1 /*
 2  * Copyright (c) 2020, 2022, Oracle and/or its affiliates. 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 package runtime.whitebox;
25 
26 /*
27  * @test
28  * @bug 8246477
29  * @summary Test to verify that WB method deflateIdleMonitors works correctly.
30  * @library /test/lib
31  * @modules java.base/jdk.internal.misc
32  *          java.management
33  * @build jdk.test.whitebox.WhiteBox
34  * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
35  * @run driver runtime.whitebox.TestWBDeflateIdleMonitors
36  */
37 import jdk.test.lib.Asserts;
38 import jdk.test.lib.process.ProcessTools;
39 import jdk.test.lib.process.OutputAnalyzer;
40 import jdk.test.whitebox.WhiteBox;
41 
42 public class TestWBDeflateIdleMonitors {
43     static final int N_DELAY = 1000;  // delay between tries
44     static final int N_TRIES = 5;     // number of times to try deflation
45 
46     public static void main(String args[]) throws Exception {
47         ProcessBuilder pb = ProcessTools.createTestJvm(
48                 "-Xbootclasspath/a:.",
49                 "-XX:+UnlockDiagnosticVMOptions",
50                 "-XX:+WhiteBoxAPI",
51                 "-Xlog:monitorinflation=info",
52                 InflateMonitorsTest.class.getName());
53 
54         OutputAnalyzer output = new OutputAnalyzer(pb.start());
55         System.out.println(output.getStdout());
56         output.shouldHaveExitValue(0);
57         output.shouldContain("WhiteBox initiated DeflateIdleMonitors");
58     }
59 
60     public static class InflateMonitorsTest {
61         static WhiteBox wb = WhiteBox.getWhiteBox();
62         public static Object obj;
63 
64         public static void main(String args[]) throws Exception {
65             obj = new Object();
66             synchronized (obj) {
67                 // The current implementation of notify-wait requires inflation.
68                 obj.wait(1);
69                 Asserts.assertEQ(wb.isMonitorInflated(obj), true,
70                                  "Monitor should be inflated.");
71             }
72             for (int cnt = 1; cnt <= N_TRIES; cnt++) {
73                 System.out.println("Deflation try #" + cnt);
74                 boolean did_deflation = wb.deflateIdleMonitors();
75                 Asserts.assertEQ(did_deflation, true,
76                                  "deflateIdleMonitors() should have worked.");
77                 if (!wb.isMonitorInflated(obj)) {
78                     // Deflation worked so no more retries needed.
79                     break;
80                 }
81                 try {
82                     System.out.println("Deflation try #" + cnt + " failed. "
83                                        + "Delaying before retry.");
84                     Thread.sleep(N_DELAY);
85                 } catch (InterruptedException ie) {
86                 }
87             }
88             Asserts.assertEQ(wb.isMonitorInflated(obj), false,
89                              "Monitor should be deflated.");
90         }
91     }
92 }