src/java.base/unix/classes/sun/nio/ch/UnixDispatcher.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package sun.nio.ch;

import java.io.FileDescriptor;
import java.io.IOException;

abstract class UnixDispatcher extends NativeDispatcher {
    private static final boolean SUPPORTS_PENDING_SIGNALS = NativeThread.supportPendingSignals();

    @Override
    void close(FileDescriptor fd) throws IOException {
        close0(fd);
    }

    private void signalThreads(long reader, long writer) {
        if (NativeThread.isNativeThread(reader))
            NativeThread.signal(reader);
        if (NativeThread.isNativeThread(writer))
            NativeThread.signal(writer);
    }

    @Override
    void implPreClose(FileDescriptor fd, long reader, long writer) throws IOException {
        if (SUPPORTS_PENDING_SIGNALS) {
            signalThreads(reader, writer);
        }
        preClose0(fd);
        if (!SUPPORTS_PENDING_SIGNALS) {
            signalThreads(reader, writer);
        }
    }

    private static native void close0(FileDescriptor fd) throws IOException;

    private static native void preClose0(FileDescriptor fd) throws IOException;

    static native void init();

    static {
        IOUtil.load();
        init();
    }
}