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

@  rev 60626 : 8251397: NPE on ClassValue.ClassValueMap.cacheArray
|  Reviewed-by: aph
~

*** 27,36 ****
--- 27,38 ----
  
  import java.util.WeakHashMap;
  import java.lang.ref.WeakReference;
  import java.util.concurrent.atomic.AtomicInteger;
  
+ import jdk.internal.misc.Unsafe;
+ 
  import static java.lang.ClassValue.ClassValueMap.probeHomeLocation;
  import static java.lang.ClassValue.ClassValueMap.probeBackupLocations;
  
  /**
   * Lazily associate a computed value with (potentially) every type.
*** 409,423 ****
--- 411,429 ----
           *  It would be pointless to make this much smaller than the Class and ClassValueMap objects themselves.
           *  Must be a power of 2.
           */
          private static final int INITIAL_ENTRIES = 32;
  
+         private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+ 
          /** Build a backing map for ClassValues.
           *  Also, create an empty cache array and install it on the class.
           */
          ClassValueMap() {
              sizeCache(INITIAL_ENTRIES);
+             // Trailing release fence to get safe publication
+             UNSAFE.storeFence();
          }
  
          Entry<?>[] getCache() { return cacheArray; }
  
          /** Initiate a query.  Store a promise (placeholder) if there is no value yet. */