends JavaTorPlugin {
-
-	WindowsTorPlugin(Executor ioExecutor,
-			Executor wakefulIoExecutor,
-			NetworkManager networkManager,
-			LocationUtils locationUtils,
-			SocketFactory torSocketFactory,
-			Clock clock,
-			ResourceProvider resourceProvider,
-			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager,
-			TorRendezvousCrypto torRendezvousCrypto,
-			PluginCallback callback,
-			String architecture,
-			long maxLatency,
-			int maxIdleTime,
-			File torDirectory,
-			int torSocksPort,
-			int torControlPort) {
-		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
-				torSocketFactory, clock, resourceProvider,
-				circumventionProvider, batteryManager,
-				torRendezvousCrypto, callback, architecture,
-				maxLatency, maxIdleTime, torDirectory, torSocksPort,
-				torControlPort);
-	}
-
-	@Override
-	protected int getProcessId() {
-		return Kernel32.INSTANCE.GetCurrentProcessId();
-	}
-
-	@Override
-	protected void waitForTorToStart(Process torProcess)
-			throws InterruptedException, PluginException {
-		// On Windows the RunAsDaemon option has no effect, so Tor won't detach.
-		// Wait for the control port to be opened, then continue to read its
-		// stdout and stderr in a background thread until it exits.
-		BlockingQueue<Boolean> success = new ArrayBlockingQueue<>(1);
-		ioExecutor.execute(() -> {
-			boolean started = false;
-			// Read the process's stdout (and redirected stderr)
-			Scanner stdout = new Scanner(torProcess.getInputStream());
-			// Log the first line of stdout (contains Tor and library versions)
-			if (stdout.hasNextLine()) LOG.info(stdout.nextLine());
-			// Startup has succeeded when the control port is open
-			while (stdout.hasNextLine()) {
-				String line = stdout.nextLine();
-				if (!started && line.contains("Opened Control listener")) {
-					success.add(true);
-					started = true;
-				}
-			}
-			stdout.close();
-			// If the control port wasn't opened, startup has failed
-			if (!started) success.add(false);
-			// Wait for the process to exit
-			try {
-				int exit = torProcess.waitFor();
-				if (LOG.isLoggable(INFO))
-					LOG.info("Tor exited with value " + exit);
-			} catch (InterruptedException e1) {
-				LOG.warning("Interrupted while waiting for Tor to exit");
-				Thread.currentThread().interrupt();
-			}
-		});
-		// Wait for the startup result
-		if (!success.take()) throw new PluginException();
-	}
-
-}

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/WindowsTorPluginFactory.java

@@ -1,77 +0,0 @@
-package org.briarproject.bramble.plugin.tor;
-
-import org.briarproject.bramble.api.battery.BatteryManager;
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.network.NetworkManager;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginCallback;
-import org.briarproject.bramble.api.plugin.TorControlPort;
-import org.briarproject.bramble.api.plugin.TorDirectory;
-import org.briarproject.bramble.api.plugin.TorSocksPort;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.bramble.api.system.ResourceProvider;
-import org.briarproject.bramble.api.system.WakefulIoExecutor;
-
-import java.io.File;
-import java.util.concurrent.Executor;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-import javax.net.SocketFactory;
-
-import static java.util.logging.Level.INFO;
-import static org.briarproject.bramble.util.OsUtils.isWindows;
-
-@Immutable
-@NotNullByDefault
-public class WindowsTorPluginFactory extends TorPluginFactory {
-
-	@Inject
-	WindowsTorPluginFactory(@IoExecutor Executor ioExecutor,
-			@WakefulIoExecutor Executor wakefulIoExecutor,
-			NetworkManager networkManager,
-			LocationUtils locationUtils,
-			EventBus eventBus,
-			SocketFactory torSocketFactory,
-			ResourceProvider resourceProvider,
-			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager,
-			Clock clock,
-			CryptoComponent crypto,
-			@TorDirectory File torDirectory,
-			@TorSocksPort int torSocksPort,
-			@TorControlPort int torControlPort) {
-		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
-				eventBus, torSocketFactory, resourceProvider,
-				circumventionProvider, batteryManager, clock, crypto,
-				torDirectory, torSocksPort, torControlPort);
-	}
-
-	@Nullable
-	@Override
-	String getArchitectureForTorBinary() {
-		if (!isWindows()) return null;
-		String arch = System.getProperty("os.arch");
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("System's os.arch is " + arch);
-		}
-		if (arch.equals("amd64")) return "windows-x86_64";
-		return null;
-	}
-
-	@Override
-	TorPlugin createPluginInstance(TorRendezvousCrypto torRendezvousCrypto,
-			PluginCallback callback,
-			String architecture) {
-		return new WindowsTorPlugin(ioExecutor, wakefulIoExecutor,
-				networkManager, locationUtils, torSocketFactory, clock,
-				resourceProvider, circumventionProvider, batteryManager,
-				torRendezvousCrypto, callback, architecture,
-				MAX_LATENCY, MAX_IDLE_TIME, torDirectory, torSocksPort,
-				torControlPort);
-	}
-}

bramble-java/src/main/java/org/briarproject/bramble/system/DesktopSecureRandomModule.java

@@ -16,7 +16,9 @@ public class DesktopSecureRandomModule {
 	@Provides
 	@Singleton
 	SecureRandomProvider provideSecureRandomProvider() {
-		if (isLinux() || isMac()) return new UnixSecureRandomProvider();
-		return () -> null; // Use system default
+		if (isLinux() || isMac())
+			return new UnixSecureRandomProvider();
+		// TODO: Create a secure random provider for Windows
+		throw new UnsupportedOperationException();
 	}
 }

bramble-java/src/test/java/org/briarproject/bramble/plugin/tor/BridgeTest.java

@@ -8,6 +8,7 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -109,6 +110,8 @@ public class BridgeTest extends BrambleTestCase {
 	@Inject
 	EventBus eventBus;
 	@Inject
+	BackoffFactory backoffFactory;
+	@Inject
 	Clock clock;
 	@Inject
 	CryptoComponent crypto;
@@ -163,8 +166,9 @@ public class BridgeTest extends BrambleTestCase {
 		};
 		factory = new UnixTorPluginFactory(ioExecutor, wakefulIoExecutor,
 				networkManager, locationUtils, eventBus, torSocketFactory,
-				resourceProvider, bridgeProvider, batteryManager, clock,
-				crypto, torDir, SOCKS_PORT, CONTROL_PORT);
+				backoffFactory, resourceProvider, bridgeProvider,
+				batteryManager, clock, crypto, torDir,
+				SOCKS_PORT, CONTROL_PORT);
 	}
 
 	@After

bramble-java/src/test/java/org/briarproject/bramble/plugin/tor/TestPluginCallback.java

@@ -43,10 +43,6 @@ public class TestPluginCallback implements PluginCallback {
 	public void pluginStateChanged(State state) {
 	}
 
-	@Override
-	public void pollingIntervalDecreased() {
-	}
-
 	@Override
 	public void handleConnection(DuplexTransportConnection c) {
 	}

bramble-java/witness.gradle

@@ -25,9 +25,7 @@ dependencyVerification {
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         'org.briarproject:obfs4proxy-linux:0.0.12:obfs4proxy-linux-0.0.12.jar:3dd83aff25fe1cb3e4eab78a02c76ac921f552be6877b3af83a472438525df2a',
-        'org.briarproject:obfs4proxy-windows:0.0.12:obfs4proxy-windows-0.0.12.jar:392aa4b9d9c6fef0c659c4068d019d6c6471991bbb62ff00553884ec36018c7b',
         'org.briarproject:tor-linux:0.4.5.12-2:tor-linux-0.4.5.12-2.jar:d275f323faf5e70b33d2c8a1bdab1bb3ab5a0d8f4e23c4a6dda03d86f4e95838',
-        'org.briarproject:tor-windows:0.4.5.12-2:tor-windows-0.4.5.12-2.jar:46599a15d099ed35a360113293f66acc119571c24ec2e37e85e4fb54b4722e07',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
         'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',

briar-headless/build.gradle

@@ -59,12 +59,7 @@ void jarFactory(Jar jarTask, jarArchitecture) {
 	}
 			{
 				it.duplicatesStrategy(DuplicatesStrategy.EXCLUDE)
-				String[] architectures = [
-						"linux-aarch64",
-						"linux-armhf",
-						"linux-x86_64",
-						"windows-x86_64"
-				]
+				String[] architectures = ["linux-aarch64", "linux-armhf", "linux-x86_64"]
 				for (String arch : architectures) {
 					if (arch != jarArchitecture) {
 						exclude "obfs4proxy_" + arch + ".zip"
@@ -117,10 +112,6 @@ task x86LinuxJar(type: Jar) {
 	jarFactory(it, 'linux-x86_64')
 }
 
-task windowsJar(type: Jar) {
-	jarFactory(it, 'windows-x86_64')
-}
-
 task linuxJars {
 	dependsOn(aarch64LinuxJar, armhfLinuxJar, x86LinuxJar)
 }

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

@@ -21,7 +21,6 @@ import org.briarproject.bramble.event.DefaultEventExecutorModule
 import org.briarproject.bramble.network.JavaNetworkModule
 import org.briarproject.bramble.plugin.tor.CircumventionModule
 import org.briarproject.bramble.plugin.tor.UnixTorPluginFactory
-import org.briarproject.bramble.plugin.tor.WindowsTorPluginFactory
 import org.briarproject.bramble.socks.SocksModule
 import org.briarproject.bramble.system.ClockModule
 import org.briarproject.bramble.system.DefaultTaskSchedulerModule
@@ -30,7 +29,6 @@ import org.briarproject.bramble.system.DesktopSecureRandomModule
 import org.briarproject.bramble.system.JavaSystemModule
 import org.briarproject.bramble.util.OsUtils.isLinux
 import org.briarproject.bramble.util.OsUtils.isMac
-import org.briarproject.bramble.util.OsUtils.isWindows
 import org.briarproject.briar.headless.blogs.HeadlessBlogModule
 import org.briarproject.briar.headless.contact.HeadlessContactModule
 import org.briarproject.briar.headless.event.HeadlessEventModule
@@ -96,15 +94,9 @@ internal class HeadlessModule(private val appDir: File) {
 
     @Provides
     @Singleton
-    internal fun providePluginConfig(
-        unixTor: UnixTorPluginFactory,
-        winTor: WindowsTorPluginFactory
-    ): PluginConfig {
-        val duplex: List<DuplexPluginFactory> = when {
-            isLinux() || isMac() -> listOf(unixTor)
-            isWindows() -> listOf(winTor)
-            else -> emptyList()
-        }
+    internal fun providePluginConfig(tor: UnixTorPluginFactory): PluginConfig {
+        val duplex: List<DuplexPluginFactory> =
+            if (isLinux() || isMac()) listOf(tor) else emptyList()
         return object : PluginConfig {
             override fun getDuplexFactories(): Collection<DuplexPluginFactory> = duplex
             override fun getSimplexFactories(): Collection<SimplexPluginFactory> = emptyList()

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

@@ -8,8 +8,6 @@ import com.github.ajalt.clikt.parameters.options.option
 import com.github.ajalt.clikt.parameters.types.int
 import org.bouncycastle.util.encoders.Base64.toBase64String
 import org.briarproject.bramble.BrambleCoreEagerSingletons
-import org.briarproject.bramble.util.OsUtils.isLinux
-import org.briarproject.bramble.util.OsUtils.isMac
 import org.briarproject.briar.BriarCoreEagerSingletons
 import org.slf4j.impl.SimpleLogger.DEFAULT_LOG_LEVEL_KEY
 import java.io.File
@@ -92,13 +90,11 @@ private class Main : CliktCommand(
         } else if (!file.isDirectory) {
             throw IOException("Data dir is not a directory: ${file.absolutePath}")
         }
-        if (isLinux() || isMac()) {
-            val perms = HashSet<PosixFilePermission>()
-            perms.add(OWNER_READ)
-            perms.add(OWNER_WRITE)
-            perms.add(OWNER_EXECUTE)
-            setPosixFilePermissions(file.toPath(), perms)
-        }
+        val perms = HashSet<PosixFilePermission>()
+        perms.add(OWNER_READ)
+        perms.add(OWNER_WRITE)
+        perms.add(OWNER_EXECUTE)
+        setPosixFilePermissions(file.toPath(), perms)
         return file
     }