HEAD - Fix for 368152: ConcurrentModificationException on startup in

ExternalFoldersManager.createPendingFolders

3 files changed, 21 insertions, 29 deletions

diff --git a/org.eclipse.jdt.core/buildnotes_jdt-core.html b/org.eclipse.jdt.core/buildnotes_jdt-core.html
index 1c817fad49..ab3c1f7729 100644
--- a/org.eclipse.jdt.core/buildnotes_jdt-core.html
+++ b/org.eclipse.jdt.core/buildnotes_jdt-core.html
@@ -52,7 +52,9 @@ Eclipse SDK 3.8.0 - %date% - 3.8.0 M6
 <h2>What's new in this drop</h2>
 
 <h3>Problem Reports Fixed</h3>
-<a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=244544">244544</a>
+<a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=368152">368152</a>
+ConcurrentModificationException on startup in ExternalFoldersManager.createPendingFolders
+<br><a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=244544">244544</a>
 codeSelect fails on constant declaration in anonymous and local classes
 <br><a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=291040">291040</a>
 codeSelect(..) does not work for a deeply nested method invocation in nested and anonymous class
diff --git a/org.eclipse.jdt.core/model/org/eclipse/jdt/core/JavaCore.java b/org.eclipse.jdt.core/model/org/eclipse/jdt/core/JavaCore.java
index bd10f5abc1..188874724b 100644
--- a/org.eclipse.jdt.core/model/org/eclipse/jdt/core/JavaCore.java
+++ b/org.eclipse.jdt.core/model/org/eclipse/jdt/core/JavaCore.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2011 IBM Corporation and others.
+ * Copyright (c) 2000, 2012 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -101,7 +101,6 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Hashtable;
-import java.util.Iterator;
 import java.util.Map;
 
 import org.eclipse.core.runtime.CoreException;
@@ -117,7 +116,6 @@ import org.eclipse.core.runtime.Plugin;
 import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.core.runtime.SubProgressMonitor;
 import org.eclipse.core.runtime.jobs.ISchedulingRule;
-import org.eclipse.core.runtime.jobs.Job;
 
 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFile;
@@ -3876,7 +3874,6 @@ public final class JavaCore extends Plugin {
 				monitor.subTask(Messages.javamodel_resetting_source_attachment_properties);
 			final IJavaProject[] projects = manager.getJavaModel().getJavaProjects();
 			HashSet visitedPaths = new HashSet();
-			HashSet externalPaths = new HashSet();
 			ExternalFoldersManager externalFoldersManager = JavaModelManager.getExternalManager();
 			for (int i = 0, length = projects.length; i < length; i++) {
 				JavaProject javaProject = (JavaProject) projects[i];
@@ -3900,32 +3897,19 @@ public final class JavaCore extends Plugin {
 						if (entry.getEntryKind() == IClasspathEntry.CPE_LIBRARY) {
 							IPath entryPath = entry.getPath();
 							if (ExternalFoldersManager.isExternalFolderPath(entryPath) && externalFoldersManager.getFolder(entryPath) == null) {
-								externalPaths.add(entryPath);
+								externalFoldersManager.addFolder(entryPath, true);
 							}
 						}
 					}
 				}
 			}
-			
-			ISchedulingRule rule = null;
 			try {
-				// Use a schedule rule to avoid a race condition (https://bugs.eclipse.org/bugs/show_bug.cgi?id=369251)
-				rule = ResourcesPlugin.getWorkspace().getRuleFactory().modifyRule(externalFoldersManager.getExternalFoldersProject());
-				Job.getJobManager().beginRule(rule, monitor);
-				
-				Iterator externalPathIter = externalPaths.iterator();
-				while (externalPathIter.hasNext()) {
-					externalFoldersManager.addFolder((IPath) externalPathIter.next(), true);
-				}
 				externalFoldersManager.createPendingFolders(monitor);
-				
-			} catch (JavaModelException jme) {
+			}
+			catch(JavaModelException jme) {
 				// Creation of external folder project failed. Log it and continue;
 				Util.log(jme, "Error while processing external folders"); //$NON-NLS-1$
-			} finally {
-				Job.getJobManager().endRule(rule);
 			}
-			
 			// initialize delta state
 			if (monitor != null)
 				monitor.subTask(Messages.javamodel_initializing_delta_state);
diff --git a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java
index d6156980e7..928b6d1c22 100644
--- a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java
+++ b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ExternalFoldersManager.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2011 IBM Corporation and others.
+ * Copyright (c) 2000, 2012 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -122,7 +122,7 @@ public class ExternalFoldersManager {
 		} while (result.exists());
 		if (scheduleForCreation) {
 			if (this.pendingFolders == null)
-				this.pendingFolders = new HashSet();
+				this.pendingFolders = Collections.synchronizedSet(new HashSet());
 			this.pendingFolders.add(externalFolderPath);
 		}
 		knownFolders.put(externalFolderPath, result);
@@ -166,16 +166,22 @@ public class ExternalFoldersManager {
 		catch(CoreException e) {
 			throw new JavaModelException(e);
 		}
-		Iterator iterator = this.pendingFolders.iterator();
-		while (iterator.hasNext()) {
-			Object folderPath = iterator.next();
+		// https://bugs.eclipse.org/bugs/show_bug.cgi?id=368152
+		// To avoid race condition (from addFolder and removeFolder, load the map elements into an array and clear the map immediately.
+		// The createLinkFolder being in the synchronized block can cause a deadlock and hence keep it out of the synchronized block. 
+		Object[] arrayOfFolders = null;
+		synchronized (this.pendingFolders) {
+			arrayOfFolders = this.pendingFolders.toArray();
+			this.pendingFolders.clear();
+		}
+
+		for (int i=0; i < arrayOfFolders.length; i++) {
 			try {
-				createLinkFolder((IPath) folderPath, false, externalFoldersProject, monitor);
+				createLinkFolder((IPath) arrayOfFolders[i], false, externalFoldersProject, monitor);
 			} catch (CoreException e) {
-				Util.log(e, "Error while creating a link for external folder :" + folderPath); //$NON-NLS-1$
+				Util.log(e, "Error while creating a link for external folder :" + arrayOfFolders[i]); //$NON-NLS-1$
 			}
 		}
-		this.pendingFolders.clear();
 	}
 	
 	public void cleanUp(IProgressMonitor monitor) throws CoreException {