Improve order of operations when importing multi-module Maven projects.

- Reduce unnecessary calls to updating projects

Signed-off-by: Snjezana Peco <snjezana.peco@redhat.com>

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/InitHandler.java

@@ -248,7 +248,9 @@ public void triggerInitialization(Collection<IPath> roots) {
 		Job.getJobManager().wakeUp(ResourcesPlugin.FAMILY_AUTO_BUILD);
 		IWorkspace workspace = ResourcesPlugin.getWorkspace();
 		if (workspace instanceof Workspace workspaceImpl) {
-			workspaceImpl.getBuildManager().waitForAutoBuildOff();
+			if (!Job.getJobManager().isSuspended()) {
+				workspaceImpl.getBuildManager().waitForAutoBuildOff();
+			}
 		}
 		Job job = new WorkspaceJob("Initialize Workspace") {
 			@Override

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/JDTLanguageServer.java

@@ -307,8 +307,6 @@ public IStatus run(IProgressMonitor monitor) {
 					classpathUpdateHandler.addElementChangeListener();
 					SourceAttachUpdateHandler attachListener = new SourceAttachUpdateHandler(client);
 					attachListener.addElementChangeListener();
-					pm.registerWatchers();
-					debugTrace(">> watchers registered");
 
 					registerCapabilities();
 					// we do not have the user setting initialized yet at this point but we should
@@ -326,10 +324,15 @@ public IStatus run(IProgressMonitor monitor) {
 					IndexUtils.copyIndexesToSharedLocation();
 					JobHelpers.waitForBuildJobs(60 * 60 * 1000); // 1 hour
 					logInfo(">> build jobs finished");
+					// https://github.com/redhat-developer/vscode-java/issues/3637 - delay registerWatchers
+					pm.registerWatchers();
+					debugTrace(">> watchers registered");
+					pm.projectsBuildFinished(monitor);
 					telemetryManager.onBuildFinished(System.currentTimeMillis());
 					workspaceDiagnosticsHandler.publishDiagnostics(monitor);
 				} catch (OperationCanceledException | CoreException e) {
 					logException(e.getMessage(), e);
+					pm.projectsBuildFinished(monitor);
 					return Status.CANCEL_STATUS;
 				}
 				return Status.OK_STATUS;
@@ -562,7 +565,7 @@ public void didChangeConfiguration(DidChangeConfigurationParams params) {
 		try {
 			boolean isAutobuildEnabled = preferenceManager.getPreferences().isAutobuildEnabled();
 			boolean autoBuildChanged = ProjectsManager.setAutoBuilding(isAutobuildEnabled);
-			if (jvmChanged || nullAnalysisOptionsUpdated && isAutobuildEnabled) {
+			if ((jvmChanged || nullAnalysisOptionsUpdated) && isAutobuildEnabled) {
 				buildWorkspace(Either.forLeft(true));
 			} else if (autoBuildChanged && isAutobuildEnabled) {
 				buildWorkspace(Either.forLeft(false));
@@ -1226,4 +1229,9 @@ private void waitForLifecycleJobs(IProgressMonitor monitor) {
 		JobHelpers.waitForJobs(DocumentLifeCycleHandler.DOCUMENT_LIFE_CYCLE_JOBS, monitor);
 	}
 
+	// for test only
+	public boolean isEventHandlerEmpty() {
+		return this.workspaceEventHandler.isEmpty();
+	}
+
 }

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/WorkspaceEventsHandler.java

@@ -57,6 +57,10 @@ public WorkspaceEventsHandler(ProjectsManager projects, JavaClientConnection con
 		Thread eventThread = new Thread(() -> {
 			while(true) {
 				try {
+					// https://github.com/redhat-developer/vscode-java/issues/3637
+					while (!pm.isBuildFinished()) {
+						Thread.sleep(200);
+					}
 					FileEvent event = queue.take();
 					handleFileEvent(event);
 				} catch (InterruptedException e) {
@@ -97,6 +101,11 @@ public void handleFileEvents(FileEvent... fileEvents) {
 		}
 	}
 
+	// for test only
+	public boolean isEmpty() {
+		return queue.isEmpty();
+	}
+
 	private void handleFileEvent(FileEvent fileEvent) {
 		CHANGE_TYPE changeType = toChangeType(fileEvent.getType());
 		if (changeType == CHANGE_TYPE.DELETED) {

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/IProjectsManager.java

@@ -103,4 +103,27 @@ default void unregisterListeners() {
 	default void projectsImported(IProgressMonitor monitor) {
 		// do nothing
 	}
+
+	/**
+	 * Executed after the projects are imported and finished.
+	 */
+	default void projectsBuildFinished(IProgressMonitor monitor) {
+		// do nothing
+	}
+
+	/**
+	 * Check whether the build is finished
+	 */
+	default boolean isBuildFinished() {
+		return true;
+	};
+
+	default boolean shouldUpdateProjects() {
+		return false;
+	}
+
+	default void setShouldUpdateProjects(boolean update) {
+		// do nothing
+	}
+
 }

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/MavenProjectImporter.java

@@ -28,6 +28,7 @@
 import org.apache.commons.lang3.StringUtils;
 import org.eclipse.core.internal.resources.Workspace;
 import org.eclipse.core.resources.IContainer;
+import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IWorkspaceRoot;
@@ -288,15 +289,18 @@ private void updateProjects(Collection<IProject> projects, long lastWorkspaceSta
 		while (iterator.hasNext()) {
 			IProject project = iterator.next();
 			project.open(monitor);
+			IFile pomFile = project.getFile(POM_FILE);
+			pomFile.refreshLocal(IResource.DEPTH_ZERO, monitor);
+			if (!needsMavenUpdate(pomFile, lastWorkspaceStateSaved)) {
+				iterator.remove();
+				continue;
+			}
 			if (Platform.OS_WIN32.equals(Platform.getOS())) {
 				project.refreshLocal(IResource.DEPTH_ONE, monitor);
 				((Workspace) ResourcesPlugin.getWorkspace()).getRefreshManager().refresh(project);
 			} else {
 				project.refreshLocal(IResource.DEPTH_INFINITE, monitor);
 			}
-			if (!needsMavenUpdate(project, lastWorkspaceStateSaved)) {
-				iterator.remove();
-			}
 		}
 		if (projects.isEmpty()) {
 			return;
@@ -318,8 +322,8 @@ public IStatus runInWorkspace(IProgressMonitor monitor) throws CoreException {
 		}.schedule();
 	}
 
-	private boolean needsMavenUpdate(IProject project, long lastWorkspaceStateSaved) {
-		return project.getFile(POM_FILE).getLocalTimeStamp() > lastWorkspaceStateSaved;
+	private boolean needsMavenUpdate(IResource pomFile, long lastWorkspaceStateSaved) {
+		return pomFile.getLocalTimeStamp() > lastWorkspaceStateSaved;
 	}
 
 	private Set<MavenProjectInfo> getMavenProjects(File directory, MavenModelManager modelManager, IProgressMonitor monitor) throws OperationCanceledException {

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/ProjectsManager.java

@@ -505,14 +505,24 @@ public IStatus runInWorkspace(IProgressMonitor monitor) {
 				return status;
 			}
 		};
+		waitForUpdateJobs();
 		job.schedule();
 		return job;
 	}
 
+	private void waitForUpdateJobs() {
+		int maxThread = preferenceManager.getPreferences().getMaxConcurrentBuilds();
+		Job[] jobs = Job.getJobManager().find(IConstants.UPDATE_PROJECT_FAMILY);
+		if (jobs != null && jobs.length > maxThread) {
+			JobHelpers.waitForJobs(IConstants.UPDATE_PROJECT_FAMILY, null);
+		}
+	}
+
 	@Override
 	public Job updateProjects(Collection<IProject> projects, boolean force) {
 		JavaLanguageServerPlugin.sendStatus(ServiceStatus.Message, "Updating project configurations...");
 		UpdateProjectsWorkspaceJob job = new UpdateProjectsWorkspaceJob(projects, force);
+		waitForUpdateJobs();
 		job.schedule();
 		return job;
 	}

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/StandardProjectsManager.java

@@ -100,6 +100,19 @@ public class StandardProjectsManager extends ProjectsManager {
 	protected static final String BUILD_SUPPORT_EXTENSION_POINT_ID = "buildSupport";
 	private static final Set<String> watchers = new LinkedHashSet<>();
 	private PreferenceManager preferenceManager;
+	private boolean buildFinished;
+	private boolean shouldUpdateProjects;
+
+	@Override
+	public boolean shouldUpdateProjects() {
+		return shouldUpdateProjects;
+	}
+
+	@Override
+	public void setShouldUpdateProjects(boolean shouldUpdateProjects) {
+		this.shouldUpdateProjects = shouldUpdateProjects;
+	}
+
 	//@formatter:off
 	private static final List<String> basicWatchers = Arrays.asList(
 			"**/*.java",
@@ -301,6 +314,10 @@ public static void configureSettings(Preferences preferences) {
 
 	public static void configureSettings(Preferences preferences, boolean cleanWorkspace) {
 		URI settingsUri = preferences.getSettingsAsURI();
+		URI formatterUri = preferences.getFormatterAsURI();
+		if (settingsUri == null && formatterUri == null && !cleanWorkspace) {
+			return;
+		}
 		Properties properties = null;
 		if (settingsUri != null) {
 			try (InputStream inputStream = settingsUri.toURL().openStream()) {
@@ -312,7 +329,6 @@ public static void configureSettings(Preferences preferences, boolean cleanWorks
 			}
 		}
 		initializeDefaultOptions(preferences);
-		URI formatterUri = preferences.getFormatterAsURI();
 		Map<String, String> formatterOptions = null;
 		if (formatterUri != null) {
 			try (InputStream inputStream = formatterUri.toURL().openStream()) {
@@ -344,7 +360,9 @@ public static void configureSettings(Preferences preferences, boolean cleanWorks
 				}
 			});
 		}
-		JavaCore.setOptions(javaOptions);
+		if (!Objects.equals(javaOptions, JavaCore.getOptions())) {
+			JavaCore.setOptions(javaOptions);
+		}
 		if (cleanWorkspace && preferences.isAutobuildEnabled()) {
 			new WorkspaceJob("Clean workspace...") {
 
@@ -382,6 +400,7 @@ public Optional<IBuildSupport> getBuildSupport(IProject project) {
 		return buildSupports().filter(bs -> bs.applies(project)).findFirst();
 	}
 
+	@Override
 	protected Stream<IBuildSupport> buildSupports() {
 		Map<Integer, IBuildSupport> supporters = new TreeMap<>();
 		IExtensionPoint extensionPoint = Platform.getExtensionRegistry().getExtensionPoint(IConstants.PLUGIN_ID, BUILD_SUPPORT_EXTENSION_POINT_ID);
@@ -648,4 +667,22 @@ public void projectsImported(IProgressMonitor monitor) {
 		androidSupport.onDidProjectsImported(monitor);
 		this.preferenceManager.getPreferences().updateAnnotationNullAnalysisOptions();
 	}
+
+	@Override
+	public void projectsBuildFinished(IProgressMonitor monitor) {
+		this.buildFinished = true;
+		if (this.shouldUpdateProjects) {
+			for (IProject project : ProjectUtils.getAllProjects()) {
+				if (ProjectUtils.isMavenProject(project)) {
+					updateProject(project, true);
+				}
+			}
+			this.shouldUpdateProjects = false;
+		}
+	}
+
+	@Override
+	public boolean isBuildFinished() {
+		return buildFinished;
+	}
 }

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/PreferenceManager.java

@@ -164,7 +164,9 @@ public static void initializeJavaCoreOptions() {
 		// workaround for https://github.com/redhat-developer/vscode-java/issues/718
 		javaCoreOptions.put(JavaCore.CORE_CIRCULAR_CLASSPATH, JavaCore.WARNING);
 		javaCoreOptions.put(JavaCore.COMPILER_IGNORE_UNNAMED_MODULE_FOR_SPLIT_PACKAGE, JavaCore.ENABLED);
-		JavaCore.setOptions(javaCoreOptions);
+		if (!Objects.equals(javaCoreOptions, JavaCore.getOptions())) {
+			JavaCore.setOptions(javaCoreOptions);
+		}
 	}
 
 	private static void reloadTemplateStore() {
@@ -226,7 +228,9 @@ public void update(Preferences preferences) {
 		}
 		Hashtable<String, String> options = JavaCore.getOptions();
 		preferences.updateTabSizeInsertSpaces(options);
-		JavaCore.setOptions(options);
+		if (!Objects.equals(options, JavaCore.getOptions())) {
+			JavaCore.setOptions(options);
+		}
 		List<String> resourceFilters = preferences.getResourceFilters();
 		IEclipsePreferences eclipsePreferences = InstanceScope.INSTANCE.getNode(IConstants.PLUGIN_ID);
 		// add the resourceFilters preference; the org.eclipse.jdt.ls.filesystem plugin uses it