1 /*
 2  * Copyright (c) 2022, 2025, 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.io.FileDescriptor;
29 import java.io.IOException;
30 
31 abstract class UnixDispatcher extends NativeDispatcher {
32     private static final boolean SUPPORTS_PENDING_SIGNALS = NativeThread.supportPendingSignals();
33 
34     @Override
35     void close(FileDescriptor fd) throws IOException {
36         close0(fd);
37     }
38 
39     private void signalThreads(long reader, long writer) {
40         if (NativeThread.isNativeThread(reader))
41             NativeThread.signal(reader);
42         if (NativeThread.isNativeThread(writer))
43             NativeThread.signal(writer);
44     }
45 
46     @Override
47     void implPreClose(FileDescriptor fd, long reader, long writer) throws IOException {
48         if (SUPPORTS_PENDING_SIGNALS) {
49             signalThreads(reader, writer);
50         }
51         preClose0(fd);
52         if (!SUPPORTS_PENDING_SIGNALS) {
53             signalThreads(reader, writer);
54         }
55     }
56 
57     private static native void close0(FileDescriptor fd) throws IOException;
58 
59     private static native void preClose0(FileDescriptor fd) throws IOException;
60 
61     static native void init();
62 
63     static {
64         IOUtil.load();
65         init();
66     }
67 }