1 /*
 2  * Copyright (c) 2025, 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
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22  */
23 
24 /**
25  * @test id=passive
26  * @summary Test Shenandoah Load Reference Barrier
27  * @requires vm.gc.Shenandoah
28  *
29  * @run main/othervm -XX:-IgnoreUnrecognizedVMOptions
30  *                  -XX:+UnlockDiagnosticVMOptions
31  *                  -XX:-BackgroundCompilation
32  *                  -XX:-UseOnStackReplacement
33  *                  -XX:-TieredCompilation
34  *                  -Xms512m -Xmx512m
35  *                  -XX:+UseShenandoahGC
36  *                  -XX:ShenandoahGCMode=passive
37  *                  -XX:+ShenandoahLoadRefBarrier
38  *                  -XX:CompileCommand=dontinline,TestShenandoahLoadRefBarrier::notInlined
39  *                  -XX:CompileCommand=dontinline,TestShenandoahLoadRefBarrier::lrb*
40  *                  -XX:CompileCommand=print,TestShenandoahLoadRefBarrier::lrb*
41  *                  -Xlog:gc+ergo,gc+barrier=debug
42  *                  TestShenandoahLoadRefBarrier
43  */
44 
45 public class TestShenandoahLoadRefBarrier {
46     private static final int LOOP_COUNT = 20_000;
47     private static A obj_a = new A();
48 
49     public static void main(String[] args) {
50         for (int i = 0; i < LOOP_COUNT; i++) {
51             lrb_1();
52         }
53     }
54 
55     private static boolean lrb_1() {
56         return TestShenandoahLoadRefBarrier.obj_a != null;
57     }
58 
59     private static class A {
60         public float float_field;
61     }
62 }