Add executor with high and low priority queues.

.idea/codeStyles/Project.xml

@@ -39,6 +39,31 @@
     <JetCodeStyleSettings>
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
     </JetCodeStyleSettings>
+    <Objective-C-extensions>
+      <file>
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Import" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Macro" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Typedef" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Enum" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Constant" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Global" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Struct" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="FunctionPredecl" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Function" />
+      </file>
+      <class>
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Property" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Synthesize" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InitMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="StaticMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InstanceMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="DeallocMethod" />
+      </class>
+      <extensions>
+        <pair source="cpp" header="h" fileNamingConvention="NONE" />
+        <pair source="c" header="h" fileNamingConvention="NONE" />
+      </extensions>
+    </Objective-C-extensions>
     <XML>
       <option name="XML_LEGACY_SETTINGS_IMPORTED" value="true" />
     </XML>

bramble-android/build.gradle

@@ -30,8 +30,8 @@ configurations {
 
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	tor 'org.briarproject:tor-android:0.3.5.8@zip'
-	tor 'org.briarproject:obfs4proxy-android:0.0.9@zip'
+	tor 'org.briarproject:tor-android:0.3.4.8@zip'
+	tor 'org.briarproject:obfs4proxy-android:0.0.7@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.19'
 

bramble-android/witness.gradle

@@ -68,8 +68,8 @@ dependencyVerification {
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
         'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
-        'org.briarproject:obfs4proxy-android:0.0.9:obfs4proxy-android-0.0.9.zip:9b7e9181535ea8d8bbe8ae6338e08cf4c5fc1e357a779393e0ce49586d459ae0',
-        'org.briarproject:tor-android:0.3.5.8:tor-android-0.3.5.8.zip:42a13a6f185be1a62f42e3f30ce66a3c099ac5ec890a65e7593111b65b44a54a',
+        'org.briarproject:obfs4proxy-android:0.0.7:obfs4proxy-android-0.0.7.zip:abdfb5d889d848de9bf214f9276abbf454808a505b870819eccc9a9e985bf617',
+        'org.briarproject:tor-android:0.3.4.8:tor-android-0.3.4.8.zip:989a0352d9d8d8172cd6c2137654e165e5d2beb10ed1211bab3814e224ad1926',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.codehaus.groovy:groovy-all:2.4.12:groovy-all-2.4.12.jar:6a56af4bd48903d56bec62821876cadefafd007360cc6bd0d8f7aa8d72b38be4',
         'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeListener.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.contact;
+
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface ContactExchangeListener {
+
+	void contactExchangeSucceeded(Author remoteAuthor);
+
+	/**
+	 * The exchange failed because the contact already exists.
+	 */
+	void duplicateContact(Author remoteAuthor);
+
+	/**
+	 * A general failure.
+	 */
+	void contactExchangeFailed();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeTask.java

@@ -41,7 +41,8 @@ public interface ContactExchangeTask {
 	/**
 	 * Exchanges contact information with a remote peer.
 	 */
-	void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
+	void startExchange(ContactExchangeListener listener,
+			LocalAuthor localAuthor, SecretKey masterSecret,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactExchangeFailedEvent.java

@@ -1,32 +0,0 @@
-package org.briarproject.bramble.api.contact.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.Nullable;
-
-@NotNullByDefault
-public class ContactExchangeFailedEvent extends Event {
-
-	@Nullable
-	private final Author duplicateRemoteAuthor;
-
-	public ContactExchangeFailedEvent(@Nullable Author duplicateRemoteAuthor) {
-		this.duplicateRemoteAuthor = duplicateRemoteAuthor;
-	}
-
-	public ContactExchangeFailedEvent() {
-		this(null);
-	}
-
-	@Nullable
-	public Author getDuplicateRemoteAuthor() {
-		return duplicateRemoteAuthor;
-	}
-
-	public boolean wasDuplicateContact() {
-		return duplicateRemoteAuthor != null;
-	}
-
-}

bramble-api/src/main/java/org/briarproject/bramble/api/contact/event/ContactExchangeSucceededEvent.java

@@ -1,20 +0,0 @@
-package org.briarproject.bramble.api.contact.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public class ContactExchangeSucceededEvent extends Event {
-
-	private final Author remoteAuthor;
-
-	public ContactExchangeSucceededEvent(Author remoteAuthor) {
-		this.remoteAuthor = remoteAuthor;
-	}
-
-	public Author getRemoteAuthor() {
-		return remoteAuthor;
-	}
-
-}

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

@@ -0,0 +1,67 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.concurrent.Executor;
+
+import javax.annotation.concurrent.GuardedBy;
+
+@NotNullByDefault
+public class PriorityExecutor {
+
+	private final Object lock = new Object();
+	private final Executor delegate, high, low;
+	@GuardedBy("lock")
+	private final Queue<Runnable> highQueue = new LinkedList<>();
+	@GuardedBy("lock")
+	private final Queue<Runnable> lowQueue = new LinkedList<>();
+
+	@GuardedBy("lock")
+	private boolean isTaskRunning = false;
+
+	public PriorityExecutor(Executor delegate) {
+		this.delegate = delegate;
+		high = r -> submit(r, true);
+		low = r -> submit(r, false);
+	}
+
+	public Executor getHighPriorityExecutor() {
+		return high;
+	}
+
+	public Executor getLowPriorityExecutor() {
+		return low;
+	}
+
+	private void submit(Runnable r, boolean isHighPriority) {
+		Runnable wrapped = () -> {
+			try {
+				r.run();
+			} finally {
+				scheduleNext();
+			}
+		};
+		synchronized (lock) {
+			if (!isTaskRunning && highQueue.isEmpty() &&
+					(isHighPriority || lowQueue.isEmpty())) {
+				isTaskRunning = true;
+				delegate.execute(wrapped);
+			} else if (isHighPriority) {
+				highQueue.add(wrapped);
+			} else {
+				lowQueue.add(wrapped);
+			}
+		}
+	}
+
+	private void scheduleNext() {
+		synchronized (lock) {
+			Runnable next = highQueue.poll();
+			if (next == null) next = lowQueue.poll();
+			if (next == null) isTaskRunning = false;
+			else delegate.execute(next);
+		}
+	}
+}

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

@@ -2,11 +2,10 @@ package org.briarproject.bramble.contact;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
+import org.briarproject.bramble.api.contact.ContactExchangeListener;
 import org.briarproject.bramble.api.contact.ContactExchangeTask;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
-import org.briarproject.bramble.api.contact.event.ContactExchangeFailedEvent;
-import org.briarproject.bramble.api.contact.event.ContactExchangeSucceededEvent;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.data.BdfDictionary;
@@ -14,7 +13,6 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -65,7 +63,6 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private final ClientHelper clientHelper;
 	private final RecordReaderFactory recordReaderFactory;
 	private final RecordWriterFactory recordWriterFactory;
-	private final EventBus eventBus;
 	private final Clock clock;
 	private final ConnectionManager connectionManager;
 	private final ContactManager contactManager;
@@ -74,6 +71,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private final StreamReaderFactory streamReaderFactory;
 	private final StreamWriterFactory streamWriterFactory;
 
+	private volatile ContactExchangeListener listener;
 	private volatile LocalAuthor localAuthor;
 	private volatile DuplexTransportConnection conn;
 	private volatile TransportId transportId;
@@ -83,9 +81,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	@Inject
 	ContactExchangeTaskImpl(DatabaseComponent db, ClientHelper clientHelper,
 			RecordReaderFactory recordReaderFactory,
-			RecordWriterFactory recordWriterFactory, EventBus eventBus,
-			Clock clock, ConnectionManager connectionManager,
-			ContactManager contactManager,
+			RecordWriterFactory recordWriterFactory, Clock clock,
+			ConnectionManager connectionManager, ContactManager contactManager,
 			TransportPropertyManager transportPropertyManager,
 			CryptoComponent crypto, StreamReaderFactory streamReaderFactory,
 			StreamWriterFactory streamWriterFactory) {
@@ -93,7 +90,6 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		this.clientHelper = clientHelper;
 		this.recordReaderFactory = recordReaderFactory;
 		this.recordWriterFactory = recordWriterFactory;
-		this.eventBus = eventBus;
 		this.clock = clock;
 		this.connectionManager = connectionManager;
 		this.contactManager = contactManager;
@@ -104,9 +100,11 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	}
 
 	@Override
-	public void startExchange(LocalAuthor localAuthor, SecretKey masterSecret,
+	public void startExchange(ContactExchangeListener listener,
+			LocalAuthor localAuthor, SecretKey masterSecret,
 			DuplexTransportConnection conn, TransportId transportId,
 			boolean alice) {
+		this.listener = listener;
 		this.localAuthor = localAuthor;
 		this.conn = conn;
 		this.transportId = transportId;
@@ -125,8 +123,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			out = conn.getWriter().getOutputStream();
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
+			listener.contactExchangeFailed();
 			tryToClose(conn);
-			eventBus.broadcast(new ContactExchangeFailedEvent());
 			return;
 		}
 
@@ -136,7 +134,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			localProperties = transportPropertyManager.getLocalProperties();
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
-			eventBus.broadcast(new ContactExchangeFailedEvent());
+			listener.contactExchangeFailed();
 			tryToClose(conn);
 			return;
 		}
@@ -198,7 +196,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			}
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
-			eventBus.broadcast(new ContactExchangeFailedEvent());
+			listener.contactExchangeFailed();
 			tryToClose(conn);
 			return;
 		}
@@ -206,7 +204,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		// Verify the contact's signature
 		if (!verify(remoteInfo.author, remoteNonce, remoteInfo.signature)) {
 			LOG.warning("Invalid signature");
-			eventBus.broadcast(new ContactExchangeFailedEvent());
+			listener.contactExchangeFailed();
 			tryToClose(conn);
 			return;
 		}
@@ -223,17 +221,15 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 					conn);
 			// Pseudonym exchange succeeded
 			LOG.info("Pseudonym exchange succeeded");
-			eventBus.broadcast(
-					new ContactExchangeSucceededEvent(remoteInfo.author));
+			listener.contactExchangeSucceeded(remoteInfo.author);
 		} catch (ContactExistsException e) {
 			logException(LOG, WARNING, e);
 			tryToClose(conn);
-			eventBus.broadcast(
-					new ContactExchangeFailedEvent(remoteInfo.author));
+			listener.duplicateContact(remoteInfo.author);
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
 			tryToClose(conn);
-			eventBus.broadcast(new ContactExchangeFailedEvent());
+			listener.contactExchangeFailed();
 		}
 	}
 

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

@@ -17,24 +17,16 @@ public interface CircumventionProvider {
 	String[] BLOCKED = {"CN", "IR", "EG", "BY", "TR", "SY", "VE"};
 
 	/**
-	 * Countries where obfs4 bridge connection are likely to work.
+	 * Countries where vanilla bridge connection are likely to work.
 	 * Should be a subset of {@link #BLOCKED}.
 	 */
-	String[] BRIDGES = { "CN", "IR", "EG", "BY", "TR", "SY", "VE" };
-
-	/**
-	 * Countries where obfs4 bridges won't work and meek is needed.
-	 * Should be a subset of {@link #BRIDGES}.
-	 */
-	String[] NEEDS_MEEK = {"CN", "IR"};
+	String[] BRIDGES = { "EG", "BY", "TR", "SY", "VE" };
 
 	boolean isTorProbablyBlocked(String countryCode);
 
 	boolean doBridgesWork(String countryCode);
 
-	boolean needsMeek(String countryCode);
-
 	@IoExecutor
-	List<String> getBridges(boolean meek);
+	List<String> getBridges();
 
 }

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

@@ -22,8 +22,6 @@ class CircumventionProviderImpl implements CircumventionProvider {
 			new HashSet<>(asList(BLOCKED));
 	private static final Set<String> BRIDGES_WORK_IN_COUNTRIES =
 			new HashSet<>(asList(BRIDGES));
-	private static final Set<String> BRIDGES_NEED_MEEK =
-			new HashSet<>(asList(NEEDS_MEEK));
 
 	@Nullable
 	private volatile List<String> bridges = null;
@@ -42,14 +40,9 @@ class CircumventionProviderImpl implements CircumventionProvider {
 		return BRIDGES_WORK_IN_COUNTRIES.contains(countryCode);
 	}
 
-	@Override
-	public boolean needsMeek(String countryCode) {
-		return BRIDGES_NEED_MEEK.contains(countryCode);
-	}
-
 	@Override
 	@IoExecutor
-	public List<String> getBridges(boolean useMeek) {
+	public List<String> getBridges() {
 		List<String> bridges = this.bridges;
 		if (bridges != null) return new ArrayList<>(bridges);
 
@@ -60,8 +53,6 @@ class CircumventionProviderImpl implements CircumventionProvider {
 		bridges = new ArrayList<>();
 		while (scanner.hasNextLine()) {
 			String line = scanner.nextLine();
-			boolean isMeekBridge = line.startsWith("Bridge meek");
-			if (useMeek && !isMeekBridge || !useMeek && isMeekBridge) continue;
 			if (!line.startsWith("#")) bridges.add(line);
 		}
 		scanner.close();

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

@@ -470,19 +470,13 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (!enable) callback.transportDisabled();
 	}
 
-	private void enableBridges(boolean enable, boolean needsMeek)
-			throws IOException {
+	private void enableBridges(boolean enable) throws IOException {
 		if (enable) {
 			Collection<String> conf = new ArrayList<>();
 			conf.add("UseBridges 1");
-			if (needsMeek) {
-				conf.add("ClientTransportPlugin meek_lite exec " +
-						obfs4File.getAbsolutePath());
-			} else {
-				conf.add("ClientTransportPlugin obfs4 exec " +
-						obfs4File.getAbsolutePath());
-			}
-			conf.addAll(circumventionProvider.getBridges(needsMeek));
+			conf.add("ClientTransportPlugin obfs4 exec " +
+					obfs4File.getAbsolutePath());
+			conf.addAll(circumventionProvider.getBridges());
 			controlConnection.setConf(conf);
 		} else {
 			controlConnection.setConf("UseBridges", "0");
@@ -722,17 +716,12 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 					enableNetwork(false);
 				} else if (network == PREF_TOR_NETWORK_WITH_BRIDGES ||
 						(automatic && bridgesWork)) {
-					if (circumventionProvider.needsMeek(country)) {
-						LOG.info("Enabling network, using meek bridges");
-						enableBridges(true, true);
-					} else {
-						LOG.info("Enabling network, using obfs4 bridges");
-						enableBridges(true, false);
-					}
+					LOG.info("Enabling network, using bridges");
+					enableBridges(true);
 					enableNetwork(true);
 				} else {
 					LOG.info("Enabling network, not using bridges");
-					enableBridges(false, false);
+					enableBridges(false);
 					enableNetwork(true);
 				}
 				if (online && wifi && charging) {

bramble-core/src/main/resources/bridges

@@ -1,5 +1,4 @@
 Bridge obfs4 78.46.188.239:37356 5A2D2F4158D0453E00C7C176978D3F41D69C45DB cert=3c0SwxpOisbohNxEc4tb875RVW8eOu1opRTVXJhafaKA/PNNtI7ElQIVOVZg1AdL5bxGCw iat-mode=0
 Bridge obfs4 52.15.78.72:9443 02069A3C5362476936B62BA6F5ACC41ABD573A9B cert=ijYG/OKc7kqu2YzKNFfeXN7/BG2BOgfEP2KyYEiGDQthnHbsOiTWHeIG0WJVW+BckzDgKw iat-mode=0
 Bridge obfs4 13.58.29.242:9443 0C58939A77DA6B6B29D4B5236A75865659607AE0 cert=OylWIEHb/ezpq1zWxW0sgKRn+9ARH2eOcQOZ8/Gew+4l+oKOhQ2jUX/Y+FSl61JorXZUWA iat-mode=0
-Bridge obfs4 45.33.37.112:9443 60A609BB4ABE8D46E634AE81ED29ADAB7776B399 cert=t5v19WmNv5Sc2YPNr8RQids365W7MY8zJwQVkOxBjUMFomMWARDzsbYpcWLLcw0J9Gm+BQ iat-mode=0
-Bridge meek_lite 0.0.2.0:2 97700DFE9F483596DDA6264C4D7DF7641E1E39CE url=https://meek.azureedge.net/ front=ajax.aspnetcdn.com
+Bridge obfs4 45.33.37.112:9443 60A609BB4ABE8D46E634AE81ED29ADAB7776B399 cert=t5v19WmNv5Sc2YPNr8RQids365W7MY8zJwQVkOxBjUMFomMWARDzsbYpcWLLcw0J9Gm+BQ iat-mode=0

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

@@ -0,0 +1,86 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.junit.Test;
+
+import java.util.List;
+import java.util.Vector;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+
+import static java.util.Arrays.asList;
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class PriorityExecutorTest extends BrambleTestCase {
+
+	@Test
+	public void testHighPriorityTasksAreDelegatedInOrderOfSubmission()
+			throws Exception {
+		Executor delegate = newSingleThreadExecutor();
+		PriorityExecutor priority = new PriorityExecutor(delegate);
+		Executor high = priority.getHighPriorityExecutor();
+		testTasksAreDelegatedInOrderOfSubmission(high);
+	}
+
+	@Test
+	public void testLowPriorityTasksAreDelegatedInOrderOfSubmission()
+			throws Exception {
+		Executor delegate = newSingleThreadExecutor();
+		PriorityExecutor priority = new PriorityExecutor(delegate);
+		Executor low = priority.getLowPriorityExecutor();
+		testTasksAreDelegatedInOrderOfSubmission(low);
+	}
+
+	@Test
+	public void testHighPriorityTasksAreRunFirst() throws Exception {
+		Executor delegate = newSingleThreadExecutor();
+		PriorityExecutor priority = new PriorityExecutor(delegate);
+		Executor high = priority.getHighPriorityExecutor();
+		Executor low = priority.getLowPriorityExecutor();
+		// Submit a task that will block, causing other tasks to be queued
+		CountDownLatch cork = new CountDownLatch(1);
+		low.execute(() -> {
+			try {
+				cork.await();
+			} catch (InterruptedException e) {
+				fail();
+			}
+		});
+		// Submit alternating tasks to the high and low priority executors
+		List<Integer> results = new Vector<>();
+		CountDownLatch tasksFinished = new CountDownLatch(10);
+		for (int i = 0; i < 10; i++) {
+			int result = i;
+			Runnable task = () -> {
+				results.add(result);
+				tasksFinished.countDown();
+			};
+			if (i % 2 == 0) high.execute(task);
+			else low.execute(task);
+		}
+		// Release the cork and wait for all tasks to finish
+		cork.countDown();
+		tasksFinished.await();
+		// The high-priority tasks should have run before the low-priority tasks
+		assertEquals(asList(0, 2, 4, 6, 8, 1, 3, 5, 7, 9), results);
+	}
+
+	private void testTasksAreDelegatedInOrderOfSubmission(Executor e)
+			throws Exception {
+		List<Integer> results = new Vector<>();
+		CountDownLatch tasksFinished = new CountDownLatch(10);
+		for (int i = 0; i < 10; i++) {
+			int result = i;
+			e.execute(() -> {
+				results.add(result);
+				tasksFinished.countDown();
+			});
+		}
+		// Wait for all the tasks to finish
+		tasksFinished.await();
+		// The tasks should have run in the order they were submitted
+		assertEquals(asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9), results);
+	}
+}

bramble-java/build.gradle

@@ -16,7 +16,7 @@ dependencies {
 	implementation fileTree(dir: 'libs', include: '*.jar')
 	implementation 'net.java.dev.jna:jna:4.5.2'
 	implementation 'net.java.dev.jna:jna-platform:4.5.2'
-	tor 'org.briarproject:tor:0.3.5.8@zip'
+	tor 'org.briarproject:tor:0.3.4.8@zip'
 	tor 'org.briarproject:obfs4proxy:0.0.7@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.19'

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

@@ -44,7 +44,7 @@ public class BridgeTest extends BrambleTestCase {
 	public static Iterable<String> data() {
 		BrambleJavaIntegrationTestComponent component =
 				DaggerBrambleJavaIntegrationTestComponent.builder().build();
-		return component.getCircumventionProvider().getBridges(false);
+		return component.getCircumventionProvider().getBridges();
 	}
 
 	private final static long TIMEOUT = SECONDS.toMillis(30);
@@ -104,12 +104,7 @@ public class BridgeTest extends BrambleTestCase {
 			}
 
 			@Override
-			public boolean needsMeek(String countryCode) {
-				return false;
-			}
-
-			@Override
-			public List<String> getBridges(boolean useMeek) {
+			public List<String> getBridges() {
 				return singletonList(bridge);
 			}
 		};

bramble-java/witness.gradle

@@ -21,7 +21,7 @@ dependencyVerification {
         'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.briarproject:obfs4proxy:0.0.7:obfs4proxy-0.0.7.zip:5b2f693262ce43a7e130f7cc7d5d1617925330640a2eb6d71085e95df8ee0642',
-        'org.briarproject:tor:0.3.5.8:tor-0.3.5.8.zip:96e83391f01984f28669235fc02fbb0243140a2b3b2c73aeffd0042c8d3ced18',
+        'org.briarproject:tor:0.3.4.8:tor-0.3.4.8.zip:bc0158c34002f471a4fe14a6a481816c918eb520a220bb027f64be902beb757f',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',
         'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',

briar-android/src/main/AndroidManifest.xml

@@ -22,7 +22,6 @@
 	<uses-permission-sdk-23 android:name="android.permission.ACCESS_COARSE_LOCATION" />
 	<uses-permission-sdk-23 android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
 	<uses-permission-sdk-23 android:name="android.permission.USE_BIOMETRIC" />
-	<uses-permission-sdk-23 android:name="android.permission.FOREGROUND_SERVICE" />
 
 	<application
 		android:name="org.briarproject.briar.android.BriarApplicationImpl"

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

@@ -67,10 +67,6 @@ public class ImageActivity extends BriarActivity
 	final static String NAME = "name";
 	final static String DATE = "date";
 
-	@RequiresApi(api = 16)
-	private final static int UI_FLAGS_DEFAULT =
-			SYSTEM_UI_FLAG_LAYOUT_STABLE | SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
-
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
@@ -142,7 +138,9 @@ public class ImageActivity extends BriarActivity
 
 		if (SDK_INT >= 16) {
 			viewModel.getOnImageClicked().observe(this, this::onImageClicked);
-			window.getDecorView().setSystemUiVisibility(UI_FLAGS_DEFAULT);
+			window.getDecorView().setSystemUiVisibility(
+					SYSTEM_UI_FLAG_LAYOUT_STABLE |
+							SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
 		}
 	}
 
@@ -208,16 +206,9 @@ public class ImageActivity extends BriarActivity
 
 	@Override
 	public void onPullComplete() {
-		showStatusBarBeforeFinishing();
 		supportFinishAfterTransition();
 	}
 
-	@Override
-	public void onBackPressed() {
-		showStatusBarBeforeFinishing();
-		super.onBackPressed();
-	}
-
 	@RequiresApi(api = 16)
 	private void onImageClicked(@Nullable Boolean clicked) {
 		if (clicked != null && clicked) {
@@ -238,8 +229,9 @@ public class ImageActivity extends BriarActivity
 
 	@RequiresApi(api = 16)
 	private void hideSystemUi(View decorView) {
-		decorView.setSystemUiVisibility(
-				SYSTEM_UI_FLAG_FULLSCREEN | UI_FLAGS_DEFAULT);
+		decorView.setSystemUiVisibility(SYSTEM_UI_FLAG_FULLSCREEN |
+				SYSTEM_UI_FLAG_LAYOUT_STABLE | SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+		);
 		appBarLayout.animate()
 				.translationYBy(-1 * appBarLayout.getHeight())
 				.alpha(0f)
@@ -249,7 +241,9 @@ public class ImageActivity extends BriarActivity
 
 	@RequiresApi(api = 16)
 	private void showSystemUi(View decorView) {
-		decorView.setSystemUiVisibility(UI_FLAGS_DEFAULT);
+		decorView.setSystemUiVisibility(
+				SYSTEM_UI_FLAG_LAYOUT_STABLE | SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+		);
 		appBarLayout.animate()
 				.translationYBy(appBarLayout.getHeight())
 				.alpha(1f)
@@ -257,18 +251,6 @@ public class ImageActivity extends BriarActivity
 				.start();
 	}
 
-	/**
-	 * If we don't show the status bar again before finishing this activity,
-	 * the return transition will "jump" down the size of the status bar
-	 * when the previous activity (with visible status bar) is shown.
-	 */
-	private void showStatusBarBeforeFinishing() {
-		if (SDK_INT >= 16 && appBarLayout.getVisibility() == GONE) {
-			View decorView = getWindow().getDecorView();
-			decorView.setSystemUiVisibility(UI_FLAGS_DEFAULT);
-		}
-	}
-
 	private void showSaveImageDialog() {
 		OnClickListener okListener = (dialog, which) -> {
 			if (SDK_INT >= 19) {

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

@@ -4,12 +4,9 @@ import android.os.Bundle;
 import android.support.annotation.UiThread;
 import android.widget.Toast;
 
+import org.briarproject.bramble.api.contact.ContactExchangeListener;
 import org.briarproject.bramble.api.contact.ContactExchangeTask;
-import org.briarproject.bramble.api.contact.event.ContactExchangeFailedEvent;
-import org.briarproject.bramble.api.contact.event.ContactExchangeSucceededEvent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -31,7 +28,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ContactExchangeActivity extends KeyAgreementActivity implements
-		EventListener {
+		ContactExchangeListener {
 
 	private static final Logger LOG =
 			Logger.getLogger(ContactExchangeActivity.class.getName());
@@ -53,20 +50,6 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 		getSupportActionBar().setTitle(R.string.add_contact_title);
 	}
 
-	@Override
-	public void onStart() {
-		super.onStart();
-		// Listen to updates from contactExchangeTask
-		eventBus.addListener(this);
-	}
-
-	@Override
-	protected void onStop() {
-		super.onStop();
-		// Stop listen to updates from contactExchangeTask
-		eventBus.addListener(this);
-	}
-
 	private void startContactExchange(KeyAgreementResult result) {
 		runOnDbThread(() -> {
 			LocalAuthor localAuthor;
@@ -80,28 +63,15 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 			}
 
 			// Exchange contact details
-			contactExchangeTask.startExchange(localAuthor,
-					result.getMasterKey(), result.getConnection(),
-					result.getTransportId(), result.wasAlice());
+			contactExchangeTask.startExchange(ContactExchangeActivity.this,
+					localAuthor, result.getMasterKey(),
+					result.getConnection(), result.getTransportId(),
+					result.wasAlice());
 		});
 	}
 
 	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof ContactExchangeSucceededEvent) {
-			contactExchangeSucceeded(
-					((ContactExchangeSucceededEvent) e).getRemoteAuthor());
-		} else if (e instanceof ContactExchangeFailedEvent) {
-			ContactExchangeFailedEvent fe = (ContactExchangeFailedEvent) e;
-			if (fe.wasDuplicateContact()) {
-				duplicateContact(fe.getDuplicateRemoteAuthor());
-			} else {
-				contactExchangeFailed();
-			}
-		}
-	}
-
-	private void contactExchangeSucceeded(Author remoteAuthor) {
+	public void contactExchangeSucceeded(Author remoteAuthor) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			String contactName = remoteAuthor.getName();
 			String format = getString(R.string.contact_added_toast);
@@ -112,7 +82,8 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 		});
 	}
 
-	private void duplicateContact(Author remoteAuthor) {
+	@Override
+	public void duplicateContact(Author remoteAuthor) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			String contactName = remoteAuthor.getName();
 			String format = getString(R.string.contact_already_exists);
@@ -123,7 +94,8 @@ public class ContactExchangeActivity extends KeyAgreementActivity implements
 		});
 	}
 
-	private void contactExchangeFailed() {
+	@Override
+	public void contactExchangeFailed() {
 		runOnUiThreadUnlessDestroyed(() -> {
 			showErrorFragment(R.string.connection_error_explanation);
 		});

briar-android/src/main/java/org/briarproject/briar/android/privategroup/conversation/GroupActivity.java

@@ -178,14 +178,6 @@ public class GroupActivity extends
 		} else super.onActivityResult(request, result, data);
 	}
 
-	@Override
-	public void onItemReceived(GroupMessageItem item) {
-		super.onItemReceived(item);
-		if (item instanceof JoinMessageItem) {
-			if (((JoinMessageItem) item).isInitial()) loadSharingContacts();
-		}
-	}
-
 	@Override
 	protected int getMaxTextLength() {
 		return MAX_GROUP_POST_TEXT_LENGTH;

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

@@ -7,20 +7,14 @@ import android.view.MenuItem;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.controller.handler.UiResultExceptionHandler;
 import org.briarproject.briar.android.view.BriarRecyclerView;
-import org.briarproject.briar.api.privategroup.JoinMessageHeader;
-import org.briarproject.briar.api.privategroup.event.GroupMessageAddedEvent;
 
 import java.util.Collection;
 
@@ -29,13 +23,10 @@ import javax.inject.Inject;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-public class GroupMemberListActivity extends BriarActivity
-		implements EventListener {
+public class GroupMemberListActivity extends BriarActivity {
 
 	@Inject
 	GroupMemberListController controller;
-	@Inject
-	EventBus eventBus;
 
 	private MemberListAdapter adapter;
 	private BriarRecyclerView list;
@@ -70,50 +61,6 @@ public class GroupMemberListActivity extends BriarActivity
 	@Override
 	public void onStart() {
 		super.onStart();
-		loadMembers();
-		eventBus.addListener(this);
-		list.startPeriodicUpdate();
-	}
-
-	@Override
-	public void onStop() {
-		super.onStop();
-		eventBus.removeListener(this);
-		list.stopPeriodicUpdate();
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof GroupMessageAddedEvent) {
-			// we can't use GroupInvitationResponseReceivedEvent, because
-			// a peer only becomes a member after joining the group by message
-			GroupMessageAddedEvent ge = (GroupMessageAddedEvent) e;
-			if (ge.getGroupId().equals(groupId) &&
-					ge.getHeader() instanceof JoinMessageHeader) {
-				loadMembers();
-			}
-		} else if (e instanceof GroupRemovedEvent) {
-			GroupRemovedEvent g = (GroupRemovedEvent) e;
-			if (g.getGroup().getId().equals(groupId)) {
-				runOnUiThreadUnlessDestroyed(
-						this::supportFinishAfterTransition);
-			}
-		}
-		// TODO ContactConnectedEvent and ContactDisconnectedEvent
-	}
-
-	@Override
-	public boolean onOptionsItemSelected(MenuItem item) {
-		switch (item.getItemId()) {
-			case android.R.id.home:
-				onBackPressed();
-				return true;
-			default:
-				return super.onOptionsItemSelected(item);
-		}
-	}
-
-	private void loadMembers() {
 		controller.loadMembers(groupId,
 				new UiResultExceptionHandler<Collection<MemberListItem>, DbException>(
 						this) {
@@ -127,6 +74,24 @@ public class GroupMemberListActivity extends BriarActivity
 						handleDbException(exception);
 					}
 				});
+		list.startPeriodicUpdate();
+	}
+
+	@Override
+	public void onStop() {
+		super.onStop();
+		list.stopPeriodicUpdate();
+	}
+
+	@Override
+	public boolean onOptionsItemSelected(MenuItem item) {
+		switch (item.getItemId()) {
+			case android.R.id.home:
+				onBackPressed();
+				return true;
+			default:
+				return super.onOptionsItemSelected(item);
+		}
 	}
 
 }

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

@@ -3,14 +3,11 @@ package org.briarproject.briar.android.sharing;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
-import org.briarproject.briar.api.blog.BlogInvitationResponse;
 import org.briarproject.briar.api.blog.BlogSharingManager;
-import org.briarproject.briar.api.blog.event.BlogInvitationResponseReceivedEvent;
 
 import java.util.Collection;
 
@@ -29,19 +26,6 @@ public class BlogSharingStatusActivity extends SharingStatusActivity {
 		component.inject(this);
 	}
 
-	@Override
-	public void eventOccurred(Event e) {
-		super.eventOccurred(e);
-		if (e instanceof BlogInvitationResponseReceivedEvent) {
-			BlogInvitationResponseReceivedEvent r =
-					(BlogInvitationResponseReceivedEvent) e;
-			BlogInvitationResponse h = r.getMessageHeader();
-			if (h.getShareableId().equals(getGroupId()) && h.wasAccepted()) {
-				loadSharedWith();
-			}
-		}
-	}
-
 	@Override
 	int getInfoText() {
 		return R.string.sharing_status_blog;

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

@@ -3,14 +3,11 @@ package org.briarproject.briar.android.sharing;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
-import org.briarproject.briar.api.forum.ForumInvitationResponse;
 import org.briarproject.briar.api.forum.ForumSharingManager;
-import org.briarproject.briar.api.forum.event.ForumInvitationResponseReceivedEvent;
 
 import java.util.Collection;
 
@@ -29,19 +26,6 @@ public class ForumSharingStatusActivity extends SharingStatusActivity {
 		component.inject(this);
 	}
 
-	@Override
-	public void eventOccurred(Event e) {
-		super.eventOccurred(e);
-		if (e instanceof ForumInvitationResponseReceivedEvent) {
-			ForumInvitationResponseReceivedEvent r =
-					(ForumInvitationResponseReceivedEvent) e;
-			ForumInvitationResponse h = r.getMessageHeader();
-			if (h.getShareableId().equals(getGroupId()) && h.wasAccepted()) {
-				loadSharedWith();
-			}
-		}
-	}
-
 	@Override
 	int getInfoText() {
 		return R.string.sharing_status_forum;

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

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.sharing;
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.CallSuper;
 import android.support.annotation.StringRes;
 import android.support.v7.widget.LinearLayoutManager;
 import android.view.MenuItem;
@@ -11,19 +10,14 @@ import android.widget.TextView;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.contact.ContactItem;
 import org.briarproject.briar.android.view.BriarRecyclerView;
-import org.briarproject.briar.api.sharing.event.ContactLeftShareableEvent;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -38,13 +32,10 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-abstract class SharingStatusActivity extends BriarActivity
-		implements EventListener {
+abstract class SharingStatusActivity extends BriarActivity {
 
 	@Inject
 	ConnectionRegistry connectionRegistry;
-	@Inject
-	EventBus eventBus;
 
 	private static final Logger LOG =
 			Logger.getLogger(SharingStatusActivity.class.getName());
@@ -77,7 +68,6 @@ abstract class SharingStatusActivity extends BriarActivity
 	@Override
 	public void onStart() {
 		super.onStart();
-		eventBus.addListener(this);
 		loadSharedWith();
 	}
 
@@ -85,28 +75,9 @@ abstract class SharingStatusActivity extends BriarActivity
 	public void onStop() {
 		super.onStop();
 		adapter.clear();
-		eventBus.removeListener(this);
 		list.showProgressBar();
 	}
 
-	@Override
-	@CallSuper
-	public void eventOccurred(Event e) {
-		if (e instanceof ContactLeftShareableEvent) {
-			ContactLeftShareableEvent c = (ContactLeftShareableEvent) e;
-			if (c.getGroupId().equals(getGroupId())) {
-				loadSharedWith();
-			}
-		} else if (e instanceof GroupRemovedEvent) {
-			GroupRemovedEvent g = (GroupRemovedEvent) e;
-			if (g.getGroup().getId().equals(getGroupId())) {
-				runOnUiThreadUnlessDestroyed(
-						this::supportFinishAfterTransition);
-			}
-		}
-		// TODO ContactConnectedEvent and ContactDisconnectedEvent
-	}
-
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		// Handle presses on the action bar items
@@ -129,7 +100,7 @@ abstract class SharingStatusActivity extends BriarActivity
 		return groupId;
 	}
 
-	protected void loadSharedWith() {
+	private void loadSharedWith() {
 		runOnDbThread(() -> {
 			try {
 				List<ContactItem> contactItems = new ArrayList<>();
@@ -147,7 +118,6 @@ abstract class SharingStatusActivity extends BriarActivity
 
 	private void displaySharedWith(List<ContactItem> contacts) {
 		runOnUiThreadUnlessDestroyed(() -> {
-			adapter.clear();
 			if (contacts.isEmpty()) list.showData();
 			else adapter.addAll(contacts);
 		});

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

@@ -82,11 +82,11 @@
 		android:layout_marginStart="@dimen/listitem_horizontal_margin"
 		android:layout_marginTop="@dimen/margin_medium"
 		android:textColor="?android:attr/textColorTertiary"
-		app:layout_constraintEnd_toStartOf="@+id/removeButton"
+		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintLeft_toRightOf="@+id/avatarView"
 		app:layout_constraintStart_toEndOf="@+id/avatarView"
 		app:layout_constraintTop_toBottomOf="@+id/messageCountView"
-		tools:text="This group is empty, but has a long status text"/>
+		tools:text="@string/groups_group_is_empty"/>
 
 	<Button
 		android:id="@+id/removeButton"
@@ -94,11 +94,9 @@
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
 		android:text="@string/groups_remove"
-		android:visibility="gone"
 		app:layout_constraintBottom_toBottomOf="@+id/divider"
 		app:layout_constraintRight_toRightOf="parent"
-		app:layout_constraintTop_toTopOf="@+id/statusView"
-		tools:visibility="visible"/>
+		tools:visibility="gone"/>
 
 	<View
 		android:id="@+id/divider"

briar-android/src/main/res/menu/group_actions.xml

@@ -13,7 +13,7 @@
 		android:id="@+id/action_group_member_list"
 		android:icon="@drawable/ic_group_white"
 		android:title="@string/groups_member_list"
-		app:showAsAction="never"/>
+		app:showAsAction="ifRoom"/>
 
 	<item
 		android:id="@+id/action_group_reveal"

briar-core/src/main/java/org/briarproject/briar/messaging/MessagingManagerImpl.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.messaging;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.client.ContactGroupFactory;
 import org.briarproject.bramble.api.contact.Contact;
@@ -33,12 +32,11 @@ import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 import org.briarproject.briar.api.messaging.event.PrivateMessageReceivedEvent;
 import org.briarproject.briar.client.ConversationClientImpl;
 
-import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
 import java.util.Map;
 import java.util.Random;
 
@@ -46,7 +44,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static java.util.Collections.emptyList;
-import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.StringUtils.fromHexString;
 import static org.briarproject.briar.client.MessageTrackerConstants.MSG_KEY_READ;
 
 @Immutable
@@ -221,26 +219,8 @@ class MessagingManagerImpl extends ConversationClientImpl
 				long timestamp = meta.getLong("timestamp");
 				boolean local = meta.getBoolean("local");
 				boolean read = meta.getBoolean("read");
-				// TODO replace fake attachments by real ones
-				boolean hasText;
-				List<AttachmentHeader> attachments;
-				Random random = new Random(id.hashCode());
-				if (random.nextBoolean()) {
-					hasText = random.nextBoolean();
-					attachments = new ArrayList<>();
-					int numAttachments = random.nextInt(10) + 1;
-					for (int i = 0; i < numAttachments; i++) {
-						byte[] b = new byte[UniqueId.LENGTH];
-						random.nextBytes(b);
-						attachments.add(new AttachmentHeader(new MessageId(b),
-								"image/jpeg"));
-					}
-				} else {
-					hasText = true;
-					attachments = emptyList();
-				}
 				headers.add(new PrivateMessageHeader(id, g, timestamp, local,
-						read, s.isSent(), s.isSeen(), hasText, attachments));
+						read, s.isSent(), s.isSeen(), true, emptyList()));
 			} catch (FormatException e) {
 				throw new DbException(e);
 			}
@@ -261,30 +241,11 @@ class MessagingManagerImpl extends ConversationClientImpl
 	@Override
 	public Attachment getAttachment(MessageId m) {
 		// TODO add real implementation
-		String[] files = new String[] {
-//				"error_animated.gif",
-//				"error_high.jpg",
-//				"error_wide.jpg",
-//				"error_huge.gif",
-//				"error_large.gif",
-//				"error_malformed.jpg",
-//				"wide.jpg",
-//				"high.jpg",
-//				"small.png",
-				"kitten1.jpg",
-				"kitten2.jpg",
-				"kitten3.gif",
-				"kitten4.jpg",
-				"kitten5.jpg",
-				"kitten6.png",
-		};
-		int index = Math.abs(m.hashCode() % files.length);
-		String file = files[index];
-		getLogger(MessagingManagerImpl.class.getName())
-				.warning("Loading file: " + file);
-
-		InputStream is = getClass().getClassLoader().getResourceAsStream(file);
-		return new Attachment(new BufferedInputStream(is));
+		byte[] bytes = fromHexString("89504E470D0A1A0A0000000D49484452" +
+				"000000010000000108060000001F15C4" +
+				"890000000A49444154789C6300010000" +
+				"0500010D0A2DB40000000049454E44AE426082");
+		return new Attachment(new ByteArrayInputStream(bytes));
 	}
 
 	@Override

briar-headless/README.md

@@ -11,10 +11,6 @@ The REST API peer comes as a `jar` file
 and needs a Java Runtime Environment (JRE) that supports at least Java 8.
 It currently works only on GNU/Linux operating systems.
 
-To build the `jar` file, you can do this:
-
-    $ ./gradlew --configure-on-demand briar-headless:jar
-
 You can start the peer (and its API server) like this:
 
     $ java -jar briar-headless/build/libs/briar-headless.jar