diff --git a/jsr166-tests/src/test/java/jsr166/ConcurrentHashMapTest.java b/jsr166-tests/src/test/java/jsr166/ConcurrentHashMapTest.java
new file mode 100644
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+++ b/jsr166-tests/src/test/java/jsr166/ConcurrentHashMapTest.java
@@ -0,0 +1,686 @@
+/*
+ * Written by Doug Lea 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.
+ */
+
+package jsr166;
+
+import junit.framework.*;
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class ConcurrentHashMapTest extends JSR166TestCase {
+
+    /**
+     * Returns a new map from Integers 1-5 to Strings "A"-"E".
+     */
+    private static ConcurrentHashMap map5() {
+        ConcurrentHashMap map = new ConcurrentHashMap(5);
+        assertTrue(map.isEmpty());
+        map.put(one, "A");
+        map.put(two, "B");
+        map.put(three, "C");
+        map.put(four, "D");
+        map.put(five, "E");
+        assertFalse(map.isEmpty());
+        assertEquals(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>> {
+        static long total;
+        static long n;
+        LexicographicList(Collection<E> c) { super(c); }
+        LexicographicList(E e) { super(Collections.singleton(e)); }
+        public int compareTo(LexicographicList<E> other) {
+            long start = System.currentTimeMillis();
+            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());
+            total += System.currentTimeMillis() - start;
+            n++;
+            return r;
+        }
+        private static final long serialVersionUID = 0;
+    }
+
+    /**
+     * Inserted elements that are subclasses of the same Comparable
+     * class are found.
+     */
+    public void testComparableFamily() {
+        ConcurrentHashMap<BI, Boolean> m =
+            new ConcurrentHashMap<BI, Boolean>();
+        for (int i = 0; i < 1000; i++) {
+            assertTrue(m.put(new CI(i), true) == null);
+        }
+        for (int i = 0; i < 1000; 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() {
+         ConcurrentHashMap<Object, Boolean> m =
+             new ConcurrentHashMap<Object, Boolean>();
+         for (int i = 0; i < 1000; i++) {
+             BI bi = new BI(i);
+             BS bs = new BS(String.valueOf(i));
+             LexicographicList<BI> bis = new LexicographicList<BI>(bi);
+             LexicographicList<BS> bss = new LexicographicList<BS>(bs);
+             assertTrue(m.putIfAbsent(bis, true) == null);
+             assertTrue(m.containsKey(bis));
+             if (m.putIfAbsent(bss, true) == null)
+                 assertTrue(m.containsKey(bss));
+             assertTrue(m.containsKey(bis));
+         }
+         for (int i = 0; i < 1000; i++) {
+             assertTrue(m.containsKey(new ArrayList(Collections.singleton(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() {
+        ConcurrentHashMap<Object, Boolean> m =
+            new ConcurrentHashMap<Object, Boolean>();
+        for (int i = 0; i < 1000; i++) {
+            m.put(new ArrayList(Collections.singleton(new BI(i))), true);
+        }
+
+        for (int i = 0; i < 1000; i++) {
+            LexicographicList<BI> bis = new LexicographicList<BI>(new BI(i));
+            assertTrue(m.containsKey(bis));
+        }
+    }
+
+    /**
+     * clear removes all pairs
+     */
+    public void testClear() {
+        ConcurrentHashMap map = map5();
+        map.clear();
+        assertEquals(0, map.size());
+    }
+
+    /**
+     * Maps with same contents are equal
+     */
+    public void testEquals() {
+        ConcurrentHashMap map1 = map5();
+        ConcurrentHashMap map2 = map5();
+        assertEquals(map1, map2);
+        assertEquals(map2, map1);
+        map1.clear();
+        assertFalse(map1.equals(map2));
+        assertFalse(map2.equals(map1));
+    }
+
+    /**
+     * contains returns true for contained value
+     */
+    public void testContains() {
+        ConcurrentHashMap map = map5();
+        assertTrue(map.contains("A"));
+        assertFalse(map.contains("Z"));
+    }
+
+    /**
+     * containsKey returns true for contained key
+     */
+    public void testContainsKey() {
+        ConcurrentHashMap map = map5();
+        assertTrue(map.containsKey(one));
+        assertFalse(map.containsKey(zero));
+    }
+
+    /**
+     * containsValue returns true for held values
+     */
+    public void testContainsValue() {
+        ConcurrentHashMap map = map5();
+        assertTrue(map.containsValue("A"));
+        assertFalse(map.containsValue("Z"));
+    }
+
+    /**
+     * enumeration returns an enumeration containing the correct
+     * elements
+     */
+    public void testEnumeration() {
+        ConcurrentHashMap map = map5();
+        Enumeration e = map.elements();
+        int count = 0;
+        while (e.hasMoreElements()) {
+            count++;
+            e.nextElement();
+        }
+        assertEquals(5, count);
+    }
+
+    /**
+     * get returns the correct element at the given key,
+     * or null if not present
+     */
+    public void testGet() {
+        ConcurrentHashMap map = map5();
+        assertEquals("A", (String)map.get(one));
+        ConcurrentHashMap empty = new ConcurrentHashMap();
+        assertNull(map.get("anything"));
+    }
+
+    /**
+     * isEmpty is true of empty map and false for non-empty
+     */
+    public void testIsEmpty() {
+        ConcurrentHashMap empty = new ConcurrentHashMap();
+        ConcurrentHashMap map = map5();
+        assertTrue(empty.isEmpty());
+        assertFalse(map.isEmpty());
+    }
+
+    /**
+     * keys returns an enumeration containing all the keys from the map
+     */
+    public void testKeys() {
+        ConcurrentHashMap map = map5();
+        Enumeration e = map.keys();
+        int count = 0;
+        while (e.hasMoreElements()) {
+            count++;
+            e.nextElement();
+        }
+        assertEquals(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));
+    }
+
+    /**
+     * keySet.toArray returns contains all keys
+     */
+    public void testKeySetToArray() {
+        ConcurrentHashMap map = map5();
+        Set s = map.keySet();
+        Object[] ar = s.toArray();
+        assertTrue(s.containsAll(Arrays.asList(ar)));
+        assertEquals(5, ar.length);
+        ar[0] = m10;
+        assertFalse(s.containsAll(Arrays.asList(ar)));
+    }
+
+    /**
+     * 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);
+        assertTrue(s.contains("A"));
+        assertTrue(s.contains("B"));
+        assertTrue(s.contains("C"));
+        assertTrue(s.contains("D"));
+        assertTrue(s.contains("E"));
+    }
+
+    /**
+     * entrySet.toArray contains all entries
+     */
+    public void testEntrySetToArray() {
+        ConcurrentHashMap map = map5();
+        Set s = map.entrySet();
+        Object[] ar = s.toArray();
+        assertEquals(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()));
+        }
+    }
+
+    /**
+     * values collection contains all values
+     */
+    public void testValues() {
+        ConcurrentHashMap map = map5();
+        Collection s = map.values();
+        assertEquals(5, s.size());
+        assertTrue(s.contains("A"));
+        assertTrue(s.contains("B"));
+        assertTrue(s.contains("C"));
+        assertTrue(s.contains("D"));
+        assertTrue(s.contains("E"));
+    }
+
+    /**
+     * entrySet contains all pairs
+     */
+    public void testEntrySet() {
+        ConcurrentHashMap map = map5();
+        Set s = map.entrySet();
+        assertEquals(5, s.size());
+        Iterator it = s.iterator();
+        while (it.hasNext()) {
+            Map.Entry e = (Map.Entry) it.next();
+            assertTrue(
+                       (e.getKey().equals(one) && e.getValue().equals("A")) ||
+                       (e.getKey().equals(two) && e.getValue().equals("B")) ||
+                       (e.getKey().equals(three) && e.getValue().equals("C")) ||
+                       (e.getKey().equals(four) && e.getValue().equals("D")) ||
+                       (e.getKey().equals(five) && e.getValue().equals("E")));
+        }
+    }
+
+    /**
+     * 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));
+    }
+
+    /**
+     * putIfAbsent works when the given key is not present
+     */
+    public void testPutIfAbsent() {
+        ConcurrentHashMap map = map5();
+        map.putIfAbsent(six, "Z");
+        assertTrue(map.containsKey(six));
+    }
+
+    /**
+     * putIfAbsent does not add the pair if the key is already present
+     */
+    public void testPutIfAbsent2() {
+        ConcurrentHashMap map = map5();
+        assertEquals("A", map.putIfAbsent(one, "Z"));
+    }
+
+    /**
+     * replace fails when the given key is not present
+     */
+    public void testReplace() {
+        ConcurrentHashMap map = map5();
+        assertNull(map.replace(six, "Z"));
+        assertFalse(map.containsKey(six));
+    }
+
+    /**
+     * replace succeeds if the key is already present
+     */
+    public void testReplace2() {
+        ConcurrentHashMap map = map5();
+        assertNotNull(map.replace(one, "Z"));
+        assertEquals("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));
+        assertFalse(map.replace(one, "Z", "Z"));
+        assertEquals("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));
+        assertTrue(map.replace(one, "A", "Z"));
+        assertEquals("Z", map.get(one));
+    }
+
+    /**
+     * remove removes the correct key-value pair from the map
+     */
+    public void testRemove() {
+        ConcurrentHashMap map = map5();
+        map.remove(five);
+        assertEquals(4, map.size());
+        assertFalse(map.containsKey(five));
+    }
+
+    /**
+     * remove(key,value) removes only if pair present
+     */
+    public void testRemove2() {
+        ConcurrentHashMap map = map5();
+        map.remove(five, "E");
+        assertEquals(4, map.size());
+        assertFalse(map.containsKey(five));
+        map.remove(four, "A");
+        assertEquals(4, map.size());
+        assertTrue(map.containsKey(four));
+    }
+
+    /**
+     * size returns the correct values
+     */
+    public void testSize() {
+        ConcurrentHashMap map = map5();
+        ConcurrentHashMap empty = new ConcurrentHashMap();
+        assertEquals(0, empty.size());
+        assertEquals(5, map.size());
+    }
+
+    /**
+     * toString contains toString of elements
+     */
+    public void testToString() {
+        ConcurrentHashMap map = map5();
+        String s = map.toString();
+        for (int i = 1; i <= 5; ++i) {
+            assertTrue(s.contains(String.valueOf(i)));
+        }
+    }
+
+    // Exception tests
+
+    /**
+     * Cannot create with negative capacity
+     */
+    public void testConstructor1() {
+        try {
+            new ConcurrentHashMap(-1,0,1);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
+
+    /**
+     * Cannot create with negative concurrency level
+     */
+    public void testConstructor2() {
+        try {
+            new ConcurrentHashMap(1,0,-1);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
+
+    /**
+     * Cannot create with only negative capacity
+     */
+    public void testConstructor3() {
+        try {
+            new ConcurrentHashMap(-1);
+            shouldThrow();
+        } catch (IllegalArgumentException success) {}
+    }
+
+    /**
+     * get(null) throws NPE
+     */
+    public void testGet_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.get(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * containsKey(null) throws NPE
+     */
+    public void testContainsKey_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.containsKey(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * containsValue(null) throws NPE
+     */
+    public void testContainsValue_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.containsValue(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * contains(null) throws NPE
+     */
+    public void testContains_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.contains(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * put(null,x) throws NPE
+     */
+    public void testPut1_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.put(null, "whatever");
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * put(x, null) throws NPE
+     */
+    public void testPut2_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.put("whatever", null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * putIfAbsent(null, x) throws NPE
+     */
+    public void testPutIfAbsent1_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.putIfAbsent(null, "whatever");
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * replace(null, x) throws NPE
+     */
+    public void testReplace_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.replace(null, "whatever");
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * replace(null, x, y) throws NPE
+     */
+    public void testReplaceValue_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.replace(null, one, "whatever");
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * putIfAbsent(x, null) throws NPE
+     */
+    public void testPutIfAbsent2_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.putIfAbsent("whatever", null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * replace(x, null) throws NPE
+     */
+    public void testReplace2_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.replace("whatever", null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * replace(x, null, y) throws NPE
+     */
+    public void testReplaceValue2_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.replace("whatever", null, "A");
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * replace(x, y, null) throws NPE
+     */
+    public void testReplaceValue3_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.replace("whatever", one, null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * remove(null) throws NPE
+     */
+    public void testRemove1_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.put("sadsdf", "asdads");
+            c.remove(null);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * remove(null, x) throws NPE
+     */
+    public void testRemove2_NullPointerException() {
+        try {
+            ConcurrentHashMap c = new ConcurrentHashMap(5);
+            c.put("sadsdf", "asdads");
+            c.remove(null, "whatever");
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * remove(x, null) returns false
+     */
+    public void testRemove3() {
+        ConcurrentHashMap c = new ConcurrentHashMap(5);
+        c.put("sadsdf", "asdads");
+        assertFalse(c.remove("sadsdf", null));
+    }
+
+    /**
+     * A deserialized map equals original
+     */
+    public void testSerialization() throws Exception {
+        Map x = map5();
+        Map y = serialClone(x);
+
+        assertNotSame(x, y);
+        assertEquals(x.size(), y.size());
+        assertEquals(x, y);
+        assertEquals(y, x);
+    }
+
+    /**
+     * SetValue of an EntrySet entry sets value in the map.
+     */
+    public void testSetValueWriteThrough() {
+        // Adapted from a bug report by Eric Zoerner
+        ConcurrentHashMap 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));
+        assertFalse(map.isEmpty());
+        Map.Entry entry1 = (Map.Entry)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(new Integer(16))) {
+            map.remove(new Integer(16));
+            entry1.setValue("XYZ");
+            assertTrue(map.containsValue("XYZ")); // fails if write-through broken
+        }
+    }
+
+}