1 /*
2 * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 /*
25 * @test TestRefprocSanity
26 * @summary Test that null references/referents work fine
27 * @key gc
28 *
29 * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC TestRefprocSanity
30 * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:+ShenandoahVerify TestRefprocSanity
31 * @run main/othervm -Xmx1g -Xms1g -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=aggressive TestRefprocSanity
32 */
33
34 import java.lang.ref.*;
35
36 public class TestRefprocSanity {
37
38 static final long TARGET_MB = Long.getLong("target", 10_000); // 10 Gb allocation
39 static final int WINDOW = 10_000;
40
41 static final Reference<MyObject>[] refs = new Reference[WINDOW];
42
43 public static void main(String[] args) throws Exception {
44 long count = TARGET_MB * 1024 * 1024 / 32;
45 int rIdx = 0;
46
47 ReferenceQueue rq = new ReferenceQueue();
48
49 for (int c = 0; c < WINDOW; c++) {
50 refs[c] = select(c, new MyObject(c), rq);
51 }
52
53 for (int c = 0; c < count; c++) {
54 verifyRefAt(rIdx);
55 refs[rIdx] = select(c, new MyObject(rIdx), rq);
56
57 rIdx++;
58 if (rIdx >= WINDOW) {
59 rIdx = 0;
60 }
61 while (rq.poll() != null); // drain
62 }
63 }
64
65 static Reference<MyObject> select(int v, MyObject ext, ReferenceQueue rq) {
66 switch (v % 10) {
67 case 0: return new SoftReference<MyObject>(null);
68 case 1: return new SoftReference<MyObject>(null, rq);
69 case 2: return new SoftReference<MyObject>(ext);
70 case 3: return new SoftReference<MyObject>(ext, rq);
71 case 4: return new WeakReference<MyObject>(null);
72 case 5: return new WeakReference<MyObject>(null, rq);
73 case 6: return new WeakReference<MyObject>(ext);
74 case 7: return new WeakReference<MyObject>(ext, rq);
75 case 8: return new PhantomReference<MyObject>(null, rq);
76 case 9: return new PhantomReference<MyObject>(ext, rq);
77 default: throw new IllegalStateException();
78 }
79 }
80
81 static void verifyRefAt(int idx) {
82 Reference<MyObject> ref = refs[idx];
83 MyObject mo = ref.get();
84 if (mo != null && mo.x != idx) {
85 throw new IllegalStateException("Referent tag is incorrect: " + mo.x + ", should be " + idx);
86 }
87 }
88
89 static class MyObject {
90 final int x;
91
92 public MyObject(int x) {
93 this.x = x;
94 }
95 }
96
97 }