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  * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCMode=iu -Xcomp -XX:CompileOnly=BarrierInInfiniteLoop::test1
34  *                   -XX:CompileOnly=BarrierInInfiniteLoop::test2 -XX:CompileOnly=BarrierInInfiniteLoop::test3 -XX:CompileCommand=quiet BarrierInInfiniteLoop
35  *
36  */
37 
38 public class BarrierInInfiniteLoop {
39     private static Object field1 = new Object();
40     private static Object field2 = new Object();
41     private static int field3;
42 
43     public static void main(String[] args) {
44         test1(false);
45         test2(false, false);
46         test3(false);
47     }
48 
49     private static void test1(boolean flag) {
50         if (flag) {
51             for (;;) {
52                 field1 = field2;
53             }
54         }
55     }
56 
57     private static void test2(boolean flag1, boolean flag2) {
58         if (flag1) {
59             for (;;) {
60                 for (;;) {
61                     if (flag2) {
62                         break;
63                     }
64                     field1 = field2;
65                 }
66             }
67         }
68     }
69 
70     private static void test3(boolean flag) {
71         if (flag) {
72             for (;;) {
73                 for (;;) {
74                     field3 = 42;
75                     if (field1 == field2) {
76                         break;
77                     }
78                 }
79             }
80         }
81     }
82 }