src/share/classes/java/lang/invoke/MemberName.java

*** 96,106 ****
       *  For a constructor, it is always {@code "<init>"}.
       */
      public String getName() {
          if (name == null) {
              expandFromVM();
!             if (name == null)  return null;
          }
          return name;
      }
  
      public MethodType getMethodOrFieldType() {
--- 96,108 ----
       *  For a constructor, it is always {@code "<init>"}.
       */
      public String getName() {
          if (name == null) {
              expandFromVM();
!             if (name == null) {
!                 return null;
!             }
          }
          return name;
      }
  
      public MethodType getMethodOrFieldType() {
*** 117,148 ****
       *  must be a method or constructor.
       */
      public MethodType getMethodType() {
          if (type == null) {
              expandFromVM();
!             if (type == null)  return null;
          }
!         if (!isInvocable())
              throw newIllegalArgumentException("not invocable, no method type");
-         if (type instanceof MethodType) {
-             return (MethodType) type;
          }
          if (type instanceof String) {
              String sig = (String) type;
              MethodType res = MethodType.fromMethodDescriptorString(sig, getClassLoader());
!             this.type = res;
!             return res;
!         }
!         if (type instanceof Object[]) {
              Object[] typeInfo = (Object[]) type;
              Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
              Class<?> rtype = (Class<?>) typeInfo[0];
              MethodType res = MethodType.methodType(rtype, ptypes);
!             this.type = res;
!             return res;
          }
!         throw new InternalError("bad method type "+type);
      }
  
      /** Return the actual type under which this method or constructor must be invoked.
       *  For non-static methods or constructors, this is the type with a leading parameter,
       *  a reference to declaring class.  For static methods, it is the same as the declared type.
--- 119,158 ----
       *  must be a method or constructor.
       */
      public MethodType getMethodType() {
          if (type == null) {
              expandFromVM();
!             if (type == null) {
!                 return null;
              }
!         }
!         if (!isInvocable()) {
              throw newIllegalArgumentException("not invocable, no method type");
          }
+ 
+         final Object typeSnapshot = type;
+         if (typeSnapshot instanceof MethodType) {
+             return (MethodType) typeSnapshot;
+         }
+ 
+         // type is not a MethodType yet.  Convert it thread-safely.
+         synchronized (this) {
              if (type instanceof String) {
                  String sig = (String) type;
                  MethodType res = MethodType.fromMethodDescriptorString(sig, getClassLoader());
!                 type = res;
!             } else if (type instanceof Object[]) {
                  Object[] typeInfo = (Object[]) type;
                  Class<?>[] ptypes = (Class<?>[]) typeInfo[1];
                  Class<?> rtype = (Class<?>) typeInfo[0];
                  MethodType res = MethodType.methodType(rtype, ptypes);
!                 type = res;
              }
!             // Make sure type is a MethodType for racing threads.
!             assert type instanceof MethodType : "bad method type " + type;
!         }
!         return (MethodType) type;
      }
  
      /** Return the actual type under which this method or constructor must be invoked.
       *  For non-static methods or constructors, this is the type with a leading parameter,
       *  a reference to declaring class.  For static methods, it is the same as the declared type.
*** 171,195 ****
       *  If it is a type member, that type itself is returned.
       */
      public Class<?> getFieldType() {
          if (type == null) {
              expandFromVM();
!             if (type == null)  return null;
          }
!         if (isInvocable())
              throw newIllegalArgumentException("not a field or nested class, no simple type");
-         if (type instanceof Class<?>) {
-             return (Class<?>) type;
          }
          if (type instanceof String) {
              String sig = (String) type;
              MethodType mtype = MethodType.fromMethodDescriptorString("()"+sig, getClassLoader());
              Class<?> res = mtype.returnType();
!             this.type = res;
!             return res;
          }
!         throw new InternalError("bad field type "+type);
      }
  
      /** Utility method to produce either the method type or field type of this member. */
      public Object getType() {
          return (isInvocable() ? getMethodType() : getFieldType());
--- 181,215 ----
       *  If it is a type member, that type itself is returned.
       */
      public Class<?> getFieldType() {
          if (type == null) {
              expandFromVM();
!             if (type == null) {
!                 return null;
              }
!         }
!         if (isInvocable()) {
              throw newIllegalArgumentException("not a field or nested class, no simple type");
          }
+ 
+         final Object typeSnapshot = type;
+         if (typeSnapshot instanceof Class<?>) {
+             return (Class<?>) typeSnapshot;
+         }
+ 
+         // type is not a Class yet.  Convert it thread-safely.
+         synchronized (this) {
              if (type instanceof String) {
                  String sig = (String) type;
                  MethodType mtype = MethodType.fromMethodDescriptorString("()"+sig, getClassLoader());
                  Class<?> res = mtype.returnType();
!                 type = res;
              }
!             // Make sure type is a Class for racing threads.
!             assert type instanceof Class<?> : "bad field type " + type;
!         }
!         return (Class<?>) type;
      }
  
      /** Utility method to produce either the method type or field type of this member. */
      public Object getType() {
          return (isInvocable() ? getMethodType() : getFieldType());
*** 199,212 ****
       *  used within the class file format to describe its type.
       */
      public String getSignature() {
          if (type == null) {
              expandFromVM();
!             if (type == null)  return null;
          }
-         if (type instanceof String)
-             return (String) type;
          if (isInvocable())
              return BytecodeDescriptor.unparse(getMethodType());
          else
              return BytecodeDescriptor.unparse(getFieldType());
      }
--- 219,232 ----
       *  used within the class file format to describe its type.
       */
      public String getSignature() {
          if (type == null) {
              expandFromVM();
!             if (type == null) {
!                 return null;
!             }
          }
          if (isInvocable())
              return BytecodeDescriptor.unparse(getMethodType());
          else
              return BytecodeDescriptor.unparse(getFieldType());
      }
*** 461,474 ****
          assert(testAnyFlags(ALL_KINDS));
          assert(this.resolution == null);  // nobody should have touched this yet
          //assert(referenceKindIsConsistent());  // do this after resolution
      }
  
      private void expandFromVM() {
!         if (!isResolved())  return;
!         if (type instanceof Object[])
!             type = null;  // don't saddle JVM w/ typeInfo
          MethodHandleNatives.expand(this);
      }
  
      // Capturing information from the Core Reflection API:
      private static int flagsMods(int flags, int mods, byte refKind) {
--- 481,501 ----
          assert(testAnyFlags(ALL_KINDS));
          assert(this.resolution == null);  // nobody should have touched this yet
          //assert(referenceKindIsConsistent());  // do this after resolution
      }
  
+     /**
+      * Calls down to the VM to fill in the fields.  This method is
+      * synchronized to avoid racing calls.
+      */
      private void expandFromVM() {
!         if (type != null) {
!             return;
!         }
!         if (!isResolved()) {
!             return;
!         }
          MethodHandleNatives.expand(this);
      }
  
      // Capturing information from the Core Reflection API:
      private static int flagsMods(int flags, int mods, byte refKind) {