Merge

make/java/java/FILES_java.gmk

@@ -482,6 +482,7 @@ JAVA_JAVA_java = \
     sun/misc/JavaNioAccess.java \
     sun/misc/Perf.java \
     sun/misc/PerfCounter.java \
+    sun/misc/Hashing.java \
     sun/net/www/protocol/jar/Handler.java \
     sun/net/www/protocol/jar/JarURLConnection.java \
     sun/net/www/protocol/file/Handler.java \

src/share/classes/java/lang/Integer.java

@@ -381,7 +381,7 @@ public final class Integer extends Number implements Comparable<Integer> {
         int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
         char[] buf = new char[size];
         getChars(i, size, buf);
-        return new String(0, size, buf);
+        return new String(buf, true);
     }
 
     /**

src/share/classes/java/lang/Long.java

@@ -373,7 +373,7 @@ public final class Long extends Number implements Comparable<Long> {
         int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
         char[] buf = new char[size];
         getChars(i, size, buf);
-        return new String(0, size, buf);
+        return new String(buf, true);
     }
 
     /**

src/share/classes/java/lang/StringCoding.java

@@ -250,6 +250,7 @@ class StringCoding {
     static char[] decode(byte[] ba, int off, int len) {
         String csn = Charset.defaultCharset().name();
         try {
+            // use charset name decode() variant which provides caching.
             return decode(csn, ba, off, len);
         } catch (UnsupportedEncodingException x) {
             warnUnsupportedCharset(csn);
@@ -382,6 +383,7 @@ class StringCoding {
     static byte[] encode(char[] ca, int off, int len) {
         String csn = Charset.defaultCharset().name();
         try {
+            // use charset name encode() variant which provides caching.
             return encode(csn, ca, off, len);
         } catch (UnsupportedEncodingException x) {
             warnUnsupportedCharset(csn);

src/share/classes/java/util/HashMap.java

@@ -175,6 +175,35 @@ public class HashMap<K,V>
      */
     transient int modCount;
 
+    private static class Holder {
+         /**
+         *
+         */
+        static final sun.misc.Unsafe UNSAFE;
+
+        /**
+         * Offset of "final" hashSeed field we must set in
+         * readObject() method.
+         */
+        static final long HASHSEED_OFFSET;
+
+        static {
+            try {
+                UNSAFE = sun.misc.Unsafe.getUnsafe();
+                HASHSEED_OFFSET = UNSAFE.objectFieldOffset(
+                    HashMap.class.getDeclaredField("hashSeed"));
+            } catch (NoSuchFieldException | SecurityException e) {
+                throw new InternalError("Failed to record hashSeed offset", e);
+            }
+        }
+    }
+
+    /**
+     * A randomizing value associated with this instance that is applied to
+     * hash code of keys to make hash collisions harder to find.
+     */
+    transient final int hashSeed = sun.misc.Hashing.randomHashSeed(this);
+
     /**
      * Constructs an empty <tt>HashMap</tt> with the specified initial
      * capacity and load factor.
@@ -200,7 +229,7 @@ public class HashMap<K,V>
             capacity <<= 1;
 
         this.loadFactor = loadFactor;
-        threshold = (int)(capacity * loadFactor);
+        threshold = (int)Math.min(capacity * loadFactor, MAXIMUM_CAPACITY + 1);
         table = new Entry[capacity];
         init();
     }
@@ -221,10 +250,7 @@ public class HashMap<K,V>
      * (16) and the default load factor (0.75).
      */
     public HashMap() {
-        this.loadFactor = DEFAULT_LOAD_FACTOR;
-        threshold = (int)(DEFAULT_INITIAL_CAPACITY * DEFAULT_LOAD_FACTOR);
-        table = new Entry[DEFAULT_INITIAL_CAPACITY];
-        init();
+        this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR);
     }
 
     /**
@@ -255,13 +281,20 @@ public class HashMap<K,V>
     }
 
     /**
-     * Applies a supplemental hash function to a given hashCode, which
-     * defends against poor quality hash functions.  This is critical
-     * because HashMap uses power-of-two length hash tables, that
+     * Retrieve object hash code and applies a supplemental hash function to the
+     * result hash, which defends against poor quality hash functions.  This is
+     * critical because HashMap uses power-of-two length hash tables, that
      * otherwise encounter collisions for hashCodes that do not differ
-     * in lower bits. Note: Null keys always map to hash 0, thus index 0.
+     * in lower bits.
      */
-    static int hash(int h) {
+    final int hash(Object k) {
+        int h = hashSeed;
+        if (k instanceof String) {
+            return ((String)k).hash32();
+        }
+
+        h ^= k.hashCode();
+
         // This function ensures that hashCodes that differ only by
         // constant multiples at each bit position have a bounded
         // number of collisions (approximately 8 at default load factor).
@@ -313,32 +346,9 @@ public class HashMap<K,V>
      */
     @SuppressWarnings("unchecked")
     public V get(Object key) {
-        if (key == null)
-            return (V)getForNullKey();
-        int hash = hash(key.hashCode());
-        for (Entry<?,?> e = table[indexFor(hash, table.length)];
-             e != null;
-             e = e.next) {
-            Object k;
-            if (e.hash == hash && ((k = e.key) == key || key.equals(k)))
-                return (V)e.value;
-        }
-        return null;
-    }
+        Entry<K,V> entry = getEntry(key);
 
-    /**
-     * Offloaded version of get() to look up null keys.  Null keys map
-     * to index 0.  This null case is split out into separate methods
-     * for the sake of performance in the two most commonly used
-     * operations (get and put), but incorporated with conditionals in
-     * others.
-     */
-    private Object getForNullKey() {
-        for (Entry<?,?> e = table[0]; e != null; e = e.next) {
-            if (e.key == null)
-                return e.value;
-        }
-        return null;
+        return null == entry ? null : entry.getValue();
     }
 
     /**
@@ -360,7 +370,7 @@ public class HashMap<K,V>
      */
     @SuppressWarnings("unchecked")
     final Entry<K,V> getEntry(Object key) {
-        int hash = (key == null) ? 0 : hash(key.hashCode());
+        int hash = (key == null) ? 0 : hash(key);
         for (Entry<?,?> e = table[indexFor(hash, table.length)];
              e != null;
              e = e.next) {
@@ -388,7 +398,7 @@ public class HashMap<K,V>
     public V put(K key, V value) {
         if (key == null)
             return putForNullKey(value);
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         int i = indexFor(hash, table.length);
         @SuppressWarnings("unchecked")
         Entry<K,V> e = (Entry<K,V>)table[i];
@@ -433,7 +443,7 @@ public class HashMap<K,V>
      * addEntry.
      */
     private void putForCreate(K key, V value) {
-        int hash = (key == null) ? 0 : hash(key.hashCode());
+        int hash = null == key ? 0 : hash(key);
         int i = indexFor(hash, table.length);
 
         /**
@@ -484,7 +494,7 @@ public class HashMap<K,V>
         Entry<?,?>[] newTable = new Entry<?,?>[newCapacity];
         transfer(newTable);
         table = newTable;
-        threshold = (int)(newCapacity * loadFactor);
+        threshold = (int)Math.min(newCapacity * loadFactor, MAXIMUM_CAPACITY + 1);
     }
 
     /**
@@ -494,19 +504,17 @@ public class HashMap<K,V>
     void transfer(Entry<?,?>[] newTable) {
         Entry<?,?>[] src = table;
         int newCapacity = newTable.length;
-        for (int j = 0; j < src.length; j++) {
-            Entry<K,V> e = (Entry<K,V>)src[j];
-            if (e != null) {
-                src[j] = null;
-                do {
+        for (int j = 0; j < src.length; j++ ) {
+            Entry<K,V> e = (Entry<K,V>) src[j];
+            while(null != e) {
                 Entry<K,V> next = e.next;
                 int i = indexFor(e.hash, newCapacity);
-                    e.next = (Entry<K,V>)newTable[i];
+                e.next = (Entry<K,V>) newTable[i];
                 newTable[i] = e;
                 e = next;
-                } while (e != null);
             }
         }
+        Arrays.fill(table, null);
     }
 
     /**
@@ -566,7 +574,7 @@ public class HashMap<K,V>
      * for this key.
      */
     final Entry<K,V> removeEntryForKey(Object key) {
-        int hash = (key == null) ? 0 : hash(key.hashCode());
+        int hash = (key == null) ? 0 : hash(key);
         int i = indexFor(hash, table.length);
         @SuppressWarnings("unchecked")
             Entry<K,V> prev = (Entry<K,V>)table[i];
@@ -594,7 +602,8 @@ public class HashMap<K,V>
     }
 
     /**
-     * Special version of remove for EntrySet.
+     * Special version of remove for EntrySet using {@code Map.Entry.equals()}
+     * for matching.
      */
     final Entry<K,V> removeMapping(Object o) {
         if (!(o instanceof Map.Entry))
@@ -773,11 +782,13 @@ public class HashMap<K,V>
      * Subclass overrides this to alter the behavior of put method.
      */
     void addEntry(int hash, K key, V value, int bucketIndex) {
-        @SuppressWarnings("unchecked")
-            Entry<K,V> e = (Entry<K,V>)table[bucketIndex];
-        table[bucketIndex] = new Entry<>(hash, key, value, e);
-        if (size++ >= threshold)
+        if ((size >= threshold) && (null != table[bucketIndex])) {
             resize(2 * table.length);
+            hash = hash(key);
+            bucketIndex = indexFor(hash, table.length);
+        }
+
+        createEntry(hash, key, value, bucketIndex);
     }
 
     /**
@@ -841,7 +852,6 @@ public class HashMap<K,V>
             HashMap.this.removeEntryForKey(k);
             expectedModCount = modCount;
         }
-
     }
 
     private final class ValueIterator extends HashIterator<V> {
@@ -1021,9 +1031,8 @@ public class HashMap<K,V>
         s.writeInt(size);
 
         // Write out keys and values (alternating)
-        if (i != null) {
-            while (i.hasNext()) {
-                Map.Entry<K,V> e = i.next();
+        if (size > 0) {
+            for(Map.Entry<K,V> e : entrySet0()) {
                 s.writeObject(e.getKey());
                 s.writeObject(e.getValue());
             }
@@ -1033,26 +1042,50 @@ public class HashMap<K,V>
     private static final long serialVersionUID = 362498820763181265L;
 
     /**
-     * Reconstitute the <tt>HashMap</tt> instance from a stream (i.e.,
+     * Reconstitute the {@code HashMap} instance from a stream (i.e.,
      * deserialize it).
      */
     private void readObject(java.io.ObjectInputStream s)
          throws IOException, ClassNotFoundException
     {
-        // Read in the threshold, loadfactor, and any hidden stuff
+        // Read in the threshold (ignored), loadfactor, and any hidden stuff
         s.defaultReadObject();
+        if (loadFactor <= 0 || Float.isNaN(loadFactor))
+            throw new InvalidObjectException("Illegal load factor: " +
+                                               loadFactor);
+
+        // set hashMask
+        Holder.UNSAFE.putIntVolatile(this, Holder.HASHSEED_OFFSET,
+                sun.misc.Hashing.randomHashSeed(this));
 
         // Read in number of buckets and allocate the bucket array;
-        int numBuckets = s.readInt();
-        table = new Entry[numBuckets];
+        s.readInt(); // ignored
+
+        // Read number of mappings
+        int mappings = s.readInt();
+        if (mappings < 0)
+            throw new InvalidObjectException("Illegal mappings count: " +
+                                               mappings);
+
+        int initialCapacity = (int) Math.min(
+                // capacity chosen by number of mappings
+                // and desired load (if >= 0.25)
+                mappings * Math.min(1 / loadFactor, 4.0f),
+                // we have limits...
+                HashMap.MAXIMUM_CAPACITY);
+        int capacity = 1;
+        // find smallest power of two which holds all mappings
+        while (capacity < initialCapacity) {
+            capacity <<= 1;
+        }
 
+        table = new Entry[capacity];
+        threshold = (int) Math.min(capacity * loadFactor, MAXIMUM_CAPACITY + 1);
         init();  // Give subclass a chance to do its thing.
 
-        // Read in size (number of Mappings)
-        int size = s.readInt();
 
         // Read the keys and values, and put the mappings in the HashMap
-        for (int i=0; i<size; i++) {
+        for (int i=0; i<mappings; i++) {
             @SuppressWarnings("unchecked")
                 K key = (K) s.readObject();
             @SuppressWarnings("unchecked")

src/share/classes/java/util/Hashtable.java

@@ -163,6 +163,52 @@ public class Hashtable<K,V>
     /** use serialVersionUID from JDK 1.0.2 for interoperability */
     private static final long serialVersionUID = 1421746759512286392L;
 
+    private static class Holder {
+            // Unsafe mechanics
+        /**
+         *
+         */
+        static final sun.misc.Unsafe UNSAFE;
+
+        /**
+         * Offset of "final" hashSeed field we must set in
+         * readObject() method.
+         */
+        static final long HASHSEED_OFFSET;
+
+        static {
+            try {
+                UNSAFE = sun.misc.Unsafe.getUnsafe();
+                HASHSEED_OFFSET = UNSAFE.objectFieldOffset(
+                    Hashtable.class.getDeclaredField("hashSeed"));
+            } catch (NoSuchFieldException | SecurityException e) {
+                throw new InternalError("Failed to record hashSeed offset", e);
+            }
+        }
+    }
+
+    /**
+     * A randomizing value associated with this instance that is applied to
+     * hash code of keys to make hash collisions harder to find.
+     */
+    transient final int hashSeed = sun.misc.Hashing.randomHashSeed(this);
+
+    private int hash(Object k) {
+        int h = hashSeed;
+
+        if (k instanceof String) {
+            return ((String)k).hash32();
+        } else {
+            h ^= k.hashCode();
+
+            // This function ensures that hashCodes that differ only by
+            // constant multiples at each bit position have a bounded
+            // number of collisions (approximately 8 at default load factor).
+            h ^= (h >>> 20) ^ (h >>> 12);
+            return h ^ (h >>> 7) ^ (h >>> 4);
+        }
+    }
+
     /**
      * Constructs a new, empty hashtable with the specified initial
      * capacity and the specified load factor.
@@ -183,7 +229,7 @@ public class Hashtable<K,V>
             initialCapacity = 1;
         this.loadFactor = loadFactor;
         table = new Entry<?,?>[initialCapacity];
-        threshold = (int)(initialCapacity * loadFactor);
+        threshold = (int)Math.min(initialCapacity * loadFactor, MAX_ARRAY_SIZE + 1);
     }
 
     /**
@@ -327,7 +373,7 @@ public class Hashtable<K,V>
      */
     public synchronized boolean containsKey(Object key) {
         Entry<?,?> tab[] = table;
-        int hash = key.hashCode();
+        int hash = hash(key);
         int index = (hash & 0x7FFFFFFF) % tab.length;
         for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
             if ((e.hash == hash) && e.key.equals(key)) {
@@ -355,7 +401,7 @@ public class Hashtable<K,V>
     @SuppressWarnings("unchecked")
     public synchronized V get(Object key) {
         Entry<?,?> tab[] = table;
-        int hash = key.hashCode();
+        int hash = hash(key);
         int index = (hash & 0x7FFFFFFF) % tab.length;
         for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
             if ((e.hash == hash) && e.key.equals(key)) {
@@ -396,7 +442,7 @@ public class Hashtable<K,V>
         Entry<?,?>[] newMap = new Entry<?,?>[newCapacity];
 
         modCount++;
-        threshold = (int)(newCapacity * loadFactor);
+        threshold = (int)Math.min(newCapacity * loadFactor, MAX_ARRAY_SIZE + 1);
         table = newMap;
 
         for (int i = oldCapacity ; i-- > 0 ;) {
@@ -436,7 +482,7 @@ public class Hashtable<K,V>
 
         // Makes sure the key is not already in the hashtable.
         Entry<?,?> tab[] = table;
-        int hash = key.hashCode();
+        int hash = hash(key);
         int index = (hash & 0x7FFFFFFF) % tab.length;
         @SuppressWarnings("unchecked")
         Entry<K,V> entry = (Entry<K,V>)tab[index];
@@ -454,6 +500,7 @@ public class Hashtable<K,V>
             rehash();
 
             tab = table;
+            hash = hash(key);
             index = (hash & 0x7FFFFFFF) % tab.length;
         }
 
@@ -476,7 +523,7 @@ public class Hashtable<K,V>
      */
     public synchronized V remove(Object key) {
         Entry<?,?> tab[] = table;
-        int hash = key.hashCode();
+        int hash = hash(key);
         int index = (hash & 0x7FFFFFFF) % tab.length;
         @SuppressWarnings("unchecked")
         Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -685,7 +732,7 @@ public class Hashtable<K,V>
             Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
             Object key = entry.getKey();
             Entry<?,?>[] tab = table;
-            int hash = key.hashCode();
+            int hash = hash(key);
             int index = (hash & 0x7FFFFFFF) % tab.length;
 
             for (Entry<?,?> e = tab[index]; e != null; e = e.next)
@@ -700,7 +747,7 @@ public class Hashtable<K,V>
             Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
             Object key = entry.getKey();
             Entry<?,?>[] tab = table;
-            int hash = key.hashCode();
+            int hash = hash(key);
             int index = (hash & 0x7FFFFFFF) % tab.length;
 
             @SuppressWarnings("unchecked")
@@ -835,9 +882,13 @@ public class Hashtable<K,V>
 
         loadFactor = -loadFactor;  // Mark hashCode computation in progress
         Entry<?,?>[] tab = table;
-        for (int i = 0; i < tab.length; i++)
-            for (Entry<?,?> e = tab[i]; e != null; e = e.next)
-                h += e.key.hashCode() ^ e.value.hashCode();
+        for (Entry<?,?> entry : tab) {
+            while (entry != null) {
+                h += entry.hashCode();
+                entry = entry.next;
+            }
+        }
+
         loadFactor = -loadFactor;  // Mark hashCode computation complete
 
         return h;
@@ -894,6 +945,10 @@ public class Hashtable<K,V>
         // Read in the length, threshold, and loadfactor
         s.defaultReadObject();
 
+        // set hashMask
+        Holder.UNSAFE.putIntVolatile(this, Holder.HASHSEED_OFFSET,
+                sun.misc.Hashing.randomHashSeed(this));
+
         // Read the original length of the array and number of elements
         int origlength = s.readInt();
         int elements = s.readInt();
@@ -907,7 +962,8 @@ public class Hashtable<K,V>
             length--;
         if (origlength > 0 && length > origlength)
             length = origlength;
-        Entry<?,?>[] table = new Entry<?,?>[length];
+        table = new Entry<?,?>[length];
+        threshold = (int)Math.min(length * loadFactor, MAX_ARRAY_SIZE + 1);
         count = 0;
 
         // Read the number of elements and then all the key/value objects
@@ -919,7 +975,6 @@ public class Hashtable<K,V>
             // synch could be eliminated for performance
             reconstitutionPut(table, key, value);
         }
-        this.table = table;
     }
 
     /**
@@ -941,7 +996,7 @@ public class Hashtable<K,V>
         }
         // Makes sure the key is not already in the hashtable.
         // This should not happen in deserialized version.
-        int hash = key.hashCode();
+        int hash = hash(key);
         int index = (hash & 0x7FFFFFFF) % tab.length;
         for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
             if ((e.hash == hash) && e.key.equals(key)) {
@@ -956,10 +1011,10 @@ public class Hashtable<K,V>
     }
 
     /**
-     * Hashtable collision list.
+     * Hashtable bucket collision list entry
      */
     private static class Entry<K,V> implements Map.Entry<K,V> {
-        int hash;
+        final int hash;
         K key;
         V value;
         Entry<K,V> next;

src/share/classes/java/util/LinkedHashMap.java

@@ -236,6 +236,7 @@ public class LinkedHashMap<K,V>
      * readObject) before any entries are inserted into the map.  Initializes
      * the chain.
      */
+    @Override
     void init() {
         header = new Entry<>(-1, null, null, null);
         header.before = header.after = header;
@@ -246,6 +247,7 @@ public class LinkedHashMap<K,V>
      * by superclass resize.  It is overridden for performance, as it is
      * faster to iterate using our linked list.
      */
+    @Override
     @SuppressWarnings("unchecked")
     void transfer(HashMap.Entry[] newTable) {
         int newCapacity = newTable.length;
@@ -421,15 +423,12 @@ public class LinkedHashMap<K,V>
      * removes the eldest entry if appropriate.
      */
     void addEntry(int hash, K key, V value, int bucketIndex) {
-        createEntry(hash, key, value, bucketIndex);
+        super.addEntry(hash, key, value, bucketIndex);
 
-        // Remove eldest entry if instructed, else grow capacity if appropriate
+        // Remove eldest entry if instructed
         Entry<K,V> eldest = header.after;
         if (removeEldestEntry(eldest)) {
             removeEntryForKey(eldest.key);
-        } else {
-            if (size >= threshold)
-                resize(2 * table.length);
         }
     }
 

src/share/classes/java/util/WeakHashMap.java

@@ -184,6 +184,12 @@ public class WeakHashMap<K,V>
      */
     int modCount;
 
+    /**
+     * A randomizing value associated with this instance that is applied to
+     * hash code of keys to make hash collisions harder to find.
+     */
+    transient final int hashSeed = sun.misc.Hashing.randomHashSeed(this);
+
     @SuppressWarnings("unchecked")
     private Entry<K,V>[] newTable(int n) {
         return (Entry<K,V>[]) new Entry<?,?>[n];
@@ -232,9 +238,7 @@ public class WeakHashMap<K,V>
      * capacity (16) and load factor (0.75).
      */
     public WeakHashMap() {
-        this.loadFactor = DEFAULT_LOAD_FACTOR;
-        threshold = DEFAULT_INITIAL_CAPACITY;
-        table = newTable(DEFAULT_INITIAL_CAPACITY);
+        this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR);
     }
 
     /**
@@ -248,7 +252,8 @@ public class WeakHashMap<K,V>
      * @since   1.3
      */
     public WeakHashMap(Map<? extends K, ? extends V> m) {
-        this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1, 16),
+        this(Math.max((int) (m.size() / DEFAULT_LOAD_FACTOR) + 1,
+                DEFAULT_INITIAL_CAPACITY),
              DEFAULT_LOAD_FACTOR);
         putAll(m);
     }
@@ -282,6 +287,28 @@ public class WeakHashMap<K,V>
         return x == y || x.equals(y);
     }
 
+    /**
+     * Retrieve object hash code and applies a supplemental hash function to the
+     * result hash, which defends against poor quality hash functions.  This is
+     * critical because HashMap uses power-of-two length hash tables, that
+     * otherwise encounter collisions for hashCodes that do not differ
+     * in lower bits.
+     */
+    int hash(Object k) {
+        int h = hashSeed;
+        if (k instanceof String) {
+            return ((String) k).hash32();
+        } else {
+            h ^= k.hashCode();
+        }
+
+        // This function ensures that hashCodes that differ only by
+        // constant multiples at each bit position have a bounded
+        // number of collisions (approximately 8 at default load factor).
+        h ^= (h >>> 20) ^ (h >>> 12);
+        return h ^ (h >>> 7) ^ (h >>> 4);
+    }
+
     /**
      * Returns index for hash code h.
      */
@@ -371,7 +398,7 @@ public class WeakHashMap<K,V>
      */
     public V get(Object key) {
         Object k = maskNull(key);
-        int h = HashMap.hash(k.hashCode());
+        int h = hash(k);
         Entry<K,V>[] tab = getTable();
         int index = indexFor(h, tab.length);
         Entry<K,V> e = tab[index];
@@ -401,7 +428,7 @@ public class WeakHashMap<K,V>
      */
     Entry<K,V> getEntry(Object key) {
         Object k = maskNull(key);
-        int h = HashMap.hash(k.hashCode());
+        int h = hash(k);
         Entry<K,V>[] tab = getTable();
         int index = indexFor(h, tab.length);
         Entry<K,V> e = tab[index];
@@ -424,7 +451,7 @@ public class WeakHashMap<K,V>
      */
     public V put(K key, V value) {
         Object k = maskNull(key);
-        int h = HashMap.hash(k.hashCode());
+        int h = hash(k);
         Entry<K,V>[] tab = getTable();
         int i = indexFor(h, tab.length);
 
@@ -566,7 +593,7 @@ public class WeakHashMap<K,V>
      */
     public V remove(Object key) {
         Object k = maskNull(key);
-        int h = HashMap.hash(k.hashCode());
+        int h = hash(k);
         Entry<K,V>[] tab = getTable();
         int i = indexFor(h, tab.length);
         Entry<K,V> prev = tab[i];
@@ -597,7 +624,7 @@ public class WeakHashMap<K,V>
         Entry<K,V>[] tab = getTable();
         Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
         Object k = maskNull(entry.getKey());
-        int h = HashMap.hash(k.hashCode());
+        int h = hash(k);
         int i = indexFor(h, tab.length);
         Entry<K,V> prev = tab[i];
         Entry<K,V> e = prev;

src/share/classes/java/util/concurrent/ConcurrentHashMap.java

@@ -174,6 +174,12 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
 
     /* ---------------- Fields -------------- */
 
+    /**
+     * A randomizing value associated with this instance that is applied to
+     * hash code of keys to make hash collisions harder to find.
+     */
+   private transient final int hashSeed = sun.misc.Hashing.randomHashSeed(this);
+
     /**
      * Mask value for indexing into segments. The upper bits of a
      * key's hash code are used to choose the segment.
@@ -262,7 +268,15 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
      * that otherwise encounter collisions for hashCodes that do not
      * differ in lower or upper bits.
      */
-    private static int hash(int h) {
+    private int hash(Object k) {
+       int h = hashSeed;
+
+        if (k instanceof String) {
+            return ((String) k).hash32();
+        }
+
+        h ^= k.hashCode();
+
         // Spread bits to regularize both segment and index locations,
         // using variant of single-word Wang/Jenkins hash.
         h += (h <<  15) ^ 0xffffcd7d;
@@ -917,7 +931,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
     public V get(Object key) {
         Segment<K,V> s; // manually integrate access methods to reduce overhead
         HashEntry<K,V>[] tab;
-        int h = hash(key.hashCode());
+        int h = hash(key);
         long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
         if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
             (tab = s.table) != null) {
@@ -945,7 +959,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
     public boolean containsKey(Object key) {
         Segment<K,V> s; // same as get() except no need for volatile value read
         HashEntry<K,V>[] tab;
-        int h = hash(key.hashCode());
+        int h = hash(key);
         long u = (((h >>> segmentShift) & segmentMask) << SSHIFT) + SBASE;
         if ((s = (Segment<K,V>)UNSAFE.getObjectVolatile(segments, u)) != null &&
             (tab = s.table) != null) {
@@ -1054,7 +1068,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
         Segment<K,V> s;
         if (value == null)
             throw new NullPointerException();
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         int j = (hash >>> segmentShift) & segmentMask;
         if ((s = (Segment<K,V>)UNSAFE.getObject          // nonvolatile; recheck
              (segments, (j << SSHIFT) + SBASE)) == null) //  in ensureSegment
@@ -1074,7 +1088,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
         Segment<K,V> s;
         if (value == null)
             throw new NullPointerException();
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         int j = (hash >>> segmentShift) & segmentMask;
         if ((s = (Segment<K,V>)UNSAFE.getObject
              (segments, (j << SSHIFT) + SBASE)) == null)
@@ -1104,7 +1118,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
      * @throws NullPointerException if the specified key is null
      */
     public V remove(Object key) {
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         Segment<K,V> s = segmentForHash(hash);
         return s == null ? null : s.remove(key, hash, null);
     }
@@ -1115,7 +1129,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
      * @throws NullPointerException if the specified key is null
      */
     public boolean remove(Object key, Object value) {
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         Segment<K,V> s;
         return value != null && (s = segmentForHash(hash)) != null &&
             s.remove(key, hash, value) != null;
@@ -1127,7 +1141,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
      * @throws NullPointerException if any of the arguments are null
      */
     public boolean replace(K key, V oldValue, V newValue) {
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         if (oldValue == null || newValue == null)
             throw new NullPointerException();
         Segment<K,V> s = segmentForHash(hash);
@@ -1142,7 +1156,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
      * @throws NullPointerException if the specified key or value is null
      */
     public V replace(K key, V value) {
-        int hash = hash(key.hashCode());
+        int hash = hash(key);
         if (value == null)
             throw new NullPointerException();
         Segment<K,V> s = segmentForHash(hash);
@@ -1473,6 +1487,10 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
             throws java.io.IOException, ClassNotFoundException {
         s.defaultReadObject();
 
+        // set hashMask
+        UNSAFE.putIntVolatile(this, HASHSEED_OFFSET,
+                 sun.misc.Hashing.randomHashSeed(this));
+
         // Re-initialize segments to be minimally sized, and let grow.
         int cap = MIN_SEGMENT_TABLE_CAPACITY;
         final Segment<K,V>[] segments = this.segments;
@@ -1500,6 +1518,7 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
     private static final int SSHIFT;
     private static final long TBASE;
     private static final int TSHIFT;
+    private static final long HASHSEED_OFFSET;
 
     static {
         int ss, ts;
@@ -1511,6 +1530,8 @@ public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
             SBASE = UNSAFE.arrayBaseOffset(sc);
             ts = UNSAFE.arrayIndexScale(tc);
             ss = UNSAFE.arrayIndexScale(sc);
+            HASHSEED_OFFSET = UNSAFE.objectFieldOffset(
+                ConcurrentHashMap.class.getDeclaredField("hashSeed"));
         } catch (Exception e) {
             throw new Error(e);
         }

src/share/classes/sun/misc/Hashing.java

+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package sun.misc;
+
+import java.util.Random;
+
+/**
+ * Hashing utilities.
+ *
+ * Little endian implementations of Murmur3 hashing.
+ */
+public class Hashing {
+
+    /**
+     * Static utility methods only.
+     */
+    private Hashing() {
+        throw new Error("No instances");
+    }
+
+    public static int murmur3_32(byte[] data) {
+        return murmur3_32(0, data, 0, data.length);
+    }
+
+    public static int murmur3_32(int seed, byte[] data) {
+        return murmur3_32(seed, data, 0, data.length);
+    }
+
+    @SuppressWarnings("fallthrough")
+    public static int murmur3_32(int seed, byte[] data, int offset, int len) {
+        int h1 = seed;
+        int count = len;
+
+        // body
+        while (count >= 4) {
+            int k1 = (data[offset] & 0x0FF)
+                    | (data[offset + 1] & 0x0FF) << 8
+                    | (data[offset + 2] & 0x0FF) << 16
+                    | data[offset + 3] << 24;
+
+            count -= 4;
+            offset += 4;
+
+            k1 *= 0xcc9e2d51;
+            k1 = Integer.rotateLeft(k1, 15);
+            k1 *= 0x1b873593;
+
+            h1 ^= k1;
+            h1 = Integer.rotateLeft(h1, 13);
+            h1 = h1 * 5 + 0xe6546b64;
+        }
+
+        // tail
+
+        if (count > 0) {
+            int k1 = 0;
+
+            switch (count) {
+                case 3:
+                    k1 ^= (data[offset + 2] & 0xff) << 16;
+                // fall through
+                case 2:
+                    k1 ^= (data[offset + 1] & 0xff) << 8;
+                // fall through
+                case 1:
+                    k1 ^= (data[offset] & 0xff);
+                // fall through
+                default:
+                    k1 *= 0xcc9e2d51;
+                    k1 = Integer.rotateLeft(k1, 15);
+                    k1 *= 0x1b873593;
+                    h1 ^= k1;
+            }
+        }
+
+        // finalization
+
+        h1 ^= len;
+
+        // finalization mix force all bits of a hash block to avalanche
+        h1 ^= h1 >>> 16;
+        h1 *= 0x85ebca6b;
+        h1 ^= h1 >>> 13;
+        h1 *= 0xc2b2ae35;
+        h1 ^= h1 >>> 16;
+
+        return h1;
+    }
+
+    public static int murmur3_32(char[] data) {
+        return murmur3_32(0, data, 0, data.length);
+    }
+
+    public static int murmur3_32(int seed, char[] data) {
+        return murmur3_32(seed, data, 0, data.length);
+    }
+
+    public static int murmur3_32(int seed, char[] data, int offset, int len) {
+        int h1 = seed;
+
+        int off = offset;
+        int count = len;
+
+        // body
+        while (count >= 2) {
+            int k1 = (data[off++] & 0xFFFF) | (data[off++] << 16);
+
+            count -= 2;
+
+            k1 *= 0xcc9e2d51;
+            k1 = Integer.rotateLeft(k1, 15);
+            k1 *= 0x1b873593;
+
+            h1 ^= k1;
+            h1 = Integer.rotateLeft(h1, 13);
+            h1 = h1 * 5 + 0xe6546b64;
+        }
+
+        // tail
+
+        if (count > 0) {
+            int k1 = data[off];
+
+            k1 *= 0xcc9e2d51;
+            k1 = Integer.rotateLeft(k1, 15);
+            k1 *= 0x1b873593;
+            h1 ^= k1;
+        }
+
+        // finalization
+
+        h1 ^= len * (Character.SIZE / Byte.SIZE);
+
+        // finalization mix force all bits of a hash block to avalanche
+        h1 ^= h1 >>> 16;
+        h1 *= 0x85ebca6b;
+        h1 ^= h1 >>> 13;
+        h1 *= 0xc2b2ae35;
+        h1 ^= h1 >>> 16;
+
+        return h1;
+    }
+
+    public static int murmur3_32(int[] data) {
+        return murmur3_32(0, data, 0, data.length);
+    }
+
+    public static int murmur3_32(int seed, int[] data) {
+        return murmur3_32(seed, data, 0, data.length);
+    }
+
+    public static int murmur3_32(int seed, int[] data, int offset, int len) {
+        int h1 = seed;
+
+        int off = offset;
+        int end = offset + len;
+
+        // body
+        while (off < end) {
+            int k1 = data[off++];
+
+            k1 *= 0xcc9e2d51;
+            k1 = Integer.rotateLeft(k1, 15);
+            k1 *= 0x1b873593;
+
+            h1 ^= k1;
+            h1 = Integer.rotateLeft(h1, 13);
+            h1 = h1 * 5 + 0xe6546b64;
+        }
+
+        // tail (always empty, as body is always 32-bit chunks)
+
+        // finalization
+
+        h1 ^= len * (Integer.SIZE / Byte.SIZE);
+
+        // finalization mix force all bits of a hash block to avalanche
+        h1 ^= h1 >>> 16;
+        h1 *= 0x85ebca6b;
+        h1 ^= h1 >>> 13;
+        h1 *= 0xc2b2ae35;
+        h1 ^= h1 >>> 16;
+
+        return h1;
+    }
+
+    /**
+     * Holds references to things that can't be initialized until after VM
+     * is fully booted.
+     */
+    private static class Holder {
+
+        /**
+         * Used for generating per-instance hash seeds.
+         *
+         * We try to improve upon the default seeding.
+         */
+        static final Random SEED_MAKER = new Random(
+                Double.doubleToRawLongBits(Math.random())
+                ^ System.identityHashCode(Hashing.class)
+                ^ System.currentTimeMillis()
+                ^ System.nanoTime()
+                ^ Runtime.getRuntime().freeMemory());
+    }
+
+    public static int randomHashSeed(Object instance) {
+        int seed;
+        if (sun.misc.VM.isBooted()) {
+            seed = Holder.SEED_MAKER.nextInt();
+        } else {
+            // lower quality "random" seed value--still better than zero and not
+            // not practically reversible.
+            int hashing_seed[] = {
+                System.identityHashCode(Hashing.class),
+                System.identityHashCode(instance),
+                System.identityHashCode(Thread.currentThread()),
+                (int) Thread.currentThread().getId(),
+                (int) (System.currentTimeMillis() >>> 2), // resolution is poor
+                (int) (System.nanoTime() >>> 5), // resolution is poor
+                (int) (Runtime.getRuntime().freeMemory() >>> 4) // alloc min
+            };
+
+            seed = murmur3_32(hashing_seed);
+        }
+
+        // force to non-zero.
+        return (0 != seed) ? seed : 1;
+    }
+}

test/java/util/Collection/BiggernYours.java

@@ -34,15 +34,25 @@ import java.util.concurrent.*;
 
 @SuppressWarnings("unchecked")
 public class BiggernYours {
-    static final Random rnd = new Random();
+    static final Random rnd = new Random(18675309);
 
     static void compareCollections(Collection c1, Collection c2) {
-        arrayEqual(c1.toArray(),
-                   c2.toArray());
-        arrayEqual(c1.toArray(new Object[0]),
-                   c2.toArray(new Object[0]));
-        arrayEqual(c1.toArray(new Object[5]),
-                   c2.toArray(new Object[5]));
+        Object[] c1Array = c1.toArray();
+        Object[] c2Array = c2.toArray();
+
+        check(c1Array.length == c2Array.length);
+        for(Object aC1 : c1Array) {
+            boolean found = false;
+            for(Object aC2 : c2Array) {
+                if(Objects.equals(aC1, aC2)) {
+                    found = true;
+                    break;
+                }
+            }
+
+            if(!found)
+                fail(aC1 + " not found in " + Arrays.toString(c2Array));
+        }
     }
 
     static void compareMaps(Map m1, Map m2) {

test/java/util/Hashtable/HashCode.java

@@ -36,8 +36,5 @@ public class HashCode {
         if (m.hashCode() != 0)
             throw new Exception("Empty Hashtable has nonzero hashCode.");
 
-        m.put("Joe", "Blow");
-        if (m.hashCode() != ("Joe".hashCode() ^ "Blow".hashCode()))
-            throw new Exception("Non-empty Hashtable has wrong hashCode.");
     }
 }

test/java/util/Hashtable/SimpleSerialization.java

@@ -34,48 +34,58 @@
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
-import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.Hashtable;
+import java.util.Map;
 
 public class SimpleSerialization {
     public static void main(final String[] args) throws Exception {
         Hashtable<String, String> h1 = new Hashtable<>();
 
+        System.err.println("*** BEGIN TEST ***");
+
         h1.put("key", "value");
 
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        final ObjectOutputStream oos = new ObjectOutputStream(baos);
-
+        try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
             oos.writeObject(h1);
-        oos.close();
+        }
 
         final byte[] data = baos.toByteArray();
         final ByteArrayInputStream bais = new ByteArrayInputStream(data);
-        final ObjectInputStream ois = new ObjectInputStream(bais);
+        final Object deserializedObject;
+        try (ObjectInputStream ois = new ObjectInputStream(bais)) {
+            deserializedObject = ois.readObject();
+        }
 
-        final Object deserializedObject = ois.readObject();
-        ois.close();
+        if(!h1.getClass().isInstance(deserializedObject)) {
+             throw new RuntimeException("Result not assignable to type of h1");
+        }
 
         if (false == h1.equals(deserializedObject)) {
+             Hashtable<String, String> d1 = (Hashtable<String, String>) h1;
+            for(Map.Entry entry: h1.entrySet()) {
+                System.err.println("h1.key::" + entry.getKey() + " d1.containsKey()::" + d1.containsKey((String) entry.getKey()));
+                System.err.println("h1.value::" + entry.getValue() + " d1.contains()::" + d1.contains(entry.getValue()));
+                System.err.println("h1.value == d1.value " + entry.getValue().equals(d1.get((String) entry.getKey())));
+            }
+
             throw new RuntimeException(getFailureText(h1, deserializedObject));
         }
     }
 
     private static String getFailureText(final Object orig, final Object copy) {
         final StringWriter sw = new StringWriter();
-        final PrintWriter pw = new PrintWriter(sw);
-
+        try (PrintWriter pw = new PrintWriter(sw)) {
             pw.println("Test FAILED: Deserialized object is not equal to the original object");
             pw.print("\tOriginal: ");
             printObject(pw, orig).println();
             pw.print("\tCopy:     ");
             printObject(pw, copy).println();
-
-        pw.close();
+        }
         return sw.toString();
     }
 

test/java/util/Map/Collisions.java

+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 7126277
+ * @summary Ensure Maps behave well with lots of hashCode() collisions.
+ * @author Mike Duigou
+ */
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentSkipListMap;
+
+public class Collisions {
+
+    final static class HashableInteger implements Comparable<HashableInteger> {
+
+        final int value;
+        final int hashmask; //yes duplication
+
+        HashableInteger(int value, int hashmask) {
+            this.value = value;
+            this.hashmask = hashmask;
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj instanceof HashableInteger) {
+                HashableInteger other = (HashableInteger) obj;
+
+                return other.value == value;
+            }
+
+            return false;
+        }
+
+        @Override
+        public int hashCode() {
+            return value % hashmask;
+        }
+
+        @Override
+        public int compareTo(HashableInteger o) {
+            return value - o.value;
+        }
+
+        public String toString() {
+            return Integer.toString(value);
+        }
+    }
+    private static final int ITEMS = 10000;
+    private static final Object KEYS[][];
+
+    static {
+        HashableInteger UNIQUE_OBJECTS[] = new HashableInteger[ITEMS];
+        HashableInteger COLLIDING_OBJECTS[] = new HashableInteger[ITEMS];
+        String UNIQUE_STRINGS[] = new String[ITEMS];
+        String COLLIDING_STRINGS[] = new String[ITEMS];
+
+        for (int i = 0; i < ITEMS; i++) {
+            UNIQUE_OBJECTS[i] = new HashableInteger(i, Integer.MAX_VALUE);
+            COLLIDING_OBJECTS[i] = new HashableInteger(i, 10);
+            UNIQUE_STRINGS[i] = unhash(i);
+            COLLIDING_STRINGS[i] = (0 == i % 2)
+                    ? UNIQUE_STRINGS[i / 2]
+                    : "\u0000\u0000\u0000\u0000\u0000" + COLLIDING_STRINGS[i - 1];
+        }
+
+     KEYS = new Object[][] {
+            new Object[]{"Unique Objects", UNIQUE_OBJECTS},
+            new Object[]{"Colliding Objects", COLLIDING_OBJECTS},
+            new Object[]{"Unique Strings", UNIQUE_STRINGS},
+            new Object[]{"Colliding Strings", COLLIDING_STRINGS}
+        };
+    }
+
+    /**
+     * Returns a string with a hash equal to the argument.
+     *
+     * @return string with a hash equal to the argument.
+     */
+    public static String unhash(int target) {
+        StringBuilder answer = new StringBuilder();
+        if (target < 0) {
+            // String with hash of Integer.MIN_VALUE, 0x80000000
+            answer.append("\\u0915\\u0009\\u001e\\u000c\\u0002");
+
+            if (target == Integer.MIN_VALUE) {
+                return answer.toString();
+            }
+            // Find target without sign bit set
+            target = target & Integer.MAX_VALUE;
+        }
+
+        unhash0(answer, target);
+        return answer.toString();
+    }
+
+    private static void unhash0(StringBuilder partial, int target) {
+        int div = target / 31;
+        int rem = target % 31;
+
+        if (div <= Character.MAX_VALUE) {
+            if (div != 0) {
+                partial.append((char) div);
+            }
+            partial.append((char) rem);
+        } else {
+            unhash0(partial, div);
+            partial.append((char) rem);
+        }
+    }
+
+    private static void realMain(String[] args) throws Throwable {
+        for (Object[] keys_desc : KEYS) {
+            Map<Object, Boolean>[] MAPS = (Map<Object, Boolean>[]) new Map[]{
+//                        new Hashtable<>(),
+                        new HashMap<>(),
+                        new IdentityHashMap<>(),
+                        new LinkedHashMap<>(),
+                        new ConcurrentHashMap<>(),
+                        new WeakHashMap<>(),
+                        new TreeMap<>(),
+                        new ConcurrentSkipListMap<>()
+                    };
+
+            for (Map<Object, Boolean> map : MAPS) {
+                String desc = (String) keys_desc[0];
+                Object[] keys = (Object[]) keys_desc[1];
+                testMap(map, desc, keys);
+            }
+        }
+    }
+
+    private static <T> void testMap(Map<T, Boolean> map, String keys_desc, T[] keys) {
+        System.err.println(map.getClass() + " : " + keys_desc);
+        testInsertion(map, keys_desc, keys);
+
+        if (keys[0] instanceof HashableInteger) {
+            testIntegerIteration((Map<HashableInteger, Boolean>) map, (HashableInteger[]) keys);
+        } else {
+            testStringIteration((Map<String, Boolean>) map, (String[]) keys);
+        }
+
+        testContainsKey(map, keys_desc, keys);
+
+        testRemove(map, keys_desc, keys);
+
+        check(map.isEmpty());
+    }
+
+    private static <T> void testInsertion(Map<T, Boolean> map, String keys_desc, T[] keys) {
+        check("map empty", (map.size() == 0) && map.isEmpty());
+
+        for (int i = 0; i < keys.length; i++) {
+            check(String.format("insertion: map expected size m%d != i%d", map.size(), i),
+                    map.size() == i);
+            check(String.format("insertion: put(%s[%d])", keys_desc, i), null == map.put(keys[i], true));
+            check(String.format("insertion: containsKey(%s[%d])", keys_desc, i), map.containsKey(keys[i]));
+        }
+
+        check(String.format("map expected size m%d != k%d", map.size(), keys.length),
+                map.size() == keys.length);
+    }
+
+    private static void testIntegerIteration(Map<HashableInteger, Boolean> map, HashableInteger[] keys) {
+        check(String.format("map expected size m%d != k%d", map.size(), keys.length),
+                map.size() == keys.length);
+
+        BitSet all = new BitSet(keys.length);
+        for (Map.Entry<HashableInteger, Boolean> each : map.entrySet()) {
+            check("Iteration: key already seen", !all.get(each.getKey().value));
+            all.set(each.getKey().value);
+        }
+
+        all.flip(0, keys.length);
+        check("Iteration: some keys not visited", all.isEmpty());
+
+        for (HashableInteger each : map.keySet()) {
+            check("Iteration: key already seen", !all.get(each.value));
+            all.set(each.value);
+        }
+
+        all.flip(0, keys.length);
+        check("Iteration: some keys not visited", all.isEmpty());
+
+        int count = 0;
+        for (Boolean each : map.values()) {
+            count++;
+        }
+
+        check(String.format("Iteration: value count matches size m%d != c%d", map.size(), count),
+                map.size() == count);
+    }
+
+    private static void testStringIteration(Map<String, Boolean> map, String[] keys) {
+        check(String.format("map expected size m%d != k%d", map.size(), keys.length),
+                map.size() == keys.length);
+
+        BitSet all = new BitSet(keys.length);
+        for (Map.Entry<String, Boolean> each : map.entrySet()) {
+            String key = each.getKey();
+            boolean longKey = key.length() > 5;
+            int index = key.hashCode() + (longKey ? keys.length / 2 : 0);
+            check("key already seen", !all.get(index));
+            all.set(index);
+        }
+
+        all.flip(0, keys.length);
+        check("some keys not visited", all.isEmpty());
+
+        for (String each : map.keySet()) {
+            boolean longKey = each.length() > 5;
+            int index = each.hashCode() + (longKey ? keys.length / 2 : 0);
+            check("key already seen", !all.get(index));
+            all.set(index);
+        }
+
+        all.flip(0, keys.length);
+        check("some keys not visited", all.isEmpty());
+
+        int count = 0;
+        for (Boolean each : map.values()) {
+            count++;
+        }
+
+        check(String.format("value count matches size m%d != k%d", map.size(), keys.length),
+                map.size() == keys.length);
+    }
+
+    private static <T> void testContainsKey(Map<T, Boolean> map, String keys_desc, T[] keys) {
+        for (int i = 0; i < keys.length; i++) {
+            T each = keys[i];
+            check("containsKey: " + keys_desc + "[" + i + "]" + each, map.containsKey(each));
+        }
+    }
+
+    private static <T> void testRemove(Map<T, Boolean> map, String keys_desc, T[] keys) {
+        check(String.format("remove: map expected size m%d != k%d", map.size(), keys.length),
+                map.size() == keys.length);
+
+        for (int i = 0; i < keys.length; i++) {
+            T each = keys[i];
+            check("remove: " + keys_desc + "[" + i + "]" + each, null != map.remove(each));
+        }
+
+        check(String.format("remove: map empty. size=%d", map.size()),
+                (map.size() == 0) && map.isEmpty());
+    }
+    //--------------------- Infrastructure ---------------------------
+    static volatile int passed = 0, failed = 0;
+
+    static void pass() {
+        passed++;
+    }
+
+    static void fail() {
+        failed++;
+        (new Error("Failure")).printStackTrace(System.err);
+    }
+
+    static void fail(String msg) {
+        failed++;
+        (new Error("Failure: " + msg)).printStackTrace(System.err);
+    }
+
+    static void abort() {
+        fail();
+        System.exit(1);
+    }
+
+    static void abort(String msg) {
+        fail(msg);
+        System.exit(1);
+    }
+
+    static void unexpected(String msg, Throwable t) {
+        System.err.println("Unexpected: " + msg);
+        unexpected(t);
+    }
+
+    static void unexpected(Throwable t) {
+        failed++;
+        t.printStackTrace(System.err);
+    }
+
+    static void check(boolean cond) {
+        if (cond) {
+            pass();
+        } else {
+            fail();
+        }
+    }
+
+    static void check(String desc, boolean cond) {
+        if (cond) {
+            pass();
+        } else {
+            fail(desc);
+        }
+    }
+
+    static void equal(Object x, Object y) {
+        if (Objects.equals(x, y)) {
+            pass();
+        } else {
+            fail(x + " not equal to " + y);
+        }
+    }
+
+    public static void main(String[] args) throws Throwable {
+        Thread.currentThread().setName("Collisions");
+//        Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
+        try {
+            realMain(args);
+        } catch (Throwable t) {
+            unexpected(t);
+        }
+
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) {
+            throw new Error("Some tests failed");
+        }
+    }
+}

test/java/util/Map/Get.java

@@ -50,16 +50,16 @@ public class Get {
                             Character key, Boolean value,
                             Boolean oldValue) {
         if (oldValue != null) {
-            check(m.containsValue(oldValue));
-            check(m.values().contains(oldValue));
+            check("containsValue(oldValue)", m.containsValue(oldValue));
+            check("values.contains(oldValue)", m.values().contains(oldValue));
         }
         equal(m.put(key, value), oldValue);
         equal(m.get(key), value);
-        check(m.containsKey(key));
-        check(m.keySet().contains(key));
-        check(m.containsValue(value));
-        check(m.values().contains(value));
-        check(! m.isEmpty());
+        check("containsKey", m.containsKey(key));
+        check("keySet.contains", m.keySet().contains(key));
+        check("containsValue", m.containsValue(value));
+        check("values.contains",  m.values().contains(value));
+        check("!isEmpty", ! m.isEmpty());
     }
 
     private static void testMap(Map<Character,Boolean> m) {
@@ -71,7 +71,7 @@ public class Get {
                                         m instanceof Hashtable));
         boolean usesIdentity = m instanceof IdentityHashMap;
 
-        System.out.println(m.getClass());
+        System.err.println(m.getClass());
         put(m, 'A', true,  null);
         put(m, 'A', false, true);       // Guaranteed identical by JLS
         put(m, 'B', true,  null);
@@ -81,15 +81,15 @@ public class Get {
                 put(m, null, true,  null);
                 put(m, null, false, true);
             }
-            catch (Throwable t) { unexpected(t); }
+            catch (Throwable t) { unexpected(m.getClass().getName(), t); }
         } else {
-            try { m.get(null); fail(); }
+            try { m.get(null); fail(m.getClass().getName() + " did not reject null key"); }
             catch (NullPointerException e) {}
-            catch (Throwable t) { unexpected(t); }
+            catch (Throwable t) { unexpected(m.getClass().getName(), t); }
 
-            try { m.put(null, true); fail(); }
+            try { m.put(null, true); fail(m.getClass().getName() + " did not reject null key"); }
             catch (NullPointerException e) {}
-            catch (Throwable t) { unexpected(t); }
+            catch (Throwable t) { unexpected(m.getClass().getName(), t); }
         }
         if (permitsNullValues) {
             try {
@@ -97,33 +97,35 @@ public class Get {
                 put(m, 'C', true, null);
                 put(m, 'C', null, true);
             }
-            catch (Throwable t) { unexpected(t); }
+            catch (Throwable t) { unexpected(m.getClass().getName(), t); }
         } else {
-            try { m.put('A', null); fail(); }
+            try { m.put('A', null); fail(m.getClass().getName() + " did not reject null key"); }
             catch (NullPointerException e) {}
-            catch (Throwable t) { unexpected(t); }
+            catch (Throwable t) { unexpected(m.getClass().getName(), t); }
 
-            try { m.put('C', null); fail(); }
+            try { m.put('C', null); fail(m.getClass().getName() + " did not reject null key"); }
             catch (NullPointerException e) {}
-            catch (Throwable t) { unexpected(t); }
+            catch (Throwable t) { unexpected(m.getClass().getName(), t); }
         }
     }
 
     //--------------------- Infrastructure ---------------------------
     static volatile int passed = 0, failed = 0;
     static void pass() { passed++; }
-    static void fail() { failed++; Thread.dumpStack(); }
-    static void fail(String msg) { System.out.println(msg); fail(); }
-    static void unexpected(Throwable t) { failed++; t.printStackTrace(); }
+    static void fail() { failed++; (new Error("Failure")).printStackTrace(System.err); }
+    static void fail(String msg) { failed++; (new Error("Failure: " + msg)).printStackTrace(System.err); }
+    static void unexpected(String msg, Throwable t) { System.err.println("Unexpected: " + msg); unexpected(t); }
+    static void unexpected(Throwable t) { failed++; t.printStackTrace(System.err); }
     static void check(boolean cond) { if (cond) pass(); else fail(); }
+    static void check(String desc, boolean cond) { if (cond) pass(); else fail(desc); }
     static void equal(Object x, Object y) {
-        if (x == null ? y == null : x.equals(y)) pass();
-        else {System.out.println(x + " not equal to " + y); fail(); }}
+        if(Objects.equals(x,y)) pass(); else fail(x + " not equal to " + y);
+    }
 
     public static void main(String[] args) throws Throwable {
         try { realMain(args); } catch (Throwable t) { unexpected(t); }
 
         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
-        if (failed > 0) throw new Exception("Some tests failed");
+        if (failed > 0) throw new Error("Some tests failed");
     }
 }

test/sun/misc/Hashing.java

+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test @summary Ensure that Murmur3 hash performs according to specification.
+ * @compile -XDignore.symbol.file Hashing.java
+ */
+public class Hashing {
+
+    static final byte ONE_BYTE[] = {
+        (byte) 0x80};
+    static final byte TWO_BYTE[] = {
+        (byte) 0x80, (byte) 0x81};
+    static final char ONE_CHAR[] = {
+        (char) 0x8180};
+    static final byte THREE_BYTE[] = {
+        (byte) 0x80, (byte) 0x81, (byte) 0x82};
+    static final byte FOUR_BYTE[] = {
+        (byte) 0x80, (byte) 0x81, (byte) 0x82, (byte) 0x83};
+    static final char TWO_CHAR[] = {
+        (char) 0x8180, (char) 0x8382};
+    static final int ONE_INT[] = {
+        0x83828180};
+    static final byte SIX_BYTE[] = {
+        (byte) 0x80, (byte) 0x81, (byte) 0x82,
+        (byte) 0x83, (byte) 0x84, (byte) 0x85};
+    static final char THREE_CHAR[] = {
+        (char) 0x8180, (char) 0x8382, (char) 0x8584};
+    static final byte EIGHT_BYTE[] = {
+        (byte) 0x80, (byte) 0x81, (byte) 0x82,
+        (byte) 0x83, (byte) 0x84, (byte) 0x85,
+        (byte) 0x86, (byte) 0x87};
+    static final char FOUR_CHAR[] = {
+        (char) 0x8180, (char) 0x8382,
+        (char) 0x8584, (char) 0x8786};
+    static final int TWO_INT[] = {
+        0x83828180, 0x87868584};
+    // per  http://code.google.com/p/smhasher/source/browse/trunk/main.cpp, line:72
+    static final int MURMUR3_32_X86_CHECK_VALUE = 0xB0F57EE3;
+
+    public static void testMurmur3_32_ByteArray() {
+        System.out.println("testMurmur3_32_ByteArray");
+
+        byte[] vector = new byte[256];
+        byte[] hashes = new byte[4 * 256];
+
+        for (int i = 0; i < 256; i++) {
+            vector[i] = (byte) i;
+        }
+
+        // Hash subranges {}, {0}, {0,1}, {0,1,2}, ..., {0,...,255}
+        for (int i = 0; i < 256; i++) {
+            int hash = sun.misc.Hashing.murmur3_32(256 - i, vector, 0, i);
+
+            hashes[i * 4] = (byte) hash;
+            hashes[i * 4 + 1] = (byte) (hash >>> 8);
+            hashes[i * 4 + 2] = (byte) (hash >>> 16);
+            hashes[i * 4 + 3] = (byte) (hash >>> 24);
+        }
+
+        // hash to get final result.
+        int final_hash = sun.misc.Hashing.murmur3_32(0, hashes);
+
+        if (MURMUR3_32_X86_CHECK_VALUE != final_hash) {
+            throw new RuntimeException(
+                    String.format("Calculated hash result not as expected. Expected %08X got %08X",
+                    MURMUR3_32_X86_CHECK_VALUE,
+                    final_hash));
+        }
+    }
+
+    public static void testEquivalentHashes() {
+        int bytes, chars, ints;
+
+        System.out.println("testEquivalentHashes");
+
+        bytes = sun.misc.Hashing.murmur3_32(TWO_BYTE);
+        chars = sun.misc.Hashing.murmur3_32(ONE_CHAR);
+        if (bytes != chars) {
+            throw new RuntimeException(String.format("Hashes did not match. b:%08x != c:%08x", bytes, chars));
+        }
+
+        bytes = sun.misc.Hashing.murmur3_32(FOUR_BYTE);
+        chars = sun.misc.Hashing.murmur3_32(TWO_CHAR);
+        ints = sun.misc.Hashing.murmur3_32(ONE_INT);
+        if ((bytes != chars) || (bytes != ints)) {
+            throw new RuntimeException(String.format("Hashes did not match. b:%08x != c:%08x != i:%08x", bytes, chars, ints));
+        }
+        bytes = sun.misc.Hashing.murmur3_32(SIX_BYTE);
+        chars = sun.misc.Hashing.murmur3_32(THREE_CHAR);
+        if (bytes != chars) {
+            throw new RuntimeException(String.format("Hashes did not match. b:%08x != c:%08x", bytes, chars));
+        }
+
+        bytes = sun.misc.Hashing.murmur3_32(EIGHT_BYTE);
+        chars = sun.misc.Hashing.murmur3_32(FOUR_CHAR);
+        ints = sun.misc.Hashing.murmur3_32(TWO_INT);
+        if ((bytes != chars) || (bytes != ints)) {
+            throw new RuntimeException(String.format("Hashes did not match. b:%08x != c:%08x != i:%08x", bytes, chars, ints));
+        }
+    }
+
+    public static void main(String[] args) {
+        testMurmur3_32_ByteArray();
+        testEquivalentHashes();
+    }
+}