8020467: Inconsistency between usage.getUsed() and isUsageThresholdExceeded() with CMS Old Gen pool
Reviewed-by: mchung, brutisso
--- a/jdk/test/java/lang/management/MemoryPoolMXBean/ThresholdTest.java Wed Oct 30 09:37:12 2013 -0700
+++ b/jdk/test/java/lang/management/MemoryPoolMXBean/ThresholdTest.java Wed Oct 30 17:54:48 2013 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 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
@@ -28,7 +28,7 @@
* MemoryPoolMXBean.isCollectionThresholdExceeded().
* @author Mandy Chung
*
- * @run main ThresholdTest
+ * @run main/othervm ThresholdTest
*/
import java.lang.management.*;
@@ -36,6 +36,9 @@
public class ThresholdTest {
public static void main(String args[]) throws Exception {
+ long[] bigObject = new long[1000000];
+
+ System.gc(); // force an initial full-gc
List<MemoryPoolMXBean> pools = ManagementFactory.getMemoryPoolMXBeans();
try {
for (MemoryPoolMXBean p : pools) {
@@ -82,6 +85,10 @@
}
p.setUsageThreshold(1);
+ // force a full gc to minimize the likelihood of running GC
+ // between getting the usage and checking the threshold
+ System.gc();
+
MemoryUsage u = p.getUsage();
if (u.getUsed() >= 1) {
if (!p.isUsageThresholdExceeded()) {