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/*
* Copyright (c) 2010, 2019, 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.
*/
package gc.cms;
/*
* @test TestMBeanCMS.java
* @bug 6581734
* @requires vm.gc.ConcMarkSweep & !vm.graal.enabled
* @summary CMS Old Gen's collection usage is zero after GC which is incorrect
* @modules java.management
* @run main/othervm -Xmx512m -verbose:gc -XX:+UseConcMarkSweepGC gc.cms.TestMBeanCMS
*
*/
import java.lang.management.GarbageCollectorMXBean;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryPoolMXBean;
import java.util.LinkedList;
import java.util.List;
// 6581734 states that memory pool usage via the mbean is wrong
// for CMS (zero, even after a collection).
//
// 6580448 states that the collection count similarly is wrong
// (stays at zero for CMS collections)
// -- closed as dup of 6581734 as the same fix resolves both.
public class TestMBeanCMS {
private String poolName = "CMS";
private String collectorName = "ConcurrentMarkSweep";
public static void main(String [] args) {
TestMBeanCMS t = null;
if (args.length==2) {
t = new TestMBeanCMS(args[0], args[1]);
} else {
System.out.println("Defaulting to monitor CMS pool and collector.");
t = new TestMBeanCMS();
}
t.run();
}
public TestMBeanCMS(String pool, String collector) {
poolName = pool;
collectorName = collector;
}
public TestMBeanCMS() {
}
public void run() {
// Use some memory, enough that we expect collections should
// have happened.
// Must run with options to ensure no stop the world full GC,
// but e.g. at least one CMS cycle.
allocationWork(300*1024*1024);
System.out.println("Done allocationWork");
// Verify some non-zero results are stored.
List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
int poolsFound = 0;
int poolsWithStats = 0;
for (int i=0; i<pools.size(); i++) {
MemoryPoolMXBean pool = pools.get(i);
String name = pool.getName();
System.out.println("found pool: " + name);
if (name.contains(poolName)) {
long usage = pool.getCollectionUsage().getUsed();
System.out.println(name + ": usage after GC = " + usage);
poolsFound++;
if (usage > 0) {
poolsWithStats++;
}
}
}
if (poolsFound == 0) {
throw new RuntimeException("No matching memory pools found: test with -XX:+UseConcMarkSweepGC");
}
List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();
int collectorsFound = 0;
int collectorsWithTime= 0;
for (int i=0; i<collectors.size(); i++) {
GarbageCollectorMXBean collector = collectors.get(i);
String name = collector.getName();
System.out.println("found collector: " + name);
if (name.contains(collectorName)) {
collectorsFound++;
System.out.println(name + ": collection count = "
+ collector.getCollectionCount());
System.out.println(name + ": collection time = "
+ collector.getCollectionTime());
if (collector.getCollectionCount() <= 0) {
throw new RuntimeException("collection count <= 0");
}
if (collector.getCollectionTime() > 0) {
collectorsWithTime++;
}
}
}
// verify:
if (poolsWithStats < poolsFound) {
throw new RuntimeException("pools found with zero stats");
}
if (collectorsWithTime<collectorsFound) {
throw new RuntimeException("collectors found with zero time");
}
System.out.println("Test passed.");
}
public void allocationWork(long target) {
long sizeAllocated = 0;
List<byte[]> list = new LinkedList<>();
long delay = 50;
long count = 0;
while (sizeAllocated < target) {
int size = 1024*1024;
byte [] alloc = new byte[size];
if (count % 2 == 0) {
list.add(alloc);
sizeAllocated+=size;
System.out.print(".");
}
try { Thread.sleep(delay); } catch (InterruptedException ie) { }
count++;
}
}
}
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