Merge branch '675-polite-executor' into 'master'

Use a polite executor for validation tasks

Closes #675

See merge request !507

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

@@ -0,0 +1,84 @@
+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 java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+
+import static java.util.logging.Level.FINE;
+
+/**
+ * An {@link Executor} that delegates its tasks to another {@link Executor}
+ * while limiting the number of tasks that are delegated concurrently. Tasks
+ * are delegated in the order they are submitted to this executor.
+ */
+@NotNullByDefault
+public class PoliteExecutor implements Executor {
+
+	private static final Level LOG_LEVEL = FINE;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private final Queue<Runnable> queue = new LinkedList<Runnable>();
+	private final Executor delegate;
+	private final int maxConcurrentTasks;
+	private final Logger log;
+
+	@GuardedBy("lock")
+	private int concurrentTasks = 0;
+
+	/**
+	 * @param tag the tag to be used for logging
+	 * @param delegate the executor to which tasks will be delegated
+	 * @param maxConcurrentTasks the maximum number of tasks that will be
+	 * delegated concurrently. If this is set to 1, tasks submitted to this
+	 * executor will run in the order they are submitted and will not run
+	 * concurrently
+	 */
+	public PoliteExecutor(String tag, Executor delegate,
+			int maxConcurrentTasks) {
+		this.delegate = delegate;
+		this.maxConcurrentTasks = maxConcurrentTasks;
+		log = Logger.getLogger(tag);
+	}
+
+	@Override
+	public void execute(final Runnable r) {
+		final long submitted = System.currentTimeMillis();
+		Runnable wrapped = new Runnable() {
+			@Override
+			public void run() {
+				if (log.isLoggable(LOG_LEVEL)) {
+					long queued = System.currentTimeMillis() - submitted;
+					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+				}
+				try {
+					r.run();
+				} finally {
+					scheduleNext();
+				}
+			}
+		};
+		synchronized (lock) {
+			if (concurrentTasks < maxConcurrentTasks) {
+				concurrentTasks++;
+				delegate.execute(wrapped);
+			} else {
+				queue.add(wrapped);
+			}
+		}
+	}
+
+	private void scheduleNext() {
+		synchronized (lock) {
+			Runnable next = queue.poll();
+			if (next == null) concurrentTasks--;
+			else delegate.execute(next);
+		}
+	}
+}

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

@@ -0,0 +1,49 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.FINE;
+
+@NotNullByDefault
+public class TimeLoggingExecutor extends ThreadPoolExecutor {
+
+	private static final Level LOG_LEVEL = FINE;
+
+	private final Logger log;
+
+	public TimeLoggingExecutor(String tag, int corePoolSize, int maxPoolSize,
+			long keepAliveTime, TimeUnit unit,
+			BlockingQueue<Runnable> workQueue,
+			RejectedExecutionHandler handler) {
+		super(corePoolSize, maxPoolSize, keepAliveTime, unit, workQueue,
+				handler);
+		log = Logger.getLogger(tag);
+	}
+
+	@Override
+	public void execute(final Runnable r) {
+		if (log.isLoggable(LOG_LEVEL)) {
+			final long submitted = System.currentTimeMillis();
+			super.execute(new Runnable() {
+				@Override
+				public void run() {
+					long started = System.currentTimeMillis();
+					long queued = started - submitted;
+					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+					r.run();
+					long executing = System.currentTimeMillis() - started;
+					log.log(LOG_LEVEL, "Execution time " + executing + " ms");
+				}
+			});
+		} else {
+			super.execute(r);
+		}
+	}
+}

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.TimeLoggingExecutor;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
@@ -31,14 +32,17 @@ public class CryptoModule {
 	public static class EagerSingletons {
 		@Inject
 		@CryptoExecutor
-		Executor cryptoExecutor;
+		ExecutorService cryptoExecutor;
 	}
 
 	/**
 	 * The maximum number of executor threads.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
 	 */
 	private static final int MAX_EXECUTOR_THREADS =
-			Runtime.getRuntime().availableProcessors();
+			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
 
 	private final ExecutorService cryptoExecutor;
 
@@ -49,8 +53,8 @@ public class CryptoModule {
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();
 		// Create a limited # of threads and keep them in the pool for 60 secs
-		cryptoExecutor = new ThreadPoolExecutor(0, MAX_EXECUTOR_THREADS,
-				60, SECONDS, queue, policy);
+		cryptoExecutor = new TimeLoggingExecutor("CryptoExecutor", 0,
+				MAX_EXECUTOR_THREADS, 60, SECONDS, queue, policy);
 	}
 
 	@Provides
@@ -85,11 +89,18 @@ public class CryptoModule {
 	@Provides
 	@Singleton
 	@CryptoExecutor
-	Executor getCryptoExecutor(LifecycleManager lifecycleManager) {
+	ExecutorService getCryptoExecutorService(
+			LifecycleManager lifecycleManager) {
 		lifecycleManager.registerForShutdown(cryptoExecutor);
 		return cryptoExecutor;
 	}
 
+	@Provides
+	@CryptoExecutor
+	Executor getCryptoExecutor() {
+		return cryptoExecutor;
+	}
+
 	@Provides
 	SecureRandom getSecureRandom(CryptoComponent crypto) {
 		return crypto.getSecureRandom();

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

@@ -67,6 +67,7 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
@@ -130,8 +131,14 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		// Don't allow reentrant locking
 		if (lock.getReadHoldCount() > 0) throw new IllegalStateException();
 		if (lock.getWriteHoldCount() > 0) throw new IllegalStateException();
+		long start = System.currentTimeMillis();
 		if (readOnly) lock.readLock().lock();
 		else lock.writeLock().lock();
+		if (LOG.isLoggable(FINE)) {
+			long duration = System.currentTimeMillis() - start;
+			if (readOnly) LOG.fine("Waited " + duration + " ms for read lock");
+			else LOG.fine("Waited " + duration + " ms for write lock");
+		}
 		try {
 			return new Transaction(db.startTransaction(), readOnly);
 		} catch (DbException e) {

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.db;
 
+import org.briarproject.bramble.TimeLoggingExecutor;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 
@@ -36,8 +37,8 @@ public class DatabaseExecutorModule {
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();
 		// Use a single thread and keep it in the pool for 60 secs
-		databaseExecutor = new ThreadPoolExecutor(0, 1, 60, SECONDS, queue,
-				policy);
+		databaseExecutor = new TimeLoggingExecutor("DatabaseExecutor", 0, 1,
+				60, SECONDS, queue, policy);
 	}
 
 	@Provides

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

@@ -1,6 +1,8 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
@@ -29,6 +31,16 @@ public class SyncModule {
 		ValidationManager validationManager;
 	}
 
+	/**
+	 * The maximum number of validation tasks to delegate to the crypto
+	 * executor concurrently.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
+	 */
+	private static final int MAX_CONCURRENT_VALIDATION_TASKS =
+			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
+
 	@Provides
 	GroupFactory provideGroupFactory(CryptoComponent crypto) {
 		return new GroupFactoryImpl(crypto);
@@ -62,10 +74,20 @@ public class SyncModule {
 
 	@Provides
 	@Singleton
-	ValidationManager getValidationManager(LifecycleManager lifecycleManager,
-			EventBus eventBus, ValidationManagerImpl validationManager) {
+	ValidationManager provideValidationManager(
+			LifecycleManager lifecycleManager, EventBus eventBus,
+			ValidationManagerImpl validationManager) {
 		lifecycleManager.registerService(validationManager);
 		eventBus.addListener(validationManager);
 		return validationManager;
 	}
+
+	@Provides
+	@Singleton
+	@ValidationExecutor
+	Executor provideValidationExecutor(
+			@CryptoExecutor Executor cryptoExecutor) {
+		return new PoliteExecutor("ValidationExecutor", cryptoExecutor,
+				MAX_CONCURRENT_VALIDATION_TASKS);
+	}
 }

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

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.sync;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for injecting the executor for validation tasks. Also used for
+ * annotating methods that should run on the validation executor.
+ * <p>
+ * The contract of this executor is that tasks may be run concurrently, and
+ * submitting a task will never block. Tasks must not run indefinitely. Tasks
+ * submitted during shutdown are discarded.
+ */
+@Qualifier
+@Target({FIELD, METHOD, PARAMETER})
+@Retention(RUNTIME)
+@interface ValidationExecutor {
+}

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.sync;
 
-import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
@@ -50,8 +49,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			Logger.getLogger(ValidationManagerImpl.class.getName());
 
 	private final DatabaseComponent db;
-	private final Executor dbExecutor;
-	private final Executor cryptoExecutor;
+	private final Executor dbExecutor, validationExecutor;
 	private final MessageFactory messageFactory;
 	private final Map<ClientId, MessageValidator> validators;
 	private final Map<ClientId, IncomingMessageHook> hooks;
@@ -60,11 +58,11 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	@Inject
 	ValidationManagerImpl(DatabaseComponent db,
 			@DatabaseExecutor Executor dbExecutor,
-			@CryptoExecutor Executor cryptoExecutor,
+			@ValidationExecutor Executor validationExecutor,
 			MessageFactory messageFactory) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
-		this.cryptoExecutor = cryptoExecutor;
+		this.validationExecutor = validationExecutor;
 		this.messageFactory = messageFactory;
 		validators = new ConcurrentHashMap<ClientId, MessageValidator>();
 		hooks = new ConcurrentHashMap<ClientId, IncomingMessageHook>();
@@ -104,6 +102,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void validateOutstandingMessages(ClientId c) {
 		try {
 			Queue<MessageId> unvalidated = new LinkedList<MessageId>();
@@ -130,6 +129,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void validateNextMessage(Queue<MessageId> unvalidated) {
 		try {
 			Message m;
@@ -167,6 +167,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void deliverOutstandingMessages(ClientId c) {
 		try {
 			Queue<MessageId> pending = new LinkedList<MessageId>();
@@ -194,6 +195,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void deliverNextPendingMessage(Queue<MessageId> pending) {
 		try {
 			boolean anyInvalid = false, allDelivered = true;
@@ -220,8 +222,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 						Message m = messageFactory.createMessage(id, raw);
 						Group g = db.getGroup(txn, m.getGroupId());
 						ClientId c = g.getClientId();
-						Metadata meta = db.getMessageMetadataForValidator(txn,
-								id);
+						Metadata meta =
+								db.getMessageMetadataForValidator(txn, id);
 						DeliveryResult result = deliverMessage(txn, m, c, meta);
 						if (result.valid) {
 							pending.addAll(getPendingDependents(txn, id));
@@ -240,8 +242,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 				db.endTransaction(txn);
 			}
 			if (invalidate != null) invalidateNextMessageAsync(invalidate);
-			deliverNextPendingMessageAsync(pending);
 			if (toShare != null) shareNextMessageAsync(toShare);
+			deliverNextPendingMessageAsync(pending);
 		} catch (NoSuchMessageException e) {
 			LOG.info("Message removed before delivery");
 			deliverNextPendingMessageAsync(pending);
@@ -249,13 +251,12 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			LOG.info("Group removed before delivery");
 			deliverNextPendingMessageAsync(pending);
 		} catch (DbException e) {
-			if (LOG.isLoggable(WARNING))
-				LOG.log(WARNING, e.toString(), e);
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		}
 	}
 
 	private void validateMessageAsync(final Message m, final Group g) {
-		cryptoExecutor.execute(new Runnable() {
+		validationExecutor.execute(new Runnable() {
 			@Override
 			public void run() {
 				validateMessage(m, g);
@@ -263,10 +264,12 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@ValidationExecutor
 	private void validateMessage(Message m, Group g) {
 		MessageValidator v = validators.get(g.getClientId());
 		if (v == null) {
-			LOG.warning("No validator");
+			if (LOG.isLoggable(WARNING))
+				LOG.warning("No validator for " + g.getClientId().getString());
 		} else {
 			try {
 				MessageContext context = v.validateMessage(m, g);
@@ -291,6 +294,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void storeMessageContext(Message m, ClientId c,
 			MessageContext context) {
 		try {
@@ -353,6 +357,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
+	@DatabaseExecutor
 	private DeliveryResult deliverMessage(Transaction txn, Message m,
 			ClientId c, Metadata meta) throws DbException {
 		// Deliver the message to the client if it's registered a hook
@@ -362,10 +367,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			try {
 				shareMsg = hook.incomingMessage(txn, m, meta);
 			} catch (InvalidMessageException e) {
-				// message is invalid, mark it as such and delete it
-				db.setMessageState(txn, m.getId(), INVALID);
-				db.deleteMessageMetadata(txn, m.getId());
-				db.deleteMessage(txn, m.getId());
+				invalidateMessage(txn, m.getId());
 				return new DeliveryResult(false, false);
 			}
 		}
@@ -373,6 +375,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		return new DeliveryResult(true, shareMsg);
 	}
 
+	@DatabaseExecutor
 	private Queue<MessageId> getPendingDependents(Transaction txn, MessageId m)
 			throws DbException {
 		Queue<MessageId> pending = new LinkedList<MessageId>();
@@ -392,6 +395,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void shareOutstandingMessages(ClientId c) {
 		try {
 			Queue<MessageId> toShare = new LinkedList<MessageId>();
@@ -424,6 +428,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void shareNextMessage(Queue<MessageId> toShare) {
 		try {
 			Transaction txn = db.startTransaction(false);
@@ -457,6 +462,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void invalidateNextMessage(Queue<MessageId> invalidate) {
 		try {
 			Transaction txn = db.startTransaction(false);
@@ -479,6 +485,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
+	@DatabaseExecutor
 	private void invalidateMessage(Transaction txn, MessageId m)
 			throws DbException {
 		db.setMessageState(txn, m, INVALID);
@@ -486,6 +493,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		db.deleteMessageMetadata(txn, m);
 	}
 
+	@DatabaseExecutor
 	private Queue<MessageId> getDependentsToInvalidate(Transaction txn,
 			MessageId m) throws DbException {
 		Queue<MessageId> invalidate = new LinkedList<MessageId>();
@@ -515,6 +523,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void loadGroupAndValidate(final Message m) {
 		try {
 			Group g;
@@ -534,6 +543,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	}
 
 	private static class DeliveryResult {
+
 		private final boolean valid, share;
 
 		private DeliveryResult(boolean valid, boolean share) {

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

@@ -0,0 +1,142 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Vector;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class PoliteExecutorTest extends BrambleTestCase {
+
+	private static final String TAG = "Test";
+	private static final int TASKS = 10;
+
+	@Test
+	public void testTasksAreDelegatedInOrderOfSubmission() throws Exception {
+		// Delegate to a single-threaded executor
+		Executor delegate = Executors.newSingleThreadExecutor();
+		// Allow all the tasks to be delegated straight away
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, TASKS * 2);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch latch = new CountDownLatch(TASKS);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					list.add(result);
+					latch.countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		latch.await();
+		// The tasks should have run in the order they were submitted
+		assertEquals(ascendingOrder(), list);
+	}
+
+	@Test
+	public void testQueuedTasksAreDelegatedInOrderOfSubmission()
+			throws Exception {
+		// Delegate to a single-threaded executor
+		Executor delegate = Executors.newSingleThreadExecutor();
+		// Allow two tasks to be delegated at a time
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, 2);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch latch = new CountDownLatch(TASKS);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					list.add(result);
+					latch.countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		latch.await();
+		// The tasks should have run in the order they were submitted
+		assertEquals(ascendingOrder(), list);
+	}
+
+	@Test
+	public void testTasksRunInParallelOnDelegate() throws Exception {
+		// Delegate to a multi-threaded executor
+		Executor delegate = Executors.newCachedThreadPool();
+		// Allow all the tasks to be delegated straight away
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, TASKS * 2);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch[] latches = new CountDownLatch[TASKS];
+		for (int i = 0; i < TASKS; i++) latches[i] = new CountDownLatch(1);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					try {
+						// Each task waits for the next task, if any, to finish
+						if (result < TASKS - 1) latches[result + 1].await();
+						list.add(result);
+					} catch (InterruptedException e) {
+						fail();
+					}
+					latches[result].countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		for (int i = 0; i < TASKS; i++) latches[i].await();
+		// The tasks should have finished in reverse order
+		assertEquals(descendingOrder(), list);
+	}
+
+	@Test
+	public void testTasksDoNotRunInParallelOnDelegate() throws Exception {
+		// Delegate to a multi-threaded executor
+		Executor delegate = Executors.newCachedThreadPool();
+		// Allow one task to be delegated at a time
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, 1);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch latch = new CountDownLatch(TASKS);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					try {
+						// Each task runs faster than the previous task
+						Thread.sleep(TASKS - result);
+						list.add(result);
+					} catch (InterruptedException e) {
+						fail();
+					}
+					latch.countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		latch.await();
+		// The tasks should have finished in the order they were submitted
+		assertEquals(ascendingOrder(), list);
+	}
+
+	private List<Integer> ascendingOrder() {
+		Integer[] array = new Integer[TASKS];
+		for (int i = 0; i < TASKS; i++) array[i] = i;
+		return Arrays.asList(array);
+	}
+
+	private List<Integer> descendingOrder() {
+		Integer[] array = new Integer[TASKS];
+		for (int i = 0; i < TASKS; i++) array[i] = TASKS - 1 - i;
+		return Arrays.asList(array);
+	}
+}

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

@@ -19,12 +19,12 @@ import org.briarproject.bramble.api.sync.ValidationManager.IncomingMessageHook;
 import org.briarproject.bramble.api.sync.ValidationManager.MessageValidator;
 import org.briarproject.bramble.api.sync.ValidationManager.State;
 import org.briarproject.bramble.api.sync.event.MessageAddedEvent;
-import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.ImmediateExecutor;
 import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.bramble.util.ByteUtils;
 import org.jmock.Expectations;
-import org.jmock.Mockery;
+import org.junit.Before;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -38,8 +38,18 @@ import static org.briarproject.bramble.api.sync.ValidationManager.State.INVALID;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.PENDING;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.UNKNOWN;
 
-public class ValidationManagerImplTest extends BrambleTestCase {
+public class ValidationManagerImplTest extends BrambleMockTestCase {
 
+	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
+	private final MessageFactory messageFactory =
+			context.mock(MessageFactory.class);
+	private final MessageValidator validator =
+			context.mock(MessageValidator.class);
+	private final IncomingMessageHook hook =
+			context.mock(IncomingMessageHook.class);
+
+	private final Executor dbExecutor = new ImmediateExecutor();
+	private final Executor validationExecutor = new ImmediateExecutor();
 	private final ClientId clientId =
 			new ClientId(TestUtils.getRandomString(5));
 	private final MessageId messageId = new MessageId(TestUtils.getRandomId());
@@ -63,23 +73,58 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 	private final MessageContext validResultWithDependencies =
 			new MessageContext(metadata, Collections.singletonList(messageId1));
 
+	private ValidationManagerImpl vm;
+
 	public ValidationManagerImplTest() {
 		// Encode the messages
 		System.arraycopy(groupId.getBytes(), 0, raw, 0, UniqueId.LENGTH);
 		ByteUtils.writeUint64(timestamp, raw, UniqueId.LENGTH);
 	}
 
+	@Before
+	public void setUp() {
+		vm = new ValidationManagerImpl(db, dbExecutor, validationExecutor,
+				messageFactory);
+		vm.registerMessageValidator(clientId, validator);
+		vm.registerIncomingMessageHook(clientId, hook);
+	}
+
+	@Test
+	public void testStartAndStop() throws Exception {
+		final Transaction txn = new Transaction(null, true);
+		final Transaction txn1 = new Transaction(null, true);
+		final Transaction txn2 = new Transaction(null, true);
+
+		context.checking(new Expectations() {{
+			// validateOutstandingMessages()
+			oneOf(db).startTransaction(true);
+			will(returnValue(txn));
+			oneOf(db).getMessagesToValidate(txn, clientId);
+			will(returnValue(Collections.emptyList()));
+			oneOf(db).commitTransaction(txn);
+			oneOf(db).endTransaction(txn);
+			// deliverOutstandingMessages()
+			oneOf(db).startTransaction(true);
+			will(returnValue(txn1));
+			oneOf(db).getPendingMessages(txn1, clientId);
+			will(returnValue(Collections.emptyList()));
+			oneOf(db).commitTransaction(txn1);
+			oneOf(db).endTransaction(txn1);
+			// shareOutstandingMessages()
+			oneOf(db).startTransaction(true);
+			will(returnValue(txn2));
+			oneOf(db).getMessagesToShare(txn2, clientId);
+			will(returnValue(Collections.emptyList()));
+			oneOf(db).commitTransaction(txn2);
+			oneOf(db).endTransaction(txn2);
+		}});
+
+		vm.startService();
+		vm.stopService();
+	}
+
 	@Test
 	public void testMessagesAreValidatedAtStartup() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, false);
@@ -87,6 +132,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn4 = new Transaction(null, false);
 		final Transaction txn5 = new Transaction(null, true);
 		final Transaction txn6 = new Transaction(null, true);
+
 		context.checking(new Expectations() {{
 			// Get messages to validate
 			oneOf(db).startTransaction(true);
@@ -165,26 +211,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn6);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testPendingMessagesAreDeliveredAtStartup() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, false);
@@ -266,26 +297,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn4);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesAreSharedAtStartup() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, true);
@@ -333,29 +349,15 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn4);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testIncomingMessagesAreShared() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
 		final Transaction txn2 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -396,33 +398,19 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn2);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testValidationContinuesAfterNoSuchMessageException()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, true);
 		final Transaction txn3 = new Transaction(null, false);
 		final Transaction txn4 = new Transaction(null, true);
 		final Transaction txn5 = new Transaction(null, true);
+
 		context.checking(new Expectations() {{
 			// Get messages to validate
 			oneOf(db).startTransaction(true);
@@ -481,33 +469,19 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn5);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testValidationContinuesAfterNoSuchGroupException()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, true);
 		final Transaction txn3 = new Transaction(null, false);
 		final Transaction txn4 = new Transaction(null, true);
 		final Transaction txn5 = new Transaction(null, true);
+
 		context.checking(new Expectations() {{
 			// Get messages to validate
 			oneOf(db).startTransaction(true);
@@ -571,28 +545,14 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn5);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testNonLocalMessagesAreValidatedWhenAdded() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -619,51 +579,20 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn1);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testLocalMessagesAreNotValidatedWhenAdded() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
-
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, null));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesWithUndeliveredDependenciesArePending()
 			throws Exception {
-
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -688,29 +617,15 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn1);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesWithDeliveredDependenciesGetDelivered()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -741,30 +656,16 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn1);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesWithInvalidDependenciesAreInvalid()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
 		final Transaction txn2 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -809,26 +710,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn2);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testRecursiveInvalidation() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final MessageId messageId3 = new MessageId(TestUtils.getRandomId());
 		final MessageId messageId4 = new MessageId(TestUtils.getRandomId());
 		final Map<MessageId, State> twoDependents =
@@ -842,6 +728,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn4 = new Transaction(null, false);
 		final Transaction txn5 = new Transaction(null, false);
 		final Transaction txn6 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -927,26 +814,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn6);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testPendingDependentsGetDelivered() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final MessageId messageId3 = new MessageId(TestUtils.getRandomId());
 		final MessageId messageId4 = new MessageId(TestUtils.getRandomId());
 		final Message message3 = new Message(messageId3, groupId, timestamp,
@@ -968,6 +840,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn4 = new Transaction(null, false);
 		final Transaction txn5 = new Transaction(null, false);
 		final Transaction txn6 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -1100,26 +973,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn6);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testOnlyReadyPendingDependentsGetDelivered() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Map<MessageId, State> twoDependencies =
 				new LinkedHashMap<MessageId, State>();
 		twoDependencies.put(messageId, DELIVERED);
@@ -1127,6 +985,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
 		final Transaction txn2 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -1162,86 +1021,6 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn2);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
-
-	@Test
-	public void testMessageDependencyCycle() throws Exception {
-		final MessageContext cycleContext = new MessageContext(metadata,
-				Collections.singletonList(messageId));
-
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
-		final Transaction txn = new Transaction(null, true);
-		final Transaction txn1 = new Transaction(null, false);
-		final Transaction txn2 = new Transaction(null, true);
-		final Transaction txn3 = new Transaction(null, false);
-		context.checking(new Expectations() {{
-			// Load the group
-			oneOf(db).startTransaction(true);
-			will(returnValue(txn));
-			oneOf(db).getGroup(txn, groupId);
-			will(returnValue(group));
-			oneOf(db).commitTransaction(txn);
-			oneOf(db).endTransaction(txn);
-			// Validate the message: valid
-			oneOf(validator).validateMessage(message, group);
-			will(returnValue(validResultWithDependencies));
-			// Store the validation result
-			oneOf(db).startTransaction(false);
-			will(returnValue(txn1));
-			oneOf(db).addMessageDependencies(txn1, message,
-					validResultWithDependencies.getDependencies());
-			oneOf(db).getMessageDependencies(txn1, messageId);
-			will(returnValue(Collections.singletonMap(messageId1, UNKNOWN)));
-			oneOf(db).mergeMessageMetadata(txn1, messageId, metadata);
-			oneOf(db).setMessageState(txn1, messageId, PENDING);
-			oneOf(db).commitTransaction(txn1);
-			oneOf(db).endTransaction(txn1);
-			// Second message is coming in
-			oneOf(db).startTransaction(true);
-			will(returnValue(txn2));
-			oneOf(db).getGroup(txn2, groupId);
-			will(returnValue(group));
-			oneOf(db).commitTransaction(txn2);
-			oneOf(db).endTransaction(txn2);
-			// Validate the message: valid
-			oneOf(validator).validateMessage(message1, group);
-			will(returnValue(cycleContext));
-			// Store the validation result
-			oneOf(db).startTransaction(false);
-			will(returnValue(txn3));
-			oneOf(db).addMessageDependencies(txn3, message1,
-					cycleContext.getDependencies());
-			oneOf(db).getMessageDependencies(txn3, messageId1);
-			will(returnValue(Collections.singletonMap(messageId, PENDING)));
-			oneOf(db).mergeMessageMetadata(txn3, messageId1, metadata);
-			oneOf(db).setMessageState(txn3, messageId1, PENDING);
-			oneOf(db).commitTransaction(txn3);
-			oneOf(db).endTransaction(txn3);
-		}});
-
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
-		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-		vm.eventOccurred(new MessageAddedEvent(message1, contactId));
-
-		context.assertIsSatisfied();
-	}
-
 }