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

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -40,11 +40,11 @@
  * It is designed to be used unchanged by at least core reflection and JDI.
  */
 public abstract class GenericDeclRepository<S extends Signature>
     extends AbstractRepository<S> {
 
-    private TypeVariable<?>[] typeParams; // caches the formal type parameters
+    private volatile TypeVariable<?>[] typeParams; // caches the formal type parameters
 
     protected GenericDeclRepository(String rawSig, GenericsFactory f) {
         super(rawSig, f);
     }
 

@@ -63,22 +63,23 @@
     /**
      * Return the formal type parameters of this generic declaration.
      * @return the formal type parameters of this generic declaration
      */
     public TypeVariable<?>[] getTypeParameters(){
-        if (typeParams == null) { // lazily initialize type parameters
+        TypeVariable<?>[] tps = typeParams;
+        if (tps == 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];
+            tps = 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 = tps; // cache overall result
         }
-        return typeParams.clone(); // return cached result
+        return tps.clone(); // return cached result
     }
 }