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* version 2 for more details (a copy is included in the LICENSE file that
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
/*
* @test
* @bug 7036199
* @summary Check that GarbageCollectionNotification contents are reasonable
* @author Frederic Parain
* @run main/othervm GarbageCollectionNotificationContentTest
*/
import java.util.*;
import java.lang.management.*;
import java.lang.reflect.*;
import javax.management.*;
import javax.management.openmbean.*;
import com.sun.management.GarbageCollectionNotificationInfo;
import com.sun.management.GcInfo;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.lang.reflect.Field;
public class GarbageCollectionNotificationContentTest {
private static HashMap<String,GarbageCollectionNotificationInfo> listenerInvoked
= new HashMap<String,GarbageCollectionNotificationInfo>();
static volatile long count = 0;
static volatile long number = 0;
static Object synchronizer = new Object();
static class GcListener implements NotificationListener {
public void handleNotification(Notification notif, Object handback) {
String type = notif.getType();
if (type.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
GarbageCollectionNotificationInfo gcNotif =
GarbageCollectionNotificationInfo.from((CompositeData) notif.getUserData());
String source = ((ObjectName)notif.getSource()).getCanonicalName();
synchronized(synchronizer) {
if(listenerInvoked.get(source) == null) {
listenerInvoked.put(((ObjectName)notif.getSource()).getCanonicalName(),gcNotif);
count++;
if(count >= number) {
synchronizer.notify();
}
}
}
}
}
}
public static void main(String[] args) throws Exception {
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
final Boolean isNotificationSupported = AccessController.doPrivileged (new PrivilegedAction<Boolean>() {
public Boolean run() {
try {
Class cl = Class.forName("sun.management.VMManagementImpl");
Field f = cl.getDeclaredField("gcNotificationSupport");
f.setAccessible(true);
return f.getBoolean(null);
} catch(ClassNotFoundException e) {
return false;
} catch(NoSuchFieldException e) {
return false;
} catch(IllegalAccessException e) {
return false;
}
}
});
if(!isNotificationSupported) {
System.out.println("GC Notification not supported by the JVM, test skipped");
return;
}
final ObjectName gcMXBeanPattern =
new ObjectName("java.lang:type=GarbageCollector,*");
Set<ObjectName> names =
mbs.queryNames(gcMXBeanPattern, null);
if (names.isEmpty())
throw new Exception("Test incorrect: no GC MXBeans");
number = names.size();
for (ObjectName n : names) {
if(mbs.isInstanceOf(n,"javax.management.NotificationEmitter")) {
listenerInvoked.put(n.getCanonicalName(),null);
GcListener listener = new GcListener();
mbs.addNotificationListener(n, listener, null, null);
}
}
// Invocation of System.gc() to trigger major GC
System.gc();
// Allocation of many short living and small objects to trigger minor GC
Object data[] = new Object[32];
for(int i = 0; i<100000000; i++) {
data[i%32] = new int[8];
}
int wakeup = 0;
synchronized(synchronizer) {
while(count != number) {
synchronizer.wait(10000);
wakeup++;
if(wakeup > 10)
break;
}
}
for (GarbageCollectionNotificationInfo notif : listenerInvoked.values() ) {
checkGarbageCollectionNotificationInfoContent(notif);
}
System.out.println("Test passed");
}
private static void checkGarbageCollectionNotificationInfoContent(GarbageCollectionNotificationInfo notif) throws Exception {
System.out.println("GC notification for "+notif.getGcName());
System.out.print("Action: "+notif.getGcAction());
System.out.println(" Cause: "+notif.getGcCause());
GcInfo info = notif.getGcInfo();
System.out.print("GC Info #" + info.getId());
System.out.print(" start:" + info.getStartTime());
System.out.print(" end:" + info.getEndTime());
System.out.println(" (" + info.getDuration() + "ms)");
Map<String, MemoryUsage> usage = info.getMemoryUsageBeforeGc();
List<String> pnames = new ArrayList<String>();
for (Map.Entry entry : usage.entrySet() ) {
String poolname = (String) entry.getKey();
pnames.add(poolname);
MemoryUsage busage = (MemoryUsage) entry.getValue();
MemoryUsage ausage = (MemoryUsage) info.getMemoryUsageAfterGc().get(poolname);
if (ausage == null) {
throw new RuntimeException("After Gc Memory does not exist" +
" for " + poolname);
}
System.out.println("Usage for pool " + poolname);
System.out.println(" Before GC: " + busage);
System.out.println(" After GC: " + ausage);
}
// check if memory usage for all memory pools are returned
List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
for (MemoryPoolMXBean p : pools ) {
if (!pnames.contains(p.getName())) {
throw new RuntimeException("GcInfo does not contain " +
"memory usage for pool " + p.getName());
}
}
}
}