1 /*
2  * Copyright (c) 2007, 2018, 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 nsk.monitoring.share.thread;
25 
26 /**
27  * Locker thread is used to lock monitor on which BlockedThread's
28  * waits.
29  */
30 public class LockerThread extends Thread {
31         private String lock = new String("a lock");
32         private Object ready = new Object();
33         private Object lockit = new Object();
34         private volatile boolean locked = false;
35 
getLock()36         public Object getLock() {
37                 return lock;
38         }
39 
isLocked()40         public boolean isLocked() {
41                 return locked;
42         }
43 
waitState()44         public void waitState() {
45                 synchronized (ready) {
46                         while (!locked) {
47                                 try {
48                                         ready.wait();
49                                 } catch (InterruptedException e) {
50                                 }
51                         }
52                 }
53 
54                 ThreadUtils.waitThreadState(this, Thread.State.WAITING);
55 
56                 System.out.println("Locker thread reached WAITING state");
57         }
58 
finish()59         public void finish() {
60                 locked = false;
61                 synchronized (lockit) {
62                         lockit.notifyAll();
63                 }
64         }
65 
run()66         public void run() {
67                 synchronized (lock) {
68                         synchronized (lockit) {
69                                 synchronized (ready) {
70                                         locked = true;
71                                         ready.notifyAll();
72                                 }
73                                 while (locked) {
74                                         try {
75                                                 lockit.wait();
76                                         } catch (InterruptedException e) {
77                                         }
78                                 }
79                         }
80                 }
81 
82                 System.out.println("Locker thread leaved WAITING state");
83         }
84 }
85