Skip to content

D
dragonwell8_jdk

openanolis / dragonwell8_jdk

通知 4
Star 2
Fork 0
D
dragonwell8_jdk
提交 789cd37f 编写于 作者: B bchristi
浏览文件
操作

8024009: Remove jdk.map.useRandomSeed system property 

Summary: Removed usage of hashSeed in Hashtable & WeakHashMap, and removed tests
Reviewed-by: alanb, mduigou
上级 efe24632
隐藏空白更改
内联 并排
Showing with 19 addition and 217 deletion
src/share/classes/java/util/Hashtable.java
浏览文件 @ 789cd37f
...@@ -168,68 +168,6 @@ public class Hashtable<K,V> ...@@ -168,68 +168,6 @@ public class Hashtable<K,V>
/** use serialVersionUID from JDK 1.0.2 for interoperability */ /** use serialVersionUID from JDK 1.0.2 for interoperability */
private static final long serialVersionUID = 1421746759512286392L; 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 * Constructs a new, empty hashtable with the specified initial
* capacity and the specified load factor. * capacity and the specified load factor.
...@@ -251,7 +189,6 @@ public class Hashtable<K,V> ...@@ -251,7 +189,6 @@ public class Hashtable<K,V>
this.loadFactor = loadFactor; this.loadFactor = loadFactor;
table = new Entry<?,?>[initialCapacity]; table = new Entry<?,?>[initialCapacity];
threshold = (int)Math.min(initialCapacity * loadFactor, MAX_ARRAY_SIZE + 1); threshold = (int)Math.min(initialCapacity * loadFactor, MAX_ARRAY_SIZE + 1);
hashSeed = initHashSeed();
} }
/** /**
...@@ -395,7 +332,7 @@ public class Hashtable<K,V> ...@@ -395,7 +332,7 @@ public class Hashtable<K,V>
*/ */
public synchronized boolean containsKey(Object key) { public synchronized boolean containsKey(Object key) {
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) { for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) { if ((e.hash == hash) && e.key.equals(key)) {
...@@ -423,7 +360,7 @@ public class Hashtable<K,V> ...@@ -423,7 +360,7 @@ public class Hashtable<K,V>
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
public synchronized V get(Object key) { public synchronized V get(Object key) {
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) { for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) { if ((e.hash == hash) && e.key.equals(key)) {
...@@ -488,7 +425,7 @@ public class Hashtable<K,V> ...@@ -488,7 +425,7 @@ public class Hashtable<K,V>
rehash(); rehash();
tab = table; tab = table;
hash = hash(key); hash = key.hashCode();
index = (hash & 0x7FFFFFFF) % tab.length; index = (hash & 0x7FFFFFFF) % tab.length;
} }
...@@ -524,7 +461,7 @@ public class Hashtable<K,V> ...@@ -524,7 +461,7 @@ public class Hashtable<K,V>
// Makes sure the key is not already in the hashtable. // Makes sure the key is not already in the hashtable.
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> entry = (Entry<K,V>)tab[index]; Entry<K,V> entry = (Entry<K,V>)tab[index];
...@@ -551,7 +488,7 @@ public class Hashtable<K,V> ...@@ -551,7 +488,7 @@ public class Hashtable<K,V>
*/ */
public synchronized V remove(Object key) { public synchronized V remove(Object key) {
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -760,7 +697,7 @@ public class Hashtable<K,V> ...@@ -760,7 +697,7 @@ public class Hashtable<K,V>
Map.Entry<?,?> entry = (Map.Entry<?,?>)o; Map.Entry<?,?> entry = (Map.Entry<?,?>)o;
Object key = entry.getKey(); Object key = entry.getKey();
Entry<?,?>[] tab = table; Entry<?,?>[] tab = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index]; e != null; e = e.next) for (Entry<?,?> e = tab[index]; e != null; e = e.next)
...@@ -775,7 +712,7 @@ public class Hashtable<K,V> ...@@ -775,7 +712,7 @@ public class Hashtable<K,V>
Map.Entry<?,?> entry = (Map.Entry<?,?>) o; Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
Object key = entry.getKey(); Object key = entry.getKey();
Entry<?,?>[] tab = table; Entry<?,?>[] tab = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
...@@ -975,7 +912,7 @@ public class Hashtable<K,V> ...@@ -975,7 +912,7 @@ public class Hashtable<K,V>
// Makes sure the key is not already in the hashtable. // Makes sure the key is not already in the hashtable.
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> entry = (Entry<K,V>)tab[index]; Entry<K,V> entry = (Entry<K,V>)tab[index];
...@@ -998,7 +935,7 @@ public class Hashtable<K,V> ...@@ -998,7 +935,7 @@ public class Hashtable<K,V>
Objects.requireNonNull(value); Objects.requireNonNull(value);
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1021,7 +958,7 @@ public class Hashtable<K,V> ...@@ -1021,7 +958,7 @@ public class Hashtable<K,V>
@Override @Override
public synchronized boolean replace(K key, V oldValue, V newValue) { public synchronized boolean replace(K key, V oldValue, V newValue) {
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1041,7 +978,7 @@ public class Hashtable<K,V> ...@@ -1041,7 +978,7 @@ public class Hashtable<K,V>
@Override @Override
public synchronized V replace(K key, V value) { public synchronized V replace(K key, V value) {
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1060,7 +997,7 @@ public class Hashtable<K,V> ...@@ -1060,7 +997,7 @@ public class Hashtable<K,V>
Objects.requireNonNull(mappingFunction); Objects.requireNonNull(mappingFunction);
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1084,7 +1021,7 @@ public class Hashtable<K,V> ...@@ -1084,7 +1021,7 @@ public class Hashtable<K,V>
Objects.requireNonNull(remappingFunction); Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1113,7 +1050,7 @@ public class Hashtable<K,V> ...@@ -1113,7 +1050,7 @@ public class Hashtable<K,V>
Objects.requireNonNull(remappingFunction); Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1148,7 +1085,7 @@ public class Hashtable<K,V> ...@@ -1148,7 +1085,7 @@ public class Hashtable<K,V>
Objects.requireNonNull(remappingFunction); Objects.requireNonNull(remappingFunction);
Entry<?,?> tab[] = table; Entry<?,?> tab[] = table;
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
@SuppressWarnings("unchecked") @SuppressWarnings("unchecked")
Entry<K,V> e = (Entry<K,V>)tab[index]; Entry<K,V> e = (Entry<K,V>)tab[index];
...@@ -1228,13 +1165,6 @@ public class Hashtable<K,V> ...@@ -1228,13 +1165,6 @@ public class Hashtable<K,V>
// Read in the length, threshold, and loadfactor // Read in the length, threshold, and loadfactor
s.defaultReadObject(); 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 // Read the original length of the array and number of elements
int origlength = s.readInt(); int origlength = s.readInt();
int elements = s.readInt(); int elements = s.readInt();
...@@ -1282,7 +1212,7 @@ public class Hashtable<K,V> ...@@ -1282,7 +1212,7 @@ public class Hashtable<K,V>
} }
// Makes sure the key is not already in the hashtable. // Makes sure the key is not already in the hashtable.
// This should not happen in deserialized version. // This should not happen in deserialized version.
int hash = hash(key); int hash = key.hashCode();
int index = (hash & 0x7FFFFFFF) % tab.length; int index = (hash & 0x7FFFFFFF) % tab.length;
for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) { for (Entry<?,?> e = tab[index] ; e != null ; e = e.next) {
if ((e.hash == hash) && e.key.equals(key)) { if ((e.hash == hash) && e.key.equals(key)) {
...@@ -1347,7 +1277,7 @@ public class Hashtable<K,V> ...@@ -1347,7 +1277,7 @@ public class Hashtable<K,V>
} }
public int hashCode() { public int hashCode() {
return (Objects.hashCode(key) ^ Objects.hashCode(value)); return hash ^ Objects.hashCode(value);
} }
public String toString() { public String toString() {
......
src/share/classes/java/util/WeakHashMap.java
浏览文件 @ 789cd37f
...@@ -190,39 +190,6 @@ public class WeakHashMap<K,V> ...@@ -190,39 +190,6 @@ public class WeakHashMap<K,V>
*/ */
int modCount; 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") @SuppressWarnings("unchecked")
private Entry<K,V>[] newTable(int n) { private Entry<K,V>[] newTable(int n) {
return (Entry<K,V>[]) new Entry<?,?>[n]; return (Entry<K,V>[]) new Entry<?,?>[n];
...@@ -253,7 +220,6 @@ public class WeakHashMap<K,V> ...@@ -253,7 +220,6 @@ public class WeakHashMap<K,V>
table = newTable(capacity); table = newTable(capacity);
this.loadFactor = loadFactor; this.loadFactor = loadFactor;
threshold = (int)(capacity * loadFactor); threshold = (int)(capacity * loadFactor);
initHashSeed();
} }
/** /**
...@@ -329,7 +295,7 @@ public class WeakHashMap<K,V> ...@@ -329,7 +295,7 @@ public class WeakHashMap<K,V>
* in lower bits. * in lower bits.
*/ */
final int hash(Object k) { final int hash(Object k) {
int h = hashSeed ^ k.hashCode(); int h = k.hashCode();
// This function ensures that hashCodes that differ only by // This function ensures that hashCodes that differ only by
// constant multiples at each bit position have a bounded // constant multiples at each bit position have a bounded
...@@ -783,8 +749,7 @@ public class WeakHashMap<K,V> ...@@ -783,8 +749,7 @@ public class WeakHashMap<K,V>
public int hashCode() { public int hashCode() {
K k = getKey(); K k = getKey();
V v = getValue(); V v = getValue();
return ((k==null ? 0 : k.hashCode()) ^ return Objects.hashCode(k) ^ Objects.hashCode(v);
(v==null ? 0 : v.hashCode()));
} }
public String toString() { public String toString() {
......
test/java/util/Map/CheckRandomHashSeed.java 已删除 100644 → 0
浏览文件 @ efe24632
/*
* 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);
}
}
}
test/java/util/Map/Collisions.java
浏览文件 @ 789cd37f
...@@ -25,8 +25,6 @@ ...@@ -25,8 +25,6 @@
* @test * @test
* @bug 7126277 * @bug 7126277
* @run main Collisions -shortrun * @run main Collisions -shortrun
* @run main/othervm -Djdk.map.althashing.threshold=0 Collisions -shortrun
* @run main/othervm -Djdk.map.useRandomSeed=true Collisions -shortrun
* @summary Ensure Maps behave well with lots of hashCode() collisions. * @summary Ensure Maps behave well with lots of hashCode() collisions.
* @author Mike Duigou * @author Mike Duigou
*/ */
......
Markdown is supported
0% 或 .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑！
想要评论请 注册 或