8355369: Remove setAccessible usage for setting final fields in java.util.concurrent

Reviewed-by: pminborg, dl, rgiulietti, alanb

Author: Viktor Klang

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

@@ -35,7 +35,9 @@
 
 package java.util.concurrent;
 
-import java.lang.reflect.Field;
+import jdk.internal.misc.Unsafe;
+
+import java.lang.invoke.VarHandle;
 import java.util.AbstractSet;
 import java.util.Collection;
 import java.util.Collections;
@@ -176,6 +178,8 @@ public ConcurrentSkipListSet<E> clone() {
             ConcurrentSkipListSet<E> clone =
                 (ConcurrentSkipListSet<E>) super.clone();
             clone.setMap(new ConcurrentSkipListMap<E,Object>(m));
+            // Needed to ensure safe publication of setMap()
+            VarHandle.releaseFence();
             return clone;
         } catch (CloneNotSupportedException e) {
             throw new InternalError();
@@ -527,12 +531,11 @@ public Spliterator<E> spliterator() {
 
     /** Initializes map field; for use in clone. */
     private void setMap(ConcurrentNavigableMap<E,Object> map) {
-        try {
-            Field mapField = ConcurrentSkipListSet.class.getDeclaredField("m");
-            mapField.setAccessible(true);
-            mapField.set(this, map);
-        } catch (IllegalAccessException | NoSuchFieldException e) {
-            throw new Error(e);
-        }
+        final Unsafe U = Unsafe.getUnsafe();
+        U.putReference(
+            this,
+            U.objectFieldOffset(ConcurrentSkipListSet.class, "m"),
+            map
+        );
     }
 }

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

@@ -35,7 +35,6 @@
 package java.util.concurrent;
 
 import java.lang.invoke.VarHandle;
-import java.lang.reflect.Field;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -57,6 +56,7 @@
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 import jdk.internal.access.SharedSecrets;
+import jdk.internal.misc.Unsafe;
 import jdk.internal.util.ArraysSupport;
 
 /**
@@ -2095,12 +2095,11 @@ public List<E> reversed() {
 
     /** Initializes the lock; for use when deserializing or cloning. */
     private void resetLock() {
-        try {
-            Field lockField = CopyOnWriteArrayList.class.getDeclaredField("lock");
-            lockField.setAccessible(true);
-            lockField.set(this, new Object());
-        } catch (IllegalAccessException | NoSuchFieldException e) {
-            throw new Error(e);
-        }
+        final Unsafe U = Unsafe.getUnsafe();
+        U.putReference(
+            this,
+            U.objectFieldOffset(CopyOnWriteArrayList.class, "lock"),
+            new Object()
+        );
     }
 }

src/java.base/share/classes/java/util/concurrent/atomic/AtomicReferenceArray.java

@@ -35,10 +35,11 @@
 
 package java.util.concurrent.atomic;
 
+import jdk.internal.misc.Unsafe;
+
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.VarHandle;
 import java.lang.reflect.Array;
-import java.lang.reflect.Field;
 import java.util.Arrays;
 import java.util.function.BinaryOperator;
 import java.util.function.UnaryOperator;
@@ -330,14 +331,13 @@ private void readObject(java.io.ObjectInputStream s)
             throw new java.io.InvalidObjectException("Not array type");
         if (a.getClass() != Object[].class)
             a = Arrays.copyOf((Object[])a, Array.getLength(a), Object[].class);
-        try {
 
-            Field arrayField = AtomicReferenceArray.class.getDeclaredField("array");
-            arrayField.setAccessible(true);
-            arrayField.set(this, a);
-        } catch (NoSuchFieldException | IllegalAccessException e) {
-            throw new Error(e);
-        }
+        final Unsafe U = Unsafe.getUnsafe();
+        U.putReference(
+            this,
+            U.objectFieldOffset(AtomicReferenceArray.class, "array"),
+            a
+        );
     }
 
     // jdk9
@@ -523,5 +523,4 @@ public final boolean weakCompareAndSetAcquire(int i, E expectedValue, E newValue
     public final boolean weakCompareAndSetRelease(int i, E expectedValue, E newValue) {
         return AA.weakCompareAndSetRelease(array, i, expectedValue, newValue);
     }
-
 }