8037924: CMM Testing: Check Min/MaxHeapFreeRatio flags allows to shrink the heap when using ParallelGC
Summary: New test implemented
Reviewed-by: ehelin, tschatzl
Contributed-by: andrey.x.zakharov@oracle.com
--- a/hotspot/test/TEST.groups Fri Apr 11 12:29:24 2014 +0200
+++ b/hotspot/test/TEST.groups Fri Apr 11 18:28:39 2014 +0200
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2013, 2014, 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
@@ -131,6 +131,7 @@
gc/metaspace/TestMetaspaceMemoryPool.java \
gc/arguments/TestDynMinHeapFreeRatio.java \
gc/arguments/TestDynMaxHeapFreeRatio.java \
+ gc/parallelScavenge/TestDynShrinkHeap.java \
runtime/InternalApi/ThreadCpuTimesDeadlock.java \
serviceability/threads/TestFalseDeadLock.java \
compiler/tiered/NonTieredLevelsTest.java \
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/gc/parallelScavenge/TestDynShrinkHeap.java Fri Apr 11 18:28:39 2014 +0200
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2014, 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 TestDynShrinkHeap
+ * @bug 8016479
+ * @summary Verify that the heap shrinks after full GC according to the current values of the Min/MaxHeapFreeRatio flags
+ * @library /testlibrary
+ * @run main/othervm -XX:+UseAdaptiveSizePolicyWithSystemGC -XX:+UseParallelGC -XX:MinHeapFreeRatio=0 -XX:MaxHeapFreeRatio=100 -verbose:gc TestDynShrinkHeap
+ */
+
+import com.oracle.java.testlibrary.TestDynamicVMOption;
+import java.lang.management.ManagementFactory;
+import java.lang.management.MemoryUsage;
+import java.util.ArrayList;
+import sun.management.ManagementFactoryHelper;
+import static com.oracle.java.testlibrary.Asserts.*;
+
+public class TestDynShrinkHeap {
+
+ public static final String MIN_FREE_RATIO_FLAG_NAME = "MinHeapFreeRatio";
+ public static final String MAX_FREE_RATIO_FLAG_NAME = "MaxHeapFreeRatio";
+
+ private static ArrayList<byte[]> list = new ArrayList<>(0);
+ private static final int M = 1024 * 1024; // to make heap more manageable by test code
+
+ private final TestDynamicVMOption maxRatioOption;
+ private final TestDynamicVMOption minRatioOption;
+
+ public TestDynShrinkHeap() {
+ minRatioOption = new TestDynamicVMOption(MIN_FREE_RATIO_FLAG_NAME);
+ maxRatioOption = new TestDynamicVMOption(MAX_FREE_RATIO_FLAG_NAME);
+ }
+
+ private final void test() {
+ System.gc();
+ MemoryUsagePrinter.printMemoryUsage("init");
+
+ eat();
+ MemoryUsagePrinter.printMemoryUsage("eaten");
+ MemoryUsage muFull = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+
+ free();
+ MemoryUsagePrinter.printMemoryUsage("free");
+ MemoryUsage muFree = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+
+ assertLessThan(muFree.getCommitted(), muFull.getCommitted(), String.format(
+ "committed free heap size is not less than committed full heap size, heap hasn't been shrunk?%n"
+ + "%s = %s%n%s = %s",
+ MIN_FREE_RATIO_FLAG_NAME,
+ ManagementFactoryHelper.getDiagnosticMXBean().getVMOption(MIN_FREE_RATIO_FLAG_NAME).getValue(),
+ MAX_FREE_RATIO_FLAG_NAME,
+ ManagementFactoryHelper.getDiagnosticMXBean().getVMOption(MAX_FREE_RATIO_FLAG_NAME).getValue()
+ ));
+ }
+
+ private void eat() {
+ for (int i = 0; i < M; i++) {
+ list.add(new byte[1024]);
+ }
+ MemoryUsagePrinter.printMemoryUsage("allocated " + M + " arrays");
+
+ list.subList(0, M / 2).clear();
+ System.gc();
+ MemoryUsagePrinter.printMemoryUsage("array halved");
+ }
+
+ private void free() {
+ maxRatioOption.setIntValue(minRatioOption.getIntValue() + 1);
+ System.gc();
+ MemoryUsagePrinter.printMemoryUsage("under pressure");
+ }
+
+ public static void main(String[] args) {
+ new TestDynShrinkHeap().test();
+ }
+}
+
+/**
+ * Prints memory usage to standard output
+ */
+class MemoryUsagePrinter {
+
+ public static String humanReadableByteCount(long bytes, boolean si) {
+ int unit = si ? 1000 : 1024;
+ if (bytes < unit) {
+ return bytes + " B";
+ }
+ int exp = (int) (Math.log(bytes) / Math.log(unit));
+ String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp - 1) + (si ? "" : "i");
+ return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
+ }
+
+ public static void printMemoryUsage(String label) {
+ MemoryUsage memusage = ManagementFactory.getMemoryMXBean().getHeapMemoryUsage();
+ float freeratio = 1f - (float) memusage.getUsed() / memusage.getCommitted();
+ System.out.format("[%-24s] init: %-7s, used: %-7s, comm: %-7s, freeRatio ~= %.1f%%%n",
+ label,
+ humanReadableByteCount(memusage.getInit(), true),
+ humanReadableByteCount(memusage.getUsed(), true),
+ humanReadableByteCount(memusage.getCommitted(), true),
+ freeratio * 100
+ );
+ }
+}