--- jsr166/src/jsr166e/LongAdderTable.java	2011/09/10 01:44:53	1.6
+++ jsr166/src/jsr166e/LongAdderTable.java	2015/01/18 20:17:33	1.11
@@ -5,6 +5,7 @@
  */
 
 package jsr166e;
+
 import jsr166e.LongAdder;
 import java.util.Map;
 import java.util.Set;
@@ -12,13 +13,13 @@ import java.io.Serializable;
 
 /**
  * A keyed table of adders, that may be useful in computing frequency
- * counts and histograms, or may be used a form of multiset.  A {@link
- * LongAdder} is associated with each key. Keys are added to the table
- * implicitly upon any attempt to update, or may be added explicitly
- * using method {@link #install}.
+ * counts and histograms, or may be used as a form of multiset.  A
+ * {@link LongAdder} is associated with each key. Keys are added to
+ * the table implicitly upon any attempt to update, or may be added
+ * explicitly using method {@link #install}.
  *
  * <p><em>jsr166e note: This class is targeted to be placed in
- * java.util.concurrent.atomic<em>
+ * java.util.concurrent.atomic.</em>
  *
  * @since 1.8
  * @author Doug Lea
@@ -31,8 +32,8 @@ public class LongAdderTable<K> implement
     private final ConcurrentHashMapV8<K, LongAdder> map;
 
     static final class CreateAdder
-        implements ConcurrentHashMapV8.MappingFunction<Object, LongAdder> {
-        public LongAdder map(Object unused) { return new LongAdder(); }
+        implements ConcurrentHashMapV8.Fun<Object, LongAdder> {
+        public LongAdder apply(Object unused) { return new LongAdder(); }
     }
 
     private static final CreateAdder createAdder = new CreateAdder();
@@ -53,13 +54,7 @@ public class LongAdderTable<K> implement
      * @return the adder associated with the key
      */
     public LongAdder install(K key) {
-        LongAdder a = map.get(key);
-        if (a == null) {
-            LongAdder r = new LongAdder();
-            if ((a = map.putIfAbsent(key, r)) == null)
-                a = r;
-        }
-        return a;
+        return map.computeIfAbsent(key, createAdder);
     }
 
     /**
@@ -71,10 +66,7 @@ public class LongAdderTable<K> implement
      * @param x the value to add
      */
     public void add(K key, long x) {
-        LongAdder a = map.get(key);
-        if (a == null)
-            a = map.computeIfAbsent(key, createAdder);
-        a.add(x);
+        map.computeIfAbsent(key, createAdder).add(x);
     }
 
     /**