1 /* 2 * Copyright (c) 2002, 2023, 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 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.nio.ch; 27 28 import java.util.concurrent.locks.LockSupport; 29 30 public class NativeThread { 31 private NativeThread() { } 32 33 /** 34 * Returns the Thread to signal the current thread or {@code null} if the current 35 * thread cannot be signalled. 36 */ 37 public static Thread threadToSignal() { 38 Thread thread = Thread.currentThread(); 39 return thread.isVirtual() ? thread : null; 40 } 41 42 /** 43 * Signals the given thread. 44 * @throws UnsupportedOperationException is not supported 45 */ 46 public static void signal(Thread thread) { 47 if (thread.isVirtual()) { 48 LockSupport.unpark(null); 49 } else { 50 throw new UnsupportedOperationException(); 51 } 52 } 53 }