1 /*
2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 package gc.g1.humongousObjects;
26
27 import gc.testlibrary.Helpers;
28 import jdk.test.lib.Asserts;
29 import jdk.test.lib.Utils;
30 import sun.hotspot.WhiteBox;
31
32 import java.io.PrintStream;
33 import java.math.BigInteger;
34 import java.util.ArrayList;
35 import java.util.List;
36 import java.util.Random;
37 import java.util.stream.Collectors;
38
39 /**
40 * @test TestHumongousMovement
41 * @summary Checks that Humongous objects are not moved during GC
42 * @requires vm.gc.G1
43 * @library /test/lib /
44 * @modules java.base/jdk.internal.misc
45 * @modules java.management
46 * @build sun.hotspot.WhiteBox
47 * @run driver ClassFileInstaller sun.hotspot.WhiteBox
48 * sun.hotspot.WhiteBox$WhiteBoxPermission
49 * @run main/othervm -XX:+UseG1GC -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xbootclasspath/a:.
50 * -XX:G1HeapRegionSize=1M -Xms200m -Xmx200m -XX:InitiatingHeapOccupancyPercent=100
51 * -Xlog:gc=info:file=TestHumongousMovement.log
52 * gc.g1.humongousObjects.TestHumongousMovement
53 */
54
55 public class TestHumongousMovement {
56
57 private static class AllocationData {
58 private final byte[] allocation;
59 public final BigInteger objectAddress;
60
61 public AllocationData(byte[] byteArray) {
62 allocation = byteArray;
63 objectAddress = new BigInteger(Long.toUnsignedString((WB.getObjectAddress(allocation))));
64 }
65
66 public boolean isAddressChanged() {
67 return !new BigInteger(Long.toUnsignedString((WB.getObjectAddress(allocation)))).equals(objectAddress);
68 }
69
70 public void printDetails(PrintStream out) {
71 BigInteger objectAddressAfterGC =
72 new BigInteger(Long.toUnsignedString((WB.getObjectAddress(allocation))));
73
74 out.println(String.format("Object stored address = %d\nObject address after GC = %d\n"
75 + "They are %sequals", objectAddress,
76 objectAddressAfterGC, !objectAddress.equals(objectAddressAfterGC) ? "not " : ""));
77 }
78
79 }
80
81 private static final WhiteBox WB = WhiteBox.getWhiteBox();
82
83 // How many allocated humongous objects should be deleted
84 private static final double HUMONGOUS_OBJECTS_DELETED_FACTOR = 0.5D;
85 // How many of free g1 regions should be used for humongous allocations
86 private static final double ALLOCATED_HUMONGOUS_REGIONS_FACTOR = 0.25D;
87
88 public static void main(String[] args) {
89
90 int g1RegionSize = WB.g1RegionSize();
91 int byteArrayMemoryOverhead = Helpers.detectByteArrayAllocationOverhead();
92
93 System.out.println("Total " + WB.g1NumMaxRegions() + " regions");
94 System.out.println("Total " + WB.g1NumFreeRegions() + " free regions");
95
96 int regionsToAllocate = (int) (WB.g1NumFreeRegions() * ALLOCATED_HUMONGOUS_REGIONS_FACTOR);
97
98 // Sanity check
99 Asserts.assertGreaterThan(regionsToAllocate, 0, "Test Bug: no regions to allocate");
100
101 System.out.println("Allocating " + regionsToAllocate + " humongous objects, each 90% of g1 region size");
102
103 List<AllocationData> allocations = new ArrayList<>();
104
105 // 90 % of maximum byte[] that takes one region
106 int hSize = (int) ((g1RegionSize - byteArrayMemoryOverhead) * 0.9);
107
108 // Sanity check
109 Asserts.assertGreaterThan(hSize, g1RegionSize / 2, "Test Bug: allocation size is not humongous");
110
111 for (int i = 0; i < regionsToAllocate; ++i) {
112 allocations.add(new AllocationData(new byte[hSize]));
113 }
114
115 Random rnd = Utils.getRandomInstance();
116
117 int toDelete = (int) (allocations.size() * HUMONGOUS_OBJECTS_DELETED_FACTOR);
118
119 for (int i = 0; i < toDelete; ++i) {
120 allocations.remove(rnd.nextInt(allocations.size()));
121 }
122
123 WB.fullGC();
124
125 List<AllocationData> movedObjects = allocations.stream()
126 .filter(AllocationData::isAddressChanged)
127 .collect(Collectors.toList());
128
129 if (movedObjects.size() > 0) {
130 System.out.println("Test failed - some humongous objects moved after Full GC");
131 movedObjects.stream().forEach(a -> a.printDetails(System.out));
132 throw new Error("Test failed - some humongous objects moved after Full GC");
133 } else {
134 System.out.println("Passed");
135 }
136 }
137 }