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

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

*** 92,104 ****
--- 92,115 ----
  
      private volatile ConstructorAccessor constructorAccessor;
      // For sharing of ConstructorAccessors. This branching structure
      // is currently only two levels deep (i.e., one root Constructor
      // and potentially many Constructor objects pointing to it.)
+     //
+     // If this branching structure would ever contain cycles, deadlocks can
+     // occur in annotation code.
      private Constructor<T>      root;
  
      /**
+      * Used by Excecutable for annotation sharing.
+      */
+     @Override
+     Executable getRoot() {
+         return root;
+     }
+ 
+     /**
       * Package-private constructor used by ReflectAccess to enable
       * instantiation of these objects in Java code from the java.lang
       * package via sun.reflect.LangReflectAccess.
       */
      Constructor(Class<T> declaringClass,
*** 130,139 ****
--- 141,153 ----
          // 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 Constructor");
+ 
          Constructor<T> res = new Constructor<>(clazz,
                                                 parameterTypes,
                                                 exceptionTypes, modifiers, slot,
                                                 signature,
                                                 annotations,