1 /*
2 * Copyright (c) 2014, 2020, 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 package gc.g1;
25
26 /*
27 * @test TestEagerReclaimHumongousRegionsClearMarkBits
28 * @bug 8051973
29 * @summary Test to make sure that eager reclaim of humongous objects correctly clears
30 * mark bitmaps at reclaim.
31 * @key randomness
32 * @requires vm.gc.G1
33 * @library /test/lib
34 * @modules java.base/jdk.internal.misc
35 * java.management
36 * @run driver gc.g1.TestEagerReclaimHumongousRegionsClearMarkBits
37 */
38
39 import java.util.ArrayList;
40 import java.util.LinkedList;
41 import java.util.Random;
42
43 import jdk.test.lib.process.OutputAnalyzer;
44 import jdk.test.lib.process.ProcessTools;
45 import jdk.test.lib.Utils;
46
47 // An object that has a few references to other instances to slow down marking.
48 class ObjectWithSomeRefs {
49 public ObjectWithSomeRefs other1;
50 public ObjectWithSomeRefs other2;
51 public ObjectWithSomeRefs other3;
52 public ObjectWithSomeRefs other4;
53 }
54
55 class TestEagerReclaimHumongousRegionsClearMarkBitsReclaimRegionFast {
56 public static final long MAX_MILLIS_FOR_RUN = 50 * 1000; // The maximum runtime for the actual test.
57
58 public static final int M = 1024*1024;
59
60 public static LinkedList<Object> garbageList = new LinkedList<Object>();
61
62 public static void genGarbage(Object large) {
63 for (int i = 0; i < 64*1024; i++) {
64 Object[] garbage = new Object[50];
65 garbage[0] = large;
66 garbageList.add(garbage);
67 }
68 garbageList.clear();
69 }
70
71 public static ArrayList<ObjectWithSomeRefs> longList = new ArrayList<ObjectWithSomeRefs>();
72
73 public static void main(String[] args) {
74
75 for (int i = 0; i < 16*1024; i++) {
76 longList.add(new ObjectWithSomeRefs());
77 }
78
79 Random rnd = Utils.getRandomInstance();
80 for (int i = 0; i < longList.size(); i++) {
81 int len = longList.size();
82 longList.get(i).other1 = longList.get(rnd.nextInt(len));
83 longList.get(i).other2 = longList.get(rnd.nextInt(len));
84 longList.get(i).other3 = longList.get(rnd.nextInt(len));
85 longList.get(i).other4 = longList.get(rnd.nextInt(len));
86 }
87
88 int[] large1 = new int[M];
89 int[] large2 = null;
90 int[] large3 = null;
91 int[] large4 = null;
92
93 Object ref_from_stack = large1;
94
95 long start_millis = System.currentTimeMillis();
96
97 for (int i = 0; i < 20; i++) {
98 long current_millis = System.currentTimeMillis();
99 if ((current_millis - start_millis) > MAX_MILLIS_FOR_RUN) {
100 System.out.println("Finishing test because maximum runtime exceeded");
101 break;
102 }
103 // A set of large objects that will be reclaimed eagerly - and hopefully marked.
104 large1 = new int[M - 20];
105 large2 = new int[M - 20];
106 large3 = new int[M - 20];
107 large4 = new int[M - 20];
108 genGarbage(large1);
109 // Make sure that the compiler cannot completely remove
110 // the allocation of the large object until here.
111 System.out.println(large1 + " " + large2 + " " + large3 + " " + large4);
112 }
113
114 // Keep the reference to the first object alive.
115 System.out.println(ref_from_stack);
116 }
117 }
118
119 public class TestEagerReclaimHumongousRegionsClearMarkBits {
120 public static void main(String[] args) throws Exception {
121 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
122 "-XX:+UseG1GC",
123 "-Xms128M",
124 "-Xmx128M",
125 "-Xmn2M",
126 "-XX:G1HeapRegionSize=1M",
127 "-XX:InitiatingHeapOccupancyPercent=0", // Want to have as much as possible initial marks.
128 "-Xlog:gc",
129 "-XX:+UnlockDiagnosticVMOptions",
130 "-XX:+VerifyAfterGC",
131 "-XX:ConcGCThreads=1", // Want to make marking as slow as possible.
132 "-XX:+IgnoreUnrecognizedVMOptions", // G1VerifyBitmaps is develop only.
133 "-XX:+G1VerifyBitmaps",
134 TestEagerReclaimHumongousRegionsClearMarkBitsReclaimRegionFast.class.getName());
135 OutputAnalyzer output = new OutputAnalyzer(pb.start());
136 output.shouldHaveExitValue(0);
137 }
138 }
139