META-INF.modules.java.base.classes.sun.nio.ch.AbstractPollSelectorImpl Maven / Gradle / Ivy

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/*
 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
 * 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.IOException;
import java.nio.channels.*;
import java.nio.channels.spi.*;
import java.util.*;


/**
 * An abstract selector impl.
 */

abstract class AbstractPollSelectorImpl
    extends SelectorImpl
{

    // The poll fd array
    PollArrayWrapper pollWrapper;

    // Initial capacity of the pollfd array
    protected final int INIT_CAP = 10;

    // The list of SelectableChannels serviced by this Selector
    protected SelectionKeyImpl[] channelArray;

    // In some impls the first entry of channelArray is bogus
    protected int channelOffset = 0;

    // The number of valid channels in this Selector's poll array
    protected int totalChannels;

    // True if this Selector has been closed
    private boolean closed = false;

    // Lock for close and cleanup
    private Object closeLock = new Object();

    AbstractPollSelectorImpl(SelectorProvider sp, int channels, int offset) {
        super(sp);
        this.totalChannels = channels;
        this.channelOffset = offset;
    }

    public void putEventOps(SelectionKeyImpl sk, int ops) {
        synchronized (closeLock) {
            if (closed)
                throw new ClosedSelectorException();
            pollWrapper.putEventOps(sk.getIndex(), ops);
        }
    }

    public Selector wakeup() {
        pollWrapper.interrupt();
        return this;
    }

    protected abstract int doSelect(long timeout) throws IOException;

    protected void implClose() throws IOException {
        synchronized (closeLock) {
            if (closed)
                return;
            closed = true;
            // Deregister channels
            for(int i=channelOffset; i= 0);
        if (i != totalChannels - 1) {
            // Copy end one over it
            SelectionKeyImpl endChannel = channelArray[totalChannels-1];
            channelArray[i] = endChannel;
            endChannel.setIndex(i);
            pollWrapper.release(i);
            PollArrayWrapper.replaceEntry(pollWrapper, totalChannels - 1,
                                          pollWrapper, i);
        } else {
            pollWrapper.release(i);
        }
        // Destroy the last one
        channelArray[totalChannels-1] = null;
        totalChannels--;
        pollWrapper.totalChannels--;
        ski.setIndex(-1);
        // Remove the key from keys and selectedKeys
        keys.remove(ski);
        selectedKeys.remove(ski);
        deregister((AbstractSelectionKey)ski);
        SelectableChannel selch = ski.channel();
        if (!selch.isOpen() && !selch.isRegistered())
            ((SelChImpl)selch).kill();
    }
}