1 /*
 2  * Copyright (c) 2022, 2024, 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.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24  */
25 package java.lang;
26 
27 /**
28  * Base class for virtual thread implementations.
29  */
30 abstract sealed class BaseVirtualThread extends Thread
31         permits VirtualThread, ThreadBuilders.BoundVirtualThread {
32 
33     /**
34      * Initializes a virtual Thread.
35      *
36      * @param name thread name, can be null
37      * @param characteristics thread characteristics
38      * @param bound true when bound to an OS thread
39      */
40     BaseVirtualThread(String name, int characteristics, boolean bound) {
41         super(name, characteristics, bound);
42     }
43 
44     /**
45      * Parks the current virtual thread until the parking permit is available or
46      * the thread is interrupted.
47      *
48      * The behavior of this method when the current thread is not this thread
49      * is not defined.
50      */
51     abstract void park();
52 
53     /**
54      * Parks current virtual thread up to the given waiting time until the parking
55      * permit is available or the thread is interrupted.
56      *
57      * The behavior of this method when the current thread is not this thread
58      * is not defined.
59      */
60     abstract void parkNanos(long nanos);
61 
62     /**
63      * Makes available the parking permit to the given this virtual thread.
64      */
65     abstract void unpark();
66 
67     /**
68      * Makes available the parking permit to the given this virtual thread. If the
69      * thread is parked then there is no guarantee that it will continue execution.
70      */
71     void lazyUnpark() {
72         unpark();
73     }
74 }
75