1 /*
 2  * Copyright (c) 2020, 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 package jdk.jfr.event.runtime;
24 
25 import java.util.concurrent.CountDownLatch;
26 import java.util.concurrent.atomic.AtomicBoolean;
27 
28 public class LatchedThread implements Runnable {
29     public final static ThreadGroup THREAD_GROUP = new ThreadGroup("Latched Threads");
30     public final Thread thread;
31     private final CountDownLatch latch = new CountDownLatch(1);
32     private final AtomicBoolean alive = new AtomicBoolean(true);
33 
34     public LatchedThread(String name, boolean isVirtual) {
35         if (isVirtual) {
36             thread = Thread.ofVirtual().name(name).unstarted(this);
37         } else {
38             thread = Thread.ofPlatform().name(name).group(THREAD_GROUP).unstarted(this);
39         }
40     }
41 
42     public LatchedThread(String name) {
43         this(name, false);
44     }
45 
46     public void start() {
47         thread.start();
48     }
49 
50     public void join() throws InterruptedException {
51         thread.join();
52     }
53 
54     public void awaitStarted() throws InterruptedException {
55         latch.await();
56     }
57 
58     public long getId() {
59         return thread.getId();
60     }
61 
62     public String getName() {
63         return thread.getName();
64     }
65 
66     public void stopAndJoin() throws InterruptedException {
67         alive.set(false);
68         synchronized (alive) {
69             alive.notify();
70         }
71         join();
72     }
73 
74     public void run() {
75         latch.countDown();
76         while (alive.get()) {
77             try {
78                 synchronized (alive) {
79                     alive.wait(10);
80                 }
81             } catch (InterruptedException e) {
82                 // ignore
83             }
84         }
85     }
86 }