--- jsr166/src/test/tck/ConcurrentHashMapTest.java	2011/03/15 19:47:06	1.23
+++ jsr166/src/test/tck/ConcurrentHashMapTest.java	2021/01/27 01:57:24	1.65
@@ -1,30 +1,48 @@
 /*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
+ * Written by Doug Lea and Martin Buchholz with assistance from
+ * members of JCP JSR-166 Expert Group and released to the public
+ * domain, as explained at
  * http://creativecommons.org/publicdomain/zero/1.0/
  * Other contributors include Andrew Wright, Jeffrey Hayes,
  * Pat Fisher, Mike Judd.
  */
 
-import junit.framework.*;
-import java.util.*;
-import java.util.concurrent.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Enumeration;
-import java.io.*;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import junit.framework.Test;
 
 public class ConcurrentHashMapTest extends JSR166TestCase {
     public static void main(String[] args) {
-        junit.textui.TestRunner.run(suite());
+        main(suite(), args);
     }
     public static Test suite() {
-        return new TestSuite(ConcurrentHashMapTest.class);
+        class Implementation implements MapImplementation {
+            public Class<?> klazz() { return ConcurrentHashMap.class; }
+            public Map emptyMap() { return new ConcurrentHashMap(); }
+            public boolean isConcurrent() { return true; }
+            public boolean permitsNullKeys() { return false; }
+            public boolean permitsNullValues() { return false; }
+            public boolean supportsSetValue() { return true; }
+        }
+        return newTestSuite(
+            ConcurrentHashMapTest.class,
+            MapTest.testSuite(new Implementation()));
     }
 
     /**
-     * Create a map from Integers 1-5 to Strings "A"-"E".
+     * Returns a new map from Items 1-5 to Strings "A"-"E".
      */
-    private static ConcurrentHashMap map5() {
-        ConcurrentHashMap map = new ConcurrentHashMap(5);
+    private static ConcurrentHashMap<Item, String> map5() {
+        ConcurrentHashMap<Item, String> map = new ConcurrentHashMap<>(5);
         assertTrue(map.isEmpty());
         map.put(one, "A");
         map.put(two, "B");
@@ -32,37 +50,200 @@ public class ConcurrentHashMapTest exten
         map.put(four, "D");
         map.put(five, "E");
         assertFalse(map.isEmpty());
-        assertEquals(5, map.size());
+        mustEqual(5, map.size());
         return map;
     }
 
+    // classes for testing Comparable fallbacks
+    static class BI implements Comparable<BI> {
+        private final int value;
+        BI(int value) { this.value = value; }
+        public int compareTo(BI other) {
+            return Integer.compare(value, other.value);
+        }
+        public boolean equals(Object x) {
+            return (x instanceof BI) && ((BI)x).value == value;
+        }
+        public int hashCode() { return 42; }
+    }
+    static class CI extends BI { CI(int value) { super(value); } }
+    static class DI extends BI { DI(int value) { super(value); } }
+
+    static class BS implements Comparable<BS> {
+        private final String value;
+        BS(String value) { this.value = value; }
+        public int compareTo(BS other) {
+            return value.compareTo(other.value);
+        }
+        public boolean equals(Object x) {
+            return (x instanceof BS) && value.equals(((BS)x).value);
+        }
+        public int hashCode() { return 42; }
+    }
+
+    static class LexicographicList<E extends Comparable<E>> extends ArrayList<E>
+        implements Comparable<LexicographicList<E>> {
+        LexicographicList(Collection<E> c) { super(c); }
+        LexicographicList(E e) { super(Collections.singleton(e)); }
+        public int compareTo(LexicographicList<E> other) {
+            int common = Math.min(size(), other.size());
+            int r = 0;
+            for (int i = 0; i < common; i++) {
+                if ((r = get(i).compareTo(other.get(i))) != 0)
+                    break;
+            }
+            if (r == 0)
+                r = Integer.compare(size(), other.size());
+            return r;
+        }
+        private static final long serialVersionUID = 0;
+    }
+
+    static class CollidingObject {
+        final String value;
+        CollidingObject(final String value) { this.value = value; }
+        public int hashCode() { return this.value.hashCode() & 1; }
+        public boolean equals(final Object obj) {
+            return (obj instanceof CollidingObject) && ((CollidingObject)obj).value.equals(value);
+        }
+    }
+
+    static class ComparableCollidingObject extends CollidingObject implements Comparable<ComparableCollidingObject> {
+        ComparableCollidingObject(final String value) { super(value); }
+        public int compareTo(final ComparableCollidingObject o) {
+            return value.compareTo(o.value);
+        }
+    }
+
+    /**
+     * Inserted elements that are subclasses of the same Comparable
+     * class are found.
+     */
+    public void testComparableFamily() {
+        int size = 500;         // makes measured test run time -> 60ms
+        ConcurrentHashMap<BI, Boolean> m = new ConcurrentHashMap<>();
+        for (int i = 0; i < size; i++) {
+            assertNull(m.put(new CI(i), true));
+        }
+        for (int i = 0; i < size; i++) {
+            assertTrue(m.containsKey(new CI(i)));
+            assertTrue(m.containsKey(new DI(i)));
+        }
+    }
+
+    /**
+     * Elements of classes with erased generic type parameters based
+     * on Comparable can be inserted and found.
+     */
+    public void testGenericComparable() {
+        int size = 120;         // makes measured test run time -> 60ms
+        ConcurrentHashMap<Object, Boolean> m = new ConcurrentHashMap<>();
+        for (int i = 0; i < size; i++) {
+            BI bi = new BI(i);
+            BS bs = new BS(String.valueOf(i));
+            LexicographicList<BI> bis = new LexicographicList<>(bi);
+            LexicographicList<BS> bss = new LexicographicList<>(bs);
+            assertNull(m.putIfAbsent(bis, true));
+            assertTrue(m.containsKey(bis));
+            if (m.putIfAbsent(bss, true) == null)
+                assertTrue(m.containsKey(bss));
+            assertTrue(m.containsKey(bis));
+        }
+        for (int i = 0; i < size; i++) {
+            assertTrue(m.containsKey(Collections.singletonList(new BI(i))));
+        }
+    }
+
+    /**
+     * Elements of non-comparable classes equal to those of classes
+     * with erased generic type parameters based on Comparable can be
+     * inserted and found.
+     */
+    public void testGenericComparable2() {
+        int size = 500;         // makes measured test run time -> 60ms
+        ConcurrentHashMap<Object, Boolean> m = new ConcurrentHashMap<>();
+        for (int i = 0; i < size; i++) {
+            m.put(Collections.singletonList(new BI(i)), true);
+        }
+
+        for (int i = 0; i < size; i++) {
+            LexicographicList<BI> bis = new LexicographicList<>(new BI(i));
+            assertTrue(m.containsKey(bis));
+        }
+    }
+
+    /**
+     * Mixtures of instances of comparable and non-comparable classes
+     * can be inserted and found.
+     */
+    public void testMixedComparable() {
+        int size = 1200;        // makes measured test run time -> 35ms
+        ConcurrentHashMap<Object, Object> map = new ConcurrentHashMap<>();
+        Random rng = new Random();
+        for (int i = 0; i < size; i++) {
+            Object x;
+            switch (rng.nextInt(4)) {
+            case 0:
+                x = new Object();
+                break;
+            case 1:
+                x = new CollidingObject(Integer.toString(i));
+                break;
+            default:
+                x = new ComparableCollidingObject(Integer.toString(i));
+            }
+            assertNull(map.put(x, x));
+        }
+        int count = 0;
+        for (Object k : map.keySet()) {
+            mustEqual(map.get(k), k);
+            ++count;
+        }
+        mustEqual(count, size);
+        mustEqual(map.size(), size);
+        for (Object k : map.keySet()) {
+            mustEqual(map.put(k, k), k);
+        }
+    }
+
     /**
      * clear removes all pairs
      */
     public void testClear() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         map.clear();
-        assertEquals(map.size(), 0);
+        mustEqual(0, map.size());
     }
 
     /**
      * Maps with same contents are equal
      */
     public void testEquals() {
-        ConcurrentHashMap map1 = map5();
-        ConcurrentHashMap map2 = map5();
-        assertEquals(map1, map2);
-        assertEquals(map2, map1);
+        ConcurrentHashMap<Item,String> map1 = map5();
+        ConcurrentHashMap<Item,String> map2 = map5();
+        mustEqual(map1, map2);
+        mustEqual(map2, map1);
         map1.clear();
         assertFalse(map1.equals(map2));
         assertFalse(map2.equals(map1));
     }
 
     /**
+     * hashCode() equals sum of each key.hashCode ^ value.hashCode
+     */
+    public void testHashCode() {
+        ConcurrentHashMap<Item,String> map = map5();
+        int sum = 0;
+        for (Map.Entry<Item,String> e : map.entrySet())
+            sum += e.getKey().hashCode() ^ e.getValue().hashCode();
+        mustEqual(sum, map.hashCode());
+    }
+
+    /**
      * contains returns true for contained value
      */
     public void testContains() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         assertTrue(map.contains("A"));
         assertFalse(map.contains("Z"));
     }
@@ -71,7 +252,7 @@ public class ConcurrentHashMapTest exten
      * containsKey returns true for contained key
      */
     public void testContainsKey() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         assertTrue(map.containsKey(one));
         assertFalse(map.containsKey(zero));
     }
@@ -80,7 +261,7 @@ public class ConcurrentHashMapTest exten
      * containsValue returns true for held values
      */
     public void testContainsValue() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         assertTrue(map.containsValue("A"));
         assertFalse(map.containsValue("Z"));
     }
@@ -90,14 +271,14 @@ public class ConcurrentHashMapTest exten
      * elements
      */
     public void testEnumeration() {
-        ConcurrentHashMap map = map5();
-        Enumeration e = map.elements();
+        ConcurrentHashMap<Item,String> map = map5();
+        Enumeration<String> e = map.elements();
         int count = 0;
         while (e.hasMoreElements()) {
             count++;
             e.nextElement();
         }
-        assertEquals(5, count);
+        mustEqual(5, count);
     }
 
     /**
@@ -105,18 +286,19 @@ public class ConcurrentHashMapTest exten
      * or null if not present
      */
     public void testGet() {
-        ConcurrentHashMap map = map5();
-        assertEquals("A", (String)map.get(one));
-        ConcurrentHashMap empty = new ConcurrentHashMap();
+        ConcurrentHashMap<Item,String> map = map5();
+        mustEqual("A", map.get(one));
+        ConcurrentHashMap<Item,String> empty = new ConcurrentHashMap<>();
         assertNull(map.get("anything"));
+        assertNull(empty.get("anything"));
     }
 
     /**
      * isEmpty is true of empty map and false for non-empty
      */
     public void testIsEmpty() {
-        ConcurrentHashMap empty = new ConcurrentHashMap();
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> empty = new ConcurrentHashMap<>();
+        ConcurrentHashMap<Item,String> map = map5();
         assertTrue(empty.isEmpty());
         assertFalse(map.isEmpty());
     }
@@ -125,40 +307,55 @@ public class ConcurrentHashMapTest exten
      * keys returns an enumeration containing all the keys from the map
      */
     public void testKeys() {
-        ConcurrentHashMap map = map5();
-        Enumeration e = map.keys();
+        ConcurrentHashMap<Item,String> map = map5();
+        Enumeration<Item> e = map.keys();
         int count = 0;
         while (e.hasMoreElements()) {
             count++;
             e.nextElement();
         }
-        assertEquals(5, count);
+        mustEqual(5, count);
     }
 
     /**
      * keySet returns a Set containing all the keys
      */
     public void testKeySet() {
-        ConcurrentHashMap map = map5();
-        Set s = map.keySet();
-        assertEquals(5, s.size());
-        assertTrue(s.contains(one));
-        assertTrue(s.contains(two));
-        assertTrue(s.contains(three));
-        assertTrue(s.contains(four));
-        assertTrue(s.contains(five));
+        ConcurrentHashMap<Item,String> map = map5();
+        Set<Item> s = map.keySet();
+        mustEqual(5, s.size());
+        mustContain(s, one);
+        mustContain(s, two);
+        mustContain(s, three);
+        mustContain(s, four);
+        mustContain(s, five);
+    }
+
+    /**
+     * Test keySet().removeAll on empty map
+     */
+    public void testKeySet_empty_removeAll() {
+        ConcurrentHashMap<Item, String> map = new ConcurrentHashMap<>();
+        Set<Item> set = map.keySet();
+        set.removeAll(Collections.emptyList());
+        assertTrue(map.isEmpty());
+        assertTrue(set.isEmpty());
+        // following is test for JDK-8163353
+        set.removeAll(Collections.emptySet());
+        assertTrue(map.isEmpty());
+        assertTrue(set.isEmpty());
     }
 
     /**
      * keySet.toArray returns contains all keys
      */
     public void testKeySetToArray() {
-        ConcurrentHashMap map = map5();
-        Set s = map.keySet();
+        ConcurrentHashMap<Item,String> map = map5();
+        Set<Item> s = map.keySet();
         Object[] ar = s.toArray();
         assertTrue(s.containsAll(Arrays.asList(ar)));
-        assertEquals(5, ar.length);
-        ar[0] = m10;
+        mustEqual(5, ar.length);
+        ar[0] = minusTen;
         assertFalse(s.containsAll(Arrays.asList(ar)));
     }
 
@@ -166,11 +363,11 @@ public class ConcurrentHashMapTest exten
      * Values.toArray contains all values
      */
     public void testValuesToArray() {
-        ConcurrentHashMap map = map5();
-        Collection v = map.values();
-        Object[] ar = v.toArray();
-        ArrayList s = new ArrayList(Arrays.asList(ar));
-        assertEquals(5, ar.length);
+        ConcurrentHashMap<Item,String> map = map5();
+        Collection<String> v = map.values();
+        String[] ar = v.toArray(new String[0]);
+        ArrayList<String> s = new ArrayList<>(Arrays.asList(ar));
+        mustEqual(5, ar.length);
         assertTrue(s.contains("A"));
         assertTrue(s.contains("B"));
         assertTrue(s.contains("C"));
@@ -182,10 +379,10 @@ public class ConcurrentHashMapTest exten
      * entrySet.toArray contains all entries
      */
     public void testEntrySetToArray() {
-        ConcurrentHashMap map = map5();
-        Set s = map.entrySet();
+        ConcurrentHashMap<Item,String> map = map5();
+        Set<Map.Entry<Item,String>> s = map.entrySet();
         Object[] ar = s.toArray();
-        assertEquals(5, ar.length);
+        mustEqual(5, ar.length);
         for (int i = 0; i < 5; ++i) {
             assertTrue(map.containsKey(((Map.Entry)(ar[i])).getKey()));
             assertTrue(map.containsValue(((Map.Entry)(ar[i])).getValue()));
@@ -196,9 +393,9 @@ public class ConcurrentHashMapTest exten
      * values collection contains all values
      */
     public void testValues() {
-        ConcurrentHashMap map = map5();
-        Collection s = map.values();
-        assertEquals(5, s.size());
+        ConcurrentHashMap<Item,String> map = map5();
+        Collection<String> s = map.values();
+        mustEqual(5, s.size());
         assertTrue(s.contains("A"));
         assertTrue(s.contains("B"));
         assertTrue(s.contains("C"));
@@ -210,12 +407,12 @@ public class ConcurrentHashMapTest exten
      * entrySet contains all pairs
      */
     public void testEntrySet() {
-        ConcurrentHashMap map = map5();
-        Set s = map.entrySet();
-        assertEquals(5, s.size());
-        Iterator it = s.iterator();
+        ConcurrentHashMap<Item, String> map = map5();
+        Set<Map.Entry<Item,String>> s = map.entrySet();
+        mustEqual(5, s.size());
+        Iterator<Map.Entry<Item,String>> it = s.iterator();
         while (it.hasNext()) {
-            Map.Entry e = (Map.Entry) it.next();
+            Map.Entry<Item,String> e = it.next();
             assertTrue(
                        (e.getKey().equals(one) && e.getValue().equals("A")) ||
                        (e.getKey().equals(two) && e.getValue().equals("B")) ||
@@ -229,22 +426,22 @@ public class ConcurrentHashMapTest exten
      * putAll adds all key-value pairs from the given map
      */
     public void testPutAll() {
-        ConcurrentHashMap empty = new ConcurrentHashMap();
-        ConcurrentHashMap map = map5();
-        empty.putAll(map);
-        assertEquals(5, empty.size());
-        assertTrue(empty.containsKey(one));
-        assertTrue(empty.containsKey(two));
-        assertTrue(empty.containsKey(three));
-        assertTrue(empty.containsKey(four));
-        assertTrue(empty.containsKey(five));
+        ConcurrentHashMap<Item,String> p = new ConcurrentHashMap<>();
+        ConcurrentHashMap<Item,String> map = map5();
+        p.putAll(map);
+        mustEqual(5, p.size());
+        assertTrue(p.containsKey(one));
+        assertTrue(p.containsKey(two));
+        assertTrue(p.containsKey(three));
+        assertTrue(p.containsKey(four));
+        assertTrue(p.containsKey(five));
     }
 
     /**
      * putIfAbsent works when the given key is not present
      */
     public void testPutIfAbsent() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         map.putIfAbsent(six, "Z");
         assertTrue(map.containsKey(six));
     }
@@ -253,15 +450,15 @@ public class ConcurrentHashMapTest exten
      * putIfAbsent does not add the pair if the key is already present
      */
     public void testPutIfAbsent2() {
-        ConcurrentHashMap map = map5();
-        assertEquals("A", map.putIfAbsent(one, "Z"));
+        ConcurrentHashMap<Item,String> map = map5();
+        mustEqual("A", map.putIfAbsent(one, "Z"));
     }
 
     /**
      * replace fails when the given key is not present
      */
     public void testReplace() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         assertNull(map.replace(six, "Z"));
         assertFalse(map.containsKey(six));
     }
@@ -270,40 +467,38 @@ public class ConcurrentHashMapTest exten
      * replace succeeds if the key is already present
      */
     public void testReplace2() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         assertNotNull(map.replace(one, "Z"));
-        assertEquals("Z", map.get(one));
+        mustEqual("Z", map.get(one));
     }
 
-
     /**
      * replace value fails when the given key not mapped to expected value
      */
     public void testReplaceValue() {
-        ConcurrentHashMap map = map5();
-        assertEquals("A", map.get(one));
+        ConcurrentHashMap<Item,String> map = map5();
+        mustEqual("A", map.get(one));
         assertFalse(map.replace(one, "Z", "Z"));
-        assertEquals("A", map.get(one));
+        mustEqual("A", map.get(one));
     }
 
     /**
      * replace value succeeds when the given key mapped to expected value
      */
     public void testReplaceValue2() {
-        ConcurrentHashMap map = map5();
-        assertEquals("A", map.get(one));
+        ConcurrentHashMap<Item,String> map = map5();
+        mustEqual("A", map.get(one));
         assertTrue(map.replace(one, "A", "Z"));
-        assertEquals("Z", map.get(one));
+        mustEqual("Z", map.get(one));
     }
 
-
     /**
      * remove removes the correct key-value pair from the map
      */
     public void testRemove() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         map.remove(five);
-        assertEquals(4, map.size());
+        mustEqual(4, map.size());
         assertFalse(map.containsKey(five));
     }
 
@@ -311,12 +506,12 @@ public class ConcurrentHashMapTest exten
      * remove(key,value) removes only if pair present
      */
     public void testRemove2() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         map.remove(five, "E");
-        assertEquals(4, map.size());
+        mustEqual(4, map.size());
         assertFalse(map.containsKey(five));
         map.remove(four, "A");
-        assertEquals(4, map.size());
+        mustEqual(4, map.size());
         assertTrue(map.containsKey(four));
     }
 
@@ -324,61 +519,101 @@ public class ConcurrentHashMapTest exten
      * size returns the correct values
      */
     public void testSize() {
-        ConcurrentHashMap map = map5();
-        ConcurrentHashMap empty = new ConcurrentHashMap();
-        assertEquals(0, empty.size());
-        assertEquals(5, map.size());
+        ConcurrentHashMap<Item,String> map = map5();
+        ConcurrentHashMap<Item,String> empty = new ConcurrentHashMap<>();
+        mustEqual(0, empty.size());
+        mustEqual(5, map.size());
     }
 
     /**
      * toString contains toString of elements
      */
     public void testToString() {
-        ConcurrentHashMap map = map5();
+        ConcurrentHashMap<Item,String> map = map5();
         String s = map.toString();
         for (int i = 1; i <= 5; ++i) {
-            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
+            assertTrue(s.contains(String.valueOf(i)));
         }
     }
 
     // Exception tests
 
     /**
-     * Cannot create with negative capacity
+     * Cannot create with only negative capacity
      */
     public void testConstructor1() {
         try {
-            new ConcurrentHashMap(-1,0,1);
+            new ConcurrentHashMap<Item,String>(-1);
             shouldThrow();
         } catch (IllegalArgumentException success) {}
     }
 
     /**
-     * Cannot create with negative concurrency level
+     * Constructor (initialCapacity, loadFactor) throws
+     * IllegalArgumentException if either argument is negative
      */
     public void testConstructor2() {
         try {
-            new ConcurrentHashMap(1,0,-1);
+            new ConcurrentHashMap<Item,String>(-1, .75f);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+
+        try {
+            new ConcurrentHashMap<Item,String>(16, -1);
             shouldThrow();
         } catch (IllegalArgumentException success) {}
     }
 
     /**
-     * Cannot create with only negative capacity
+     * Constructor (initialCapacity, loadFactor, concurrencyLevel)
+     * throws IllegalArgumentException if any argument is negative
      */
     public void testConstructor3() {
         try {
-            new ConcurrentHashMap(-1);
+            new ConcurrentHashMap<Item,String>(-1, .75f, 1);
             shouldThrow();
         } catch (IllegalArgumentException success) {}
+
+        try {
+            new ConcurrentHashMap<Item,String>(16, -1, 1);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+
+        try {
+            new ConcurrentHashMap<Item,String>(16, .75f, -1);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
+
+    /**
+     * ConcurrentHashMap(map) throws NullPointerException if the given
+     * map is null
+     */
+    public void testConstructor4() {
+        try {
+            new ConcurrentHashMap<Item,String>(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * ConcurrentHashMap(map) creates a new map with the same mappings
+     * as the given map
+     */
+    public void testConstructor5() {
+        ConcurrentHashMap<Item,String> map1 = map5();
+        ConcurrentHashMap<Item,String> map2 = new ConcurrentHashMap<>(map1);
+        assertTrue(map2.equals(map1));
+        map2.put(one, "F");
+        assertFalse(map2.equals(map1));
     }
 
     /**
      * get(null) throws NPE
      */
     public void testGet_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.get(null);
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -388,8 +623,8 @@ public class ConcurrentHashMapTest exten
      * containsKey(null) throws NPE
      */
     public void testContainsKey_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.containsKey(null);
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -399,8 +634,8 @@ public class ConcurrentHashMapTest exten
      * containsValue(null) throws NPE
      */
     public void testContainsValue_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.containsValue(null);
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -410,8 +645,8 @@ public class ConcurrentHashMapTest exten
      * contains(null) throws NPE
      */
     public void testContains_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.contains(null);
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -421,8 +656,8 @@ public class ConcurrentHashMapTest exten
      * put(null,x) throws NPE
      */
     public void testPut1_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.put(null, "whatever");
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -432,9 +667,9 @@ public class ConcurrentHashMapTest exten
      * put(x, null) throws NPE
      */
     public void testPut2_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.put("whatever", null);
+            c.put(zero, null);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -443,8 +678,8 @@ public class ConcurrentHashMapTest exten
      * putIfAbsent(null, x) throws NPE
      */
     public void testPutIfAbsent1_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.putIfAbsent(null, "whatever");
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -454,8 +689,8 @@ public class ConcurrentHashMapTest exten
      * replace(null, x) throws NPE
      */
     public void testReplace_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
             c.replace(null, "whatever");
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -465,9 +700,9 @@ public class ConcurrentHashMapTest exten
      * replace(null, x, y) throws NPE
      */
     public void testReplaceValue_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.replace(null, one, "whatever");
+            c.replace(null, "A", "B");
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -476,21 +711,20 @@ public class ConcurrentHashMapTest exten
      * putIfAbsent(x, null) throws NPE
      */
     public void testPutIfAbsent2_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.putIfAbsent("whatever", null);
+            c.putIfAbsent(zero, null);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
 
-
     /**
      * replace(x, null) throws NPE
      */
     public void testReplace2_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.replace("whatever", null);
+            c.replace(one, null);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -499,9 +733,9 @@ public class ConcurrentHashMapTest exten
      * replace(x, null, y) throws NPE
      */
     public void testReplaceValue2_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.replace("whatever", null, "A");
+            c.replace(one, null, "A");
             shouldThrow();
         } catch (NullPointerException success) {}
     }
@@ -510,21 +744,20 @@ public class ConcurrentHashMapTest exten
      * replace(x, y, null) throws NPE
      */
     public void testReplaceValue3_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.replace("whatever", one, null);
+            c.replace(zero, "A", null);
             shouldThrow();
         } catch (NullPointerException success) {}
     }
 
-
     /**
      * remove(null) throws NPE
      */
     public void testRemove1_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
+        c.put(one, "asdads");
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.put("sadsdf", "asdads");
             c.remove(null);
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -534,9 +767,9 @@ public class ConcurrentHashMapTest exten
      * remove(null, x) throws NPE
      */
     public void testRemove2_NullPointerException() {
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
+        c.put(one, "asdads");
         try {
-            ConcurrentHashMap c = new ConcurrentHashMap(5);
-            c.put("sadsdf", "asdads");
             c.remove(null, "whatever");
             shouldThrow();
         } catch (NullPointerException success) {}
@@ -546,52 +779,80 @@ public class ConcurrentHashMapTest exten
      * remove(x, null) returns false
      */
     public void testRemove3() {
-        ConcurrentHashMap c = new ConcurrentHashMap(5);
-        c.put("sadsdf", "asdads");
-        assertFalse(c.remove("sadsdf", null));
+        ConcurrentHashMap<Item,String> c = new ConcurrentHashMap<>(5);
+        c.put(one, "asdads");
+        assertFalse(c.remove(one, null));
     }
 
     /**
-     * A deserialized map equals original
+     * A deserialized/reserialized map equals original
      */
     public void testSerialization() throws Exception {
-        ConcurrentHashMap q = map5();
+        Map<Item,String> x = map5();
+        Map<Item,String> y = serialClone(x);
 
-        ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
-        ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
-        out.writeObject(q);
-        out.close();
-
-        ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
-        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
-        ConcurrentHashMap r = (ConcurrentHashMap)in.readObject();
-        assertEquals(q.size(), r.size());
-        assertTrue(q.equals(r));
-        assertTrue(r.equals(q));
+        assertNotSame(x, y);
+        mustEqual(x.size(), y.size());
+        mustEqual(x, y);
+        mustEqual(y, x);
     }
 
-
     /**
      * SetValue of an EntrySet entry sets value in the map.
      */
+    @SuppressWarnings("unchecked")
     public void testSetValueWriteThrough() {
         // Adapted from a bug report by Eric Zoerner
-        ConcurrentHashMap map = new ConcurrentHashMap(2, 5.0f, 1);
+        ConcurrentHashMap<Object,Object> map = new ConcurrentHashMap<>(2, 5.0f, 1);
         assertTrue(map.isEmpty());
         for (int i = 0; i < 20; i++)
-            map.put(new Integer(i), new Integer(i));
+            map.put(itemFor(i), itemFor(i));
         assertFalse(map.isEmpty());
-        Map.Entry entry1 = (Map.Entry)map.entrySet().iterator().next();
-
-        // assert that entry1 is not 16
-        assertTrue("entry is 16, test not valid",
-                   !entry1.getKey().equals(new Integer(16)));
-
-        // remove 16 (a different key) from map
-        // which just happens to cause entry1 to be cloned in map
-        map.remove(new Integer(16));
-        entry1.setValue("XYZ");
-        assertTrue(map.containsValue("XYZ")); // fails
+        Item key = itemFor(16);
+        Map.Entry<Object,Object> entry1 = map.entrySet().iterator().next();
+        // Unless it happens to be first (in which case remainder of
+        // test is skipped), remove a possibly-colliding key from map
+        // which, under some implementations, may cause entry1 to be
+        // cloned in map
+        if (!entry1.getKey().equals(key)) {
+            map.remove(key);
+            entry1.setValue("XYZ");
+            assertTrue(map.containsValue("XYZ")); // fails if write-through broken
+        }
     }
 
+    /**
+     * Tests performance of removeAll when the other collection is much smaller.
+     * ant -Djsr166.tckTestClass=ConcurrentHashMapTest -Djsr166.methodFilter=testRemoveAll_performance -Djsr166.expensiveTests=true tck
+     */
+    public void testRemoveAll_performance() {
+        final int mapSize = expensiveTests ? 1_000_000 : 100;
+        final int iterations = expensiveTests ? 500 : 2;
+        final ConcurrentHashMap<Item, Item> map = new ConcurrentHashMap<>();
+        for (int i = 0; i < mapSize; i++) {
+            Item I = itemFor(i);
+            map.put(I, I);
+        }
+        Set<Item> keySet = map.keySet();
+        Collection<Item> removeMe = Arrays.asList(new Item[] { minusOne, minusTwo });
+        for (int i = 0; i < iterations; i++)
+            assertFalse(keySet.removeAll(removeMe));
+        mustEqual(mapSize, map.size());
+    }
+
+    public void testReentrantComputeIfAbsent() {
+        ConcurrentHashMap<Item, Item> map = new ConcurrentHashMap<>(16);
+        try {
+            for (int i = 0; i < 100; i++) { // force a resize
+                map.computeIfAbsent(new Item(i), key -> new Item(findValue(map, key)));
+            }
+            fail("recursive computeIfAbsent should throw IllegalStateException");
+        } catch (IllegalStateException success) {}
+    }
+
+    private static Item findValue(ConcurrentHashMap<Item, Item> map,
+                                  Item key) {
+        return (key.value % 5 == 0) ?  key :
+            map.computeIfAbsent(new Item(key.value + 1), k -> new Item(findValue(map, k)));
+    }
 }