--- a/jdk/src/share/classes/java/util/Hashtable.java Fri Sep 13 10:48:12 2013 +0200
+++ b/jdk/src/share/classes/java/util/Hashtable.java Thu Sep 12 14:22:53 2013 -0700
@@ -168,68 +168,6 @@
/** 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 final boolean USE_HASHSEED;
-
- static {
- String hashSeedProp = java.security.AccessController.doPrivileged(
- new sun.security.action.GetPropertyAction(
- "jdk.map.useRandomSeed"));
- boolean localBool = (null != hashSeedProp)
- ? Boolean.parseBoolean(hashSeedProp) : false;
- USE_HASHSEED = localBool;
-
- if (USE_HASHSEED) {
- 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);
- }
- } else {
- UNSAFE = null;
- HASHSEED_OFFSET = 0;
- }
- }
- }
-
- /**
- * A randomizing value associated with this instance that is applied to
- * hash code of keys to make hash collisions harder to find.
- *
- * Non-final so it can be set lazily, but be sure not to set more than once.
- */
- transient final int hashSeed;
-
- /**
- * Return an initial value for the hashSeed, or 0 if the random seed is not
- * enabled.
- */
- final int initHashSeed() {
- if (sun.misc.VM.isBooted() && Holder.USE_HASHSEED) {
- int seed = ThreadLocalRandom.current().nextInt();
- return (seed != 0) ? seed : 1;
- }
- return 0;
- }
-
- private int hash(Object k) {
- return hashSeed ^ k.hashCode();
- }
-
/**
* Constructs a new, empty hashtable with the specified initial
* capacity and the specified load factor.
@@ -251,7 +189,6 @@
this.loadFactor = loadFactor;
table = new Entry<?,?>[initialCapacity];
threshold = (int)Math.min(initialCapacity * loadFactor, MAX_ARRAY_SIZE + 1);
- hashSeed = initHashSeed();
}
/**
@@ -395,7 +332,7 @@
*/
public synchronized boolean containsKey(Object key) {
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) {
@@ -423,7 +360,7 @@
@SuppressWarnings("unchecked")
public synchronized V get(Object key) {
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) {
@@ -488,7 +425,7 @@
rehash();
tab = table;
- hash = hash(key);
+ hash = key.hashCode();
index = (hash & 0x7FFFFFFF) % tab.length;
}
@@ -524,7 +461,7 @@
// Makes sure the key is not already in the hashtable.
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> entry = (Entry<K,V>)tab[index];
@@ -551,7 +488,7 @@
*/
public synchronized V remove(Object key) {
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -760,7 +697,7 @@
Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
Object key = entry.getKey();
Entry<?,?>[] tab = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index]; e != null; e = e.next)
@@ -775,7 +712,7 @@
Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
Object key = entry.getKey();
Entry<?,?>[] tab = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
@@ -975,7 +912,7 @@
// Makes sure the key is not already in the hashtable.
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> entry = (Entry<K,V>)tab[index];
@@ -998,7 +935,7 @@
Objects.requireNonNull(value);
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1021,7 +958,7 @@
@Override
public synchronized boolean replace(K key, V oldValue, V newValue) {
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1041,7 +978,7 @@
@Override
public synchronized V replace(K key, V value) {
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1060,7 +997,7 @@
Objects.requireNonNull(mappingFunction);
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1084,7 +1021,7 @@
Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1113,7 +1050,7 @@
Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1148,7 +1085,7 @@
Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table;
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index];
@@ -1228,13 +1165,6 @@
// Read in the length, threshold, and loadfactor
s.defaultReadObject();
- // set hashMask
- if (Holder.USE_HASHSEED) {
- int seed = ThreadLocalRandom.current().nextInt();
- Holder.UNSAFE.putIntVolatile(this, Holder.HASHSEED_OFFSET,
- (seed != 0) ? seed : 1);
- }
-
// Read the original length of the array and number of elements
int origlength = s.readInt();
int elements = s.readInt();
@@ -1282,7 +1212,7 @@
}
// Makes sure the key is not already in the hashtable.
// This should not happen in deserialized version.
- int hash = hash(key);
+ int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) {
@@ -1347,7 +1277,7 @@
}
public int hashCode() {
- return (Objects.hashCode(key) ^ Objects.hashCode(value));
+ return hash ^ Objects.hashCode(value);
}
public String toString() {
--- a/jdk/src/share/classes/java/util/WeakHashMap.java Fri Sep 13 10:48:12 2013 +0200
+++ b/jdk/src/share/classes/java/util/WeakHashMap.java Thu Sep 12 14:22:53 2013 -0700
@@ -190,39 +190,6 @@
*/
int modCount;
- private static class Holder {
- static final boolean USE_HASHSEED;
-
- static {
- String hashSeedProp = java.security.AccessController.doPrivileged(
- new sun.security.action.GetPropertyAction(
- "jdk.map.useRandomSeed"));
- boolean localBool = (null != hashSeedProp)
- ? Boolean.parseBoolean(hashSeedProp) : false;
- USE_HASHSEED = localBool;
- }
- }
-
- /**
- * A randomizing value associated with this instance that is applied to
- * hash code of keys to make hash collisions harder to find.
- *
- * Non-final so it can be set lazily, but be sure not to set more than once.
- */
- transient int hashSeed;
-
- /**
- * Initialize the hashing mask value.
- */
- final void initHashSeed() {
- if (sun.misc.VM.isBooted() && Holder.USE_HASHSEED) {
- // Do not set hashSeed more than once!
- // assert hashSeed == 0;
- int seed = ThreadLocalRandom.current().nextInt();
- hashSeed = (seed != 0) ? seed : 1;
- }
- }
-
@SuppressWarnings("unchecked")
private Entry<K,V>[] newTable(int n) {
return (Entry<K,V>[]) new Entry<?,?>[n];
@@ -253,7 +220,6 @@
table = newTable(capacity);
this.loadFactor = loadFactor;
threshold = (int)(capacity * loadFactor);
- initHashSeed();
}
/**
@@ -329,7 +295,7 @@
* in lower bits.
*/
final int hash(Object k) {
- int h = hashSeed ^ k.hashCode();
+ int h = k.hashCode();
// This function ensures that hashCodes that differ only by
// constant multiples at each bit position have a bounded
@@ -783,8 +749,7 @@
public int hashCode() {
K k = getKey();
V v = getValue();
- return ((k==null ? 0 : k.hashCode()) ^
- (v==null ? 0 : v.hashCode()));
+ return Objects.hashCode(k) ^ Objects.hashCode(v);
}
public String toString() {
--- a/jdk/test/java/util/Map/CheckRandomHashSeed.java Fri Sep 13 10:48:12 2013 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,91 +0,0 @@
-/*
- * Copyright (c) 2013, 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 8005698
- * @summary Check operation of jdk.map.useRandomSeed property
- * @run main CheckRandomHashSeed
- * @run main/othervm -Djdk.map.useRandomSeed=false CheckRandomHashSeed
- * @run main/othervm -Djdk.map.useRandomSeed=bogus CheckRandomHashSeed
- * @run main/othervm -Djdk.map.useRandomSeed=true CheckRandomHashSeed true
- * @author Brent Christian
- */
-import java.lang.reflect.Field;
-import java.util.Map;
-import java.util.HashMap;
-import java.util.LinkedHashMap;
-import java.util.Hashtable;
-import java.util.WeakHashMap;
-
-public class CheckRandomHashSeed {
- private final static String PROP_NAME = "jdk.map.useRandomSeed";
- static boolean expectRandom = false;
-
- public static void main(String[] args) {
- if (args.length > 0 && args[0].equals("true")) {
- expectRandom = true;
- }
- String hashSeedProp = System.getProperty(PROP_NAME);
- boolean propSet = (null != hashSeedProp)
- ? Boolean.parseBoolean(hashSeedProp) : false;
- if (expectRandom != propSet) {
- throw new Error("Error in test setup: " + (expectRandom ? "" : "not " ) + "expecting random hashSeed, but " + PROP_NAME + " is " + (propSet ? "" : "not ") + "enabled");
- }
-
- testMap(new WeakHashMap());
- testMap(new Hashtable());
- }
-
- private static void testMap(Map map) {
- int hashSeed = getHashSeed(map);
- boolean hashSeedIsZero = (hashSeed == 0);
-
- if (expectRandom != hashSeedIsZero) {
- System.out.println("Test passed for " + map.getClass().getSimpleName() + " - expectRandom: " + expectRandom + ", hashSeed: " + hashSeed);
- } else {
- throw new Error ("Test FAILED for " + map.getClass().getSimpleName() + " - expectRandom: " + expectRandom + ", hashSeed: " + hashSeed);
- }
- }
-
- private static int getHashSeed(Map map) {
- try {
- if (map instanceof HashMap || map instanceof LinkedHashMap) {
- map.put("Key", "Value");
- Field hashSeedField = HashMap.class.getDeclaredField("hashSeed");
- hashSeedField.setAccessible(true);
- int hashSeed = hashSeedField.getInt(map);
- return hashSeed;
- } else {
- map.put("Key", "Value");
- Field hashSeedField = map.getClass().getDeclaredField("hashSeed");
- hashSeedField.setAccessible(true);
- int hashSeed = hashSeedField.getInt(map);
- return hashSeed;
- }
- } catch(Exception e) {
- e.printStackTrace();
- throw new Error(e);
- }
- }
-}