8064846: Lazy-init thread safety problems in core reflection

Summary: Make several fields in core reflection volatile
Reviewed-by: jfranck, shade, plevart

src/share/classes/sun/reflect/generics/repository/ClassRepository.java

@@ -42,8 +42,11 @@ public class ClassRepository extends GenericDeclRepository<ClassSignature> {
 
     public static final ClassRepository NONE = ClassRepository.make("Ljava/lang/Object;", null);
 
-    private volatile Type superclass; // caches the generic superclass info
-    private volatile Type[] superInterfaces; // caches the generic superinterface info
+    /** The generic superclass info.  Lazily initialized. */
+    private volatile Type superclass;
+
+    /** The generic superinterface info.  Lazily initialized. */
+    private volatile Type[] superInterfaces;
 
  // private, to enforce use of static factory
     private ClassRepository(String rawSig, GenericsFactory f) {
@@ -79,7 +82,7 @@ public class ClassRepository extends GenericDeclRepository<ClassSignature> {
  * with which the repository was created.
  */
 
-    public Type getSuperclass(){
+    public Type getSuperclass() {
         Type superclass = this.superclass;
         if (superclass == null) { // lazily initialize superclass
             Reifier r = getReifier(); // obtain visitor
@@ -88,25 +91,24 @@ public class ClassRepository extends GenericDeclRepository<ClassSignature> {
             // extract result from visitor and cache it
             superclass = r.getResult();
             this.superclass = superclass;
-            }
+        }
         return superclass; // return cached result
     }
 
-    public Type[] getSuperInterfaces(){
+    public Type[] getSuperInterfaces() {
         Type[] superInterfaces = this.superInterfaces;
         if (superInterfaces == null) { // lazily initialize super interfaces
             // first, extract super interface subtree(s) from AST
             TypeTree[] ts  = getTree().getSuperInterfaces();
             // create array to store reified subtree(s)
-            Type[] sis = new Type[ts.length];
+            superInterfaces = new Type[ts.length];
             // reify all subtrees
             for (int i = 0; i < ts.length; i++) {
                 Reifier r = getReifier(); // obtain visitor
                 ts[i].accept(r);// reify subtree
                 // extract result from visitor and store it
-                sis[i] = r.getResult();
+                superInterfaces[i] = r.getResult();
             }
-            superInterfaces = sis; // cache overall result
             this.superInterfaces = superInterfaces;
         }
         return superInterfaces.clone(); // return cached result

src/share/classes/sun/reflect/generics/repository/GenericDeclRepository.java

@@ -42,7 +42,8 @@ import sun.reflect.generics.visitor.Reifier;
 public abstract class GenericDeclRepository<S extends Signature>
     extends AbstractRepository<S> {
 
-    private volatile TypeVariable<?>[] typeParams; // caches the formal type parameters
+    /** The formal type parameters.  Lazily initialized. */
+    private volatile TypeVariable<?>[] typeParams;
 
     protected GenericDeclRepository(String rawSig, GenericsFactory f) {
         super(rawSig, f);
@@ -55,8 +56,7 @@ public abstract class GenericDeclRepository<S extends Signature>
  * If the corresponding field is non-null, it is returned.
  * If not, it is created lazily. This is done by selecting the appropriate
  * part of the tree and transforming it into a reflective object
- * using a visitor.
- * a visitor, which is created by feeding it the factory
+ * using a visitor, which is created by feeding it the factory
  * with which the repository was created.
  */
 
@@ -64,22 +64,21 @@ public abstract class GenericDeclRepository<S extends Signature>
      * Return the formal type parameters of this generic declaration.
      * @return the formal type parameters of this generic declaration
      */
-    public TypeVariable<?>[] getTypeParameters(){
-        TypeVariable[] typeParams = this.typeParams;
+    public TypeVariable<?>[] getTypeParameters() {
+        TypeVariable<?>[] typeParams = this.typeParams;
         if (typeParams == null) { // lazily initialize type parameters
             // first, extract type parameter subtree(s) from AST
             FormalTypeParameter[] ftps = getTree().getFormalTypeParameters();
             // create array to store reified subtree(s)
-            TypeVariable<?>[] tps = new TypeVariable<?>[ftps.length];
+            typeParams = new TypeVariable<?>[ftps.length];
             // reify all subtrees
             for (int i = 0; i < ftps.length; i++) {
                 Reifier r = getReifier(); // obtain visitor
                 ftps[i].accept(r); // reify subtree
                 // extract result from visitor and store it
-                tps[i] = (TypeVariable<?>) r.getResult();
+                typeParams[i] = (TypeVariable<?>) r.getResult();
             }
-            typeParams = tps; // cache overall result
-            this.typeParams = typeParams;
+            this.typeParams = typeParams; // cache overall result
         }
         return typeParams.clone(); // return cached result
     }

src/share/classes/sun/reflect/generics/scope/AbstractScope.java

@@ -42,7 +42,9 @@ public abstract class AbstractScope<D extends GenericDeclaration>
     implements Scope {
 
     private final D recvr; // the declaration whose scope this instance represents
-    private volatile Scope enclosingScope; // the enclosing scope of this scope
+
+    /** The enclosing scope of this scope.  Lazily initialized. */
+    private volatile Scope enclosingScope;
 
     /**
      * Constructor. Takes a reflective object whose scope the newly