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/*
* Copyright (c) 2011, 2020, 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
* @key stress randomness
*
* @summary converted from VM Testbase gc/gctests/StringInternSync.
* VM Testbase keywords: [gc, stress, stressopt, feature_perm_removal_jdk7, nonconcurrent]
* VM Testbase readme:
* The test verifies that String.intern is correctly synchronized.
* Test interns same strings in different threads and verifies that all interned equal
* strings are same objects.
* This test interns a few large strings.
*
* @library /vmTestbase
* /test/lib
* @run main/othervm
* -XX:+UnlockDiagnosticVMOptions
* -XX:+VerifyStringTableAtExit
* gc.gctests.StringInternSync.StringInternSync
* -ms low
*/
package gc.gctests.StringInternSync;
import java.util.*;
import java.util.ArrayList;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import nsk.share.TestBug;
import nsk.share.TestFailure;
import nsk.share.gc.*;
import nsk.share.gc.gp.MemoryStrategy;
import nsk.share.gc.gp.MemoryStrategyAware;
import nsk.share.gc.gp.string.RandomStringProducer;
public class StringInternSync extends ThreadedGCTest implements MemoryStrategyAware {
// The list of strings which will be interned
static final List<String> stringsToIntern = new ArrayList();
// The global container for references to internded strings
static final List<List<String>> internedStrings = new ArrayList<List<String>>();
// Approximate size occupied by all interned strings
long sizeOfAllInteredStrings = 0;
// maximum size of one string
int maxStringSize;
RandomStringProducer gp = new RandomStringProducer();
MemoryStrategy memoryStrategy;
ReadWriteLock rwlock = new ReentrantReadWriteLock();
@Override
public void setMemoryStrategy(MemoryStrategy memoryStrategy) {
this.memoryStrategy = memoryStrategy;
}
private class StringGenerator implements Runnable {
List<String> internedLocal;
public StringGenerator(List<String> internedLocal) {
this.internedLocal = internedLocal;
}
public void run() {
try {
rwlock.readLock().lock();
internedLocal.clear();
for (String str : stringsToIntern) {
// Intern copy of string
// and save reference to it
internedLocal.add(new String(str).intern());
}
} finally {
rwlock.readLock().unlock();
}
// after each iteration 0 thread
// lock our main resource and verify String.intern
if (internedLocal == internedStrings.get(0)) {
try {
rwlock.writeLock().lock();
// We select first list and compare all other with it
// if 2 strings are equal they should be the same "=="
List<String> interned = internedStrings.get(0);
for (List<String> list : internedStrings) {
if (list == interned) {
continue;
}
if (list.size() == 0) {
continue; // this thread haven't got lock
}
if (list.size() != interned.size()) {
throw new TestFailure("Size of interned string list differ from origial."
+ " interned " + list.size() + " original " + interned.size());
}
for (int i = 0; i < interned.size(); i++) {
String str = interned.get(i);
if (!str.equals(list.get(i))) {
throw new TestFailure("The interned strings are not the equals.");
}
if (str != list.get(i)) {
throw new TestFailure("The equal interned strings are not the same.");
}
}
list.clear();
}
interned.clear();
stringsToIntern.clear();
for (long currentSize = 0; currentSize <= sizeOfAllInteredStrings; currentSize++) {
stringsToIntern.add(gp.create(maxStringSize));
currentSize += maxStringSize;
}
} finally {
rwlock.writeLock().unlock();
}
}
}
}
@Override
public void run() {
sizeOfAllInteredStrings = 10 * 1024 * 1024; // let use 100 * strings of size 10000
maxStringSize = (int) (sizeOfAllInteredStrings / memoryStrategy.getSize(sizeOfAllInteredStrings));
log.debug("The overall size of interned strings : " + sizeOfAllInteredStrings / (1024 * 1024) + "M");
log.debug("The count of interned strings : " + sizeOfAllInteredStrings / maxStringSize);
for (long currentSize = 0; currentSize <= sizeOfAllInteredStrings; currentSize++) {
stringsToIntern.add(gp.create(maxStringSize));
currentSize += maxStringSize;
}
super.run();
}
@Override
protected Runnable createRunnable(int i) {
ArrayList list = new ArrayList();
internedStrings.add(list);
return new StringGenerator(list);
}
public static void main(String[] args) {
GC.runTest(new StringInternSync(), args);
}
}
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