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