8305104: Remove the old core reflection implementation

src/hotspot/share/classfile/verifier.cpp

@@ -293,9 +293,6 @@ bool Verifier::is_eligible_for_verification(InstanceKlass* klass, bool should_ve
     // As of the fix for 4486457 we disable verification for all of the
     // dynamically-generated bytecodes associated with
     // jdk/internal/reflect/SerializationConstructorAccessor.
-    // NOTE: this is called too early in the bootstrapping process to be
-    // guarded by Universe::is_gte_jdk14x_version().
-    // Also for lambda generated code, gte jdk8
     (!is_reflect_accessor));
 }
 

src/java.base/share/classes/jdk/internal/reflect/MethodHandleAccessorFactory.java

@@ -303,6 +303,17 @@ static void ensureClassInitialized(Class<?> defc) {
 
     /*
      * Returns true if NativeAccessor should be used.
+     *
+     * Native accessor, i.e. VM reflection implementation, is used if one of
+     * the following conditions is met:
+     * 1. during VM early startup and method handle support is fully initialized
+     * 2. a Java native method
+     * 3. -Djdk.reflect.useNativeAccessorOnly=true is set
+     * 4. the member takes a variable number of arguments and the last parameter
+     *    is an array (see details below)
+     * 5. the member's method type has an arity >= 255
+     *
+     * Otherwise, direct invocation of method handles is used.
      */
     private static boolean useNativeAccessor(Executable member) {
         if (!VM.isJavaLangInvokeInited())

src/java.base/share/classes/jdk/internal/reflect/ReflectionFactory.java

@@ -540,6 +540,10 @@ public final Constructor<OptionalDataException> newOptionalDataExceptionForSeria
     // Internals only below this point
     //
 
+    /*
+     * If -Djdk.reflect.useNativeAccessorOnly is set, use the native accessor only.
+     * For testing purpose only.
+     */
     static boolean useNativeAccessorOnly() {
         return config().useNativeAccessorOnly;
     }
@@ -548,11 +552,6 @@ private static boolean disableSerialConstructorChecks() {
         return config().disableSerialConstructorChecks;
     }
 
-    // New implementation uses direct invocation of method handles
-    private static final int METHOD_MH_ACCESSOR = 0x1;
-    private static final int FIELD_MH_ACCESSOR = 0x2;
-    private static final int ALL_MH_ACCESSORS = METHOD_MH_ACCESSOR | FIELD_MH_ACCESSOR;
-
     /**
      * The configuration is lazily initialized after the module system is initialized. The
      * default config would be used before the proper config is loaded.
@@ -564,17 +563,6 @@ private static boolean disableSerialConstructorChecks() {
      */
     private static @Stable Config config;
 
-    // "Inflation" mechanism. Loading bytecodes to implement
-    // Method.invoke() and Constructor.newInstance() currently costs
-    // 3-4x more than an invocation via native code for the first
-    // invocation (though subsequent invocations have been benchmarked
-    // to be over 20x faster). Unfortunately this cost increases
-    // startup time for certain applications that use reflection
-    // intensively (but only once per class) to bootstrap themselves.
-    // To avoid this penalty we reuse the existing JVM entry points
-    // for the first few invocations of Methods and Constructors and
-    // then switch to the bytecode-based implementations.
-
     private static final Config DEFAULT_CONFIG = new Config(false, // useNativeAccessorOnly
                                                             false); // disableSerialConstructorChecks
 
@@ -599,9 +587,7 @@ private static Config config() {
             return c;
         }
 
-        // Defer initialization until module system is initialized so as
-        // to avoid inflation and spinning bytecode in unnamed modules
-        // during early startup.
+        // Always use the default configuration until the module system is initialized.
         if (!VM.isModuleSystemInited()) {
             return DEFAULT_CONFIG;
         }
@@ -612,20 +598,13 @@ private static Config config() {
     private static Config loadConfig() {
         assert VM.isModuleSystemInited();
 
-        boolean useNativeAccessorOnly = DEFAULT_CONFIG.useNativeAccessorOnly;
-        boolean disableSerialConstructorChecks = DEFAULT_CONFIG.disableSerialConstructorChecks;
-
         Properties props = GetPropertyAction.privilegedGetProperties();
-        String val = props.getProperty("jdk.reflect.useNativeAccessorOnly");
-        if (val != null && val.equals("true")) {
-            useNativeAccessorOnly = true;
-        }
-
-        disableSerialConstructorChecks =
+        boolean useNativeAccessorOnly =
+            "true".equals(props.getProperty("jdk.reflect.useNativeAccessorOnly"));
+        boolean disableSerialConstructorChecks =
             "true".equals(props.getProperty("jdk.disableSerialConstructorChecks"));
 
-        return new Config(useNativeAccessorOnly,
-                          disableSerialConstructorChecks);
+        return new Config(useNativeAccessorOnly, disableSerialConstructorChecks);
     }
 
     /**

test/jdk/java/lang/reflect/Field/NegativeTest.java

@@ -24,7 +24,7 @@
 /**
  * @test
  * @bug 8277451
- * @run testng/othervm NegativeTest
+ * @run testng NegativeTest
  * @summary Test exception thrown due to bad receiver and bad value on
  *          Field with and without setAccessible(true)
  */