/*
* Copyright (c) 2004, 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 low memory detection of non-heap memory pool.
*
* The test set a listener to be notified when any of the non-heap pools
* exceed 80%. It then starts a thread that continuously loads classes.
* In the HotSpot implementation this causes metaspace to be consumed.
* Test completes when we the notification is received or an OutOfMemory
* is generated.
*/
import java.lang.management.*;
import javax.management.*;
import javax.management.openmbean.CompositeData;
import java.util.*;
public class LowMemoryTest2 {
private static volatile boolean listenerInvoked = false;
private static String INDENT = " ";
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)) {
listenerInvoked = true;
MemoryNotificationInfo minfo = MemoryNotificationInfo.
from((CompositeData) notif.getUserData());
System.out.print("Notification for " + minfo.getPoolName());
System.out.print(" [type = " + type);
System.out.println(" count = " + minfo.getCount() + "]");
System.out.println(INDENT + "usage = " + minfo.getUsage());
}
}
}
// Loads classes Test100001, Test100002, .... until OutOfMemoryErrror or
// low memory notification
static class BoundlessLoaderThread extends ClassLoader implements Runnable {
private final List<MemoryPoolMXBean> pools;
public BoundlessLoaderThread(List<MemoryPoolMXBean> pools) {
this.pools = pools;
}
static int count = 100000;
Class loadNext() {
// public class TestNNNNNN extends java.lang.Object{
// public TestNNNNNN();
// Code:
// 0: aload_0
// 1: invokespecial #1; //Method java/lang/Object."<init>":()V
// 4: return
// }
int begin[] = {
0xca, 0xfe, 0xba, 0xbe, 0x00, 0x00, 0x00, 0x30,
0x00, 0x0a, 0x0a, 0x00, 0x03, 0x00, 0x07, 0x07,
0x00, 0x08, 0x07, 0x00, 0x09, 0x01, 0x00, 0x06,
0x3c, 0x69, 0x6e, 0x69, 0x74, 0x3e, 0x01, 0x00,
0x03, 0x28, 0x29, 0x56, 0x01, 0x00, 0x04, 0x43,
0x6f, 0x64, 0x65, 0x0c, 0x00, 0x04, 0x00, 0x05,
0x01, 0x00, 0x0a, 0x54, 0x65, 0x73, 0x74 };
int end [] = {
0x01, 0x00, 0x10,
0x6a, 0x61, 0x76, 0x61, 0x2f, 0x6c, 0x61, 0x6e,
0x67, 0x2f, 0x4f, 0x62, 0x6a, 0x65, 0x63, 0x74,
0x00, 0x21, 0x00, 0x02, 0x00, 0x03, 0x00, 0x00,
0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x04,
0x00, 0x05, 0x00, 0x01, 0x00, 0x06, 0x00, 0x00,
0x00, 0x11, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00,
0x00, 0x05, 0x2a, 0xb7, 0x00, 0x01, 0xb1, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00 };
// TestNNNNNN
int load_count = count++;
if (load_count > 999999) {
// The test will create a corrupt class file if the count
// exceeds 999999. Fix the test if this exception is thrown.
throw new RuntimeException("Load count exceeded");
}
String name = "Test" + Integer.toString(load_count);
byte value[];
try {
value = name.substring(4).getBytes("UTF-8");
} catch (java.io.UnsupportedEncodingException x) {
throw new Error();
}
// construct class file
int len = begin.length + value.length + end.length;
byte b[] = new byte[len];
int i, pos=0;
for (i=0; i<begin.length; i++) {
b[pos++] = (byte)begin[i];
}
for (i=0; i<value.length; i++) {
b[pos++] = value[i];
}
for (i=0; i<end.length; i++) {
b[pos++] = (byte)end[i];
}
return defineClass(name, b, 0, b.length);
}
/*
* Load classes until MemoryPoolMXBean.getUsageThresholdCount() > 0.
* Then wait for the memory threshold notification to be received.
*/
public void run() {
// Load classes until MemoryPoolMXBean.getUsageThresholdCount() > 0
boolean isThresholdCountSet = false;
try {
while (!isThresholdCountSet) {
// the classes are small so we load 10 at a time
for (int i=0; i<10; i++) {
loadNext();
}
if (isAnyUsageAboveThreshold(pools)) {
// UsageThresholdCount is only updated during GC.
// Force GC to update counters.
// If we don't force a GC we may get an
// OutOfMemoryException before the counters are updated.
System.out.println("Force GC");
System.gc();
}
isThresholdCountSet = isAnyThresholdCountSet(pools);
}
} catch (OutOfMemoryError e) {
e.printStackTrace();
MemoryUtil.printMemoryPools(pools);
throw e;
}
System.out.println("thresholdExceeded. Waiting for notification");
while (!listenerInvoked) {
try {
Thread.currentThread().sleep(10);
} catch (InterruptedException x) {}
}
}
private boolean isAnyUsageAboveThreshold(List<MemoryPoolMXBean> pools) {
for (MemoryPoolMXBean p : pools) {
if (p.isUsageThresholdExceeded()) {
System.out.println("isAnyUsageAboveThreshold is true for " + p.getName());
MemoryUtil.printMemoryPool(p);
return true;
}
}
return false;
}
private boolean isAnyThresholdCountSet(List<MemoryPoolMXBean> pools) {
for (MemoryPoolMXBean p : pools) {
if (p.getUsageThresholdCount() > 0) {
System.out.println("isAnyThresholdCountSet is true for " + p.getName());
MemoryUtil.printMemoryPool(p);
return true;
}
}
return false;
}
}
public static void main(String args[]) {
// The pools list will only contain the pools that we are interested in.
List<MemoryPoolMXBean> pools = new ArrayList<MemoryPoolMXBean>();
// Set threshold of 80% of all NON_HEAP memory pools
// In the Hotspot implementation this means we should get a notification
// if the CodeCache or metaspace fills up.
for (MemoryPoolMXBean p : ManagementFactory.getMemoryPoolMXBeans()) {
if (p.getType() == MemoryType.NON_HEAP && p.isUsageThresholdSupported()) {
// set threshold
MemoryUsage mu = p.getUsage();
long max = mu.getMax();
if (max < 0) {
throw new RuntimeException("There is no maximum set for "
+ p.getName() + " memory pool so the test is invalid");
}
long threshold = (max * 80) / 100;
p.setUsageThreshold(threshold);
pools.add(p);
System.out.println("Selected memory pool for low memory " +
"detection.");
MemoryUtil.printMemoryPool(p);
}
}
// Install the listener
MemoryMXBean mm = ManagementFactory.getMemoryMXBean();
SensorListener l2 = new SensorListener();
NotificationEmitter emitter = (NotificationEmitter) mm;
emitter.addNotificationListener(l2, null, null);
// Start the thread loading classes
Thread thr = new Thread(new BoundlessLoaderThread(pools));
thr.start();
// Wait for the thread to terminate
try {
thr.join();
} catch (InterruptedException x) {
throw new RuntimeException(x);
}
if (listenerInvoked) {
System.out.println("Notification received - test passed.");
} else {
throw new RuntimeException("Test failed - notification not received!");
}
}
}