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/*
* Copyright (c) 2003, 2016, 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 4530538 6980984
* @summary Basic unit test of memory management testing:
* 1) setUsageThreshold() and getUsageThreshold()
* 2) test low memory detection on the old generation.
*
* @author Mandy Chung
*
* @modules jdk.management
* @build MemoryManagement MemoryUtil
* @run main/othervm/timeout=600 -Xmn8m -XX:+IgnoreUnrecognizedVMOptions -XX:G1HeapRegionSize=1 -XX:-UseLargePages MemoryManagement
*/
import java.lang.management.*;
import java.util.*;
import javax.management.*;
import javax.management.openmbean.CompositeData;
public class MemoryManagement {
private static final MemoryMXBean mm = ManagementFactory.getMemoryMXBean();
private static final List pools =
Collections.synchronizedList(ManagementFactory.getMemoryPoolMXBeans());
private static final List managers =
Collections.synchronizedList(ManagementFactory.getMemoryManagerMXBeans());
private static volatile MemoryPoolMXBean mpool = null;
private static volatile boolean trace = false;
private static volatile boolean testFailed = false;
private static final int NUM_CHUNKS = 2;
// Must match -Xmn set on the @run line
private static final int YOUNG_GEN_SIZE = 8 * 1024 * 1024;
private static volatile long chunkSize;
private static volatile int listenerInvoked = 0;
static class SensorListener implements NotificationListener {
public void handleNotification(Notification notif, Object handback) {
String type = notif.getType();
if (type.equals(MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED) ||
type.equals(MemoryNotificationInfo.
MEMORY_COLLECTION_THRESHOLD_EXCEEDED)) {
MemoryNotificationInfo minfo = MemoryNotificationInfo.
from((CompositeData) notif.getUserData());
MemoryUtil.printMemoryNotificationInfo(minfo, type);
listenerInvoked++;
}
}
}
private static long newThreshold;
public static void main(String args[]) throws Exception {
if (args.length > 0 && args[0].equals("trace")) {
trace = true;
}
if (trace) {
MemoryUtil.printMemoryPools(pools);
MemoryUtil.printMemoryManagers(managers);
}
// Find the Old generation which supports low memory detection
ListIterator iter = pools.listIterator();
while (iter.hasNext()) {
MemoryPoolMXBean p = (MemoryPoolMXBean) iter.next();
if (p.getType() == MemoryType.HEAP &&
p.isUsageThresholdSupported()) {
mpool = p;
if (trace) {
System.out.println("Selected memory pool for low memory " +
"detection.");
MemoryUtil.printMemoryPool(mpool);
}
break;
}
}
SensorListener listener = new SensorListener();
NotificationEmitter emitter = (NotificationEmitter) mm;
emitter.addNotificationListener(listener, null, null);
Thread allocator = new AllocatorThread();
// The chunk size needs to be larger than YOUNG_GEN_SIZE,
// otherwise we will get intermittent failures when objects
// end up in the young gen instead of the old gen.
final long epsilon = 1024;
chunkSize = YOUNG_GEN_SIZE + epsilon;
// Now set threshold
MemoryUsage mu = mpool.getUsage();
newThreshold = mu.getUsed() + (chunkSize * NUM_CHUNKS);
// Sanity check. Make sure the new threshold isn't too large.
// Tweak the test if this fails.
final long headRoom = chunkSize * 2;
final long max = mu.getMax();
if (max != -1 && newThreshold > max - headRoom) {
throw new RuntimeException("TEST FAILED: newThreshold: " + newThreshold +
" is too near the maximum old gen size: " + max +
" used: " + mu.getUsed() + " headRoom: " + headRoom);
}
System.out.println("Setting threshold for " + mpool.getName() +
" from " + mpool.getUsageThreshold() + " to " + newThreshold +
". Current used = " + mu.getUsed());
mpool.setUsageThreshold(newThreshold);
if (mpool.getUsageThreshold() != newThreshold) {
throw new RuntimeException("TEST FAILED: " +
"Threshold for Memory pool " + mpool.getName() +
"is " + mpool.getUsageThreshold() + " but expected to be" +
newThreshold);
}
// Start the AllocatorThread to continously allocate memory
System.out.println("Starting an AllocatorThread to allocate memory.");
allocator.start();
try {
allocator.join();
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
if (listenerInvoked == 0) {
throw new RuntimeException("No listener is invoked");
}
if (testFailed)
throw new RuntimeException("TEST FAILED.");
System.out.println("Test passed.");
}
static class AllocatorThread extends Thread {
private List objectPool = new ArrayList();
public void run() {
int iterations = 0;
int numElements = (int) (chunkSize / 4); // minimal object size
while (listenerInvoked == 0) {
iterations++;
if (trace) {
System.out.println(" Iteration " + iterations +
": before allocation " +
mpool.getUsage().getUsed());
}
Object[] o = new Object[numElements];
if (iterations <= NUM_CHUNKS) {
// only hold a reference to the first NUM_CHUNKS
// allocated objects
objectPool.add(o);
}
if (trace) {
System.out.println(" " +
" after allocation " +
mpool.getUsage().getUsed());
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
}
System.out.println("AllocatedThread finished memory allocation " +
" num_iteration = " + iterations);
}
}
}
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