8235521: Replacement API for Unsafe::ensureClassInitialized

Reviewed-by: alanb, chegar, psandoz

src/java.base/share/classes/java/lang/invoke/MethodHandles.java

@@ -27,6 +27,7 @@ package java.lang.invoke;
 
 import jdk.internal.access.JavaLangAccess;
 import jdk.internal.access.SharedSecrets;
+import jdk.internal.misc.Unsafe;
 import jdk.internal.misc.VM;
 import jdk.internal.module.IllegalAccessLogger;
 import jdk.internal.org.objectweb.asm.ClassReader;
@@ -2243,7 +2244,8 @@ public class MethodHandles {
                 Class<?> lookupClass = lookup.lookupClass();
                 ClassLoader loader = lookupClass.getClassLoader();
                 ProtectionDomain pd = (loader != null) ? lookup.lookupClassProtectionDomain() : null;
-                Class<?> c = JLA.defineClass(loader, lookupClass, name, bytes, pd, initialize, classFlags, classData);
+                Class<?> c = SharedSecrets.getJavaLangAccess()
+                        .defineClass(loader, lookupClass, name, bytes, pd, initialize, classFlags, classData);
                 assert !isNestmate() || c.getNestHost() == lookupClass.getNestHost();
                 return c;
             }
@@ -2263,7 +2265,7 @@ public class MethodHandles {
         private ProtectionDomain lookupClassProtectionDomain() {
             ProtectionDomain pd = cachedProtectionDomain;
             if (pd == null) {
-                cachedProtectionDomain = pd = JLA.protectionDomain(lookupClass);
+                cachedProtectionDomain = pd = SharedSecrets.getJavaLangAccess().protectionDomain(lookupClass);
             }
             return pd;
         }
@@ -2283,8 +2285,6 @@ public class MethodHandles {
          */
         static final Lookup PUBLIC_LOOKUP = new Lookup(Object.class, null, UNCONDITIONAL);
 
-        static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
-
         private static void checkUnprivilegedlookupClass(Class<?> lookupClass) {
             String name = lookupClass.getName();
             if (name.startsWith("java.lang.invoke."))
@@ -2586,6 +2586,43 @@ assertEquals("[x, y, z]", pb.command().toString());
             return accessClass(targetClass);
         }
 
+        /**
+         * Ensures that {@code targetClass} has been initialized. The class
+         * to be initialized must be {@linkplain #accessClass accessible}
+         * to this {@code Lookup} object.  This method causes {@code targetClass}
+         * to be initialized if it has not been already initialized,
+         * as specified in JVMS {@jvms 5.5}.
+         *
+         * @param targetClass the class to be initialized
+         * @return {@code targetClass} that has been initialized
+         *
+         * @throws  IllegalArgumentException if {@code targetClass} is a primitive type or {@code void}
+         *          or array class
+         * @throws  IllegalAccessException if {@code targetClass} is not
+         *          {@linkplain #accessClass accessible} to this lookup
+         * @throws  ExceptionInInitializerError if the class initialization provoked
+         *          by this method fails
+         * @throws  SecurityException if a security manager is present and it
+         *          <a href="MethodHandles.Lookup.html#secmgr">refuses access</a>
+         * @since 15
+         * @jvms 5.5 Initialization
+         */
+        public Class<?> ensureInitialized(Class<?> targetClass) throws IllegalAccessException {
+            if (targetClass.isPrimitive())
+                throw new IllegalArgumentException(targetClass + " is a primitive class");
+            if (targetClass.isArray())
+                throw new IllegalArgumentException(targetClass + " is an array class");
+
+            if (!VerifyAccess.isClassAccessible(targetClass, lookupClass, prevLookupClass, allowedModes)) {
+                throw new MemberName(targetClass).makeAccessException("access violation", this);
+            }
+            checkSecurityManager(targetClass, null);
+
+            // ensure class initialization
+            Unsafe.getUnsafe().ensureClassInitialized(targetClass);
+            return targetClass;
+        }
+
         /**
          * Determines if a class can be accessed from the lookup context defined by
          * this {@code Lookup} object. The static initializer of the class is not run.

src/java.base/share/classes/jdk/internal/access/SharedSecrets.java

@@ -27,6 +27,7 @@ package jdk.internal.access;
 
 import javax.crypto.SealedObject;
 import java.io.ObjectInputFilter;
+import java.lang.invoke.MethodHandles;
 import java.lang.module.ModuleDescriptor;
 import java.util.ResourceBundle;
 import java.util.jar.JarFile;
@@ -37,7 +38,6 @@ import java.io.ObjectInputStream;
 import java.io.RandomAccessFile;
 import java.security.ProtectionDomain;
 import java.security.Signature;
-import jdk.internal.misc.Unsafe;
 
 /** A repository of "shared secrets", which are a mechanism for
     calling implementation-private methods in another package without
@@ -49,7 +49,7 @@ import jdk.internal.misc.Unsafe;
     for this purpose, namely the loss of compile-time checking. */
 
 public class SharedSecrets {
-    private static final Unsafe unsafe = Unsafe.getUnsafe();
+    private static final MethodHandles.Lookup lookup = MethodHandles.lookup();
     private static JavaAWTAccess javaAWTAccess;
     private static JavaAWTFontAccess javaAWTFontAccess;
     private static JavaBeansAccess javaBeansAccess;
@@ -81,7 +81,7 @@ public class SharedSecrets {
         if (javaUtilJarAccess == null) {
             // Ensure JarFile is initialized; we know that this class
             // provides the shared secret
-            unsafe.ensureClassInitialized(JarFile.class);
+            ensureClassInitialized(JarFile.class);
         }
         return javaUtilJarAccess;
     }
@@ -105,8 +105,7 @@ public class SharedSecrets {
     public static JavaLangInvokeAccess getJavaLangInvokeAccess() {
         if (javaLangInvokeAccess == null) {
             try {
-                Class<?> c = Class.forName("java.lang.invoke.MethodHandleImpl");
+                Class.forName("java.lang.invoke.MethodHandleImpl", true, null);
-                unsafe.ensureClassInitialized(c);
             } catch (ClassNotFoundException e) {};
         }
         return javaLangInvokeAccess;
@@ -118,7 +117,7 @@ public class SharedSecrets {
 
     public static JavaLangModuleAccess getJavaLangModuleAccess() {
         if (javaLangModuleAccess == null) {
-            unsafe.ensureClassInitialized(ModuleDescriptor.class);
+            ensureClassInitialized(ModuleDescriptor.class);
         }
         return javaLangModuleAccess;
     }
@@ -145,7 +144,7 @@ public class SharedSecrets {
 
     public static JavaNetUriAccess getJavaNetUriAccess() {
         if (javaNetUriAccess == null)
-            unsafe.ensureClassInitialized(java.net.URI.class);
+            ensureClassInitialized(java.net.URI.class);
         return javaNetUriAccess;
     }
 
@@ -155,7 +154,7 @@ public class SharedSecrets {
 
     public static JavaNetURLAccess getJavaNetURLAccess() {
         if (javaNetURLAccess == null)
-            unsafe.ensureClassInitialized(java.net.URL.class);
+            ensureClassInitialized(java.net.URL.class);
         return javaNetURLAccess;
     }
 
@@ -165,7 +164,7 @@ public class SharedSecrets {
 
     public static JavaNetInetAddressAccess getJavaNetInetAddressAccess() {
         if (javaNetInetAddressAccess == null)
-            unsafe.ensureClassInitialized(java.net.InetAddress.class);
+            ensureClassInitialized(java.net.InetAddress.class);
         return javaNetInetAddressAccess;
     }
 
@@ -175,7 +174,7 @@ public class SharedSecrets {
 
     public static JavaNetHttpCookieAccess getJavaNetHttpCookieAccess() {
         if (javaNetHttpCookieAccess == null)
-            unsafe.ensureClassInitialized(java.net.HttpCookie.class);
+            ensureClassInitialized(java.net.HttpCookie.class);
         return javaNetHttpCookieAccess;
     }
 
@@ -187,7 +186,7 @@ public class SharedSecrets {
         if (javaNioAccess == null) {
             // Ensure java.nio.Buffer is initialized, which provides the
             // shared secret.
-            unsafe.ensureClassInitialized(java.nio.Buffer.class);
+            ensureClassInitialized(java.nio.Buffer.class);
         }
         return javaNioAccess;
     }
@@ -198,7 +197,7 @@ public class SharedSecrets {
 
     public static JavaIOAccess getJavaIOAccess() {
         if (javaIOAccess == null) {
-            unsafe.ensureClassInitialized(Console.class);
+            ensureClassInitialized(Console.class);
         }
         return javaIOAccess;
     }
@@ -209,7 +208,7 @@ public class SharedSecrets {
 
     public static JavaIOFilePermissionAccess getJavaIOFilePermissionAccess() {
         if (javaIOFilePermissionAccess == null)
-            unsafe.ensureClassInitialized(FilePermission.class);
+            ensureClassInitialized(FilePermission.class);
 
         return javaIOFilePermissionAccess;
     }
@@ -220,7 +219,7 @@ public class SharedSecrets {
 
     public static JavaIOFileDescriptorAccess getJavaIOFileDescriptorAccess() {
         if (javaIOFileDescriptorAccess == null)
-            unsafe.ensureClassInitialized(FileDescriptor.class);
+            ensureClassInitialized(FileDescriptor.class);
 
         return javaIOFileDescriptorAccess;
     }
@@ -231,14 +230,14 @@ public class SharedSecrets {
 
     public static JavaSecurityAccess getJavaSecurityAccess() {
         if (javaSecurityAccess == null) {
-            unsafe.ensureClassInitialized(ProtectionDomain.class);
+            ensureClassInitialized(ProtectionDomain.class);
         }
         return javaSecurityAccess;
     }
 
     public static JavaUtilZipFileAccess getJavaUtilZipFileAccess() {
         if (javaUtilZipFileAccess == null)
-            unsafe.ensureClassInitialized(java.util.zip.ZipFile.class);
+            ensureClassInitialized(java.util.zip.ZipFile.class);
         return javaUtilZipFileAccess;
     }
 
@@ -276,7 +275,7 @@ public class SharedSecrets {
 
     public static JavaUtilResourceBundleAccess getJavaUtilResourceBundleAccess() {
         if (javaUtilResourceBundleAccess == null)
-            unsafe.ensureClassInitialized(ResourceBundle.class);
+            ensureClassInitialized(ResourceBundle.class);
         return javaUtilResourceBundleAccess;
     }
 
@@ -286,7 +285,7 @@ public class SharedSecrets {
 
     public static JavaObjectInputStreamReadString getJavaObjectInputStreamReadString() {
         if (javaObjectInputStreamReadString == null) {
-            unsafe.ensureClassInitialized(ObjectInputStream.class);
+            ensureClassInitialized(ObjectInputStream.class);
         }
         return javaObjectInputStreamReadString;
     }
@@ -297,7 +296,7 @@ public class SharedSecrets {
 
     public static JavaObjectInputStreamAccess getJavaObjectInputStreamAccess() {
         if (javaObjectInputStreamAccess == null) {
-            unsafe.ensureClassInitialized(ObjectInputStream.class);
+            ensureClassInitialized(ObjectInputStream.class);
         }
         return javaObjectInputStreamAccess;
     }
@@ -308,7 +307,7 @@ public class SharedSecrets {
 
     public static JavaObjectInputFilterAccess getJavaObjectInputFilterAccess() {
         if (javaObjectInputFilterAccess == null) {
-            unsafe.ensureClassInitialized(ObjectInputFilter.Config.class);
+            ensureClassInitialized(ObjectInputFilter.Config.class);
         }
         return javaObjectInputFilterAccess;
     }
@@ -323,7 +322,7 @@ public class SharedSecrets {
 
     public static JavaIORandomAccessFileAccess getJavaIORandomAccessFileAccess() {
         if (javaIORandomAccessFileAccess == null) {
-            unsafe.ensureClassInitialized(RandomAccessFile.class);
+            ensureClassInitialized(RandomAccessFile.class);
         }
         return javaIORandomAccessFileAccess;
     }
@@ -334,7 +333,7 @@ public class SharedSecrets {
 
     public static JavaSecuritySignatureAccess getJavaSecuritySignatureAccess() {
         if (javaSecuritySignatureAccess == null) {
-            unsafe.ensureClassInitialized(Signature.class);
+            ensureClassInitialized(Signature.class);
         }
         return javaSecuritySignatureAccess;
     }
@@ -345,8 +344,14 @@ public class SharedSecrets {
 
     public static JavaxCryptoSealedObjectAccess getJavaxCryptoSealedObjectAccess() {
         if (javaxCryptoSealedObjectAccess == null) {
-            unsafe.ensureClassInitialized(SealedObject.class);
+            ensureClassInitialized(SealedObject.class);
         }
         return javaxCryptoSealedObjectAccess;
     }
+
+    private static void ensureClassInitialized(Class<?> c) {
+        try {
+            MethodHandles.lookup().ensureInitialized(c);
+        } catch (IllegalAccessException e) {}
+    }
 }

src/java.desktop/share/classes/sun/awt/AWTAccessor.java

@@ -25,8 +25,6 @@
 
 package sun.awt;
 
-import jdk.internal.misc.Unsafe;
-
 import javax.accessibility.AccessibleContext;
 import java.awt.*;
 import java.awt.event.FocusEvent.Cause;
@@ -34,7 +32,6 @@ import java.awt.dnd.DragSourceContext;
 import java.awt.dnd.DropTargetContext;
 import java.awt.dnd.peer.DragSourceContextPeer;
 import java.awt.dnd.peer.DropTargetContextPeer;
-import java.awt.event.AWTEventListener;
 import java.awt.event.InputEvent;
 import java.awt.event.InvocationEvent;
 import java.awt.event.KeyEvent;
@@ -44,6 +41,7 @@ import java.awt.image.BufferStrategy;
 import java.awt.peer.ComponentPeer;
 
 import java.awt.peer.MenuComponentPeer;
+import java.lang.invoke.MethodHandles;;
 import java.lang.reflect.InvocationTargetException;
 import java.security.AccessControlContext;
 
@@ -61,8 +59,6 @@ import javax.accessibility.AccessibleBundle;
  */
 public final class AWTAccessor {
 
-    private static final Unsafe unsafe = Unsafe.getUnsafe();
-
     /*
      * We don't need any objects of this class.
      * It's rather a collection of static methods
@@ -877,7 +873,7 @@ public final class AWTAccessor {
      */
     public static ComponentAccessor getComponentAccessor() {
         if (componentAccessor == null) {
-            unsafe.ensureClassInitialized(Component.class);
+            ensureClassInitialized(Component.class);
         }
 
         return componentAccessor;
@@ -895,7 +891,7 @@ public final class AWTAccessor {
      */
     public static ContainerAccessor getContainerAccessor() {
         if (containerAccessor == null) {
-            unsafe.ensureClassInitialized(Container.class);
+            ensureClassInitialized(Container.class);
         }
 
         return containerAccessor;
@@ -913,7 +909,7 @@ public final class AWTAccessor {
      */
     public static WindowAccessor getWindowAccessor() {
         if (windowAccessor == null) {
-            unsafe.ensureClassInitialized(Window.class);
+            ensureClassInitialized(Window.class);
         }
         return windowAccessor;
     }
@@ -930,7 +926,7 @@ public final class AWTAccessor {
      */
     public static AWTEventAccessor getAWTEventAccessor() {
         if (awtEventAccessor == null) {
-            unsafe.ensureClassInitialized(AWTEvent.class);
+            ensureClassInitialized(AWTEvent.class);
         }
         return awtEventAccessor;
     }
@@ -947,7 +943,7 @@ public final class AWTAccessor {
      */
     public static InputEventAccessor getInputEventAccessor() {
         if (inputEventAccessor == null) {
-            unsafe.ensureClassInitialized(InputEvent.class);
+            ensureClassInitialized(InputEvent.class);
         }
         return inputEventAccessor;
     }
@@ -964,7 +960,7 @@ public final class AWTAccessor {
      */
     public static MouseEventAccessor getMouseEventAccessor() {
         if (mouseEventAccessor == null) {
-            unsafe.ensureClassInitialized(MouseEvent.class);
+            ensureClassInitialized(MouseEvent.class);
         }
         return mouseEventAccessor;
     }
@@ -981,7 +977,7 @@ public final class AWTAccessor {
      */
     public static FrameAccessor getFrameAccessor() {
         if (frameAccessor == null) {
-            unsafe.ensureClassInitialized(Frame.class);
+            ensureClassInitialized(Frame.class);
         }
         return frameAccessor;
     }
@@ -998,7 +994,7 @@ public final class AWTAccessor {
      */
     public static KeyboardFocusManagerAccessor getKeyboardFocusManagerAccessor() {
         if (kfmAccessor == null) {
-            unsafe.ensureClassInitialized(KeyboardFocusManager.class);
+            ensureClassInitialized(KeyboardFocusManager.class);
         }
         return kfmAccessor;
     }
@@ -1015,7 +1011,7 @@ public final class AWTAccessor {
      */
     public static MenuComponentAccessor getMenuComponentAccessor() {
         if (menuComponentAccessor == null) {
-            unsafe.ensureClassInitialized(MenuComponent.class);
+            ensureClassInitialized(MenuComponent.class);
         }
         return menuComponentAccessor;
     }
@@ -1032,7 +1028,7 @@ public final class AWTAccessor {
      */
     public static EventQueueAccessor getEventQueueAccessor() {
         if (eventQueueAccessor == null) {
-            unsafe.ensureClassInitialized(EventQueue.class);
+            ensureClassInitialized(EventQueue.class);
         }
         return eventQueueAccessor;
     }
@@ -1049,7 +1045,7 @@ public final class AWTAccessor {
      */
     public static PopupMenuAccessor getPopupMenuAccessor() {
         if (popupMenuAccessor == null) {
-            unsafe.ensureClassInitialized(PopupMenu.class);
+            ensureClassInitialized(PopupMenu.class);
         }
         return popupMenuAccessor;
     }
@@ -1066,7 +1062,7 @@ public final class AWTAccessor {
      */
     public static FileDialogAccessor getFileDialogAccessor() {
         if (fileDialogAccessor == null) {
-            unsafe.ensureClassInitialized(FileDialog.class);
+            ensureClassInitialized(FileDialog.class);
         }
         return fileDialogAccessor;
     }
@@ -1084,7 +1080,7 @@ public final class AWTAccessor {
      */
     public static ScrollPaneAdjustableAccessor getScrollPaneAdjustableAccessor() {
         if (scrollPaneAdjustableAccessor == null) {
-            unsafe.ensureClassInitialized(ScrollPaneAdjustable.class);
+            ensureClassInitialized(ScrollPaneAdjustable.class);
         }
         return scrollPaneAdjustableAccessor;
     }
@@ -1101,7 +1097,7 @@ public final class AWTAccessor {
      */
     public static CheckboxMenuItemAccessor getCheckboxMenuItemAccessor() {
         if (checkboxMenuItemAccessor == null) {
-            unsafe.ensureClassInitialized(CheckboxMenuItemAccessor.class);
+            ensureClassInitialized(CheckboxMenuItemAccessor.class);
         }
         return checkboxMenuItemAccessor;
     }
@@ -1118,7 +1114,7 @@ public final class AWTAccessor {
      */
     public static CursorAccessor getCursorAccessor() {
         if (cursorAccessor == null) {
-            unsafe.ensureClassInitialized(CursorAccessor.class);
+            ensureClassInitialized(CursorAccessor.class);
         }
         return cursorAccessor;
     }
@@ -1135,7 +1131,7 @@ public final class AWTAccessor {
      */
     public static MenuBarAccessor getMenuBarAccessor() {
         if (menuBarAccessor == null) {
-            unsafe.ensureClassInitialized(MenuBarAccessor.class);
+            ensureClassInitialized(MenuBarAccessor.class);
         }
         return menuBarAccessor;
     }
@@ -1152,7 +1148,7 @@ public final class AWTAccessor {
      */
     public static MenuItemAccessor getMenuItemAccessor() {
         if (menuItemAccessor == null) {
-            unsafe.ensureClassInitialized(MenuItemAccessor.class);
+            ensureClassInitialized(MenuItemAccessor.class);
         }
         return menuItemAccessor;
     }
@@ -1169,7 +1165,7 @@ public final class AWTAccessor {
      */
     public static MenuAccessor getMenuAccessor() {
         if (menuAccessor == null) {
-            unsafe.ensureClassInitialized(MenuAccessor.class);
+            ensureClassInitialized(MenuAccessor.class);
         }
         return menuAccessor;
     }
@@ -1186,7 +1182,7 @@ public final class AWTAccessor {
      */
     public static KeyEventAccessor getKeyEventAccessor() {
         if (keyEventAccessor == null) {
-            unsafe.ensureClassInitialized(KeyEventAccessor.class);
+            ensureClassInitialized(KeyEventAccessor.class);
         }
         return keyEventAccessor;
     }
@@ -1203,7 +1199,7 @@ public final class AWTAccessor {
      */
     public static ClientPropertyKeyAccessor getClientPropertyKeyAccessor() {
         if (clientPropertyKeyAccessor == null) {
-            unsafe.ensureClassInitialized(ClientPropertyKeyAccessor.class);
+            ensureClassInitialized(ClientPropertyKeyAccessor.class);
         }
         return clientPropertyKeyAccessor;
     }
@@ -1220,7 +1216,7 @@ public final class AWTAccessor {
      */
     public static SystemTrayAccessor getSystemTrayAccessor() {
         if (systemTrayAccessor == null) {
-            unsafe.ensureClassInitialized(SystemTrayAccessor.class);
+            ensureClassInitialized(SystemTrayAccessor.class);
         }
         return systemTrayAccessor;
     }
@@ -1237,7 +1233,7 @@ public final class AWTAccessor {
      */
     public static TrayIconAccessor getTrayIconAccessor() {
         if (trayIconAccessor == null) {
-            unsafe.ensureClassInitialized(TrayIconAccessor.class);
+            ensureClassInitialized(TrayIconAccessor.class);
         }
         return trayIconAccessor;
     }
@@ -1254,7 +1250,7 @@ public final class AWTAccessor {
      */
     public static DefaultKeyboardFocusManagerAccessor getDefaultKeyboardFocusManagerAccessor() {
         if (defaultKeyboardFocusManagerAccessor == null) {
-            unsafe.ensureClassInitialized(DefaultKeyboardFocusManagerAccessor.class);
+            ensureClassInitialized(DefaultKeyboardFocusManagerAccessor.class);
         }
         return defaultKeyboardFocusManagerAccessor;
     }
@@ -1271,7 +1267,7 @@ public final class AWTAccessor {
     public static SequencedEventAccessor getSequencedEventAccessor() {
         if (sequencedEventAccessor == null) {
             try {
-                unsafe.ensureClassInitialized(
+                ensureClassInitialized(
                         Class.forName("java.awt.SequencedEvent"));
             } catch (ClassNotFoundException ignore) {
             }
@@ -1291,7 +1287,7 @@ public final class AWTAccessor {
      */
     public static ToolkitAccessor getToolkitAccessor() {
         if (toolkitAccessor == null) {
-            unsafe.ensureClassInitialized(Toolkit.class);
+            ensureClassInitialized(Toolkit.class);
         }
 
         return toolkitAccessor;
@@ -1316,7 +1312,7 @@ public final class AWTAccessor {
      */
     public static SystemColorAccessor getSystemColorAccessor() {
         if (systemColorAccessor == null) {
-            unsafe.ensureClassInitialized(SystemColor.class);
+            ensureClassInitialized(SystemColor.class);
         }
 
         return systemColorAccessor;
@@ -1334,7 +1330,7 @@ public final class AWTAccessor {
      */
     public static AccessibleContextAccessor getAccessibleContextAccessor() {
         if (accessibleContextAccessor == null) {
-            unsafe.ensureClassInitialized(AccessibleContext.class);
+            ensureClassInitialized(AccessibleContext.class);
         }
         return accessibleContextAccessor;
     }
@@ -1351,7 +1347,7 @@ public final class AWTAccessor {
      */
     public static AccessibleBundleAccessor getAccessibleBundleAccessor() {
         if (accessibleBundleAccessor == null) {
-            unsafe.ensureClassInitialized(AccessibleBundle.class);
+            ensureClassInitialized(AccessibleBundle.class);
         }
         return accessibleBundleAccessor;
     }
@@ -1368,7 +1364,7 @@ public final class AWTAccessor {
      */
     public static DragSourceContextAccessor getDragSourceContextAccessor() {
         if (dragSourceContextAccessor == null) {
-            unsafe.ensureClassInitialized(DragSourceContext.class);
+            ensureClassInitialized(DragSourceContext.class);
         }
         return dragSourceContextAccessor;
     }
@@ -1385,7 +1381,7 @@ public final class AWTAccessor {
      */
     public static DropTargetContextAccessor getDropTargetContextAccessor() {
         if (dropTargetContextAccessor == null) {
-            unsafe.ensureClassInitialized(DropTargetContext.class);
+            ensureClassInitialized(DropTargetContext.class);
         }
         return dropTargetContextAccessor;
     }
@@ -1397,4 +1393,9 @@ public final class AWTAccessor {
         AWTAccessor.dropTargetContextAccessor = accessor;
     }
 
+    private static void ensureClassInitialized(Class<?> c) {
+        try {
+            MethodHandles.lookup().ensureInitialized(c);
+        } catch (IllegalAccessException e) {}
+    }
 }

src/java.desktop/share/classes/sun/swing/SwingAccessor.java

@@ -25,9 +25,8 @@
 
 package sun.swing;
 
-import jdk.internal.misc.Unsafe;
-
 import java.awt.*;
+import java.lang.invoke.MethodHandles;
 import javax.swing.*;
 
 import javax.swing.text.JTextComponent;
@@ -40,8 +39,6 @@ import javax.swing.text.JTextComponent;
  * for another example.
  */
 public final class SwingAccessor {
-    private static final Unsafe unsafe = Unsafe.getUnsafe();
-
     /**
      * We don't need any objects of this class.
      * It's rather a collection of static methods
@@ -142,7 +139,7 @@ public final class SwingAccessor {
      */
     public static JComponentAccessor getJComponentAccessor() {
         if (jComponentAccessor == null) {
-            unsafe.ensureClassInitialized(JComponent.class);
+            ensureClassInitialized(JComponent.class);
         }
 
         return jComponentAccessor;
@@ -165,7 +162,7 @@ public final class SwingAccessor {
      */
     public static JTextComponentAccessor getJTextComponentAccessor() {
         if (jtextComponentAccessor == null) {
-            unsafe.ensureClassInitialized(JTextComponent.class);
+            ensureClassInitialized(JTextComponent.class);
         }
 
         return jtextComponentAccessor;
@@ -188,7 +185,7 @@ public final class SwingAccessor {
      */
     public static JLightweightFrameAccessor getJLightweightFrameAccessor() {
         if (jLightweightFrameAccessor == null) {
-            unsafe.ensureClassInitialized(JLightweightFrame.class);
+            ensureClassInitialized(JLightweightFrame.class);
         }
         return jLightweightFrameAccessor;
     }
@@ -210,7 +207,7 @@ public final class SwingAccessor {
      */
     public static UIDefaultsAccessor getUIDefaultsAccessor() {
         if (uiDefaultsAccessor == null) {
-            unsafe.ensureClassInitialized(UIDefaults.class);
+            ensureClassInitialized(UIDefaults.class);
         }
         return uiDefaultsAccessor;
     }
@@ -232,7 +229,7 @@ public final class SwingAccessor {
      */
     public static RepaintManagerAccessor getRepaintManagerAccessor() {
         if (repaintManagerAccessor == null) {
-            unsafe.ensureClassInitialized(RepaintManager.class);
+            ensureClassInitialized(RepaintManager.class);
         }
         return repaintManagerAccessor;
     }
@@ -247,7 +244,7 @@ public final class SwingAccessor {
      */
     public static PopupFactoryAccessor getPopupFactoryAccessor() {
         if (popupFactoryAccessor == null) {
-            unsafe.ensureClassInitialized(PopupFactory.class);
+            ensureClassInitialized(PopupFactory.class);
         }
         return popupFactoryAccessor;
     }
@@ -269,7 +266,7 @@ public final class SwingAccessor {
      */
     public static KeyStrokeAccessor getKeyStrokeAccessor() {
         if (keyStrokeAccessor == null) {
-            unsafe.ensureClassInitialized(KeyStroke.class);
+            ensureClassInitialized(KeyStroke.class);
         }
         return keyStrokeAccessor;
     }
@@ -280,4 +277,10 @@ public final class SwingAccessor {
     public static void setKeyStrokeAccessor(KeyStrokeAccessor accessor) {
         SwingAccessor.keyStrokeAccessor = accessor;
     }
+
+    private static void ensureClassInitialized(Class<?> c) {
+        try {
+            MethodHandles.lookup().ensureInitialized(c);
+        } catch (IllegalAccessException e) {}
+    }
 }

src/java.management/share/classes/sun/management/ManagementFactoryHelper.java

@@ -25,6 +25,7 @@
 
 package sun.management;
 
+import java.lang.invoke.MethodHandles;
 import java.lang.management.*;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -39,7 +40,6 @@ import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
 
-import jdk.internal.access.SharedSecrets;
 import jdk.internal.misc.VM;
 import jdk.internal.misc.VM.BufferPool;
 
@@ -63,7 +63,9 @@ public class ManagementFactoryHelper {
     static {
         // make sure that the management lib is loaded within
         // java.lang.management.ManagementFactory
-        jdk.internal.misc.Unsafe.getUnsafe().ensureClassInitialized(ManagementFactory.class);
+        try {
+            MethodHandles.lookup().ensureInitialized(ManagementFactory.class);
+        } catch (IllegalAccessException e) {}
     }
 
     private static final VMManagement jvm = new VMManagementImpl();

src/java.security.jgss/share/classes/sun/security/krb5/KerberosSecrets.java

@@ -25,11 +25,10 @@
 
 package sun.security.krb5;
 
+import java.lang.invoke.MethodHandles;
 import javax.security.auth.kerberos.KeyTab;
-import jdk.internal.misc.Unsafe;
 
 public class KerberosSecrets {
-    private static final Unsafe unsafe = Unsafe.getUnsafe();
     private static JavaxSecurityAuthKerberosAccess javaxSecurityAuthKerberosAccess;
 
     public static void setJavaxSecurityAuthKerberosAccess
@@ -39,8 +38,11 @@ public class KerberosSecrets {
 
     public static JavaxSecurityAuthKerberosAccess
             getJavaxSecurityAuthKerberosAccess() {
-        if (javaxSecurityAuthKerberosAccess == null)
+        if (javaxSecurityAuthKerberosAccess == null) {
-            unsafe.ensureClassInitialized(KeyTab.class);
+            try {
+                MethodHandles.lookup().ensureInitialized(KeyTab.class);
+            } catch (IllegalAccessException e) {}
+        }
         return javaxSecurityAuthKerberosAccess;
     }
 }

src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/NodeClass.java

@@ -33,6 +33,7 @@ import static org.graalvm.compiler.graph.Node.WithAllEdges;
 import static org.graalvm.compiler.serviceprovider.GraalUnsafeAccess.getUnsafe;
 
 import java.lang.annotation.Annotation;
+import java.lang.invoke.MethodHandles;
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -133,6 +134,7 @@ public final class NodeClass<T> extends FieldIntrospection<T> {
     public static <T> NodeClass<T> get(Class<T> clazz) {
         int numTries = 0;
         while (true) {
+            @SuppressWarnings("removal")
             boolean shouldBeInitializedBefore = UNSAFE.shouldBeInitialized(clazz);
 
             NodeClass<T> result = getUnchecked(clazz);
@@ -146,13 +148,18 @@ public final class NodeClass<T> extends FieldIntrospection<T> {
              * information without failing gates.
              */
             numTries++;
+            @SuppressWarnings("removal")
             boolean shouldBeInitializedAfter = UNSAFE.shouldBeInitialized(clazz);
             String msg = "GR-9537 Reflective field access of TYPE field returned null. This is probably a bug in HotSpot class initialization. " +
                             " clazz: " + clazz.getTypeName() + ", numTries: " + numTries +
                             ", shouldBeInitializedBefore: " + shouldBeInitializedBefore + ", shouldBeInitializedAfter: " + shouldBeInitializedAfter;
             if (numTries <= 100) {
                 TTY.println(msg);
-                UNSAFE.ensureClassInitialized(clazz);
+                try {
+                    MethodHandles.lookup().ensureInitialized(clazz);
+                } catch (IllegalAccessException e) {
+                    throw new RuntimeException(e);
+                }
             } else {
                 throw GraalError.shouldNotReachHere(msg);
             }

src/jdk.jfr/share/classes/jdk/jfr/internal/SecuritySupport.java

@@ -59,7 +59,6 @@ import java.util.Objects;
 import java.util.PropertyPermission;
 import java.util.concurrent.Callable;
 
-import jdk.internal.misc.Unsafe;
 import jdk.internal.module.Modules;
 import jdk.jfr.Event;
 import jdk.jfr.FlightRecorder;
@@ -73,7 +72,6 @@ import jdk.jfr.internal.consumer.FileAccess;
  * {@link AccessController#doPrivileged(PrivilegedAction)}
  */
 public final class SecuritySupport {
-    private final static Unsafe unsafe = Unsafe.getUnsafe();
     private final static MethodHandles.Lookup LOOKUP = MethodHandles.lookup();
     private final static Module JFR_MODULE = Event.class.getModule();
     public  final static SafePath JFC_DIRECTORY = getPathInProperty("java.home", "lib/jfr");
@@ -433,7 +431,11 @@ public final class SecuritySupport {
     }
 
     static void ensureClassIsInitialized(Class<?> clazz) {
-        unsafe.ensureClassInitialized(clazz);
+        try {
+            MethodHandles.privateLookupIn(clazz, LOOKUP).ensureInitialized(clazz);
+        } catch (IllegalAccessException e) {
+            throw new InternalError(e);
+        }
     }
 
     static Class<?> defineClass(Class<?> lookupClass, byte[] bytes) {

src/jdk.unsupported/share/classes/sun/misc/Unsafe.java

@@ -699,8 +699,19 @@ public final class Unsafe {
      * Detects if the given class may need to be initialized. This is often
      * needed in conjunction with obtaining the static field base of a
      * class.
+     *
+     * @deprecated No replacement API for this method.  As multiple threads
+     * may be trying to initialize the same class or interface at the same time.
+     * The only reliable result returned by this method is {@code false}
+     * indicating that the given class has been initialized.  Instead, simply
+     * call {@link java.lang.invoke.MethodHandles.Lookup#ensureInitialized(Class)}
+     * that does nothing if the given class has already been initialized.
+     * This method is subject to removal in a future version of JDK.
+     *
      * @return false only if a call to {@code ensureClassInitialized} would have no effect
+     *
      */
+    @Deprecated(since = "15", forRemoval = true)
     @ForceInline
     public boolean shouldBeInitialized(Class<?> c) {
         return theInternalUnsafe.shouldBeInitialized(c);
@@ -710,7 +721,11 @@ public final class Unsafe {
      * Ensures the given class has been initialized. This is often
      * needed in conjunction with obtaining the static field base of a
      * class.
+     *
+     * @deprecated Use the {@link java.lang.invoke.MethodHandles.Lookup#ensureInitialized(Class)}
+     * method instead.  This method is subject to removal in a future version of JDK.
      */
+    @Deprecated(since = "15", forRemoval = true)
     @ForceInline
     public void ensureClassInitialized(Class<?> c) {
         theInternalUnsafe.ensureClassInitialized(c);

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/Main.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.lang.invoke.MethodHandles;
+import java.lang.reflect.Method;
+
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+import static org.testng.Assert.*;
+
+/**
+ * @test
+ * @bug 8235521
+ * @summary Tests for Lookup::ensureClassInitialized
+ * @build java.base/* m1/* m2/* Main
+ * @run testng/othervm --add-modules m1 Main
+ */
+
+public class Main {
+    // Test access to public java.lang class
+    @Test
+    public void testPublic() throws Exception {
+        assertFalse(Helper.isInitialized(PublicInit.class));
+        MethodHandles.lookup().ensureInitialized(PublicInit.class);
+        assertTrue(Helper.isInitialized(PublicInit.class));
+        // no-op if already initialized
+        MethodHandles.lookup().ensureInitialized(PublicInit.class);
+    }
+
+    // access denied to package-private java.lang class
+    @Test(expectedExceptions = { IllegalAccessException.class })
+    public void testPackagePrivate() throws Exception {
+        Class<?> c = Class.forName("java.lang.DefaultInit", false, null);
+        assertFalse(Helper.isInitialized(c));
+        // access denied
+        MethodHandles.lookup().ensureInitialized(c);
+    }
+
+    // access denied to public class in a non-exported package
+    @Test(expectedExceptions = { IllegalAccessException.class })
+    public void testNonExportedPackage() throws Exception {
+        Class<?> c = Class.forName("jdk.internal.misc.VM", false, null);
+        // access denied
+        MethodHandles.lookup().ensureInitialized(c);
+    }
+
+    // invoke p1.Test::test to test module boundary access
+    @Test
+    public void testModuleAccess() throws Exception {
+        Class<?> c = Class.forName("p1.Test");
+        Method m = c.getMethod("test");
+        m.invoke(null);
+    }
+
+    @Test(expectedExceptions = { IllegalArgumentException.class })
+    public void testArrayType() throws Exception {
+        Class<?> arrayType = PublicInit.class.arrayType();
+        MethodHandles.lookup().ensureInitialized(arrayType);
+    }
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/java.base/java/lang/DefaultInit.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.lang;
+
+class DefaultInit {
+    private static boolean initialized;
+    static {
+        initialized = true;
+    }
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/java.base/java/lang/Helper.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.lang;
+
+import jdk.internal.misc.Unsafe;
+
+public class Helper {
+    private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+    public static boolean isInitialized(Class<?> c) {
+        return !UNSAFE.shouldBeInitialized(c);
+    }
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/java.base/java/lang/PublicInit.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.lang;
+
+public class PublicInit {
+    private static boolean initialized;
+    static {
+        initialized = true;
+    }
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m1/module-info.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+module m1 {
+    requires m2;
+    exports p1;
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m1/p1/A.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p1;
+
+import java.lang.invoke.MethodHandles;
+
+public class A {
+    static final Object lock;
+    static {
+        try {
+            MethodHandles.lookup().ensureInitialized(A.class);
+            lock = new Object();
+        } catch (IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m1/p1/B.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p1;
+
+class B {
+    private static final B INSTANCE = new B();
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m1/p1/Test.java

@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package p1;
+
+import p1.internal.*;
+import static java.lang.invoke.MethodHandles.Lookup.*;
+
+import java.lang.invoke.MethodHandles;
+
+/*
+ * Test::test is invoked by Main class
+ */
+public class Test {
+    public static void test() throws Exception {
+        clinitInvokeEnsureClassInitialized();
+        testModuleAccess();
+        testPackageAccess();
+        testFullPrivilegeAccess();
+    }
+
+    /*
+     * A::<clinit> calls Lookup::ensureClassInitialized(A.class)
+     */
+    public static void clinitInvokeEnsureClassInitialized() throws Exception {
+        assertFalse(Helper.isInitialized(A.class));
+
+        // same package and public type
+        MethodHandles.lookup().ensureInitialized(A.class);
+        assertTrue(Helper.isInitialized(A.class));
+    }
+
+    /*
+     * Test Lookup with MODULE access to initialize class in this module
+     * and another module it reads.
+     */
+    public static void testModuleAccess() throws Exception {
+        MethodHandles.Lookup lookup = MethodHandles.lookup().dropLookupMode(PACKAGE);
+        assertTrue((lookup.lookupModes() & PACKAGE) == 0);
+
+        assertFalse(Helper.isInitialized(p2.T.class));
+        // exported by another module
+        lookup.ensureInitialized(p2.T.class);
+        assertTrue(Helper.isInitialized(p2.T.class));
+
+        // non-exported type in another module
+        Class<?> x = Class.forName(p2.T.class.getModule(), "p2.internal.X");
+        assertFalse(Helper.isInitialized(x));
+        try {
+            lookup.ensureInitialized(x);
+            throw new AssertionError(lookup + " should not have access to " + x);
+        } catch (IllegalAccessException e) {}
+
+        // no access to package-private class in the same module
+        try {
+            lookup.ensureInitialized(E.class);
+            throw new AssertionError(lookup + " should not have access to " + E.class);
+        } catch (IllegalAccessException e) {}
+    }
+
+    /*
+     * Test Lookup with PACKAGE access
+     */
+    public static void testPackageAccess() throws Exception {
+        MethodHandles.Lookup lookup = MethodHandles.lookup().dropLookupMode(PRIVATE);
+        assertTrue((lookup.lookupModes() & PRIVATE) == 0);
+        // verify these classes are not initialized
+        assertFalse(Helper.isInitialized(B.class));
+        assertFalse(Helper.isInitialized(C.class));
+        assertFalse(Helper.isInitialized(E.class));
+
+        // same package but package-private
+        lookup.ensureInitialized(B.class);
+        assertTrue(Helper.isInitialized(B.class));
+
+        // different package and public type
+        lookup.ensureInitialized(C.class);
+        assertTrue(Helper.isInitialized(C.class));
+
+        // different package and non-public types
+        Class<?> d = Class.forName(Test.class.getModule(), "p1.internal.D");
+        assertFalse(Helper.isInitialized(d));
+        try {
+            lookup.ensureInitialized(d);
+            throw new AssertionError(lookup + " should not have access to " + d);
+        } catch (IllegalAccessException e) {}
+    }
+
+    /*
+     * Test Lookup with full privilege access
+     */
+    public static void testFullPrivilegeAccess() throws Exception {
+        MethodHandles.Lookup lookup = MethodHandles.lookup();
+        // these classes have been initialized
+        assertTrue(Helper.isInitialized(A.class)); // same package and public type
+        assertTrue(Helper.isInitialized(B.class)); // same package but package-private
+        assertTrue(Helper.isInitialized(C.class)); // different package and public type
+
+        // verify access to these classes
+        lookup.ensureInitialized(A.class);
+        lookup.ensureInitialized(B.class);
+        lookup.ensureInitialized(C.class);
+
+        // different package and non-public types
+        Class<?> d = Class.forName(Test.class.getModule(), "p1.internal.D");
+        try {
+            assertFalse(Helper.isInitialized(d));
+            lookup.ensureInitialized(d);
+            throw new AssertionError(lookup + " should not have access to " + d);
+        } catch (IllegalAccessException e) {}
+
+        // nestmate and same package
+        assertFalse(Helper.isInitialized(E.class));
+        assertTrue(Test.class.isNestmateOf(E.class));
+        lookup.ensureInitialized(E.class);
+    }
+
+    public static void assertTrue(boolean v) {
+        if (!v) {
+            throw new AssertionError("unexpected result");
+        }
+    }
+
+    public static void assertFalse(boolean v) {
+        if (v) {
+            throw new AssertionError("unexpected result");
+        }
+    }
+
+    // nestmate
+    static class E {
+    }
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m1/p1/internal/C.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p1.internal;
+
+public class C {
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m1/p1/internal/D.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p1.internal;
+
+class D {
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m2/module-info.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+module m2 {
+    exports p2 to m1;
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m2/p2/T.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p2;
+
+public class T {
+}

test/jdk/java/lang/invoke/MethodHandles/ensureInitialized/m2/p2/internal/X.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package p2.internal;
+
+public class X {
+}