Fixes #2408

Refactor CatchingScheduledExecutor to only execute one-shot tasks and use Timer for reoccuring classes.

src/main/java/org/cryptomator/common/CatchingExecutors.java

@@ -10,6 +10,7 @@
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
@@ -22,12 +23,28 @@ public final class CatchingExecutors {
 
 	private CatchingExecutors() { /* NO-OP */ }
 
-	public static class CatchingScheduledThreadPoolExecutor extends ScheduledThreadPoolExecutor {
+	/**
+	 * Executor suitable for scheduled, <em>one-shot</em> Tasks.
+	 * <p>
+	 * This executor does not support repeated execution, see {@link OneShotScheduledExecutorService}
+	 */
+	public static class CatchingScheduledThreadPoolExecutor extends ScheduledThreadPoolExecutor implements OneShotScheduledExecutorService {
 
 		public CatchingScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory) {
 			super(corePoolSize, threadFactory);
 		}
 
+		@Override
+		public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initalDelay, long period, TimeUnit unit) {
+			throw new UnsupportedOperationException("This is an one-shot executor service!");
+		}
+
+		@Override
+		public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initalDelay, long delay, TimeUnit unit) {
+			throw new UnsupportedOperationException("This is an one-shot executor service!");
+		}
+
+
 		@Override
 		protected void afterExecute(Runnable runnable, Throwable throwable) {
 			super.afterExecute(runnable, throwable);
@@ -77,6 +94,7 @@ private static void afterExecuteTask(Task<?> task) {
 	}
 
 	private static void afterExecuteFuture(Future<?> future) {
+		assert future.isDone(): "Future must be in Done state to extract possible exception";
 		try {
 			future.get();
 		} catch (CancellationException ce) {

src/main/java/org/cryptomator/common/CommonsModule.java

@@ -28,7 +28,6 @@
 import java.security.SecureRandom;
 import java.util.Comparator;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -92,9 +91,9 @@ static Settings provideSettings(SettingsProvider settingsProvider) {
 
 	@Provides
 	@Singleton
-	static ScheduledExecutorService provideScheduledExecutorService(ShutdownHook shutdownHook) {
+	static OneShotScheduledExecutorService provideScheduledExecutorService(ShutdownHook shutdownHook) {
 		final AtomicInteger threadNumber = new AtomicInteger(1);
-		ScheduledExecutorService executorService = new CatchingExecutors.CatchingScheduledThreadPoolExecutor(NUM_SCHEDULER_THREADS, r -> {
+		OneShotScheduledExecutorService executorService = new CatchingExecutors.CatchingScheduledThreadPoolExecutor(NUM_SCHEDULER_THREADS, r -> {
 			String name = String.format("App Scheduled Executor %02d", threadNumber.getAndIncrement());
 			Thread t = new Thread(r);
 			t.setName(name);

src/main/java/org/cryptomator/common/OneShotScheduledExecutorService.java

@@ -0,0 +1,12 @@
+package org.cryptomator.common;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Marker interface to indicate the used {@link ScheduledExecutorService} does not support repeated execution via {@link java.util.concurrent.ScheduledExecutorService#scheduleAtFixedRate(Runnable, long, long, TimeUnit)}} or {@link java.util.concurrent.ScheduledExecutorService#scheduleWithFixedDelay(Runnable, long, long, TimeUnit)}.
+ * Calling one of those methods must throw an {@link UnsupportedOperationException}.
+ */
+public interface OneShotScheduledExecutorService extends ScheduledExecutorService {
+
+}

src/main/java/org/cryptomator/common/settings/SettingsProvider.java

@@ -15,6 +15,7 @@
 import com.google.gson.JsonParseException;
 import com.google.gson.JsonParser;
 import org.cryptomator.common.Environment;
+import org.cryptomator.common.OneShotScheduledExecutorService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -34,7 +35,6 @@
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
 import java.util.Optional;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
@@ -50,11 +50,11 @@ public class SettingsProvider implements Supplier<Settings> {
 	private final AtomicReference<ScheduledFuture<?>> scheduledSaveCmd = new AtomicReference<>();
 	private final Supplier<Settings> settings = Suppliers.memoize(this::load);
 	private final Environment env;
-	private final ScheduledExecutorService scheduler;
+	private final OneShotScheduledExecutorService scheduler;
 	private final Gson gson;
 
 	@Inject
-	public SettingsProvider(SettingsJsonAdapter settingsJsonAdapter, Environment env, ScheduledExecutorService scheduler) {
+	public SettingsProvider(SettingsJsonAdapter settingsJsonAdapter, Environment env, OneShotScheduledExecutorService scheduler) {
 		this.env = env;
 		this.scheduler = scheduler;
 		this.gson = new GsonBuilder() //

src/main/java/org/cryptomator/common/vaults/AutoLocker.java

@@ -7,25 +7,34 @@
 import javax.inject.Singleton;
 import javafx.collections.ObservableList;
 import java.time.Instant;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.concurrent.ExecutorService;
 
 @Singleton
 public class AutoLocker {
 
 	private static final Logger LOG = LoggerFactory.getLogger(AutoLocker.class);
 
-	private final ScheduledExecutorService scheduler;
+	private final ExecutorService executor;
+	private final Timer timer;
 	private final ObservableList<Vault> vaultList;
 
 	@Inject
-	public AutoLocker(ScheduledExecutorService scheduler, ObservableList<Vault> vaultList) {
-		this.scheduler = scheduler;
+	public AutoLocker(ExecutorService executor, ObservableList<Vault> vaultList) {
+		this.executor = executor;
+		this.timer = new Timer("AutoLocker.SubmitTickTimer", true);
 		this.vaultList = vaultList;
 	}
 
 	public void init() {
-		scheduler.scheduleAtFixedRate(this::tick, 0, 1, TimeUnit.MINUTES);
+		TimerTask submitTask = new TimerTask() {
+			@Override
+			public void run() {
+				executor.submit(AutoLocker.this::tick);
+			}
+		};
+		timer.scheduleAtFixedRate(submitTask, 0, 1000);
 	}
 
 	private void tick() {
@@ -46,7 +55,6 @@ private void autolock(Vault vault) {
 
 	private boolean exceedsIdleTime(Vault vault) {
 		assert vault.isUnlocked();
-		// TODO: shouldn't we read these properties from within FX Application Thread?
 		if (vault.getVaultSettings().autoLockWhenIdle().get()) {
 			int maxIdleSeconds = vault.getVaultSettings().autoLockIdleSeconds().get();
 			var deadline = vault.getStats().getLastActivity().plusSeconds(maxIdleSeconds);

src/main/java/org/cryptomator/ui/migration/MigrationRunController.java

@@ -38,10 +38,9 @@
 import javafx.scene.control.ContentDisplay;
 import javafx.stage.Stage;
 import java.util.Arrays;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.TimeUnit;
 
 import static org.cryptomator.common.Constants.MASTERKEY_FILENAME;
 import static org.cryptomator.common.Constants.VAULTCONFIG_FILENAME;
@@ -55,7 +54,6 @@ public class MigrationRunController implements FxController {
 	private final Stage window;
 	private final Vault vault;
 	private final ExecutorService executor;
-	private final ScheduledExecutorService scheduler;
 	private final KeychainManager keychain;
 	private final ObjectProperty<FileSystemCapabilityChecker.Capability> missingCapability;
 	private final FxApplicationWindows appWindows;
@@ -73,11 +71,10 @@ public class MigrationRunController implements FxController {
 	public NiceSecurePasswordField passwordField;
 
 	@Inject
-	public MigrationRunController(@MigrationWindow Stage window, @MigrationWindow Vault vault, ExecutorService executor, ScheduledExecutorService scheduler, KeychainManager keychain, @Named("capabilityErrorCause") ObjectProperty<FileSystemCapabilityChecker.Capability> missingCapability, @FxmlScene(FxmlFile.MIGRATION_START) Lazy<Scene> startScene, @FxmlScene(FxmlFile.MIGRATION_SUCCESS) Lazy<Scene> successScene, @FxmlScene(FxmlFile.MIGRATION_CAPABILITY_ERROR) Lazy<Scene> capabilityErrorScene, @FxmlScene(FxmlFile.MIGRATION_IMPOSSIBLE) Lazy<Scene> impossibleScene, FxApplicationWindows appWindows) {
+	public MigrationRunController(@MigrationWindow Stage window, @MigrationWindow Vault vault, ExecutorService executor, KeychainManager keychain, @Named("capabilityErrorCause") ObjectProperty<FileSystemCapabilityChecker.Capability> missingCapability, @FxmlScene(FxmlFile.MIGRATION_START) Lazy<Scene> startScene, @FxmlScene(FxmlFile.MIGRATION_SUCCESS) Lazy<Scene> successScene, @FxmlScene(FxmlFile.MIGRATION_CAPABILITY_ERROR) Lazy<Scene> capabilityErrorScene, @FxmlScene(FxmlFile.MIGRATION_IMPOSSIBLE) Lazy<Scene> impossibleScene, FxApplicationWindows appWindows) {
 		this.window = window;
 		this.vault = vault;
 		this.executor = executor;
-		this.scheduler = scheduler;
 		this.keychain = keychain;
 		this.missingCapability = missingCapability;
 		this.appWindows = appWindows;
@@ -113,11 +110,13 @@ public void migrate() {
 		CharSequence password = passwordField.getCharacters();
 		vault.stateProperty().transition(VaultState.Value.NEEDS_MIGRATION, VaultState.Value.PROCESSING);
 		passwordField.setDisable(true);
-		ScheduledFuture<?> progressSyncTask = scheduler.scheduleAtFixedRate(() -> {
-			Platform.runLater(() -> {
-				migrationProgress.set(volatileMigrationProgress);
-			});
-		}, 0, MIGRATION_PROGRESS_UPDATE_MILLIS, TimeUnit.MILLISECONDS);
+		Timer timer = new Timer("Migration Timer", true);
+		timer.scheduleAtFixedRate(new TimerTask() {
+			@Override
+			public void run() {
+				Platform.runLater(() -> migrationProgress.set(volatileMigrationProgress));
+			}
+		}, 0, MIGRATION_PROGRESS_UPDATE_MILLIS);
 		Tasks.create(() -> {
 			Migrators migrators = Migrators.get();
 			migrators.migrate(vault.getPath(), VAULTCONFIG_FILENAME, MASTERKEY_FILENAME, password, this::migrationProgressChanged, this::migrationRequiresInput);
@@ -154,7 +153,7 @@ public void migrate() {
 			appWindows.showErrorWindow(e, window, startScene.get());
 		}).andFinally(() -> {
 			passwordField.setDisable(false);
-			progressSyncTask.cancel(true);
+			timer.cancel();
 		}).runOnce(executor);
 	}