src/share/classes/java/lang/reflect/Method.java

rev 10466 : 8054987: (reflect) Add sharing of annotations between instances of Executable
Reviewed-by: duke

*** 77,86 ****
--- 77,89 ----
      private byte[]              annotationDefault;
      private volatile MethodAccessor methodAccessor;
      // For sharing of MethodAccessors. This branching structure is
      // currently only two levels deep (i.e., one root Method and
      // potentially many Method objects pointing to it.)
+     //
+     // If this branching structure would ever contain cycles, deadlocks can
+     // occur in annotation code.
      private Method              root;
  
      // Generics infrastructure
      private String getGenericSignature() {return signature;}
  
*** 142,160 ****
--- 145,174 ----
          // method in the VM. (All of this contortion is only necessary
          // because of the "accessibility" bit in AccessibleObject,
          // which implicitly requires that new java.lang.reflect
          // objects be fabricated for each reflective call on Class
          // objects.)
+         if (this.root != null)
+             throw new IllegalArgumentException("Can not copy a non-root Method");
+ 
          Method res = new Method(clazz, name, parameterTypes, returnType,
                                  exceptionTypes, modifiers, slot, signature,
                                  annotations, parameterAnnotations, annotationDefault);
          res.root = this;
          // Might as well eagerly propagate this if already present
          res.methodAccessor = methodAccessor;
          return res;
      }
  
+     /**
+      * Used by Excecutable for annotation sharing.
+      */
+     @Override
+     Executable getRoot() {
+         return root;
+     }
+ 
      @Override
      boolean hasGenericInformation() {
          return (getGenericSignature() != null);
      }