diff --git a/.gitignore b/.gitignore
index 6efbcd1..483cdf5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,4 +8,5 @@ javacore.*
 heapdump.*
 core.*
 Snap.*
-
+target
+tests/*/*.jar
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildDescription.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildDescription.java
new file mode 100755
index 0000000..d057db8
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildDescription.java
@@ -0,0 +1,42 @@
+/*******************************************************************************
+ * Copyright (c) 2011 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *     Jens Kuebler - [126121] - Initial API
+ *     Morgan Stanley - [126121] Updated parallel build patch by fixing concurrency issues 
+ *******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import org.eclipse.core.resources.IBuildConfiguration;
+import org.eclipse.core.resources.IBuildContext;
+
+import org.eclipse.core.resources.IBuildDescription;
+
+/**
+ * 
+ */
+public class BuildDescription implements IBuildDescription {
+
+	private IBuildContext buildContext;
+	
+	private IBuildConfiguration buildConfiguration;
+	
+	public BuildDescription(IBuildContext buildContext, IBuildConfiguration buildConfiguration) {
+		super();
+		this.buildContext = buildContext;
+		this.buildConfiguration = buildConfiguration;
+	}
+	
+	public IBuildContext getBuildContext() {
+		return buildContext;
+	}
+
+	public IBuildConfiguration getBuildConfiguration() {
+		return buildConfiguration;
+	}
+
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildManager.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildManager.java
index fadcdac..605dd44 100644
--- a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildManager.java
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildManager.java
@@ -11,6 +11,8 @@
  * Anton Leherbauer (Wind River) - [305858] Allow Builder to return null rule
  * James Blackburn (Broadcom) - [306822] Provide Context for Builder getRule()
  * Broadcom Corporation - ongoing development
+ * 	   Jens Kuebler - [126121] - Initial changes to support parallel build
+ * 	   Morgan Stanley - [126121] Fixing parallel build concurrency issues
  *******************************************************************************/
 package org.eclipse.core.internal.events;
 
@@ -99,10 +101,10 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 	private final Set<IProject> builtProjects = new HashSet<IProject>();
 
 	//the following four fields only apply for the lifetime of a single builder invocation.
-	protected InternalBuilder currentBuilder;
-	private DeltaDataTree currentDelta;
-	private ElementTree currentLastBuiltTree;
-	private ElementTree currentTree;
+	protected final ThreadLocal<InternalBuilder> currentBuilder = new ThreadLocal<InternalBuilder>();
+	private final ThreadLocal<DeltaDataTree> currentDelta = new ThreadLocal<DeltaDataTree>();
+	private final ThreadLocal<ElementTree> currentLastBuiltTree = new ThreadLocal<ElementTree>();
+	private final ThreadLocal<ElementTree> currentTree = new ThreadLocal<ElementTree>();
 
 	/**
 	 * Caches the IResourceDelta for a pair of trees
@@ -134,18 +136,29 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 
 	private void basicBuild(int trigger, IncrementalProjectBuilder builder, Map<String, String> args, MultiStatus status, IProgressMonitor monitor) {
 		try {
-			currentBuilder = builder;
+		    // flag required for different locking behaviour
+		    boolean notParallel = !(trigger == IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD || trigger == IncrementalProjectBuilder.PARALLEL_FULL_BUILD);
+		    
+		    // Builder impl may not know about Parallel build types and it is not even interesting on the per project level
+		    if (trigger == IncrementalProjectBuilder.PARALLEL_FULL_BUILD) {
+		        trigger = IncrementalProjectBuilder.FULL_BUILD;
+		    }
+		    if (trigger == IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD) {
+		        trigger = IncrementalProjectBuilder.CLEAN_BUILD;
+		    }
+ 
+		    currentBuilder.set(builder);
 			//clear any old requests to forget built state
-			currentBuilder.clearLastBuiltStateRequests();
+			currentBuilder.get().clearLastBuiltStateRequests();
 			// Figure out want kind of build is needed
-			boolean clean = trigger == IncrementalProjectBuilder.CLEAN_BUILD;
-			currentLastBuiltTree = currentBuilder.getLastBuiltTree();
+			boolean clean = (trigger == IncrementalProjectBuilder.CLEAN_BUILD);
+			currentLastBuiltTree.set(currentBuilder.get().getLastBuiltTree());
 
 			// Does the build command respond to this trigger?
 			boolean isBuilding = builder.getCommand().isBuilding(trigger);
 
 			// If no tree is available we have to do a full build
-			if (!clean && currentLastBuiltTree == null) {
+			if (!clean && currentLastBuiltTree.get() == null) {
 				// Bug 306746 - Don't promote build to FULL_BUILD if builder doesn't AUTO_BUILD
 				if (trigger == IncrementalProjectBuilder.AUTO_BUILD && !isBuilding)
 					return;
@@ -157,24 +170,24 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 			//don't build if this builder doesn't respond to the trigger
 			if (!isBuilding) {
 				if (clean)
-					currentBuilder.setLastBuiltTree(null);
+					currentBuilder.get().setLastBuiltTree(null);
 				return;
 			}
 
 			// For incremental builds, grab a pointer to the current state before computing the delta
-			currentTree = ((trigger == IncrementalProjectBuilder.FULL_BUILD) || clean) ? null : workspace.getElementTree();
+			currentTree.set(((trigger == IncrementalProjectBuilder.FULL_BUILD) || clean) ? null : workspace.getElementTree());
 			int depth = -1;
 			ISchedulingRule rule = null;
 			try {
 				//short-circuit if none of the projects this builder cares about have changed.
-				if (!needsBuild(currentBuilder, trigger)) {
+				if (!needsBuild(currentBuilder.get(), trigger)) {
 					//use up the progress allocated for this builder
 					monitor.beginTask("", 1); //$NON-NLS-1$
 					monitor.done();
 					return;
 				}
 				rule = builder.getRule(trigger, args);
-				String name = currentBuilder.getLabel();
+				String name = currentBuilder.get().getLabel();
 				String message;
 				if (name != null)
 					message = NLS.bind(Messages.events_invoking_2, name, builder.getProject().getFullPath());
@@ -183,48 +196,50 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 				monitor.subTask(message);
 				hookStartBuild(builder, trigger);
 				// Make the current tree immutable before releasing the WS lock
-				if (rule != null && currentTree != null)
+				if (rule != null && currentTree.get() != null)
 					workspace.newWorkingTree();
 				//release workspace lock while calling builders
-				depth = getWorkManager().beginUnprotected();
+				if (notParallel) {
+				    depth = getWorkManager().beginUnprotected();
+				}
 				// Acquire the rule required for running this builder
 				if (rule != null) {
 					Job.getJobManager().beginRule(rule, monitor);
 					// Now that we've acquired the rule, changes may have been made concurrently, ensure we're pointing at the 
 					// correct currentTree so delta contains concurrent changes made in areas guarded by the scheduling rule
-					if (currentTree != null)
-						currentTree = workspace.getElementTree();
+					if (currentTree.get() != null)
+						currentTree.set(workspace.getElementTree());
 				}
 				//do the build
-				SafeRunner.run(getSafeRunnable(trigger, args, status, monitor));
+				SafeRunner.run(getSafeRunnable(trigger, args, status, monitor, currentBuilder.get()));
 			} finally {
 				// Re-acquire the WS lock, then release the scheduling rule
-				if (depth >= 0)
+			    if (notParallel && depth >= 0)
 					getWorkManager().endUnprotected(depth);
 				if (rule != null)
 					Job.getJobManager().endRule(rule);
 				// Be sure to clean up after ourselves.
-				if (clean || currentBuilder.wasForgetStateRequested()) {
-					currentBuilder.setLastBuiltTree(null);
-				} else if (currentBuilder.wasRememberStateRequested()) {
+				if (clean || currentBuilder.get().wasForgetStateRequested()) {
+					currentBuilder.get().setLastBuiltTree(null);
+				} else if (currentBuilder.get().wasRememberStateRequested()) {
 					// If remember last build state, and FULL_BUILD
 					// last tree must be set to => null for next build
 					if (trigger == IncrementalProjectBuilder.FULL_BUILD)
-						currentBuilder.setLastBuiltTree(null);
+						currentBuilder.get().setLastBuiltTree(null);
 					// else don't modify the last built tree
 				} else {
 					// remember the current state as the last built state.
 					ElementTree lastTree = workspace.getElementTree();
-					lastTree.immutable();
-					currentBuilder.setLastBuiltTree(lastTree);
+//					lastTree.immutable();
+					currentBuilder.get().setLastBuiltTree(lastTree);
 				}
 				hookEndBuild(builder);
 			}
 		} finally {
-			currentBuilder = null;
-			currentTree = null;
-			currentLastBuiltTree = null;
-			currentDelta = null;
+		    currentBuilder.set(null);
+		    currentTree.set(null);
+		    currentLastBuiltTree.set(null);
+		    currentDelta.set(null);
 		}
 	}
 
@@ -234,7 +249,12 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 				checkCanceled(trigger, monitor);
 				BuildCommand command = (BuildCommand) commands[i];
 				IProgressMonitor sub = Policy.subMonitorFor(monitor, 1);
-				IncrementalProjectBuilder builder = getBuilder(buildConfiguration, command, i, status, context);
+				IncrementalProjectBuilder builder;
+				if(IncrementalProjectBuilder.PARALLEL_FULL_BUILD == trigger || IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD == trigger) {
+				    builder = getParallelBuilder(buildConfiguration, command, i, status, context);
+				} else {
+				    builder = getBuilder(buildConfiguration, command, i, status, context);
+				}
 				if (builder != null)
 					basicBuild(trigger, builder, command.getArguments(false), status, sub);
 			}
@@ -362,26 +382,57 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 	 * they are given.
 	 * @return A status indicating if the build succeeded or failed
 	 */
-	public IStatus build(IBuildConfiguration[] configs, IBuildConfiguration[] requestedConfigs, int trigger, IProgressMonitor monitor) {
-		monitor = Policy.monitorFor(monitor);
-		try {
-			monitor.beginTask(Messages.events_building_0, TOTAL_BUILD_WORK);
-			if (!canRun(trigger))
-				return Status.OK_STATUS;
-			try {
-				hookStartBuild(configs, trigger);
-				MultiStatus status = new MultiStatus(ResourcesPlugin.PI_RESOURCES, IResourceStatus.BUILD_FAILED, Messages.events_errors, null);
-				basicBuildLoop(configs, requestedConfigs, trigger, status, monitor);
-				return status;
-			} finally {
-				hookEndBuild(trigger);
-			}
-		} finally {
-			monitor.done();
-			if (trigger == IncrementalProjectBuilder.INCREMENTAL_BUILD || trigger == IncrementalProjectBuilder.FULL_BUILD)
-				autoBuildJob.avoidBuild();
-		}
-	}
+    public IStatus build(final IBuildConfiguration[] configs, final IBuildConfiguration[] requestedConfigs, final int trigger, final IProgressMonitor monitor) {
+        if (trigger == IncrementalProjectBuilder.PARALLEL_FULL_BUILD || trigger == IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD) {
+            
+            final String buildType = (trigger == IncrementalProjectBuilder.PARALLEL_FULL_BUILD) ? "Parallel full build" : "Parallel clean build";
+            Job job = new Job(buildType) {
+                
+                @Override
+                protected IStatus run(IProgressMonitor monitor) {
+                    try {
+                        IBuildConfiguration[] buildConfigs = requestedConfigs.length > 0 ? requestedConfigs : configs; 
+                        if (trigger == IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD) {                            
+                            buildParallel(IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD, monitor, buildConfigs);
+                        }
+                        buildParallel(IncrementalProjectBuilder.PARALLEL_FULL_BUILD, monitor, buildConfigs);
+                    } catch (CoreException e) {
+                        e.printStackTrace();
+                        return new Status(IStatus.ERROR, ResourcesPlugin.PI_RESOURCES, buildType + " finished with error", e);
+                    } 
+                    
+                    return new Status(IStatus.OK, ResourcesPlugin.PI_RESOURCES, buildType + " finished successfully");
+                }
+            };
+            
+            job.setPriority(Job.LONG);
+            job.schedule();
+
+            autoBuildJob.avoidBuild();
+            
+            return Status.OK_STATUS;
+            
+        } else {            
+            IProgressMonitor myMonitor = Policy.monitorFor(monitor);
+            try {
+                myMonitor.beginTask(Messages.events_building_0, TOTAL_BUILD_WORK);
+                if (!canRun(trigger))
+                    return Status.OK_STATUS;
+                try {
+                    hookStartBuild(configs, trigger);
+                    MultiStatus status = new MultiStatus(ResourcesPlugin.PI_RESOURCES, IResourceStatus.BUILD_FAILED, Messages.events_errors, null);
+                    basicBuildLoop(configs, requestedConfigs, trigger, status, myMonitor);
+                    return status;
+                } finally {
+                    hookEndBuild(trigger);
+                }
+            } finally {
+                myMonitor.done();
+                if (trigger == IncrementalProjectBuilder.INCREMENTAL_BUILD || trigger == IncrementalProjectBuilder.FULL_BUILD)
+                    autoBuildJob.avoidBuild();
+            }
+        }
+    }
 
 	/**
 	 * Runs the builder with the given name on the given project config.
@@ -480,13 +531,13 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 	}
 
 	private String debugBuilder() {
-		return currentBuilder == null ? "<no builder>" : currentBuilder.getClass().getName(); //$NON-NLS-1$
+		return currentBuilder.get() == null ? "<no builder>" : currentBuilder.get().getClass().getName(); //$NON-NLS-1$
 	}
 
 	private String debugProject() {
-		if (currentBuilder == null)
+		if (currentBuilder.get() == null)
 			return "<no project>"; //$NON-NLS-1$
-		return currentBuilder.getProject().getFullPath().toString();
+		return currentBuilder.get().getProject().getFullPath().toString();
 	}
 
 	/**
@@ -498,8 +549,12 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 		switch (trigger) {
 			case IncrementalProjectBuilder.FULL_BUILD :
 				return "FULL_BUILD"; //$NON-NLS-1$
+			case IncrementalProjectBuilder.PARALLEL_FULL_BUILD :
+			    return "PARALLEL_FULL_BUILD"; //$NON-NLS-1$
 			case IncrementalProjectBuilder.CLEAN_BUILD :
 				return "CLEAN_BUILD"; //$NON-NLS-1$
+			case IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD :
+			    return "PARALLEL_CLEAN_BUILD"; //$NON-NLS-1$
 			case IncrementalProjectBuilder.AUTO_BUILD :
 			case IncrementalProjectBuilder.INCREMENTAL_BUILD :
 			default :
@@ -581,18 +636,20 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 		//try to match on builder index, but if not match is found, use the builder name and config name
 		//this is because older workspace versions did not store builder infos in build spec order
 		BuilderPersistentInfo nameMatch = null;
-		for (Iterator<BuilderPersistentInfo> it = infos.iterator(); it.hasNext();) {
-			BuilderPersistentInfo info = it.next();
-			// match on name, config name and build spec index if known
-			// Note: the config name may be null for builders that don't support configurations, or old workspaces
-			if (info.getBuilderName().equals(builderName) && (info.getConfigName() == null || info.getConfigName().equals(configName))) {
-				//we have found a match on name alone
-				if (nameMatch == null)
-					nameMatch = info;
-				//see if the index matches
-				if (buildSpecIndex == -1 || info.getBuildSpecIndex() == -1 || buildSpecIndex == info.getBuildSpecIndex())
-					return info;
-			}
+		synchronized(infos) {
+    		for (Iterator<BuilderPersistentInfo> it = infos.iterator(); it.hasNext();) {
+    			BuilderPersistentInfo info = it.next();
+    			// match on name, config name and build spec index if known
+    			// Note: the config name may be null for builders that don't support configurations, or old workspaces
+    			if (info.getBuilderName().equals(builderName) && (info.getConfigName() == null || info.getConfigName().equals(configName))) {
+    				//we have found a match on name alone
+    				if (nameMatch == null)
+    					nameMatch = info;
+    				//see if the index matches
+    				if (buildSpecIndex == -1 || info.getBuildSpecIndex() == -1 || buildSpecIndex == info.getBuildSpecIndex())
+    					return info;
+    			}
+    		}
 		}
 		//no exact index match, so return name match, if any
 		return nameMatch;
@@ -645,7 +702,7 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 	IResourceDelta getDelta(IProject project) {
 		try {
 			lock.acquire();
-			if (currentTree == null) {
+			if (currentTree.get() == null) {
 				if (Policy.DEBUG_BUILD_FAILURE)
 					Policy.debug("Build: no tree for delta " + debugBuilder() + " [" + debugProject() + "]"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 				return null;
@@ -657,7 +714,7 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 				return null;
 			}
 			//check if this project has changed
-			if (currentDelta != null && currentDelta.findNodeAt(project.getFullPath()) == null) {
+			if (currentDelta.get() != null && currentDelta.get().findNodeAt(project.getFullPath()) == null) {
 				//if the project never existed (not in delta and not in current tree), return null
 				if (!project.exists())
 					return null;
@@ -665,7 +722,7 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 				return ResourceDeltaFactory.newEmptyDelta(project);
 			}
 			//now check against the cache
-			IResourceDelta result = (IResourceDelta) deltaCache.getDelta(project.getFullPath(), currentLastBuiltTree, currentTree);
+			IResourceDelta result = (IResourceDelta) deltaCache.getDelta(project.getFullPath(), currentLastBuiltTree.get(), currentTree.get());
 			if (result != null)
 				return result;
 
@@ -674,8 +731,8 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 				startTime = System.currentTimeMillis();
 				Policy.debug("Computing delta for project: " + project.getName()); //$NON-NLS-1$
 			}
-			result = ResourceDeltaFactory.computeDelta(workspace, currentLastBuiltTree, currentTree, project.getFullPath(), -1);
-			deltaCache.cache(project.getFullPath(), currentLastBuiltTree, currentTree, result);
+			result = ResourceDeltaFactory.computeDelta(workspace, currentLastBuiltTree.get(), currentTree.get(), project.getFullPath(), -1);
+			deltaCache.cache(project.getFullPath(), currentLastBuiltTree.get(), currentTree.get(), result);
 			if (Policy.DEBUG_BUILD_FAILURE && result == null)
 				Policy.debug("Build: no delta " + debugBuilder() + " [" + debugProject() + "] " + project.getFullPath()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 			if (Policy.DEBUG_BUILD_DELTA) {
@@ -692,7 +749,7 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 	/**
 	 * Returns the safe runnable instance for invoking a builder
 	 */
-	private ISafeRunnable getSafeRunnable(final int trigger, final Map<String, String> args, final MultiStatus status, final IProgressMonitor monitor) {
+	private ISafeRunnable getSafeRunnable(final int trigger, final Map<String, String> args, final MultiStatus status, final IProgressMonitor monitor, final InternalBuilder builder) {
 		return new ISafeRunnable() {
 			public void handleException(Throwable e) {
 				if (e instanceof OperationCanceledException) {
@@ -700,18 +757,18 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 						Policy.debug("Build canceled"); //$NON-NLS-1$
 					//just discard built state when a builder cancels, to ensure
 					//that it is called again on the very next build.
-					currentBuilder.forgetLastBuiltState();
+					builder.forgetLastBuiltState();
 					throw (OperationCanceledException) e;
 				}
 				//ResourceStats.buildException(e);
 				// don't log the exception....it is already being logged in SafeRunner#run
 
 				//add a generic message to the MultiStatus
-				String builderName = currentBuilder.getLabel();
+				String builderName = builder.getLabel();
 				if (builderName == null || builderName.length() == 0)
-					builderName = currentBuilder.getClass().getName();
-				String pluginId = currentBuilder.getPluginId();
-				String message = NLS.bind(Messages.events_builderError, builderName, currentBuilder.getProject().getName());
+					builderName = builder.getClass().getName();
+				String pluginId = builder.getPluginId();
+				String message = NLS.bind(Messages.events_builderError, builderName, builder.getProject().getName());
 				status.add(new Status(IStatus.ERROR, pluginId, IResourceStatus.BUILD_FAILED, message, e));
 
 				//add the exception status to the MultiStatus
@@ -722,13 +779,15 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 			public void run() throws Exception {
 				IProject[] prereqs = null;
 				//invoke the appropriate build method depending on the trigger
-				if (trigger != IncrementalProjectBuilder.CLEAN_BUILD)
-					prereqs = currentBuilder.build(trigger, args, monitor);
-				else
-					currentBuilder.clean(monitor);
-				if (prereqs == null)
-					prereqs = new IProject[0];
-				currentBuilder.setInterestingProjects(prereqs.clone());
+				if (trigger == IncrementalProjectBuilder.CLEAN_BUILD) {
+				    builder.clean(monitor);
+				} else {
+				    prereqs = builder.build(trigger, args, monitor);
+				}
+
+				if (prereqs == null) prereqs = new IProject[0];
+
+				builder.setInterestingProjects(prereqs.clone());
 			}
 		};
 	}
@@ -920,9 +979,9 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 	 * to the given project, and false otherwise.
 	 */
 	private boolean isInterestingProject(IProject project) {
-		if (project.equals(currentBuilder.getProject()))
+		if (project.equals(currentBuilder.get().getProject()))
 			return true;
-		IProject[] interestingProjects = currentBuilder.getInterestingProjects();
+		IProject[] interestingProjects = currentBuilder.get().getInterestingProjects();
 		for (int i = 0; i < interestingProjects.length; i++) {
 			if (interestingProjects[i].equals(project)) {
 				return true;
@@ -950,7 +1009,7 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 			case IncrementalProjectBuilder.FULL_BUILD :
 				return true;
 			case IncrementalProjectBuilder.INCREMENTAL_BUILD :
-				if (currentBuilder.callOnEmptyDelta())
+				if (currentBuilder.get().callOnEmptyDelta())
 					return true;
 				//fall through and check if there is a delta
 		}
@@ -959,20 +1018,20 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 		ElementTree oldTree = builder.getLastBuiltTree();
 		ElementTree newTree = workspace.getElementTree();
 		long start = System.currentTimeMillis();
-		currentDelta = (DeltaDataTree) deltaTreeCache.getDelta(null, oldTree, newTree);
-		if (currentDelta == null) {
+		currentDelta.set((DeltaDataTree) deltaTreeCache.getDelta(null, oldTree, newTree));
+		if (currentDelta.get() == null) {
 			if (Policy.DEBUG_BUILD_NEEDED) {
 				String message = "Checking if need to build. Starting delta computation between: " + oldTree.toString() + " and " + newTree.toString(); //$NON-NLS-1$ //$NON-NLS-2$
 				Policy.debug(message);
 			}
-			currentDelta = newTree.getDataTree().forwardDeltaWith(oldTree.getDataTree(), ResourceComparator.getBuildComparator());
+			currentDelta.set(newTree.getDataTree().forwardDeltaWith(oldTree.getDataTree(), ResourceComparator.getBuildComparator()));
 			if (Policy.DEBUG_BUILD_NEEDED)
 				Policy.debug("End delta computation. (" + (System.currentTimeMillis() - start) + "ms)."); //$NON-NLS-1$ //$NON-NLS-2$
-			deltaTreeCache.cache(null, oldTree, newTree, currentDelta);
+			deltaTreeCache.cache(null, oldTree, newTree, currentDelta.get());
 		}
 
 		//search for the builder's project
-		if (currentDelta.findNodeAt(builder.getProject().getFullPath()) != null) {
+		if (currentDelta.get().findNodeAt(builder.getProject().getFullPath()) != null) {
 			if (Policy.DEBUG_BUILD_NEEDED)
 				Policy.debug(toString(builder) + " needs building because of changes in: " + builder.getProject().getName()); //$NON-NLS-1$
 			return true;
@@ -981,7 +1040,7 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 		//search for builder's interesting projects
 		IProject[] projects = builder.getInterestingProjects();
 		for (int i = 0; i < projects.length; i++) {
-			if (currentDelta.findNodeAt(projects[i].getFullPath()) != null) {
+			if (currentDelta.get().findNodeAt(projects[i].getFullPath()) != null) {
 				if (Policy.DEBUG_BUILD_NEEDED)
 					Policy.debug(toString(builder) + " needs building because of changes in: " + projects[i].getName()); //$NON-NLS-1$
 				return true;
@@ -1143,4 +1202,98 @@ public class BuildManager implements ICoreConstants, IManager, ILifecycleListene
 			Policy.log(status);
 		return workspace.getRoot();
 	}
+	
+    public void buildParallel(final int trigger, IProgressMonitor monitor, IBuildConfiguration[] configs) throws CoreException {        
+        
+        final boolean clean = (trigger == IncrementalProjectBuilder.PARALLEL_CLEAN_BUILD);
+        
+        long start = System.currentTimeMillis();
+        if (clean) {            
+            Policy.log(new ResourceStatus(IStatus.INFO, "Starting parallel cleaning of " + configs.length + " projects..."));
+        } else {
+            Policy.log(new ResourceStatus(IStatus.INFO, "Starting parallel build of " + configs.length + " projects..."));
+        }
+        final SharedProgressMonitor sharedProgress = new SharedProgressMonitor(Policy.monitorFor(monitor));
+        
+        List<IProject> projects = new ArrayList<IProject>();
+        DirectedGraphs<IProject> directedGraphs = new DirectedGraphs<IProject>();
+        for (IBuildConfiguration config : configs) {
+            projects.add(config.getProject());
+            directedGraphs.addNode(new Node<IProject>(config.getProject()));
+        }
+
+        // cleaning does not require building the graph
+        if (trigger == IncrementalProjectBuilder.PARALLEL_FULL_BUILD) {
+            for (IProject project : projects) {
+                if (!project.isAccessible())
+                    continue;
+                ProjectDescription desc = ((Project)project).internalGetDescription();
+                if (desc == null)
+                    continue;
+                IProject[] refs = desc.getAllReferences(false);
+                Node<IProject> node = directedGraphs.getNodeWithContent(project);
+                for (IProject referencedProject : refs) {
+                    Node<IProject> node2 = directedGraphs.getNodeWithContent(referencedProject);
+                    if(node2 != null) {
+                        node2.addOutgoingEdge(node);
+                    }
+                }
+            }
+        }
+        
+        hookStartBuild(configs, trigger);
+        
+        final MultiStatus status = new MultiStatus(ResourcesPlugin.PI_RESOURCES, IResourceStatus.INTERNAL_ERROR, Messages.events_errors, null);
+        
+        if (clean) {
+            sharedProgress.beginTask("Cleaning projects in parallel:", projects.size());
+        } else {
+            sharedProgress.beginTask("Building projects in parallel:", projects.size());
+        }
+        
+        ThreadPoolBuilder threadPoolBuilder = new ThreadPoolBuilder();
+        try {           
+            IBuildExecutor buildExecutor = new IBuildExecutor() {
+                public void executeBuild(IBuildDescription buildDescription, SharedProgressMonitor sharedProgress) {
+                    IProgressMonitor progressMonitor = new NullProgressMonitor();
+                    try {
+                        sharedProgress.addProjectName(buildDescription.getBuildConfiguration().getProject().getName());
+                        basicBuild(buildDescription.getBuildConfiguration(), trigger, buildDescription.getBuildContext(), status, progressMonitor);
+                    } finally {
+                        sharedProgress.removeProjectName(buildDescription.getBuildConfiguration().getProject().getName());
+                        sharedProgress.worked(1);
+                    }
+                }};
+                threadPoolBuilder.run(directedGraphs, buildExecutor, sharedProgress);
+        } catch (InterruptedException e) {
+            status.add(new Status(IStatus.ERROR, ResourcesPlugin.PI_RESOURCES, Messages.events_errors, e));
+        } finally {
+            hookEndBuild(trigger);
+            long finish = System.currentTimeMillis();
+            if (clean) {
+                Policy.log(new ResourceStatus(IStatus.INFO, "Finished parallel clean in " + (finish - start) + "ms"));
+            } else {
+                Policy.log(new ResourceStatus(IStatus.INFO, "Finished parallel build in " + (finish - start) + "ms"));              
+            }
+            sharedProgress.done();
+        } 
+    }
+
+    private IncrementalProjectBuilder getParallelBuilder(IBuildConfiguration buildConfiguration, BuildCommand command, int buildSpecIndex, MultiStatus status, IBuildContext buildContext) throws CoreException {
+        // always construct a new builder for parallel builds (think about pooling here)
+        InternalBuilder result = initializeBuilder(command.getBuilderName(), buildConfiguration, buildSpecIndex, status);
+        command.setBuilders(result);
+        result.setCommand(command);
+        result.setBuildConfig(buildConfiguration);
+        result.startupOnInitialize();
+        //      }
+
+        if (!validateNature(result, command.getBuilderName())) {
+            //skip this builder and null its last built tree because it is invalid
+            //if the nature gets added or re-enabled a full build will be triggered
+            result.setLastBuiltTree(null);
+            return null;
+        }
+        return (IncrementalProjectBuilder) result;
+    }	
 }
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildRunnable.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildRunnable.java
new file mode 100755
index 0000000..995a745
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/BuildRunnable.java
@@ -0,0 +1,52 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2005 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Jens Kuebler - [126121] - Initial changes to support parallel build
+ *     Morgan Stanley - [126121] Fixing parallel build concurrency issues
+*******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.BlockingQueue;
+
+import org.eclipse.core.internal.resources.BuildConfiguration;
+import org.eclipse.core.resources.IProject;
+
+// The worker instance that is executed in a ThreadPool worker thread
+public final class BuildRunnable implements Runnable {
+	
+	private final Node<IProject> currentNode;
+	private final BlockingQueue<Node<IProject>> queue;
+	private final IBuildExecutor executor;
+	private final SharedProgressMonitor sharedProgress;
+
+	protected BuildRunnable(Node<IProject> currentNode, BlockingQueue<Node<IProject>> queue, IBuildExecutor executor, SharedProgressMonitor sharedMonitor) {
+		this.currentNode = currentNode;
+		this.queue = queue;
+		this.executor = executor;
+		this.sharedProgress = sharedMonitor;
+	}
+	
+	public void run() {			
+			if (sharedProgress.isCanceled()) {
+				return;
+			}			
+//			System.out.println("start compile " + currentNode.getContent()); //$NON-NLS-1$
+			BuildDescription buildDescription = new BuildDescription(null, new BuildConfiguration(currentNode.getContent()));
+			executor.executeBuild(buildDescription, sharedProgress);
+//			System.out.println("end compile " + currentNode.getContent()); //$NON-NLS-1$
+			List<Node<IProject>> outgoingNodes = new ArrayList<Node<IProject>>(currentNode.getOutgoingEdges()); 
+			currentNode.removeAllOutgoingEdges();
+			for (Node<IProject> node : outgoingNodes) {
+				if(node.getIncomingEdges().isEmpty()) {
+					queue.add(node);
+				}
+			}
+	}
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/DirectedGraphs.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/DirectedGraphs.java
new file mode 100755
index 0000000..116fdf5
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/DirectedGraphs.java
@@ -0,0 +1,67 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2005 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Jens Kuebler - [126121] - Initial changes to support parallel build
+ *******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+/**
+ * A directed graph holds all nodes. Nodes need not be connected which is why a container object is required
+ * 
+ * @author jens
+ *
+ */
+public class DirectedGraphs<T> {
+	
+	private Set<Node<T>> nodes;
+
+	public DirectedGraphs() {
+		nodes = Collections.synchronizedSet(new HashSet<Node<T>>());
+	}
+	
+	public void addNode(Node<T> node) {
+		nodes.add(node);
+	}
+
+	public void removeNode(Node<T> node) {
+		nodes.remove(node);
+	}
+	
+	public void addAll(Collection<Node<T>> nodesToBeAdded) {
+		nodes.addAll(nodesToBeAdded);
+	}
+	
+	public Node<T> getNodeWithContent(T content) {
+		for (Node<T> node : nodes) {
+			if(content.equals(node.getContent())) {
+				return node;
+			}
+		}
+		return null;
+	}
+	
+	public synchronized Set<Node<T>> getRootNodes() {
+		Set<Node<T>> set = new LinkedHashSet<Node<T>>();
+		for (Node<T> node : nodes) {
+			if(node.getIncomingEdges().isEmpty()) {
+				set.add(node);
+			}
+		}
+		return set;
+	}
+	
+	public boolean isEmtpy() {
+		return nodes.isEmpty();
+	}
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/IBuildExecutor.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/IBuildExecutor.java
new file mode 100755
index 0000000..9364bf7
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/IBuildExecutor.java
@@ -0,0 +1,23 @@
+/*******************************************************************************
+ * Copyright (c) 2011 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *     Jens Kuebler - [126121] - Initial changes to support parallel build
+ *******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import org.eclipse.core.resources.IBuildDescription;
+
+
+/**
+ * 
+ */
+public interface IBuildExecutor {
+	
+	public void executeBuild(IBuildDescription buildDescription, SharedProgressMonitor sharedProgress);
+
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/Node.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/Node.java
new file mode 100755
index 0000000..3d3f454
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/Node.java
@@ -0,0 +1,138 @@
+/*******************************************************************************
+ * Copyright (c) 2011 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Jens Kuebler - [126121] - Initial changes to support parallel build
+ *******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import java.text.MessageFormat;
+
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+/**
+ * A simple node object having references to other node objects 
+ *
+ * @param <T>
+ */
+public class Node<T> {
+	
+	private Set<Node<T>> incomingEdges;
+
+	private Set<Node<T>> outgoingEdges;
+	
+	private T content;
+	
+	public Node(T content) {
+		this.content = content;
+		incomingEdges = new LinkedHashSet<Node<T>>(); 
+		outgoingEdges = new LinkedHashSet<Node<T>>(); 
+	}
+	
+	public T getContent() {
+		return content;
+	}
+
+	public void setContent(T content) {
+		this.content = content;
+	}
+
+	public synchronized Set<Node<T>> getIncomingEdges() {
+		return incomingEdges;
+	}
+
+	public synchronized Set<Node<T>> getOutgoingEdges() {
+		return outgoingEdges;
+	}
+
+	public synchronized void addIncomingEdge(Node<T> node) {
+		if(!incomingEdges.contains(node)) {
+			incomingEdges.add(node);
+			node.addOutgoingEdge(this);
+		}
+	}
+
+	public synchronized void addOutgoingEdge(Node<T> node) {
+		if(!outgoingEdges.contains(node)) {
+			outgoingEdges.add(node);
+			node.addIncomingEdge(this);
+		}
+	}
+	
+	public synchronized void removeOutgoingEdge(Node<T> node) {
+		if(outgoingEdges.contains(node)) {
+			outgoingEdges.remove(node);
+			node.removeIncomingEdge(this);
+		}
+	}
+	
+	public synchronized void removeIncomingEdge(Node<T> node) {
+		if(incomingEdges.contains(node)) {
+			incomingEdges.remove(node);
+			node.removeOutgoingEdge(this);
+		}
+	}
+
+	public synchronized void removeAllOutgoingEdges() {
+		for (Iterator<Node<T>> iterator = outgoingEdges.iterator(); iterator.hasNext();) {
+			Node<T> node = iterator.next();
+			node.internalRemoveIncomingEdge(this);
+			iterator.remove();
+		}
+	}
+
+	public synchronized void removeAllIncomingEdges() {
+		for (Iterator<Node<T>> iterator = incomingEdges.iterator(); iterator.hasNext();) {
+			Node<T> node = iterator.next();
+			node.internalRemoveOutgoingEdge(this);
+			iterator.remove();
+		}
+	}
+
+	synchronized void internalRemoveOutgoingEdge(Node<T> node) {
+		outgoingEdges.remove(node);
+	}
+
+	synchronized void internalRemoveIncomingEdge(Node<T> node) {
+		incomingEdges.remove(node);
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + ((content == null) ? 0 : content.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		Node other = (Node) obj;
+		if (content == null) {
+			if (other.content != null)
+				return false;
+		} else if (!content.equals(other.content))
+			return false;
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return MessageFormat.format("Node [content={0}]", content); //$NON-NLS-1$
+	}
+
+	
+	
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/SharedProgressMonitor.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/SharedProgressMonitor.java
new file mode 100755
index 0000000..57d6785
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/SharedProgressMonitor.java
@@ -0,0 +1,89 @@
+/*******************************************************************************
+ * Copyright (c) 2011 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Morgan Stanley - [126121] Fixing parallel build concurrency issues
+ *******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+
+/**
+ * Simple thread-safe {@link IProgressMonitor} wrapper used by the parallel builder to add/remove names of
+ * projects that are actually building.
+ */
+public class SharedProgressMonitor implements IProgressMonitor {
+
+	private final IProgressMonitor progressMonitor;
+	private final Set<String> projectNames = new LinkedHashSet<String>();
+	private String taskNamePrefix = "";
+	
+	public SharedProgressMonitor(IProgressMonitor progressMonitor) {
+		this.progressMonitor = progressMonitor;
+	}
+
+	public synchronized void beginTask(String name, int totalWork) {
+		taskNamePrefix = name;
+		progressMonitor.beginTask(name, totalWork);
+	}
+
+	public synchronized void done() {
+		progressMonitor.done();
+	}
+
+	public synchronized void internalWorked(double work) {
+		progressMonitor.internalWorked(work);
+	}
+
+	public boolean isCanceled() {
+		return progressMonitor.isCanceled();
+	}
+
+	public synchronized void setCanceled(boolean value) {
+		progressMonitor.setCanceled(value);
+	}
+
+	public synchronized void setTaskName(String name) {
+		progressMonitor.setTaskName(name);
+	}
+
+	public synchronized void subTask(String name) {
+		progressMonitor.subTask(name);
+	}
+
+	public synchronized void worked(int work) {
+		progressMonitor.worked(work);
+	}
+	
+	public synchronized void addProjectName(String projName) {
+		projectNames.add(projName);
+		setTaskName(taskNamePrefix + " " + getProjectNames(projectNames));
+	}
+	
+	public synchronized void removeProjectName(String projName) {
+		projectNames.remove(projName);
+		setTaskName(taskNamePrefix + " " + getProjectNames(projectNames));
+	}	
+	
+	private static String getProjectNames(Set<String> projectNames) {
+		StringBuilder builder = new StringBuilder("[");
+		boolean first = true;
+		for (String name : projectNames) {
+			if (first) {
+				first = false;
+			} else {
+				builder.append(", ");
+			}
+			builder.append(name);
+		}
+		builder.append("]");
+		return builder.toString();
+	}
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/ThreadPoolBuilder.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/ThreadPoolBuilder.java
new file mode 100755
index 0000000..3009caa
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/events/ThreadPoolBuilder.java
@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2011 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Jens Kuebler - [126121] - Initial changes to support parallel build
+ *     Morgan Stanley - [126121] Fixing parallel build concurrency issues
+ *******************************************************************************/
+package org.eclipse.core.internal.events;
+
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+
+import org.eclipse.core.resources.IProject;
+
+public class ThreadPoolBuilder {
+	
+	private ExecutorService threadPool;
+	
+	private BlockingQueue<Node<IProject>> queue;
+
+	public ThreadPoolBuilder() {
+		final int threadNum = Runtime.getRuntime().availableProcessors() > 1 ? Runtime.getRuntime().availableProcessors() - 1 : 1;
+		threadPool = Executors.newFixedThreadPool(threadNum);
+		queue = new ArrayBlockingQueue<Node<IProject>>(6000);
+	}
+	
+	public void run(DirectedGraphs<IProject> directedGraphs, IBuildExecutor runnable, SharedProgressMonitor sharedProgress) throws InterruptedException {
+//		System.out.println("ThreadPool started...");
+		queue.addAll(directedGraphs.getRootNodes());
+		while (!threadPool.isShutdown()) {
+			if(directedGraphs.isEmtpy() || sharedProgress.isCanceled()) {
+				threadPool.shutdown();
+			} else {
+				Node<IProject>nodeToCompile = queue.take();
+				directedGraphs.removeNode((Node<IProject>) nodeToCompile);
+				threadPool.execute(new BuildRunnable(nodeToCompile, queue, runnable, sharedProgress));
+			}
+		}
+		// blocking the main builder thread (Worker-N) until all the threads finishes 
+		threadPool.awaitTermination(60, TimeUnit.SECONDS);
+//		System.out.println("ThreadPool finished...");
+	}
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IBuildDescription.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IBuildDescription.java
new file mode 100755
index 0000000..4bc1cdf
--- /dev/null
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IBuildDescription.java
@@ -0,0 +1,22 @@
+/*******************************************************************************
+ * Copyright (c) 2011 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.core.resources;
+
+/**
+ * 
+ */
+public interface IBuildDescription {
+	
+	IBuildContext getBuildContext();
+	
+	IBuildConfiguration getBuildConfiguration();
+
+}
diff --git a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IncrementalProjectBuilder.java b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IncrementalProjectBuilder.java
index 4c3a0f2..6e8e354 100644
--- a/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IncrementalProjectBuilder.java
+++ b/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IncrementalProjectBuilder.java
@@ -11,6 +11,8 @@
  * Anton Leherbauer (Wind River) - [305858] Allow Builder to return null rule
  * James Blackburn (Broadcom) - [306822] Provide Context for Builder getRule()
  * Broadcom Corporation - build configurations and references
+ * Jens Kuebler - [126121] - Initial changes to support parallel build
+ * Morgan Stanley - [126121] Adding support for parallel clean build
  *******************************************************************************/
 package org.eclipse.core.resources;
 
@@ -50,6 +52,9 @@ public abstract class IncrementalProjectBuilder extends InternalBuilder implemen
 	 * @see IWorkspace#build(int, IProgressMonitor)
 	 */
 	public static final int FULL_BUILD = 6;
+	
+    public static final int PARALLEL_FULL_BUILD = 7;
+    
 	/**
 	 * Build kind constant (value 9) indicating an automatic build request.  When
 	 * autobuild is turned on, these builds are triggered automatically whenever
@@ -84,6 +89,8 @@ public abstract class IncrementalProjectBuilder extends InternalBuilder implemen
 	 * @since 3.0
 	 */
 	public static final int CLEAN_BUILD = 15;
+	
+	public static final int PARALLEL_CLEAN_BUILD = 16;
 
 	/**
 	 * Runs this builder in the specified manner. Subclasses should implement
@@ -451,7 +458,7 @@ public abstract class IncrementalProjectBuilder extends InternalBuilder implemen
 	 * @since 3.6
 	 */
 	public ISchedulingRule getRule(int kind, Map<String,String> args) {
-		return getRule();
+		return getProject();
 	}
 
 	/**