--- jsr166/src/test/tck/ConcurrentHashMap8Test.java	2015/05/24 01:23:17	1.29
+++ jsr166/src/test/tck/ConcurrentHashMap8Test.java	2018/01/07 23:31:01	1.36
@@ -11,12 +11,13 @@ import static java.util.Spliterator.NONN
 import java.util.AbstractMap;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.Spliterator;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.LongAdder;
 import java.util.function.BiFunction;
@@ -62,7 +63,7 @@ public class ConcurrentHashMap8Test exte
      */
     public void testComputeIfAbsent() {
         ConcurrentHashMap map = map5();
-        map.computeIfAbsent(six, (x) -> "Z");
+        map.computeIfAbsent(six, x -> "Z");
         assertTrue(map.containsKey(six));
     }
 
@@ -71,7 +72,7 @@ public class ConcurrentHashMap8Test exte
      */
     public void testComputeIfAbsent2() {
         ConcurrentHashMap map = map5();
-        assertEquals("A", map.computeIfAbsent(one, (x) -> "Z"));
+        assertEquals("A", map.computeIfAbsent(one, x -> "Z"));
     }
 
     /**
@@ -79,7 +80,7 @@ public class ConcurrentHashMap8Test exte
      */
     public void testComputeIfAbsent3() {
         ConcurrentHashMap map = map5();
-        map.computeIfAbsent(six, (x) -> null);
+        map.computeIfAbsent(six, x -> null);
         assertFalse(map.containsKey(six));
     }
 
@@ -184,7 +185,7 @@ public class ConcurrentHashMap8Test exte
      */
     public void testReplaceAll() {
         ConcurrentHashMap<Integer, String> map = map5();
-        map.replaceAll((x, y) -> { return x > 3 ? "Z" : y; });
+        map.replaceAll((x, y) -> (x > 3) ? "Z" : y);
         assertEquals("A", map.get(one));
         assertEquals("B", map.get(two));
         assertEquals("C", map.get(three));
@@ -209,8 +210,8 @@ public class ConcurrentHashMap8Test exte
         Set set1 = map.keySet();
         Set set2 = map.keySet(true);
         set2.add(six);
-        assertTrue(((ConcurrentHashMap.KeySetView)set2).getMap() == map);
-        assertTrue(((ConcurrentHashMap.KeySetView)set1).getMap() == map);
+        assertSame(map, ((ConcurrentHashMap.KeySetView)set2).getMap());
+        assertSame(map, ((ConcurrentHashMap.KeySetView)set1).getMap());
         assertEquals(set2.size(), map.size());
         assertEquals(set1.size(), map.size());
         assertTrue((Boolean)map.get(six));
@@ -304,10 +305,10 @@ public class ConcurrentHashMap8Test exte
         assertFalse(set.add(one));
         assertTrue(set.add(six));
         assertTrue(set.add(seven));
-        assertTrue(set.getMappedValue() == one);
-        assertTrue(map.get(one) != one);
-        assertTrue(map.get(six) == one);
-        assertTrue(map.get(seven) == one);
+        assertSame(one, set.getMappedValue());
+        assertNotSame(one, map.get(one));
+        assertSame(one, map.get(six));
+        assertSame(one, map.get(seven));
     }
 
     void checkSpliteratorCharacteristics(Spliterator<?> sp,
@@ -406,7 +407,7 @@ public class ConcurrentHashMap8Test exte
         Integer[] elements = new Integer[size];
         for (int i = 0; i < size; i++)
             elements[i] = i;
-        Collections.shuffle(Arrays.asList(elements));
+        shuffle(elements);
         Collection<Integer> full = populatedSet(elements);
 
         Iterator it = full.iterator();
@@ -496,7 +497,7 @@ public class ConcurrentHashMap8Test exte
         Integer[] elements = new Integer[size];
         for (int i = 0; i < size; i++)
             elements[i] = i;
-        Collections.shuffle(Arrays.asList(elements));
+        shuffle(elements);
         Collection<Integer> full = populatedSet(elements);
 
         assertTrue(Arrays.asList(elements).containsAll(Arrays.asList(full.toArray())));
@@ -526,7 +527,7 @@ public class ConcurrentHashMap8Test exte
         Integer[] elements = new Integer[size];
         for (int i = 0; i < size; i++)
             elements[i] = i;
-        Collections.shuffle(Arrays.asList(elements));
+        shuffle(elements);
         Collection<Integer> full = populatedSet(elements);
 
         Arrays.fill(a, 42);
@@ -542,7 +543,7 @@ public class ConcurrentHashMap8Test exte
     }
 
     /**
-     * A deserialized serialized set is equal
+     * A deserialized/reserialized set equals original
      */
     public void testSerialization() throws Exception {
         int size = 20;
@@ -1088,4 +1089,30 @@ public class ConcurrentHashMap8Test exte
         assertNull(r);
     }
 
+    /**
+     * Tests performance of computeIfAbsent when the element is present.
+     * See JDK-8161372
+     * ant -Djsr166.tckTestClass=ConcurrentHashMapTest -Djsr166.methodFilter=testcomputeIfAbsent_performance -Djsr166.expensiveTests=true tck
+     */
+    public void testcomputeIfAbsent_performance() {
+        final int mapSize = 20;
+        final int iterations = expensiveTests ? (1 << 23) : mapSize * 2;
+        final int threads = expensiveTests ? 10 : 2;
+        final ConcurrentHashMap<Integer, Integer> map = new ConcurrentHashMap<>();
+        for (int i = 0; i < mapSize; i++)
+            map.put(i, i);
+        final ExecutorService pool = Executors.newFixedThreadPool(2);
+        try (PoolCleaner cleaner = cleaner(pool)) {
+            Runnable r = new CheckedRunnable() {
+                public void realRun() {
+                    int result = 0;
+                    for (int i = 0; i < iterations; i++)
+                        result += map.computeIfAbsent(i % mapSize, k -> k + k);
+                    if (result == -42) throw new Error();
+                }};
+            for (int i = 0; i < threads; i++)
+                pool.execute(r);
+        }
+    }
+
 }