/*
* Copyright (c) 2003, 2010, 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
* @summary Basic unit test of memory management testing:
* 1) setUsageThreshold() and getUsageThreshold()
* 2) test low memory detection on the old generation.
*
* @author Mandy Chung
*
* @build LowMemoryTest MemoryUtil
* @run main/othervm/timeout=600 LowMemoryTest
*/
import java.lang.management.*;
import java.util.*;
import javax.management.*;
import javax.management.openmbean.CompositeData;
public class LowMemoryTest {
private static MemoryMXBean mm = ManagementFactory.getMemoryMXBean();
private static List pools = ManagementFactory.getMemoryPoolMXBeans();
private static List managers = ManagementFactory.getMemoryManagerMXBeans();
private static MemoryPoolMXBean mpool = null;
private static boolean trace = false;
private static boolean testFailed = false;
private static final int NUM_TRIGGERS = 5;
private static final int NUM_CHUNKS = 2;
private static long chunkSize;
private static boolean listenerInvoked = false;
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 = true;
}
}
}
static class TestListener implements NotificationListener {
private int triggers = 0;
private long[] count = new long[NUM_TRIGGERS * 2];
private long[] usedMemory = new long[NUM_TRIGGERS * 2];
public void handleNotification(Notification notif, Object handback) {
MemoryNotificationInfo minfo = MemoryNotificationInfo.
from((CompositeData) notif.getUserData());
count[triggers] = minfo.getCount();
usedMemory[triggers] = minfo.getUsage().getUsed();
triggers++;
}
public void checkResult() throws Exception {
if (triggers != NUM_TRIGGERS) {
throw new RuntimeException("Unexpected number of triggers = " +
triggers + " but expected to be " + NUM_TRIGGERS);
}
for (int i = 0; i < triggers; i++) {
if (count[i] != i+1) {
throw new RuntimeException("Unexpected count of" +
" notification #" + i +
" count = " + count[i] +
" but expected to be " + (i+1));
}
if (usedMemory[i] < newThreshold) {
throw new RuntimeException("Used memory = " +
usedMemory[i] + " is less than the threshold = " +
newThreshold);
}
}
}
}
private static long newThreshold;
public static void main(String args[]) throws Exception {
if (args.length > 0 && args[0].equals("trace")) {
trace = true;
}
// 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;
}
}
TestListener listener = new TestListener();
SensorListener l2 = new SensorListener();
NotificationEmitter emitter = (NotificationEmitter) mm;
emitter.addNotificationListener(listener, null, null);
emitter.addNotificationListener(l2, null, null);
Thread allocator = new AllocatorThread();
Thread sweeper = new SweeperThread();
// Now set threshold
MemoryUsage mu = mpool.getUsage();
chunkSize = (mu.getMax() - mu.getUsed()) / 20;
newThreshold = mu.getUsed() + (chunkSize * NUM_CHUNKS);
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);
}
allocator.start();
sweeper.start();
try {
allocator.join();
sweeper.join();
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
listener.checkResult();
if (testFailed)
throw new RuntimeException("TEST FAILED.");
System.out.println("Test passed.");
}
private static void goSleep(long ms) {
try {
Thread.sleep(ms);
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
}
private static Object go = new Object();
private static boolean waiting = false; // No thread is waiting.
// Synchronizes two thread. If no thread is waiting then wait
// for notification from a different thread and if it is
// is waiting then send notification.
// In this test case this method is used to synchronize sweeper
// thread and alocater thread to reach a particular point.
private static void wait_or_notify() {
synchronized (go) {
if (waiting == false) {
waiting = true;
System.out.println(" Waiting ");
try {
go.wait();
} catch (InterruptedException e) {
e.printStackTrace();
testFailed = true;
}
waiting = false;
} else {
System.out.println(" Notify ");
go.notify();
}
}
}
private static List objectPool = new ArrayList();
static class AllocatorThread extends Thread {
public void doTask() {
int iterations = 0;
int numElements = (int) (chunkSize / 4); // minimal object size
while (!listenerInvoked) {
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());
}
goSleep(100);
}
}
public void run() {
for (int i = 1; i <= NUM_TRIGGERS; i++) {
System.out.println("AllocatorThread is doing task " + i);
doTask();
synchronized (sweep) {
sweep.notify();
}
// System.out.print(" Allocater Thread ");
// If sweeper thread is waiting then send notify
// else wait for notification from sweeper thread.
wait_or_notify();
if (testFailed) return;
}
}
}
private static Object sweep = new Object();
static class SweeperThread extends Thread {
private void doTask() {
for (; mpool.getUsage().getUsed() >=
mpool.getUsageThreshold();) {
// clear all allocated objects and invoke GC
objectPool.clear();
mm.gc();
goSleep(100);
}
}
public void run() {
for (int i = 1; i <= NUM_TRIGGERS; i++) {
synchronized (sweep) {
while (!listenerInvoked) {
try {
sweep.wait();
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("Unexpected exception.");
testFailed = true;
}
}
}
System.out.println("SweepThread is doing task " + i);
doTask();
listenerInvoked = false;
// System.out.print(" Sweeper Thread ");
// If Allocater thread is waiting wait send notify
// else wait for notfication from allocater thread.
wait_or_notify();
if (testFailed) return;
}
}
}
}