1 /* 2 * Copyright (c) 2002, 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. 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 29 // Signalling operations on native threads 30 31 public class NativeThread { 32 private static final long VIRTUAL_THREAD_ID = -1L; 33 34 /** 35 * Returns the id of the current native thread if the platform can signal 36 * native threads, 0 if the platform can not signal native threads, or 37 * -1L if the current thread is a virtual thread. 38 */ 39 public static long current() { 40 if (Thread.currentThread().isVirtual()) { 41 return VIRTUAL_THREAD_ID; 42 } else { 43 // no support for signalling threads on Windows 44 return 0; 45 } 46 } 47 48 /** 49 * Signals the given native thread. 50 * 51 * @throws IllegalArgumentException if tid is not a token to a native thread 52 */ 53 static void signal(long tid) { 54 throw new UnsupportedOperationException(); 55 } 56 57 /** 58 * Returns true the tid is the id of a native thread. 59 */ 60 static boolean isNativeThread(long tid) { 61 return false; 62 } 63 64 /** 65 * Returns true if tid is -1L. 66 * @see #current() 67 */ 68 static boolean isVirtualThread(long tid) { 69 return (tid == VIRTUAL_THREAD_ID); 70 } 71 }