/*
* Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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.
*
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*/
/*
* @test
* @bug 6396794
* @summary Check that LastGcInfo contents are reasonable
* @author Eamonn McManus
* @run main/othervm GcInfoCompositeType
*/
import java.util.*;
import java.lang.management.*;
import java.lang.reflect.*;
import javax.management.*;
import javax.management.openmbean.*;
import com.sun.management.GcInfo;
public class GcInfoCompositeType {
private static int tested = 0;
public static void main(String[] args) throws Exception {
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
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");
System.gc();
for (ObjectName n : names)
tested += test(mbs, n);
if (tested == 0)
throw new Exception("No MXBeans were tested");
System.out.println("Test passed");
}
private static int test(MBeanServer mbs, ObjectName n) throws Exception {
System.out.println("Testing " + n);
MBeanInfo mbi = mbs.getMBeanInfo(n);
MBeanAttributeInfo lastGcAI = null;
for (MBeanAttributeInfo mbai : mbi.getAttributes()) {
if (mbai.getName().equals("LastGcInfo")) {
lastGcAI = mbai;
break;
}
}
if (lastGcAI == null)
throw new Exception("No LastGcInfo attribute");
CompositeType declaredType =
(CompositeType) lastGcAI.getDescriptor().getFieldValue("openType");
checkType(declaredType);
CompositeData cd =
(CompositeData) mbs.getAttribute(n, "LastGcInfo");
if (cd == null) {
System.out.println("Value of attribute null");
return 0;
} else
return checkType(cd.getCompositeType());
}
private static int checkType(CompositeType ct) throws Exception {
Method[] methods = GcInfo.class.getMethods();
Set<String> getters = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
for (Method m : methods) {
if (m.getName().startsWith("get") && m.getParameterTypes().length == 0)
getters.add(m.getName().substring(3));
}
Set<String> items = new HashSet<String>(ct.keySet());
System.out.println("Items at start: " + items);
// Now check that all the getters have a corresponding item in the
// CompositeType, except the following:
// getClass() inherited from Object should not be an item;
// getCompositeType() inherited from CompositeData is not useful so
// our hack removes it too.
// Also track which items had corresponding getters, to make sure
// there is at least one item which does not (GcThreadCount or
// another gc-type-specific item).
final String[] surplus = {"Class", "CompositeType"};
for (String key : ct.keySet()) {
if (getters.remove(key))
items.remove(key);
}
if (!getters.equals(new HashSet<String>(Arrays.asList(surplus)))) {
throw new Exception("Wrong getters: " + getters);
}
if (items.isEmpty()) {
System.out.println("No type-specific items");
return 0;
} else {
System.out.println("Type-specific items: " + items);
return 1;
}
}
}