Fix 550705: tricky intermittent verify error

diff --git a/org.aspectj.matcher/src/main/java/org/aspectj/weaver/World.java b/org.aspectj.matcher/src/main/java/org/aspectj/weaver/World.java
index af85253153c9d642cd8441c53394b5cb4809de4d..4e625d841155c15565aac2bb94dde3afa1895dcc 100644 (file)
--- a/org.aspectj.matcher/src/main/java/org/aspectj/weaver/World.java
+++ b/org.aspectj.matcher/src/main/java/org/aspectj/weaver/World.java
@@ -1,17 +1,12 @@
 /* *******************************************************************
  * Copyright (c) 2002 Palo Alto Research Center, Incorporated (PARC).
- *               2005 Contributors
+ *               2005,2020 Contributors
  * 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:
- *     PARC     initial implementation
- *     Adrian Colyer, Andy Clement, overhaul for generics, Abraham Nevado
  * ******************************************************************/
-
 package org.aspectj.weaver;
 
 import java.lang.ref.Reference;
@@ -22,7 +17,6 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
@@ -53,6 +47,12 @@ import org.aspectj.weaver.tools.TraceFactory;
 
 /**
  * A World is a collection of known types and crosscutting members.
+ *
+ * @author PARC
+ * @author Adrian Colyer
+ * @author Andy Clement
+ * @author Abraham Nevado
+ * @author Joseph MacFarlane
  */
 public abstract class World implements Dump.INode {
 
@@ -1179,7 +1179,15 @@ public abstract class World implements Dump.INode {
 
                private void insertInExpendableMap(String key, ResolvedType type) {
                        if (useExpendableMap) {
-                               if (!expendableMap.containsKey(key)) {
+                               // Need to check both whether the entry is gone, or whether the entry has had
+                               // the WR to the value cleared.
+                               Reference<ResolvedType> existingReference = expendableMap.get(key);
+                               if (existingReference == null || existingReference.get() == null) {
+                                       // If a previous key is in there, WeakHashMap.put will update the value on the
+                                       // entry but not the key. We can't allow this as the old key won't
+                                       // be directly referenced by the new type, meaning that the key and value
+                                       // might be GC'd independently.
+                                       expendableMap.remove(key);
                                        if (policy == USE_SOFT_REFS) {
                                                expendableMap.put(key, new SoftReference<ResolvedType>(type));
                                        } else {
@@ -1246,9 +1254,14 @@ public abstract class World implements Dump.INode {
                                throw new BCException("Attempt to add generic type to typemap " + type.toString() + " (should be raw)");
                        }
 
-
                        if (w.isExpendable(type)) {
                                if (useExpendableMap) {
+                                       // If a previous key is in there, WeakHashMap.put will update the value on the
+                                       // entry but not the key. We can't allow this as the old key won't be directly
+                                       // referenced by the new type, meaning that the key and value might
+                                       // be GC'd independently.
+                                       expendableMap.remove(key);
+
                                        // Dont use reference queue for tracking if not profiling...
                                        if (policy == USE_WEAK_REFS) {
                                                if (memoryProfiling) {
@@ -1421,8 +1434,8 @@ public abstract class World implements Dump.INode {
                                DeclarePrecedence orderer = null; // Records the declare
                                // precedence statement that
                                // gives the first ordering
-                               for (Iterator<Declare> i = world.getCrosscuttingMembersSet().getDeclareDominates().iterator(); i.hasNext();) {
-                                       DeclarePrecedence d = (DeclarePrecedence) i.next();
+                               for (Declare declare : world.getCrosscuttingMembersSet().getDeclareDominates()) {
+                                       DeclarePrecedence d = (DeclarePrecedence) declare;
                                        int thisOrder = d.compare(firstAspect, secondAspect);
                                        if (thisOrder != 0) {
                                                if (orderer == null) {