Return early when starting/stopping if not in expected state.

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

@@ -37,8 +37,14 @@ public interface LifecycleManager {
 	 */
 	enum LifecycleState {
 
-		STARTING, MIGRATING_DATABASE, COMPACTING_DATABASE, STARTING_SERVICES,
+		CREATED,
-		RUNNING, STOPPING;
+		STARTING,
+		MIGRATING_DATABASE,
+		COMPACTING_DATABASE,
+		STARTING_SERVICES,
+		RUNNING,
+		STOPPING,
+		STOPPED;
 
 		public boolean isAfter(LifecycleState state) {
 			return ordinal() > state.ordinal();

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

@@ -18,7 +18,7 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Semaphore;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.ThreadSafe;
@@ -29,10 +29,12 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.COMPACTING_DATABASE;
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.CREATED;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.MIGRATING_DATABASE;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING_SERVICES;
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPED;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.CLOCK_ERROR;
@@ -60,12 +62,11 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 	private final List<Service> services;
 	private final List<OpenDatabaseHook> openDatabaseHooks;
 	private final List<ExecutorService> executors;
-	private final Semaphore startStopSemaphore = new Semaphore(1);
 	private final CountDownLatch dbLatch = new CountDownLatch(1);
 	private final CountDownLatch startupLatch = new CountDownLatch(1);
 	private final CountDownLatch shutdownLatch = new CountDownLatch(1);
-
+	private final AtomicReference<LifecycleState> state =
-	private volatile LifecycleState state = STARTING;
+			new AtomicReference<>(CREATED);
 
 	@Inject
 	LifecycleManagerImpl(DatabaseComponent db, EventBus eventBus,
@@ -102,8 +103,8 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 
 	@Override
 	public StartResult startServices(SecretKey dbKey) {
-		if (!startStopSemaphore.tryAcquire()) {
+		if (!state.compareAndSet(CREATED, STARTING)) {
-			LOG.info("Already starting or stopping");
+			LOG.warning("Already running");
 			return ALREADY_RUNNING;
 		}
 		long now = clock.currentTimeMillis();
@@ -135,7 +136,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 			});
 
 			LOG.info("Starting services");
-			state = STARTING_SERVICES;
+			state.set(STARTING_SERVICES);
 			dbLatch.countDown();
 			eventBus.broadcast(new LifecycleEvent(STARTING_SERVICES));
 
@@ -148,7 +149,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 				}
 			}
 
-			state = RUNNING;
+			state.set(RUNNING);
 			startupLatch.countDown();
 			eventBus.broadcast(new LifecycleEvent(RUNNING));
 			return SUCCESS;
@@ -164,69 +165,58 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		} catch (ServiceException e) {
 			logException(LOG, WARNING, e);
 			return SERVICE_ERROR;
-		} finally {
-			startStopSemaphore.release();
 		}
 	}
 
 	@Override
 	public void onDatabaseMigration() {
-		state = MIGRATING_DATABASE;
+		state.set(MIGRATING_DATABASE);
 		eventBus.broadcast(new LifecycleEvent(MIGRATING_DATABASE));
 	}
 
 	@Override
 	public void onDatabaseCompaction() {
-		state = COMPACTING_DATABASE;
+		state.set(COMPACTING_DATABASE);
 		eventBus.broadcast(new LifecycleEvent(COMPACTING_DATABASE));
 	}
 
 	@Override
 	public void stopServices() {
-		try {
+		if (!state.compareAndSet(RUNNING, STOPPING)) {
-			startStopSemaphore.acquire();
+			LOG.warning("Not running");
-		} catch (InterruptedException e) {
-			LOG.warning("Interrupted while waiting to stop services");
 			return;
 		}
-		try {
+		LOG.info("Stopping services");
-			if (state == STOPPING) {
+		eventBus.broadcast(new LifecycleEvent(STOPPING));
-				LOG.info("Already stopped");
+		for (Service s : services) {
-				return;
-			}
-			LOG.info("Stopping services");
-			state = STOPPING;
-			eventBus.broadcast(new LifecycleEvent(STOPPING));
-			for (Service s : services) {
-				try {
-					long start = now();
-					s.stopService();
-					if (LOG.isLoggable(FINE)) {
-						logDuration(LOG, "Stopping service "
-								+ s.getClass().getSimpleName(), start);
-					}
-				} catch (ServiceException e) {
-					logException(LOG, WARNING, e);
-				}
-			}
-			for (ExecutorService e : executors) {
-				if (LOG.isLoggable(FINE)) {
-					LOG.fine("Stopping executor "
-							+ e.getClass().getSimpleName());
-				}
-				e.shutdownNow();
-			}
 			try {
 				long start = now();
-				db.close();
+				s.stopService();
-				logDuration(LOG, "Closing database", start);
+				if (LOG.isLoggable(FINE)) {
-			} catch (DbException e) {
+					logDuration(LOG, "Stopping service "
+							+ s.getClass().getSimpleName(), start);
+				}
+			} catch (ServiceException e) {
 				logException(LOG, WARNING, e);
 			}
-			shutdownLatch.countDown();
-		} finally {
-			startStopSemaphore.release();
 		}
+		for (ExecutorService e : executors) {
+			if (LOG.isLoggable(FINE)) {
+				LOG.fine("Stopping executor "
+						+ e.getClass().getSimpleName());
+			}
+			e.shutdownNow();
+		}
+		try {
+			long start = now();
+			db.close();
+			logDuration(LOG, "Closing database", start);
+		} catch (DbException e) {
+			logException(LOG, WARNING, e);
+		}
+		state.set(STOPPED);
+		shutdownLatch.countDown();
+		eventBus.broadcast(new LifecycleEvent(STOPPED));
 	}
 
 	@Override
@@ -246,6 +236,6 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 
 	@Override
 	public LifecycleState getLifecycleState() {
-		return state;
+		return state.get();
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/lifecycle/LifecycleManagerImplTest.java

@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager.OpenDatabaseHook;
+import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.event.LifecycleEvent;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.test.BrambleMockTestCase;
@@ -13,12 +14,10 @@ import org.jmock.Expectations;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import static junit.framework.TestCase.assertTrue;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPED;
+import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.CLOCK_ERROR;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.SUCCESS;
 import static org.briarproject.bramble.api.system.Clock.MAX_REASONABLE_TIME_MS;
@@ -31,6 +30,8 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
 	private final EventBus eventBus = context.mock(EventBus.class);
 	private final Clock clock = context.mock(Clock.class);
+	private final OpenDatabaseHook hook = context.mock(OpenDatabaseHook.class);
+	private final Service service = context.mock(Service.class);
 
 	private final SecretKey dbKey = getSecretKey();
 
@@ -45,8 +46,6 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 	public void testOpenDatabaseHooksAreCalledAtStartup() throws Exception {
 		long now = System.currentTimeMillis();
 		Transaction txn = new Transaction(null, false);
-		AtomicBoolean called = new AtomicBoolean(false);
-		OpenDatabaseHook hook = transaction -> called.set(true);
 
 		context.checking(new DbExpectations() {{
 			oneOf(clock).currentTimeMillis();
@@ -55,6 +54,7 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(false));
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
 			oneOf(db).removeTemporaryMessages(txn);
+			oneOf(hook).onDatabaseOpened(txn);
 			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
 		}});
 
@@ -62,7 +62,38 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 
 		assertEquals(SUCCESS, lifecycleManager.startServices(dbKey));
 		assertEquals(RUNNING, lifecycleManager.getLifecycleState());
-		assertTrue(called.get());
+	}
+
+	@Test
+	public void testServicesAreStartedAndStopped() throws Exception {
+		long now = System.currentTimeMillis();
+		Transaction txn = new Transaction(null, false);
+
+		context.checking(new DbExpectations() {{
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(db).open(dbKey, lifecycleManager);
+			will(returnValue(false));
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			oneOf(db).removeTemporaryMessages(txn);
+			oneOf(service).startService();
+			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
+		}});
+
+		lifecycleManager.registerService(service);
+
+		assertEquals(SUCCESS, lifecycleManager.startServices(dbKey));
+		assertEquals(RUNNING, lifecycleManager.getLifecycleState());
+		context.assertIsSatisfied();
+
+		context.checking(new Expectations() {{
+			oneOf(db).close();
+			oneOf(service).stopService();
+			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
+		}});
+
+		lifecycleManager.stopServices();
+		assertEquals(STOPPED, lifecycleManager.getLifecycleState());
 	}
 
 	@Test
@@ -89,6 +120,31 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 		assertEquals(STARTING, lifecycleManager.getLifecycleState());
 	}
 
+	@Test
+	public void testSecondCallToStartServicesReturnsEarly() throws Exception {
+		long now = System.currentTimeMillis();
+		Transaction txn = new Transaction(null, false);
+
+		context.checking(new DbExpectations() {{
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(db).open(dbKey, lifecycleManager);
+			will(returnValue(false));
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			oneOf(db).removeTemporaryMessages(txn);
+			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
+		}});
+
+		assertEquals(SUCCESS, lifecycleManager.startServices(dbKey));
+		assertEquals(RUNNING, lifecycleManager.getLifecycleState());
+		context.assertIsSatisfied();
+
+		// Calling startServices() again should not try to open the DB or
+		// start the services again
+		assertEquals(ALREADY_RUNNING, lifecycleManager.startServices(dbKey));
+		assertEquals(RUNNING, lifecycleManager.getLifecycleState());
+	}
+
 	@Test
 	public void testSecondCallToStopServicesReturnsEarly() throws Exception {
 		long now = System.currentTimeMillis();
@@ -101,7 +157,7 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(false));
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
 			oneOf(db).removeTemporaryMessages(txn);
-			exactly(2).of(eventBus).broadcast(with(any(LifecycleEvent.class)));
+			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
 		}});
 
 		assertEquals(SUCCESS, lifecycleManager.startServices(dbKey));
@@ -109,17 +165,17 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(LifecycleEvent.class)));
 			oneOf(db).close();
+			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
 		}});
 
 		lifecycleManager.stopServices();
-		assertEquals(STOPPING, lifecycleManager.getLifecycleState());
+		assertEquals(STOPPED, lifecycleManager.getLifecycleState());
 		context.assertIsSatisfied();
 
 		// Calling stopServices() again should not broadcast another event or
 		// try to close the DB again
 		lifecycleManager.stopServices();
-		assertEquals(STOPPING, lifecycleManager.getLifecycleState());
+		assertEquals(STOPPED, lifecycleManager.getLifecycleState());
 	}
 }