1 /*
2 * Copyright (c) 2014, 2015, 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 * @library /testlibrary
31 * @modules java.base/sun.misc
32 * java.management
33 */
34
35 import java.util.ArrayList;
36 import java.util.LinkedList;
37 import java.util.Random;
38
39 import jdk.test.lib.OutputAnalyzer;
40 import jdk.test.lib.ProcessTools;
41
42 // An object that has a few references to other instances to slow down marking.
43 class ObjectWithSomeRefs {
44 public ObjectWithSomeRefs other1;
45 public ObjectWithSomeRefs other2;
46 public ObjectWithSomeRefs other3;
47 public ObjectWithSomeRefs other4;
48 }
49
50 class ReclaimRegionFast {
51 public static final long MAX_MILLIS_FOR_RUN = 50 * 1000; // The maximum runtime for the actual test.
52
53 public static final int M = 1024*1024;
54
55 public static LinkedList<Object> garbageList = new LinkedList<Object>();
56
57 public static void genGarbage(Object large) {
58 for (int i = 0; i < 64*1024; i++) {
59 Object[] garbage = new Object[50];
60 garbage[0] = large;
61 garbageList.add(garbage);
62 }
63 garbageList.clear();
64 }
65
66 public static ArrayList<ObjectWithSomeRefs> longList = new ArrayList<ObjectWithSomeRefs>();
67
68 public static void main(String[] args) {
69
70 for (int i = 0; i < 16*1024; i++) {
71 longList.add(new ObjectWithSomeRefs());
72 }
73
74 Random rnd = new Random();
75 for (int i = 0; i < longList.size(); i++) {
76 int len = longList.size();
77 longList.get(i).other1 = longList.get(rnd.nextInt(len));
78 longList.get(i).other2 = longList.get(rnd.nextInt(len));
79 longList.get(i).other3 = longList.get(rnd.nextInt(len));
80 longList.get(i).other4 = longList.get(rnd.nextInt(len));
81 }
82
83 int[] large1 = new int[M];
84 int[] large2 = null;
85 int[] large3 = null;
86 int[] large4 = null;
87
88 Object ref_from_stack = large1;
89
90 long start_millis = System.currentTimeMillis();
91
92 for (int i = 0; i < 20; i++) {
93 long current_millis = System.currentTimeMillis();
94 if ((current_millis - start_millis) > MAX_MILLIS_FOR_RUN) {
95 System.out.println("Finishing test because maximum runtime exceeded");
96 break;
97 }
98 // A set of large objects that will be reclaimed eagerly - and hopefully marked.
99 large1 = new int[M - 20];
100 large2 = new int[M - 20];
101 large3 = new int[M - 20];
102 large4 = new int[M - 20];
103 genGarbage(large1);
104 // Make sure that the compiler cannot completely remove
105 // the allocation of the large object until here.
106 System.out.println(large1 + " " + large2 + " " + large3 + " " + large4);
107 }
108
109 // Keep the reference to the first object alive.
110 System.out.println(ref_from_stack);
111 }
112 }
113
114 public class TestEagerReclaimHumongousRegionsClearMarkBits {
115 public static void main(String[] args) throws Exception {
116 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
117 "-XX:+UseG1GC",
118 "-Xms128M",
119 "-Xmx128M",
120 "-Xmn2M",
121 "-XX:G1HeapRegionSize=1M",
122 "-XX:InitiatingHeapOccupancyPercent=0", // Want to have as much as possible initial marks.
123 "-XX:+PrintGC",
124 "-XX:+UnlockDiagnosticVMOptions",
125 "-XX:+VerifyAfterGC",
126 "-XX:ConcGCThreads=1", // Want to make marking as slow as possible.
127 "-XX:+IgnoreUnrecognizedVMOptions", // G1VerifyBitmaps is develop only.
128 "-XX:+G1VerifyBitmaps",
129 ReclaimRegionFast.class.getName());
130 OutputAnalyzer output = new OutputAnalyzer(pb.start());
131 output.shouldHaveExitValue(0);
132 }
133 }
134