Perform cleanup of tmp mount points dir only once.

main/commons/src/main/java/org/cryptomator/common/mountpoint/IrregularUnmountCleaner.java

@@ -1,20 +1,44 @@
 package org.cryptomator.common.mountpoint;
 
+import org.cryptomator.common.Environment;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.inject.Inject;
+import javax.inject.Singleton;
 import java.io.IOException;
 import java.nio.file.DirectoryNotEmptyException;
 import java.nio.file.Files;
 import java.nio.file.LinkOption;
 import java.nio.file.Path;
 import java.nio.file.attribute.BasicFileAttributes;
+import java.util.Optional;
 
+@Singleton
 class IrregularUnmountCleaner {
 
 	public static Logger LOG = LoggerFactory.getLogger(IrregularUnmountCleaner.class);
 
-	public static void removeIrregularUnmountDebris(Path dirContainingMountPoints) {
+	private final Optional<Path> tmpMountPointDir;
+	private volatile boolean alreadyChecked = false;
+
+	@Inject
+	public IrregularUnmountCleaner(Environment env) {
+		this.tmpMountPointDir = env.getMountPointsDir();
+	}
+
+
+	public void clearIrregularUnmountDebrisIfNeeded() {
+		if (alreadyChecked || tmpMountPointDir.isEmpty()) {
+			return; //nuthin to do
+		}
+		if (Files.exists(tmpMountPointDir.get(), LinkOption.NOFOLLOW_LINKS)) {
+			clearIrregularUnmountDebris(tmpMountPointDir.get());
+		}
+		alreadyChecked = true;
+	}
+
+	private void clearIrregularUnmountDebris(Path dirContainingMountPoints) {
 		IOException cleanupFailed = new IOException("Cleanup failed");
 
 		try {
@@ -41,11 +65,12 @@ class IrregularUnmountCleaner {
 			}
 		} catch (IOException e) {
 			LOG.warn("Unable to perform cleanup of mountpoint dir {}.", dirContainingMountPoints, e);
+		} finally {
+			alreadyChecked = true;
 		}
-
 	}
 
-	private static void deleteEmptyDir(Path dir) throws IOException {
+	private void deleteEmptyDir(Path dir) throws IOException {
 		assert Files.isDirectory(dir, LinkOption.NOFOLLOW_LINKS);
 		try {
 			Files.delete(dir); // attempt to delete dir non-recursively (will fail, if there are contents)
@@ -54,7 +79,7 @@ class IrregularUnmountCleaner {
 		}
 	}
 
-	private static void deleteDeadLink(Path symlink) throws IOException {
+	private void deleteDeadLink(Path symlink) throws IOException {
 		assert Files.isSymbolicLink(symlink);
 		if (Files.notExists(symlink)) { // following link: target does not exist
 			Files.delete(symlink);

main/commons/src/main/java/org/cryptomator/common/mountpoint/TemporaryMountPointChooser.java

@@ -1,6 +1,5 @@
 package org.cryptomator.common.mountpoint;
 
-import org.apache.commons.lang3.SystemUtils;
 import org.cryptomator.common.Environment;
 import org.cryptomator.common.settings.VaultSettings;
 import org.cryptomator.common.vaults.Volume;
@@ -11,11 +10,8 @@ import javax.inject.Inject;
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
-import java.nio.file.LinkOption;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.Optional;
-import java.util.concurrent.atomic.AtomicBoolean;
 
 class TemporaryMountPointChooser implements MountPointChooser {
 
@@ -24,12 +20,14 @@ class TemporaryMountPointChooser implements MountPointChooser {
 
 	private final VaultSettings vaultSettings;
 	private final Environment environment;
+	private final IrregularUnmountCleaner cleaner;
 	private volatile boolean clearedDebris;
 
 	@Inject
-	public TemporaryMountPointChooser(VaultSettings vaultSettings, Environment environment) {
+	public TemporaryMountPointChooser(VaultSettings vaultSettings, Environment environment, IrregularUnmountCleaner cleaner) {
 		this.vaultSettings = vaultSettings;
 		this.environment = environment;
+		this.cleaner = cleaner;
 	}
 
 	@Override
@@ -43,23 +41,13 @@ class TemporaryMountPointChooser implements MountPointChooser {
 
 	@Override
 	public Optional<Path> chooseMountPoint(Volume caller) {
-		clearDebrisIfNeeded();
+		assert environment.getMountPointsDir().isPresent();
+		//clean leftovers of not-regularly unmounted vaults
+		//see https://github.com/cryptomator/cryptomator/issues/1013 and https://github.com/cryptomator/cryptomator/issues/1061
+		cleaner.clearIrregularUnmountDebrisIfNeeded();
 		return this.environment.getMountPointsDir().map(this::choose);
 	}
 
-	//clean leftovers of not-regularly unmounted vaults
-	//see https://github.com/cryptomator/cryptomator/issues/1013 and https://github.com/cryptomator/cryptomator/issues/1061
-	private synchronized void clearDebrisIfNeeded() {
-		assert environment.getMountPointsDir().isPresent();
-		if (clearedDebris) {
-			return; // already cleared
-		}
-		Path mountPointDir = environment.getMountPointsDir().get();
-		if (Files.exists(mountPointDir, LinkOption.NOFOLLOW_LINKS)) {
-			IrregularUnmountCleaner.removeIrregularUnmountDebris(mountPointDir);
-		}
-		clearedDebris = true;
-	}
 
 	private Path choose(Path parent) {
 		String basename = this.vaultSettings.mountName().get();