src/java.base/windows/classes/sun/nio/ch/SocketDispatcher.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * 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).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.nio.ch;

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

import jdk.internal.access.JavaIOFileDescriptorAccess;
import jdk.internal.access.SharedSecrets;

/**
 * Allows different platforms to call different native methods
 * for read and write operations.
 */

class SocketDispatcher extends NativeDispatcher {
    private static final JavaIOFileDescriptorAccess fdAccess =
            SharedSecrets.getJavaIOFileDescriptorAccess();

    SocketDispatcher() { }

    @Override
    int read(FileDescriptor fd, long address, int len) throws IOException {
        return read0(fd, address, len);
    }

    @Override
    long readv(FileDescriptor fd, long address, int len) throws IOException {
        return readv0(fd, address, len);
    }

    @Override
    int write(FileDescriptor fd, long address, int len) throws IOException {
        return write0(fd, address, len);
    }

    @Override
    long writev(FileDescriptor fd, long address, int len) throws IOException {
        return writev0(fd, address, len);
    }

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

    static void invalidateAndClose(FileDescriptor fd) throws IOException {
        assert fd.valid();
        int fdVal = fdAccess.get(fd);
        fdAccess.set(fd, -1);
        close0(fdVal);
    }

    // -- Native methods --

    private static native int read0(FileDescriptor fd, long address, int len)
        throws IOException;

    private static native long readv0(FileDescriptor fd, long address, int len)
        throws IOException;

    private static native int write0(FileDescriptor fd, long address, int len)
        throws IOException;

    private static native long writev0(FileDescriptor fd, long address, int len)
        throws IOException;

    private static native void close0(int fdVal) throws IOException;

    static {
        IOUtil.load();
    }
}