changeset 27332:a0fb4831cb69

8132720: Add tests which checks that Humongous objects are not moved after Full GC Reviewed-by: jmasa, dfazunen
author kzhaldyb
date Wed, 13 Jan 2016 20:19:15 +0300
parents 7ff72b98b9eb
children 3b71845ff335
files test/gc/g1/humongousObjects/TestHumongousMovement.java
diffstat 1 files changed, 138 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/gc/g1/humongousObjects/TestHumongousMovement.java	Wed Jan 13 20:19:15 2016 +0300
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2015, 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.g1.humongousObjects;
+
+import gc.testlibrary.Helpers;
+import jdk.test.lib.Asserts;
+import jdk.test.lib.Utils;
+import sun.hotspot.WhiteBox;
+
+import java.io.PrintStream;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.stream.Collectors;
+
+/**
+ * @test TestHumongousMovement
+ * @summary Checks that Humongous objects are not moved during GC
+ * @requires vm.gc=="G1" | vm.gc=="null"
+ * @library /testlibrary /test/lib /
+ * @modules java.management
+ * @build sun.hotspot.WhiteBox
+ *        gc.testlibrary.Helpers
+ *        gc.g1.humongousObjects.TestHumongousMovement
+ * @run driver ClassFileInstaller sun.hotspot.WhiteBox
+ *      sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
+ *                   -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:InitiatingHeapOccupancyPercent=100
+ *                   -Xlog:gc=info:file=TestHumongousMovement.log
+ *                   gc.g1.humongousObjects.TestHumongousMovement
+ */
+
+public class TestHumongousMovement {
+
+    private static class AllocationData {
+        private final byte[] allocation;
+        public final BigInteger objectAddress;
+
+        public AllocationData(byte[] byteArray) {
+            allocation = byteArray;
+            objectAddress = new BigInteger(Long.toUnsignedString((WB.getObjectAddress(allocation))));
+        }
+
+        public boolean isAddressChanged() {
+            return !new BigInteger(Long.toUnsignedString((WB.getObjectAddress(allocation)))).equals(objectAddress);
+        }
+
+        public void printDetails(PrintStream out) {
+            BigInteger objectAddressAfterGC =
+                    new BigInteger(Long.toUnsignedString((WB.getObjectAddress(allocation))));
+
+            out.println(String.format("Object stored address = %d\nObject address after GC = %d\n"
+                            + "They are %sequals", objectAddress,
+                    objectAddressAfterGC, !objectAddress.equals(objectAddressAfterGC) ? "not " : ""));
+        }
+
+    }
+
+    private static final WhiteBox WB = WhiteBox.getWhiteBox();
+
+    // How many allocated humongous objects should be deleted
+    private static final double HUMONGOUS_OBJECTS_DELETED_FACTOR = 0.5D;
+    // How many of free g1 regions should be used for humongous allocations
+    private static final double ALLOCATED_HUMONGOUS_REGIONS_FACTOR = 0.25D;
+
+    public static void main(String[] args) {
+
+        int g1RegionSize = WB.g1RegionSize();
+        int byteArrayMemoryOverhead = Helpers.detectByteArrayAllocationOverhead();
+
+        System.out.println("Total " + WB.g1NumMaxRegions() + " regions");
+        System.out.println("Total " + WB.g1NumFreeRegions() + " free regions");
+
+        int regionsToAllocate = (int) (WB.g1NumFreeRegions() * ALLOCATED_HUMONGOUS_REGIONS_FACTOR);
+
+        // Sanity check
+        Asserts.assertGreaterThan(regionsToAllocate, 0, "Test Bug: no regions to allocate");
+
+        System.out.println("Allocating " + regionsToAllocate + " humongous objects, each 90% of g1 region size");
+
+        List<AllocationData> allocations = new ArrayList<>();
+
+        // 90 % of maximum byte[] that takes one region
+        int hSize = (int) ((g1RegionSize - byteArrayMemoryOverhead) * 0.9);
+
+        // Sanity check
+        Asserts.assertGreaterThan(hSize, g1RegionSize / 2, "Test Bug: allocation size is not humongous");
+
+        for (int i = 0; i < regionsToAllocate; ++i) {
+            allocations.add(new AllocationData(new byte[hSize]));
+        }
+
+        Random rnd = Utils.getRandomInstance();
+
+        int toDelete = (int) (allocations.size() * HUMONGOUS_OBJECTS_DELETED_FACTOR);
+
+        for (int i = 0; i < toDelete; ++i) {
+            allocations.remove(rnd.nextInt(allocations.size()));
+        }
+
+        WB.fullGC();
+
+        List<AllocationData> movedObjects = allocations.stream()
+                .filter(AllocationData::isAddressChanged)
+                .collect(Collectors.toList());
+
+        if (movedObjects.size() > 0) {
+            System.out.println("Test failed - some humongous objects moved after Full GC");
+            movedObjects.stream().forEach(a -> a.printDetails(System.out));
+            throw new Error("Test failed - some humongous objects moved after Full GC");
+        } else {
+            System.out.println("Passed");
+        }
+    }
+}