8325949: Create an internal utility method for creating VarHandle instances

Reviewed-by: rriggs

Author: minborg

src/java.base/share/classes/java/lang/ThreadBuilders.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -34,6 +34,7 @@
 import java.util.concurrent.Executor;
 import java.util.concurrent.ThreadFactory;
 import jdk.internal.misc.Unsafe;
+import jdk.internal.invoke.MhUtil;
 import jdk.internal.vm.ContinuationSupport;
 
 /**
@@ -273,15 +274,9 @@ public ThreadFactory factory() {
      * Base ThreadFactory implementation.
      */
     private abstract static class BaseThreadFactory implements ThreadFactory {
-        private static final VarHandle COUNT;
-        static {
-            try {
-                MethodHandles.Lookup l = MethodHandles.lookup();
-                COUNT = l.findVarHandle(BaseThreadFactory.class, "count", long.class);
-            } catch (Exception e) {
-                throw new InternalError(e);
-            }
-        }
+        private static final VarHandle COUNT = MhUtil.findVarHandle(
+                MethodHandles.lookup(), "count", long.class);
+
         private final String name;
         private final int characteristics;
         private final UncaughtExceptionHandler uhe;

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

@@ -25,6 +25,7 @@
 
 package java.lang.invoke;
 
+import jdk.internal.invoke.MhUtil;
 import jdk.internal.vm.annotation.DontInline;
 import jdk.internal.vm.annotation.ForceInline;
 import jdk.internal.vm.annotation.Hidden;
@@ -681,16 +682,9 @@ private static NamedFunction getNamedFunction(String name, MethodType type)
     }
 
     private static class Lazy {
-        private static final MethodHandle MH_asSpreader;
-
-        static {
-            try {
-                MH_asSpreader = IMPL_LOOKUP.findVirtual(MethodHandle.class, "asSpreader",
-                        MethodType.methodType(MethodHandle.class, Class.class, int.class));
-            } catch (ReflectiveOperationException ex) {
-                throw newInternalError(ex);
-            }
-        }
+        private static final MethodHandle MH_asSpreader = MhUtil.findVirtual(
+                IMPL_LOOKUP, MethodHandle.class, "asSpreader",
+                MethodType.methodType(MethodHandle.class, Class.class, int.class));
     }
 
     static {

src/java.base/share/classes/java/net/Socket.java

@@ -27,6 +27,7 @@
 
 import jdk.internal.event.SocketReadEvent;
 import jdk.internal.event.SocketWriteEvent;
+import jdk.internal.invoke.MhUtil;
 import sun.security.util.SecurityConstants;
 
 import java.io.InputStream;
@@ -102,14 +103,10 @@
 public class Socket implements java.io.Closeable {
     private static final VarHandle STATE, IN, OUT;
     static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            STATE = l.findVarHandle(Socket.class, "state", int.class);
-            IN = l.findVarHandle(Socket.class, "in", InputStream.class);
-            OUT = l.findVarHandle(Socket.class, "out", OutputStream.class);
-        } catch (Exception e) {
-            throw new InternalError(e);
-        }
+        MethodHandles.Lookup l = MethodHandles.lookup();
+        STATE = MhUtil.findVarHandle(l, "state", int.class);
+        IN = MhUtil.findVarHandle(l, "in", InputStream.class);
+        OUT = MhUtil.findVarHandle(l, "out", OutputStream.class);
     }
 
     // the underlying SocketImpl, may be null, may be swapped when connecting

src/java.base/share/classes/java/nio/channels/SelectionKey.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2024, 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
@@ -25,6 +25,8 @@
 
 package java.nio.channels;
 
+import jdk.internal.invoke.MhUtil;
+
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 
@@ -429,15 +431,9 @@ public final boolean isAcceptable() {
 
     // -- Attachments --
 
-    private static final VarHandle ATTACHMENT;
-    static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            ATTACHMENT = l.findVarHandle(SelectionKey.class, "attachment", Object.class);
-        } catch (Exception e) {
-            throw new InternalError(e);
-        }
-    }
+    private static final VarHandle ATTACHMENT = MhUtil.findVarHandle(
+            MethodHandles.lookup(), "attachment", Object.class);
+
     private volatile Object attachment;
 
     /**

src/java.base/share/classes/java/nio/channels/spi/AbstractSelectionKey.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2024, 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
@@ -30,6 +30,7 @@
 import java.nio.channels.SelectionKey;
 import java.nio.channels.Selector;
 
+import jdk.internal.invoke.MhUtil;
 import sun.nio.ch.SelectionKeyImpl;
 import sun.nio.ch.SelectorImpl;
 
@@ -46,15 +47,8 @@
 public abstract class AbstractSelectionKey
     extends SelectionKey
 {
-    private static final VarHandle INVALID;
-    static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            INVALID = l.findVarHandle(AbstractSelectionKey.class, "invalid", boolean.class);
-        } catch (Exception e) {
-            throw new InternalError(e);
-        }
-    }
+    private static final VarHandle INVALID = MhUtil.findVarHandle(
+            MethodHandles.lookup(), "invalid", boolean.class);
 
     /**
      * Initializes a new instance of this class.

src/java.base/share/classes/java/nio/channels/spi/AbstractSelector.java

@@ -32,6 +32,8 @@
 import java.nio.channels.Selector;
 import java.util.HashSet;
 import java.util.Set;
+
+import jdk.internal.invoke.MhUtil;
 import sun.nio.ch.Interruptible;
 import sun.nio.ch.SelectorImpl;
 
@@ -72,15 +74,9 @@
 public abstract class AbstractSelector
     extends Selector
 {
-    private static final VarHandle CLOSED;
-    static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            CLOSED = l.findVarHandle(AbstractSelector.class, "closed", boolean.class);
-        } catch (Exception e) {
-            throw new InternalError(e);
-        }
-    }
+    private static final VarHandle CLOSED = MhUtil.findVarHandle(
+            MethodHandles.lookup(), "closed", boolean.class);
+
     private volatile boolean closed;
 
     // The provider that created this selector

src/java.base/share/classes/java/util/concurrent/CompletableFuture.java

@@ -35,6 +35,8 @@
 
 package java.util.concurrent;
 
+import jdk.internal.invoke.MhUtil;
+
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import java.util.concurrent.locks.LockSupport;
@@ -3079,14 +3081,10 @@ static final class MinimalStage<T> extends CompletableFuture<T> {
     private static final VarHandle STACK;
     private static final VarHandle NEXT;
     static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            RESULT = l.findVarHandle(CompletableFuture.class, "result", Object.class);
-            STACK = l.findVarHandle(CompletableFuture.class, "stack", Completion.class);
-            NEXT = l.findVarHandle(Completion.class, "next", Completion.class);
-        } catch (ReflectiveOperationException e) {
-            throw new ExceptionInInitializerError(e);
-        }
+        MethodHandles.Lookup l = MethodHandles.lookup();
+        RESULT = MhUtil.findVarHandle(l, "result", Object.class);
+        STACK = MhUtil.findVarHandle(l, "stack", Completion.class);
+        NEXT = MhUtil.findVarHandle(l, Completion.class, "next", Completion.class);
 
         // Reduce the risk of rare disastrous classloading in first call to
         // LockSupport.park: https://bugs.openjdk.org/browse/JDK-8074773

src/java.base/share/classes/java/util/concurrent/Exchanger.java

@@ -36,6 +36,8 @@
 
 package java.util.concurrent;
 
+import jdk.internal.invoke.MhUtil;
+
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import java.util.concurrent.locks.LockSupport;
@@ -530,15 +532,11 @@ public V exchange(V x, long timeout, TimeUnit unit)
     private static final VarHandle ENTRY;
     private static final VarHandle AA;
     static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            BOUND = l.findVarHandle(Exchanger.class, "bound", int.class);
-            MATCH = l.findVarHandle(Node.class, "match", Object.class);
-            ENTRY = l.findVarHandle(Slot.class, "entry", Node.class);
-            AA = MethodHandles.arrayElementVarHandle(Slot[].class);
-        } catch (ReflectiveOperationException e) {
-            throw new ExceptionInInitializerError(e);
-        }
+        MethodHandles.Lookup l = MethodHandles.lookup();
+        BOUND = MhUtil.findVarHandle(l, "bound", int.class);
+        MATCH = MhUtil.findVarHandle(l, Node.class, "match", Object.class);
+        ENTRY = MhUtil.findVarHandle(l, Slot.class, "entry", Node.class);
+        AA = MethodHandles.arrayElementVarHandle(Slot[].class);
     }
 
 }

src/java.base/share/classes/java/util/concurrent/FutureTask.java

@@ -35,6 +35,8 @@
 
 package java.util.concurrent;
 
+import jdk.internal.invoke.MhUtil;
+
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import java.util.concurrent.locks.LockSupport;
@@ -582,14 +584,10 @@ public String toString() {
     private static final VarHandle RUNNER;
     private static final VarHandle WAITERS;
     static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            STATE = l.findVarHandle(FutureTask.class, "state", int.class);
-            RUNNER = l.findVarHandle(FutureTask.class, "runner", Thread.class);
-            WAITERS = l.findVarHandle(FutureTask.class, "waiters", WaitNode.class);
-        } catch (ReflectiveOperationException e) {
-            throw new ExceptionInInitializerError(e);
-        }
+        MethodHandles.Lookup l = MethodHandles.lookup();
+        STATE = MhUtil.findVarHandle(l, "state", int.class);
+        RUNNER = MhUtil.findVarHandle(l, "runner", Thread.class);
+        WAITERS = MhUtil.findVarHandle(l, "waiters", WaitNode.class);
 
         // Reduce the risk of rare disastrous classloading in first call to
         // LockSupport.park: https://bugs.openjdk.org/browse/JDK-8074773

src/java.base/share/classes/java/util/concurrent/Phaser.java

@@ -35,6 +35,8 @@
 
 package java.util.concurrent;
 
+import jdk.internal.invoke.MhUtil;
+
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import java.util.concurrent.atomic.AtomicReference;
@@ -1137,15 +1139,9 @@ public boolean block() {
     }
 
     // VarHandle mechanics
-    private static final VarHandle STATE;
+    private static final VarHandle STATE = MhUtil.findVarHandle(
+            MethodHandles.lookup(), "state", long.class);
     static {
-        try {
-            MethodHandles.Lookup l = MethodHandles.lookup();
-            STATE = l.findVarHandle(Phaser.class, "state", long.class);
-        } catch (ReflectiveOperationException e) {
-            throw new ExceptionInInitializerError(e);
-        }
-
         // Reduce the risk of rare disastrous classloading in first call to
         // LockSupport.park: https://bugs.openjdk.org/browse/JDK-8074773
         Class<?> ensureLoaded = LockSupport.class;