8024616: JSR292: lazily initialize core NamedFunctions used for bootstrapping

Reviewed-by: jrose

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

@@ -257,12 +257,12 @@ class DirectMethodHandle extends MethodHandle {
         assert(names.length == nameCursor);
         if (doesAlloc) {
             // names = { argx,y,z,... new C, init method }
-            names[NEW_OBJ] = new Name(NF_allocateInstance, names[DMH_THIS]);
-            names[GET_MEMBER] = new Name(NF_constructorMethod, names[DMH_THIS]);
+            names[NEW_OBJ] = new Name(Lazy.NF_allocateInstance, names[DMH_THIS]);
+            names[GET_MEMBER] = new Name(Lazy.NF_constructorMethod, names[DMH_THIS]);
         } else if (needsInit) {
-            names[GET_MEMBER] = new Name(NF_internalMemberNameEnsureInit, names[DMH_THIS]);
+            names[GET_MEMBER] = new Name(Lazy.NF_internalMemberNameEnsureInit, names[DMH_THIS]);
         } else {
-            names[GET_MEMBER] = new Name(NF_internalMemberName, names[DMH_THIS]);
+            names[GET_MEMBER] = new Name(Lazy.NF_internalMemberName, names[DMH_THIS]);
         }
         Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, GET_MEMBER+1, Object[].class);
         assert(outArgs[outArgs.length-1] == names[GET_MEMBER]);  // look, shifted args!
@@ -637,18 +637,18 @@ class DirectMethodHandle extends MethodHandle {
         final int RESULT    = nameCursor-1;  // either the call or the cast
         Name[] names = arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
         if (needsInit)
-            names[INIT_BAR] = new Name(NF_ensureInitialized, names[DMH_THIS]);
+            names[INIT_BAR] = new Name(Lazy.NF_ensureInitialized, names[DMH_THIS]);
         if (needsCast && !isGetter)
-            names[PRE_CAST] = new Name(NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
+            names[PRE_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[SET_VALUE]);
         Object[] outArgs = new Object[1 + linkerType.parameterCount()];
         assert(outArgs.length == (isGetter ? 3 : 4));
         outArgs[0] = UNSAFE;
         if (isStatic) {
-            outArgs[1] = names[F_HOLDER]  = new Name(NF_staticBase, names[DMH_THIS]);
-            outArgs[2] = names[F_OFFSET]  = new Name(NF_staticOffset, names[DMH_THIS]);
+            outArgs[1] = names[F_HOLDER]  = new Name(Lazy.NF_staticBase, names[DMH_THIS]);
+            outArgs[2] = names[F_OFFSET]  = new Name(Lazy.NF_staticOffset, names[DMH_THIS]);
         } else {
-            outArgs[1] = names[OBJ_CHECK] = new Name(NF_checkBase, names[OBJ_BASE]);
-            outArgs[2] = names[F_OFFSET]  = new Name(NF_fieldOffset, names[DMH_THIS]);
+            outArgs[1] = names[OBJ_CHECK] = new Name(Lazy.NF_checkBase, names[OBJ_BASE]);
+            outArgs[2] = names[F_OFFSET]  = new Name(Lazy.NF_fieldOffset, names[DMH_THIS]);
         }
         if (!isGetter) {
             outArgs[3] = (needsCast ? names[PRE_CAST] : names[SET_VALUE]);
@@ -656,7 +656,7 @@ class DirectMethodHandle extends MethodHandle {
         for (Object a : outArgs)  assert(a != null);
         names[LINKER_CALL] = new Name(linker, outArgs);
         if (needsCast && isGetter)
-            names[POST_CAST] = new Name(NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
+            names[POST_CAST] = new Name(Lazy.NF_checkCast, names[DMH_THIS], names[LINKER_CALL]);
         for (Name n : names)  assert(n != null);
         String fieldOrStatic = (isStatic ? "Static" : "Field");
         String lambdaName = (linkerName + fieldOrStatic);  // significant only for debugging
@@ -665,7 +665,12 @@ class DirectMethodHandle extends MethodHandle {
         return new LambdaForm(lambdaName, ARG_LIMIT, names, RESULT);
     }
 
-    private static final NamedFunction
+    /**
+     * Pre-initialized NamedFunctions for bootstrapping purposes.
+     * Factored in an inner class to delay initialization until first usage.
+     */
+    private static class Lazy {
+        static final NamedFunction
                 NF_internalMemberName,
                 NF_internalMemberNameEnsureInit,
                 NF_ensureInitialized,
@@ -709,4 +714,5 @@ class DirectMethodHandle extends MethodHandle {
                 throw newInternalError(ex);
             }
         }
+    }
 }

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

@@ -435,7 +435,7 @@ import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
                 // Spread the array.
                 MethodHandle aload = MethodHandles.arrayElementGetter(spreadArgType);
                 Name array = names[argIndex];
-                names[nameCursor++] = new Name(NF_checkSpreadArgument, array, spreadArgCount);
+                names[nameCursor++] = new Name(Lazy.NF_checkSpreadArgument, array, spreadArgCount);
                 for (int j = 0; j < spreadArgCount; i++, j++) {
                     indexes[i] = nameCursor;
                     names[nameCursor++] = new Name(aload, array, j);
@@ -480,7 +480,12 @@ import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
         throw new WrongMethodTypeException("Array is not of length "+n);
     }
 
-    private static final NamedFunction NF_checkSpreadArgument;
+    /**
+     * Pre-initialized NamedFunctions for bootstrapping purposes.
+     * Factored in an inner class to delay initialization until first usage.
+     */
+    private static class Lazy {
+        static final NamedFunction NF_checkSpreadArgument;
         static {
             try {
                 NF_checkSpreadArgument = new NamedFunction(MethodHandleImpl.class
@@ -490,6 +495,7 @@ import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
                 throw newInternalError(ex);
             }
         }
+    }
 
     /** Factory method:  Collect or filter selected argument(s). */
     static MethodHandle makeCollectArguments(MethodHandle target,