1 /*
 2  * Copyright (c) 2020, 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  * @test
26  * @bug 8237837 8244721
27  * @summary  Shenandoah: assert(mem == __null) failed: only one safepoint
28  * @requires vm.flavor == "server"
29  * @requires vm.gc.Shenandoah
30  *
31  * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xcomp -XX:CompileOnly=BarrierInInfiniteLoop::test1
32  *                   -XX:CompileOnly=BarrierInInfiniteLoop::test2 -XX:CompileOnly=BarrierInInfiniteLoop::test3 -XX:CompileCommand=quiet BarrierInInfiniteLoop
33  *
34  */
35 
36 public class BarrierInInfiniteLoop {
37     private static Object field1 = new Object();
38     private static Object field2 = new Object();
39     private static int field3;
40 
41     public static void main(String[] args) {
42         test1(false);
43         test2(false, false);
44         test3(false);
45     }
46 
47     private static void test1(boolean flag) {
48         if (flag) {
49             for (;;) {
50                 field1 = field2;
51             }
52         }
53     }
54 
55     private static void test2(boolean flag1, boolean flag2) {
56         if (flag1) {
57             for (;;) {
58                 for (;;) {
59                     if (flag2) {
60                         break;
61                     }
62                     field1 = field2;
63                 }
64             }
65         }
66     }
67 
68     private static void test3(boolean flag) {
69         if (flag) {
70             for (;;) {
71                 for (;;) {
72                     field3 = 42;
73                     if (field1 == field2) {
74                         break;
75                     }
76                 }
77             }
78         }
79     }
80 }