Revert "Bug 531554 - Pref to allow null scheduling rule for Java Builder"I20190227-1800

This reverts commit 749e6f86b20add3c4fa8193fea1a613d6b0a897b.

Conflicts:
	org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/BuilderTests.java

9 files changed, 118 insertions, 321 deletions

diff --git a/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/env/BuildEnv.java b/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/env/BuildEnv.java
index c8c022c482..c4da45e2d8 100644
--- a/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/env/BuildEnv.java
+++ b/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/env/BuildEnv.java
@@ -18,12 +18,7 @@ import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IMarker;
@@ -43,52 +38,45 @@ import org.eclipse.jdt.apt.core.internal.util.Visitors.AnnotationVisitor;
 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.JavaCore;
-import org.eclipse.jdt.core.compiler.BuildContext;
 import org.eclipse.jdt.core.compiler.CategorizedProblem;
-import org.eclipse.jdt.core.dom.AST;
-import org.eclipse.jdt.core.dom.ASTNode;
-import org.eclipse.jdt.core.dom.AbstractTypeDeclaration;
-import org.eclipse.jdt.core.dom.Annotation;
-import org.eclipse.jdt.core.dom.CompilationUnit;
-import org.eclipse.jdt.core.dom.IBinding;
-import org.eclipse.jdt.core.dom.ITypeBinding;
-
+import org.eclipse.jdt.core.compiler.BuildContext;
+import org.eclipse.jdt.core.dom.*;
 import com.sun.mirror.apt.Filer;
 import com.sun.mirror.declaration.AnnotationTypeDeclaration;
 import com.sun.mirror.declaration.PackageDeclaration;
 import com.sun.mirror.declaration.TypeDeclaration;
 
 public class BuildEnv extends AbstractCompilationEnv
-{
+{	
 	private boolean _hasRaisedErrors = false;
 
-	private final BuildFilerImpl _filer;
+	private final BuildFilerImpl _filer;	
 
 	/**
 	 * Set of strings that indicate new type dependencies introduced on the file
 	 * each string is a fully-qualified type name.
 	 */
 	private Set<String> _typeDependencies = new HashSet<>();
-
+	
 	/**
-	 * Indicates whether we are in batch mode or not. This gets flipped only
-	 * during build and could be flipped back and forth.
+	 * Indicates whether we are in batch mode or not. This gets flipped only 
+	 * during build and could be flipped back and forth. 
 	 */
 	private boolean _batchMode = false; // off by default.
 
-	/**
+	/** 
 	 * Holds all the files that contains annotation that are to be processed during build.
-	 * If we are not in batch mode, <code>super._file</code> holds the file
-	 * being processed at the time.
-	 */
+	 * If we are not in batch mode, <code>super._file</code> holds the file 
+	 * being processed at the time. 
+	 */ 
 	private BuildContext[] _filesWithAnnotation = null;
-
+	
 	/**
 	 * These are files that are part of a build but does not have annotations on it.
-	 * During batch mode processing, these files still also need to be included.
+	 * During batch mode processing, these files still also need to be included. 
 	 */
 	private BuildContext[] _additionFiles = null;
-	/**
+	/** 
 	 * This is intialized when <code>_batchMode</code> is set to be <code>true</code> or
 	 * when batch processing is expected. <p>
 	 * It is also set in build mode for perf reason rather than parsing and resolving
@@ -97,29 +85,29 @@ public class BuildEnv extends AbstractCompilationEnv
 	 */
 	private CompilationUnit[] _astRoots = null;
 	private List<MarkerInfo> _markerInfos = null;
-
+    
     /**
      * Constructor for creating a processor environment used during build.
      * @param filesWithAnnotations
      * @param additionalFiles
      * @param units
      * @param javaProj
-     * @param isTestCode
+     * @param isTestCode 
      * @param phase
      */
     BuildEnv(
 			final BuildContext[] filesWithAnnotations,
 			final BuildContext[] additionalFiles,
 			final IJavaProject javaProj, boolean isTestCode) {
-
+    	
     	super(null, null, javaProj, Phase.BUILD, isTestCode);
 		_filer = new BuildFilerImpl(this);
 		_filesWithAnnotation = filesWithAnnotations;
 		_additionFiles = additionalFiles;
 		_problems = new ArrayList<>();
 		_markerInfos = new ArrayList<>();
-
-		if (AptPlugin.DEBUG_COMPILATION_ENV) AptPlugin.trace(
+		
+		if (AptPlugin.DEBUG_COMPILATION_ENV) AptPlugin.trace( 
 				"constructed " + this + " for " + _filesWithAnnotation.length + " files"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 	}
 
@@ -139,12 +127,12 @@ public class BuildEnv extends AbstractCompilationEnv
     @Override
 	public TypeDeclaration getTypeDeclaration(String name)
     {
-		checkValid();
+		checkValid();		
 		TypeDeclaration decl = super.getTypeDeclaration(name);
-
-		if (!_batchMode)
+		
+		if (!_batchMode) 
 			addTypeDependency(name);
-
+			
 		return decl;
     }
 
@@ -154,7 +142,7 @@ public class BuildEnv extends AbstractCompilationEnv
 	 */
 	public boolean hasRaisedErrors(){
 		return _hasRaisedErrors;
-	}
+	}	
 
 	public static InputStreamReader getFileReader( final IFile file ) throws IOException, CoreException {
 		return new InputStreamReader(getInputStream(file), file.getCharset());
@@ -179,7 +167,7 @@ public class BuildEnv extends AbstractCompilationEnv
 	 */
     @Override
 	public void close(){
-    	if( isClosed() )
+    	if( isClosed() ) 
     		return;
     	_markerInfos = null;
     	_astRoot = null;
@@ -187,13 +175,13 @@ public class BuildEnv extends AbstractCompilationEnv
     	_astRoots = null;
     	_filesWithAnnotation = null;
     	_problems = null;
-        _modelCompUnit2astCompUnit.clear();
+        _modelCompUnit2astCompUnit.clear();		
 		_hasRaisedErrors = false;
 		super.close();
     }
-
+    
     /**
-     *
+     * 
      * @param resource null to indicate current resource
      * @param start the starting offset of the marker
      * @param end -1 to indicate unknow ending offset.
@@ -202,21 +190,21 @@ public class BuildEnv extends AbstractCompilationEnv
      * @param line the line number of where the marker should be
      */
     @Override
-	void addMessage(IFile resource,
-       		        int start,
+	void addMessage(IFile resource, 
+       		        int start, 
     				int end,
-                    Severity severity,
-                    String msg,
+                    Severity severity, 
+                    String msg, 
                     int line,
                     String[] arguments)
     {
     	checkValid();
-
+    	
     	if( resource == null )
     		resource = getFile();
-
+    	
     	_hasRaisedErrors |= severity == MessagerImpl.Severity.ERROR;
-
+    	
     	// Eclipse doesn't support INFO-level IProblems, so we send them to the log instead.
     	if ( severity == Severity.INFO) {
     		StringBuilder sb = new StringBuilder();
@@ -248,69 +236,69 @@ public class BuildEnv extends AbstractCompilationEnv
     		AptPlugin.log(status);
     		return;
     	}
-
+    	
     	if( resource == null ){
     		assert _batchMode : "not in batch mode but don't know about current resource"; //$NON-NLS-1$
     		addMarker(start, end, severity, msg, line, arguments);
     	}
-    	else
+    	else    	
     		addProblem(resource, start, end, severity, msg, line, arguments);
     }
-
+    
     private void addProblem(
-    		IFile resource,
-		    int start,
+    		IFile resource, 
+		    int start, 
 			int end,
-            Severity severity,
-            String msg,
+            Severity severity, 
+            String msg, 
             int line,
             String[] arguments)
-    {
-
+    {	 
+    	 	
     	APTProblem problem = createProblem(resource, start, end, severity, msg, line, arguments);
     	_problems.add(problem);
     }
-
+    
     private void addMarker(
-    		int start,
+    		int start, 
 			int end,
-            Severity severity,
-            String msg,
+            Severity severity, 
+            String msg, 
             int line,
             String[] arguments)
-    {
-
+    {    	
+    	
     	// Note that the arguments are ignored -- no quick-fix for markers.
     	_markerInfos.add(new MarkerInfo(start, end, severity, msg, line));
     }
-
+    
     @Override
 	public Map<String, AnnotationTypeDeclaration> getAnnotationTypes()
     {
     	checkValid();
-    	assert _astRoot != null && _file != null && !_batchMode :
+    	assert _astRoot != null && _file != null && !_batchMode : 
     		"operation not available under batch mode."; //$NON-NLS-1$
     	return super.getAnnotationTypes();
     }
-
+    
     /**
 	 * Return all annotations at declaration level within all compilation unit(s)
-	 * associated with this environment. All the files associated with this environment will
+	 * associated with this environment. All the files associated with this environment will 
 	 * be parsed and resolved for all declaration level elements at the return of this call.
-	 *
+	 * 
 	 * @param file2Annotations populated by this method to map files to the annotation types
 	 *        if contains. May be null.
 	 * @return the map containing all annotation types found within this environment.
 	 */
     public Map<String, AnnotationTypeDeclaration> getAllAnnotationTypes(
     		final Map<BuildContext, Set<AnnotationTypeDeclaration>> file2Annotations) {
-
+    	
     	checkValid();
-    	if( _filesWithAnnotation == null )
+    	if( _filesWithAnnotation == null )  
     		return getAnnotationTypes();
-
+    	
 		final List<Annotation> instances = new ArrayList<>();
-		final Map<String, AnnotationTypeDeclaration> decls =
+		final Map<String, AnnotationTypeDeclaration> decls = 
 			new HashMap<>();
 		final AnnotationVisitor visitor = new AnnotationVisitor(instances);
 		for( int astIndex=0, len=_astRoots.length; astIndex<len; astIndex++ ){
@@ -318,13 +306,13 @@ public class BuildEnv extends AbstractCompilationEnv
 				System.err.println();
 			_astRoots[astIndex].accept(visitor);
 			final Set<AnnotationTypeDeclaration> perFileAnnos = new HashSet<>();
-
+			
 			for (int instanceIndex=0, size = instances.size(); instanceIndex < size; instanceIndex++) {
 				final Annotation instance = instances.get(instanceIndex);
 				final ITypeBinding annoType = instance.resolveTypeBinding();
 				if (annoType == null)
 					continue;
-				final TypeDeclarationImpl decl =
+				final TypeDeclarationImpl decl = 
 					Factory.createReferenceType(annoType, this);
 				if (decl != null && decl.kind() == EclipseMirrorObject.MirrorKind.TYPE_ANNOTATION){
 					final AnnotationTypeDeclaration annoDecl = (AnnotationTypeDeclaration)decl;
@@ -336,37 +324,37 @@ public class BuildEnv extends AbstractCompilationEnv
 				file2Annotations.put(_filesWithAnnotation[astIndex], perFileAnnos);
 			visitor.reset();
 		}
-
+		
 		return decls;
 	}
 
 	/**
 	 * @return - the extra type dependencies for the files under compilation
 	 */
-	public Set<String> getTypeDependencies()  { return _typeDependencies; }
-
+	public Set<String> getTypeDependencies()  { return _typeDependencies; }	
+	
 	/**
-	 * Switch to batch processing mode.
-	 * Note: Call to this method will cause all files associated with this environment to be
+	 * Switch to batch processing mode. 
+	 * Note: Call to this method will cause all files associated with this environment to be 
 	 * read and parsed.
 	 */
-	public void beginBatchProcessing(){
+	public void beginBatchProcessing(){		
 		if( _phase != Phase.BUILD )
 			throw new IllegalStateException("No batch processing outside build."); //$NON-NLS-1$
-
+		
 		if( _batchMode ) return;
 		checkValid();
-
+		
 		_batchMode = true;
 		_file = null;
 		_astRoot = null;
 	}
-
+	
 	public void completedBatchProcessing(){
 		postMarkers();
 		completedProcessing();
 	}
-
+	
 	void createASTs(BuildContext[] cpResults){
 		final int len = cpResults.length;
 		final ICompilationUnit[] units = new ICompilationUnit[len];
@@ -378,17 +366,17 @@ public class BuildEnv extends AbstractCompilationEnv
 		createASTs(_javaProject, units, _requestor = new CallbackRequestor(units));
 	}
 
-	public void beginFileProcessing(BuildContext result){
+	public void beginFileProcessing(BuildContext result){		
 		if( result == null )
 			throw new IllegalStateException("missing compilation result"); //$NON-NLS-1$
 		_batchMode = false;
 		final IFile file = result.getFile();
 		if( file.equals(_file) ) // this is a no-op
 			return;
-
+		
 		_astRoot = null;
 		_file = null;
-
+		
 		// need to match up the file with the ast.
 		if( _filesWithAnnotation != null ){
 			for( int i=0, len=_filesWithAnnotation.length; i<len; i++ ){
@@ -398,37 +386,37 @@ public class BuildEnv extends AbstractCompilationEnv
 				}
 			}
 		}
-
+		
 		if( _file == null || _astRoot == null)
 			throw new IllegalStateException(
 					"file " +  //$NON-NLS-1$
-					file.getName() +
+					file.getName() + 
 					" is not in the list to be processed."); //$NON-NLS-1$
 	}
-
+	
 	public void completedFileProcessing(){
 		completedProcessing();
 	}
-
+	
 	@Override
 	protected void completedProcessing(){
 		_problems.clear();
 		_typeDependencies.clear();
 		super.completedProcessing();
 	}
-
+	
 	@Override
 	public List<? extends CategorizedProblem> getProblems(){
 		if( !_problems.isEmpty() )
 			EnvUtil.updateProblemLength(_problems, getAstCompilationUnit());
 		return _problems;
 	}
-
+	
 	// Implementation for EclipseAnnotationProcessorEnvironment
 	@Override
 	public CompilationUnit getAST()
 	{
-		if( _batchMode )
+		if( _batchMode ) 
 			return null;
 		return _astRoot;
 	}
@@ -436,12 +424,12 @@ public class BuildEnv extends AbstractCompilationEnv
 	@Override
 	public void addTypeDependency(final String fullyQualifiedTypeName )
 	{
-		if(!_batchMode){
+		if(!_batchMode){			
 			_typeDependencies.add( fullyQualifiedTypeName );
 		}
 	}
 	// End of implementation for EclipseAnnotationProcessorEnvironment
-
+	
 	/**
 	 * Include all the types from all files, files with and without annotations on it
 	 * if we are in batch mode. Otherwise, just the types from the file that's currently
@@ -455,15 +443,15 @@ public class BuildEnv extends AbstractCompilationEnv
 		final List<AbstractTypeDeclaration> typeDecls = new ArrayList<>();
 		for( int i=0, len=_astRoots.length; i<len; i++ )
         	typeDecls.addAll( _astRoots[i].types() );
-
+		
 		getTypeDeclarationsFromAdditionFiles(typeDecls);
-
+		
 		return typeDecls;
     }
-
+	
 	private void getTypeDeclarationsFromAdditionFiles(List<AbstractTypeDeclaration> typeDecls){
 		if( _additionFiles == null || _additionFiles.length == 0 ) return;
-
+	
 		final int len = _additionFiles.length;
 		final ICompilationUnit[] units = new ICompilationUnit[len];
 		for( int i=0; i<len; i++ ){
@@ -473,7 +461,7 @@ public class BuildEnv extends AbstractCompilationEnv
 		}
 		BaseRequestor r = new BaseRequestor(units);
 		createASTs(_javaProject, units, r);
-
+		
 		CompilationUnit[] asts = r.asts;
 		for( CompilationUnit ast : asts ){
 			if( ast != null ){
@@ -481,19 +469,19 @@ public class BuildEnv extends AbstractCompilationEnv
 			}
 		}
 	}
-
+	
 	@Override
 	protected Map<ASTNode, List<Annotation>> getASTNodesWithAnnotations()
     {
 		if( !_batchMode )
 			return super.getASTNodesWithAnnotations();
     	final Map<ASTNode, List<Annotation>> astNode2Anno = new HashMap<>();
-        final AnnotatedNodeVisitor visitor = new AnnotatedNodeVisitor(astNode2Anno);
+        final AnnotatedNodeVisitor visitor = new AnnotatedNodeVisitor(astNode2Anno);        
         for( int i=0, len=_astRoots.length; i<len; i++ )
         	_astRoots[i].accept( visitor );
         return astNode2Anno;
     }
-
+	
 	@Override
 	protected IFile getFileForNode(final ASTNode node)
 	{
@@ -506,12 +494,12 @@ public class BuildEnv extends AbstractCompilationEnv
 		}
 		throw new IllegalStateException();
 	}
-
+	
 	/**
 	 * Go through the list of compilation unit in this environment and looking for
 	 * the declaration node of the given binding.
-	 * @param binding
-	 * @return the compilation unit that defines the given binding or null if no
+	 * @param binding 
+	 * @return the compilation unit that defines the given binding or null if no 
 	 * match is found.
 	 */
 	@Override
@@ -519,7 +507,7 @@ public class BuildEnv extends AbstractCompilationEnv
 	{
 		if( !_batchMode )
 			return super.searchLocallyForBinding(binding);
-
+		
 		for( int i=0, len=_astRoots.length; i<len; i++ ){
 			ASTNode node = _astRoots[i].findDeclaringNode(binding);
 			if( node != null)
@@ -527,12 +515,12 @@ public class BuildEnv extends AbstractCompilationEnv
 		}
 		return null;
 	}
-
+	
 	/**
 	 * Go through the list of compilation unit in this environment and looking for
 	 * the declaration node of the given binding.
-	 * @param binding
-	 * @return the compilation unit that defines the given binding or null if no
+	 * @param binding 
+	 * @return the compilation unit that defines the given binding or null if no 
 	 * match is found.
 	 */
 	@Override
@@ -540,7 +528,7 @@ public class BuildEnv extends AbstractCompilationEnv
 	{
 		if( !_batchMode )
 			return super.searchLocallyForIFile(binding);
-
+		
 		for( int i=0, len=_astRoots.length; i<len; i++ ){
 			ASTNode node = _astRoots[i].findDeclaringNode(binding);
 			if( node != null)
@@ -548,7 +536,7 @@ public class BuildEnv extends AbstractCompilationEnv
 		}
 		return null;
 	}
-
+	
 	/**
      * @param file
      * @return the compilation unit associated with the given file.
@@ -558,7 +546,7 @@ public class BuildEnv extends AbstractCompilationEnv
 	@Override
 	public CompilationUnit getASTFrom(final IFile file)
 	{
-		if( file == null )
+		if( file == null ) 
     		return null;
     	else if( file.equals(_file) )
     		return _astRoot;
@@ -570,15 +558,15 @@ public class BuildEnv extends AbstractCompilationEnv
     	}
     	return null;
 	}
-
+	
 	/**
 	 * @return the current ast being processed if in per-file mode.
 	 * If in batch mode, one of the asts being processed (no guarantee which
-	 * one will be returned.
+	 * one will be returned.  
 	 */
 	@Override
 	protected AST getCurrentDietAST(){
-
+		
 		if( _astRoot != null )
 			return _astRoot.getAST();
 		else{
@@ -587,7 +575,7 @@ public class BuildEnv extends AbstractCompilationEnv
 			return _astRoots[0].getAST();
 		}
 	}
-
+	
 	void postMarkers()
     {
 		if( _markerInfos == null || _markerInfos.size() == 0 )
@@ -598,8 +586,8 @@ public class BuildEnv extends AbstractCompilationEnv
 	        final IWorkspaceRunnable runnable = new IWorkspaceRunnable(){
 	            @Override
 				public void run(IProgressMonitor monitor)
-	            {
-	                for( MarkerInfo markerInfo : _markerInfos ){
+	            {		
+	                for( MarkerInfo markerInfo : _markerInfos ){	                  
 						try{
 		                    final IMarker marker = _javaProject.getProject().createMarker(AptPlugin.APT_BATCH_PROCESSOR_PROBLEM_MARKER);
 		                    markerInfo.copyIntoMarker(marker);
@@ -611,7 +599,7 @@ public class BuildEnv extends AbstractCompilationEnv
 	            }
 	        };
 	        IWorkspace ws = _javaProject.getProject().getWorkspace();
-			ws.run(runnable, _javaProject.getProject(), IWorkspace.AVOID_UPDATE, null);
+			ws.run(runnable, null);
 		}
 		catch(CoreException e){
 			AptPlugin.log(e, "Failed to post markers"); //$NON-NLS-1$
@@ -620,17 +608,17 @@ public class BuildEnv extends AbstractCompilationEnv
 			_markerInfos.clear();
 		}
     }
-
+	
 	public BuildContext[] getFilesWithAnnotation()
 	{
 		return _filesWithAnnotation;
 	}
-
+	
 	public BuildContext[] getFilesWithoutAnnotation()
 	{
 		return _additionFiles;
 	}
-
+	
 	private class CallbackRequestor extends BaseRequestor {
 		CallbackRequestor(ICompilationUnit[] parseUnits) {
 			super(parseUnits);
@@ -641,7 +629,7 @@ public class BuildEnv extends AbstractCompilationEnv
 			// then assign the asts, then begin dispatch
 			_astRoots = asts;
 			_callback.run(BuildEnv.this);
-		}
+		}		
 	}
-
+	
 }
diff --git a/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/generatedfile/GeneratedSourceFolderManager.java b/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/generatedfile/GeneratedSourceFolderManager.java
index f709eafa6c..697c1b2dd2 100644
--- a/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/generatedfile/GeneratedSourceFolderManager.java
+++ b/org.eclipse.jdt.apt.core/src/org/eclipse/jdt/apt/core/internal/generatedfile/GeneratedSourceFolderManager.java
@@ -488,7 +488,7 @@ public class GeneratedSourceFolderManager {
 	    };
 	    IWorkspace ws = ResourcesPlugin.getWorkspace();
 	    try{
-	    	ws.run(runnable, srcFolder.getProject(), IWorkspace.AVOID_UPDATE, null);
+	    	ws.run(runnable, ws.getRoot(), IWorkspace.AVOID_UPDATE, null);
 	    }catch(CoreException e){
 			AptPlugin.log(e, "Runnable for deleting old generated source folder " + srcFolder.getName() + " failed."); //$NON-NLS-1$ //$NON-NLS-2$
 		}
diff --git a/org.eclipse.jdt.core.tests.builder/plugin.xml b/org.eclipse.jdt.core.tests.builder/plugin.xml
index a2cf6324a2..bf08c103ed 100644
--- a/org.eclipse.jdt.core.tests.builder/plugin.xml
+++ b/org.eclipse.jdt.core.tests.builder/plugin.xml
@@ -24,14 +24,4 @@
           <managedMarker markerType="org.eclipse.jdt.core.tests.compile.problem"/>
        </compilationParticipant>
    </extension>
-     <extension
-           id="TimeStampBuilder"
-           point="org.eclipse.core.resources.builders">
-        <builder
-              hasNature="false">
-           <run
-                 class="org.eclipse.jdt.core.tests.builder.TimeStampBuilder">
-           </run>
-        </builder>
-     </extension>
 </plugin>
diff --git a/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/BuilderTests.java b/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/BuilderTests.java
index 0c45e7ed5a..ec9718a8e5 100644
--- a/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/BuilderTests.java
+++ b/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/BuilderTests.java
@@ -544,7 +544,6 @@ public class BuilderTests extends TestCase {
 			TestAttributeBuilderTests.class,
 			Bug530366Test.class,
 			Bug531382Test.class,
-			ParallelBuildTests.class,
 			LeakTestsBefore9.class,
 		};
 		List<Class<?>> list = new ArrayList<>(Arrays.asList(classes));
diff --git a/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/ParallelBuildTests.java b/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/ParallelBuildTests.java
deleted file mode 100644
index d964ae6da7..0000000000
--- a/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/ParallelBuildTests.java
+++ /dev/null
@@ -1,100 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2018 Red Hat Inc. 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:
- *     Mickael Istria (Red Hat Inc.) - Initial implementation
- *******************************************************************************/
-package org.eclipse.jdt.core.tests.builder;
-
-import java.util.Collections;
-
-import org.eclipse.core.internal.events.BuildCommand;
-import org.eclipse.core.resources.ICommand;
-import org.eclipse.core.resources.IProject;
-import org.eclipse.core.resources.IProjectDescription;
-import org.eclipse.core.resources.IWorkspaceDescription;
-import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.NullProgressMonitor;
-import org.eclipse.core.runtime.preferences.InstanceScope;
-import org.eclipse.jdt.core.JavaCore;
-import org.eclipse.jdt.internal.core.builder.JavaBuilder;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-
-public class ParallelBuildTests extends BuilderTests {
-
-	private int initialMaxParallelBuilds;
-
-	public ParallelBuildTests(String name) {
-		super(name);
-	}
-
-	public static junit.framework.Test suite() {
-		return buildTestSuite(ParallelBuildTests.class);
-	}
-
-	@Before
-	@Override
-	protected void setUp() throws Exception {
-		super.setUp();
-		TimeStampBuilder.clear();
-		this.initialMaxParallelBuilds = env.getWorkspace().getDescription().getMaxConcurrentBuilds();
-		InstanceScope.INSTANCE.getNode(JavaCore.PLUGIN_ID).putBoolean(JavaBuilder.PREF_NULL_SCHEDULING_RULE, true);
-	}
-
-	@After
-	@Override
-	protected void tearDown() throws Exception {
-		setMaxParallelBuilds(this.initialMaxParallelBuilds);
-		InstanceScope.INSTANCE.getNode(JavaCore.PLUGIN_ID).remove(JavaBuilder.PREF_NULL_SCHEDULING_RULE);
-		super.tearDown();
-	}
-
-	@Test
-	public void testJDTBuildAllowParallelBuildsForOtherProjects() throws CoreException {
-		IProject javaProject1 = env.getProject(env.addProject(getClass().getSimpleName() + "_javaProject1"));
-		addBuilder(javaProject1.getProject());
-		//
-		IProject javaProject2 = env.getProject(env.addProject(getClass().getSimpleName() + "_javaProject2"));
-		env.addRequiredProject(javaProject2.getFullPath(), javaProject1.getFullPath());
-		addBuilder(javaProject2.getProject());
-		//
-		IProject rawProject1 = env.getWorkspace().getRoot().getProject(getClass().getSimpleName() + System.currentTimeMillis());
-		rawProject1.create(new NullProgressMonitor());
-		rawProject1.open(new NullProgressMonitor());
-		addBuilder(rawProject1);
-		IProject rawProject2 = env.getWorkspace().getRoot().getProject(getClass().getSimpleName() + System.currentTimeMillis());
-		rawProject2.create(new NullProgressMonitor());
-		rawProject2.open(new NullProgressMonitor());
-		addBuilder(rawProject2);
-		setMaxParallelBuilds(3);
-
-		env.fullBuild();
-		// verify that rawProject could build in parallel
-		assertTrue(TimeStampBuilder.start(rawProject1) < TimeStampBuilder.end(rawProject2));
-		assertTrue(TimeStampBuilder.start(rawProject2) < TimeStampBuilder.end(rawProject1));
-	}
-
-	private void setMaxParallelBuilds(int n) throws CoreException {
-		IWorkspaceDescription desc = env.getWorkspace().getDescription();
-		desc.setMaxConcurrentBuilds(n);
-		env.getWorkspace().setDescription(desc);
-	}
-
-	private void addBuilder(IProject project) throws CoreException {
-		IProjectDescription desc1 = project.getDescription();
-		ICommand[] newCommands = new ICommand[desc1.getBuildSpec().length + 1];
-		System.arraycopy(desc1.getBuildSpec(), 0, newCommands, 0, desc1.getBuildSpec().length);
-		BuildCommand builderCommand = new BuildCommand();
-		builderCommand.setBuilderName(TimeStampBuilder.ID);
-		builderCommand.setArguments(Collections.singletonMap(TimeStampBuilder.PAUSE_DURATION, Integer.toString(1000)));
-		newCommands[newCommands.length - 1] = builderCommand;
-		desc1.setBuildSpec(newCommands);
-		project.setDescription(desc1, new NullProgressMonitor());
-	}
-}
diff --git a/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/TimeStampBuilder.java b/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/TimeStampBuilder.java
deleted file mode 100644
index 48fb76554f..0000000000
--- a/org.eclipse.jdt.core.tests.builder/src/org/eclipse/jdt/core/tests/builder/TimeStampBuilder.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2018 Red Hat Inc. 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:
- *     Mickael Istria (Red Hat Inc.) - Initial implementation
- *******************************************************************************/
-package org.eclipse.jdt.core.tests.builder;
-
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.eclipse.core.resources.IProject;
-import org.eclipse.core.resources.IncrementalProjectBuilder;
-import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.core.runtime.jobs.ISchedulingRule;
-
-public class TimeStampBuilder extends IncrementalProjectBuilder {
-
-	public static final String ID = TimeStampBuilder.class.getName();
-	public static final String PAUSE_DURATION = "pauseDuration";
-	private static final Map<IProject, Long> starts = Collections.synchronizedMap(new HashMap<>());
-	private static final Map<IProject, Long> ends = Collections.synchronizedMap(new HashMap<>());
-
-	@Override
-	protected IProject[] build(int kind, Map<String, String> args, IProgressMonitor monitor) throws CoreException {
-		starts.put(getProject(), Long.valueOf(System.currentTimeMillis()));
-		try {
-			int pauseDuration = 1000;
-			if (args.containsKey(PAUSE_DURATION)) {
-				pauseDuration = Integer.parseInt(args.get(PAUSE_DURATION));
-			}
-			Thread.sleep(pauseDuration);
-			ends.put(getProject(), Long.valueOf(System.currentTimeMillis()));
-		} catch (InterruptedException e) {
-			e.printStackTrace();
-		}
-		return new IProject[0];
-	}
-
-	@Override
-	public ISchedulingRule getRule(int kind, Map<String, String> args) {
-		return null;
-	}
-
-	public static long end(IProject project) throws CoreException {
-		return ends.get(project).longValue();
-	}
-
-	public static long start(IProject project) throws CoreException {
-		return starts.get(project).longValue();
-	}
-
-	public static void clear() {
-		starts.clear();
-		ends.clear();
-	}
-
-}
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 f5e15bd45d..d27dacbcd7 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
@@ -156,7 +156,6 @@ import org.eclipse.core.runtime.Plugin;
 import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.core.runtime.SubMonitor;
 import org.eclipse.core.runtime.jobs.ISchedulingRule;
-import org.eclipse.core.runtime.jobs.MultiRule;
 import org.eclipse.jdt.core.compiler.CharOperation;
 import org.eclipse.jdt.core.compiler.IProblem;
 import org.eclipse.jdt.core.search.IJavaSearchConstants;
@@ -4568,11 +4567,7 @@ public final class JavaCore extends Plugin {
 			};
 			mainMonitor.subTask(Messages.javamodel_building_after_upgrade);
 			try {
-				ResourcesPlugin.getWorkspace().run(
-					runnable,
-					new MultiRule(Arrays.stream(projects).map(IJavaProject::getResource).toArray(ISchedulingRule[]::new)),
-					IWorkspace.AVOID_UPDATE,
-					mainMonitor.split(1));
+				ResourcesPlugin.getWorkspace().run(runnable, mainMonitor.split(1));
 			} catch (CoreException e) {
 				// could not touch all projects
 			}
diff --git a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessor.java b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessor.java
index 29f746a9ff..0aa71bebef 100644
--- a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessor.java
+++ b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/DeltaProcessor.java
@@ -34,7 +34,6 @@ import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.IWorkspaceRunnable;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.*;
-import org.eclipse.core.runtime.jobs.MultiRule;
 import org.eclipse.jdt.core.*;
 import org.eclipse.jdt.core.compiler.CharOperation;
 import org.eclipse.jdt.internal.compiler.SourceElementParser;
@@ -902,7 +901,7 @@ public class DeltaProcessor {
 							}
 						};
 						try {
-							ResourcesPlugin.getWorkspace().run(runnable, new MultiRule(projectsToTouch), IWorkspace.AVOID_UPDATE, monitor);
+							ResourcesPlugin.getWorkspace().run(runnable, monitor);
 						} catch (CoreException e) {
 							throw new JavaModelException(e);
 						}
diff --git a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/builder/JavaBuilder.java b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/builder/JavaBuilder.java
index abf0ebc7a7..907c1d627c 100644
--- a/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/builder/JavaBuilder.java
+++ b/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/builder/JavaBuilder.java
@@ -16,8 +16,7 @@ package org.eclipse.jdt.internal.core.builder;
 
 import org.eclipse.core.resources.*;
 import org.eclipse.core.runtime.*;
-import org.eclipse.core.runtime.jobs.ISchedulingRule;
-import org.eclipse.core.runtime.preferences.InstanceScope;
+
 import org.eclipse.jdt.core.*;
 import org.eclipse.jdt.core.compiler.*;
 import org.eclipse.jdt.internal.compiler.util.SimpleLookupTable;
@@ -31,7 +30,6 @@ import java.util.*;
 @SuppressWarnings({"rawtypes", "unchecked"})
 public class JavaBuilder extends IncrementalProjectBuilder {
 
-public static final String PREF_NULL_SCHEDULING_RULE = "useNullSchedulingRule"; //$NON-NLS-1$
 IProject currentProject;
 JavaProject javaProject;
 IWorkspaceRoot workspaceRoot;
@@ -809,12 +807,4 @@ public String toString() {
 		? "JavaBuilder for unknown project" //$NON-NLS-1$
 		: "JavaBuilder for " + this.currentProject.getName(); //$NON-NLS-1$
 }
-
-	@Override
-	public ISchedulingRule getRule(int kind, Map<String, String> args) {
-		if (InstanceScope.INSTANCE.getNode(JavaCore.PLUGIN_ID).getBoolean(PREF_NULL_SCHEDULING_RULE, false)) {
-			return null;
-		}
-		return super.getRule(kind, args);
-	}
 }