1 /*
2 * Copyright (c) 2018, Red Hat, Inc. 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 /*
26 * @test id=default
27 * @summary Test that null references/referents work fine
28 * @requires vm.gc.Shenandoah
29 *
30 * @run main/othervm -Xmx128m -Xms128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
31 * -XX:+UseShenandoahGC
32 * -XX:+ShenandoahVerify
33 * TestRefprocSanity
34 *
35 * @run main/othervm -Xmx128m -Xms128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
36 * -XX:+UseShenandoahGC
37 * TestRefprocSanity
38 *
39 * @run main/othervm -Xmx128m -Xms128m -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions
40 * -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive
41 * TestRefprocSanity
42 */
43
44 import java.lang.ref.*;
45
46 public class TestRefprocSanity {
47
48 static final long TARGET_MB = Long.getLong("target", 1_000); // 1 Gb allocation
49 static final int WINDOW = 1_000;
50
51 static final Reference<MyObject>[] refs = new Reference[WINDOW];
52
53 static Object sink;
54
55 public static void main(String[] args) throws Exception {
56 long count = TARGET_MB * 1024 * 1024 / 128;
57 int rIdx = 0;
58
59 ReferenceQueue rq = new ReferenceQueue();
60
61 for (int c = 0; c < WINDOW; c++) {
62 refs[c] = select(c, new MyObject(c), rq);
63 }
64
65 for (int c = 0; c < count; c++) {
66 verifyRefAt(rIdx);
67 refs[rIdx] = select(c, new MyObject(rIdx), rq);
68
69 rIdx++;
70 if (rIdx >= WINDOW) {
71 rIdx = 0;
72 }
73
74 // Do allocations to force GCs
75 sink = new byte[100];
76
77 // Drain the refqueue
78 while (rq.poll() != null);
79 }
80 }
81
82 static Reference<MyObject> select(int v, MyObject ext, ReferenceQueue rq) {
83 switch (v % 10) {
84 case 0: return new SoftReference<MyObject>(null);
85 case 1: return new SoftReference<MyObject>(null, rq);
86 case 2: return new SoftReference<MyObject>(ext);
87 case 3: return new SoftReference<MyObject>(ext, rq);
88 case 4: return new WeakReference<MyObject>(null);
89 case 5: return new WeakReference<MyObject>(null, rq);
90 case 6: return new WeakReference<MyObject>(ext);
91 case 7: return new WeakReference<MyObject>(ext, rq);
92 case 8: return new PhantomReference<MyObject>(null, rq);
93 case 9: return new PhantomReference<MyObject>(ext, rq);
94 default: throw new IllegalStateException();
95 }
96 }
97
98 static void verifyRefAt(int idx) {
99 Reference<MyObject> ref = refs[idx];
100 MyObject mo = ref.get();
101 if (mo != null && mo.x != idx) {
102 throw new IllegalStateException("Referent tag is incorrect: " + mo.x + ", should be " + idx);
103 }
104 }
105
106 static class MyObject {
107 final int x;
108
109 public MyObject(int x) {
110 this.x = x;
111 }
112 }
113
114 }