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

@@ -44,11 +44,13 @@
  import sun.reflect.annotation.AnnotationType;
  import sun.reflect.annotation.AnnotationParser;
  import java.lang.annotation.Annotation;
  import java.lang.annotation.AnnotationFormatError;
  import java.nio.ByteBuffer;
+ import java.util.Optional;
  import java.util.StringJoiner;
+ import java.util.function.Function;
  
  /**
   * A {@code Method} provides information about, and access to, a single method
   * on a class or interface.  The reflected method may be a class method
   * or an instance method (including an abstract method).

@@ -95,10 +97,11 @@
      // If this branching structure would ever contain cycles, deadlocks can
      // occur in annotation code.
      private Method              root;
      // Hash code of this object
      private int                 hash;
+     private volatile Optional<?>     codeModel;
  
      // Generics infrastructure
      private String getGenericSignature() {return signature;}
  
      // Accessor for factory

@@ -230,10 +233,25 @@
      @Override
      public int getModifiers() {
          return modifiers;
      }
  
+     /* package */
+     Optional<?> setCodeModelIfNeeded(Function<Method, Optional<?>> modelFactory) {
+         Optional<?> localRef = codeModel;
+         if (localRef == null) {
+             synchronized (this) {
+                 localRef = codeModel;
+                 if (localRef == null) {
+                     Optional<?> op = modelFactory.apply(this);
+                     codeModel = localRef = op;
+                 }
+             }
+         }
+         return localRef;
+     }
+ 
      /**
       * {@inheritDoc}
       * @throws GenericSignatureFormatError {@inheritDoc}
       * @since 1.5
       * @jls 8.4.4 Generic Methods