Fix race condition in SpringIndexer initialization

headless-services/commons/commons-java/src/main/java/org/springframework/ide/vscode/commons/languageserver/java/AbstractJavaProjectCache.java

@@ -13,7 +13,10 @@ package org.springframework.ide.vscode.commons.languageserver.java;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicReference;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.ide.vscode.commons.java.IJavaProject;
 import org.springframework.ide.vscode.commons.languageserver.Sts4LanguageServer;
 import org.springframework.ide.vscode.commons.util.FileObserver;
@@ -33,6 +36,8 @@ import com.google.common.cache.CacheBuilder;
  */
 public abstract class AbstractJavaProjectCache<K, P extends IJavaProject> implements JavaProjectCache<K, P> {
 	
+	private static final Logger log = LoggerFactory.getLogger(AbstractJavaProjectCache.class);
+	
 	protected Sts4LanguageServer server;
 
 	private ListenerList<Listener> listeners = new ListenerList<>();
@@ -47,15 +52,23 @@ public abstract class AbstractJavaProjectCache<K, P extends IJavaProject> implem
 	public P project(K key) {
 		if (key != null) {
 			try {
-				return cache.get(key, () -> {
-					try {
-						P project = createProject(key);
-						attachListeners(key, project);
-						return project;
-					} catch (Throwable t) {
-						throw new ExecutionException(t);
+				AtomicReference<P> createdProject = new AtomicReference<P>(null);
+				try {
+					return cache.get(key, () -> {
+						try {
+							P project = createProject(key);
+							createdProject.set(project);
+							attachListeners(key, project);
+							return project;
+						} catch (Throwable t) {
+							throw new ExecutionException(t);
+						}
+					});
+				} finally {
+					if (createdProject.get()!=null) {
+						notifyProjectCreated(createdProject.get());
 					}
-				});
+				}
 			} catch (ExecutionException e) {
 				Log.log(e);
 				return null;
@@ -84,6 +97,7 @@ public abstract class AbstractJavaProjectCache<K, P extends IJavaProject> implem
 
 	@Override
 	public void addListener(Listener listener) {
+		log.info("Add listener {} to {}", listener, this);
 		listeners.add(listener);
 	}
 
@@ -93,14 +107,17 @@ public abstract class AbstractJavaProjectCache<K, P extends IJavaProject> implem
 	}
 	
 	final protected void notifyProjectCreated(P project) {
+		log.info("project created {}", project);
 		listeners.forEach(l -> l.created(project));
 	}
 	
 	final protected void notifyProjectChanged(P project) {
+		log.info("project changed {}", project);
 		listeners.forEach(l -> l.changed(project));
 	}
 	
 	final protected void notifyProjectDeleted(P project) {
+		log.info("project deleted {}", project);
 		listeners.forEach(l -> l.deleted(project));
 	}
 

headless-services/commons/commons-java/src/main/java/org/springframework/ide/vscode/commons/languageserver/java/JavaProjectFinder.java

@@ -11,6 +11,7 @@
 package org.springframework.ide.vscode.commons.languageserver.java;
 
 import java.util.Optional;
+import java.util.concurrent.CompletableFuture;
 import java.util.function.Predicate;
 
 import org.eclipse.lsp4j.TextDocumentIdentifier;

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/BootLanguageServerParams.java

@@ -83,7 +83,7 @@ public class BootLanguageServerParams {
 	public static LSFactory<BootLanguageServerParams> createDefault() {
 		return (SimpleLanguageServer server) -> {
 			// Initialize project finders, project caches and project observers
-			JdtLsProjectCache jdtProjectCache = new JdtLsProjectCache(server, createFallbackProjectCache(server));
+			JdtLsProjectCache jdtProjectCache = new JdtLsProjectCache(server, () -> createFallbackProjectCache(server));
 			DefaultSpringPropertyIndexProvider indexProvider = new DefaultSpringPropertyIndexProvider(jdtProjectCache, jdtProjectCache);
 			indexProvider.setProgressService(server.getProgressService());
 

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/java/utils/SpringIndexer.java

@@ -150,10 +150,7 @@ public class SpringIndexer {
 				}
 			}
 		}, "Spring Annotation Index Update Worker");
-		server.onInitialized(() -> {
-			log.debug("onServerInitialized {}", this);
-			updateWorker.start();
-		});
+		server.onInitialized(updateWorker::start);
 		getWorkspaceService().onDidChangeWorkspaceFolders(evt -> {
 			log.debug("workspace roots have changed event arrived - added: " + evt.getEvent().getAdded() + " - removed: " + evt.getEvent().getRemoved());
 			refresh();

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/jdt/ls/JdtLsProjectCache.java

@@ -38,6 +38,8 @@ import org.springframework.ide.vscode.commons.util.CollectorUtil;
 import org.springframework.ide.vscode.commons.util.ExceptionUtil;
 import org.springframework.ide.vscode.commons.util.UriUtil;
 
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableList;
 
 import reactor.core.Disposable;
@@ -45,17 +47,17 @@ import reactor.core.Disposable;
 public class JdtLsProjectCache implements JavaProjectsService {
 	
 	private CompletableFuture<Void> initialized = new CompletableFuture<Void>();
-	
+
 	private SimpleLanguageServer server;
 	private Map<String, JdtLsProject> table = new HashMap<String, JdtLsProject>();
 	private Logger log = LoggerFactory.getLogger(JdtLsProjectCache.class);
 	private List<Listener> listeners = new ArrayList<>();
 
-	private final JavaProjectsService fallback;
+	private final Supplier<JavaProjectsService> fallback;
 
-	public JdtLsProjectCache(SimpleLanguageServer server, JavaProjectsService fallback) {
+	public JdtLsProjectCache(SimpleLanguageServer server, Supplier<JavaProjectsService> fallback) {
 		Assert.isNotNull(fallback);
-		this.fallback = fallback;
+		this.fallback = Suppliers.memoize(fallback);
 		this.server = server;
 		CompletableFuture<Disposable> disposable = new CompletableFuture<Disposable>();
 		this.server.onInitialized(() -> {
@@ -110,7 +112,7 @@ public class JdtLsProjectCache implements JavaProjectsService {
 	public void addListener(Listener listener) {
 		initialized.handle((success, failed) -> {
 			if (failed!=null) {
-				fallback.addListener(listener);
+				fallback.get().addListener(listener);
 			} else {
 				synchronized (listeners) {
 					listeners.add(listener);
@@ -124,7 +126,7 @@ public class JdtLsProjectCache implements JavaProjectsService {
 	public void removeListener(Listener listener) {
 		initialized.handle((success, failed) -> {
 			if (failed!=null) {
-				fallback.removeListener(listener);
+				fallback.get().removeListener(listener);
 			} else {
 				synchronized (listeners) {
 					listeners.remove(listener);
@@ -171,9 +173,13 @@ public class JdtLsProjectCache implements JavaProjectsService {
 
 	@Override
 	public Optional<IJavaProject> find(TextDocumentIdentifier doc) {
+		log.info("find {} ",doc.getUri());
 		if (initialized.isDone()) {
 			if (initialized.isCompletedExceptionally()) {
-				return fallback.find(doc);
+				log.info("find {} delegating to fallback", doc.getUri());
+				Optional<IJavaProject> result = fallback.get().find(doc);
+				log.info("find => {}", result);
+				return result;
 			}
 			String uri = UriUtil.normalize(doc.getUri());
 	
@@ -186,6 +192,7 @@ public class JdtLsProjectCache implements JavaProjectsService {
 				}
 			}
 		}
+		log.info("find => NOT INITIALIZED YET");
 		return Optional.empty();
 	}