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/*
* Copyright 2000-2004 Sun Microsystems, Inc. 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package sun.nio.ch;
import java.io.IOException;
import java.nio.channels.*;
import java.nio.channels.spi.*;
import java.net.SocketException;
import java.util.*;
import sun.misc.*;
/**
* Base Selector implementation class.
*/
abstract class SelectorImpl
extends AbstractSelector
{
// The set of keys with data ready for an operation
protected Set<SelectionKey> selectedKeys;
// The set of keys registered with this Selector
protected HashSet<SelectionKey> keys;
// Public views of the key sets
private Set<SelectionKey> publicKeys; // Immutable
private Set<SelectionKey> publicSelectedKeys; // Removal allowed, but not addition
protected SelectorImpl(SelectorProvider sp) {
super(sp);
keys = new HashSet<SelectionKey>();
selectedKeys = new HashSet<SelectionKey>();
if (Util.atBugLevel("1.4")) {
publicKeys = keys;
publicSelectedKeys = selectedKeys;
} else {
publicKeys = Collections.unmodifiableSet(keys);
publicSelectedKeys = Util.ungrowableSet(selectedKeys);
}
}
public Set<SelectionKey> keys() {
if (!isOpen() && !Util.atBugLevel("1.4"))
throw new ClosedSelectorException();
return publicKeys;
}
public Set<SelectionKey> selectedKeys() {
if (!isOpen() && !Util.atBugLevel("1.4"))
throw new ClosedSelectorException();
return publicSelectedKeys;
}
protected abstract int doSelect(long timeout) throws IOException;
private int lockAndDoSelect(long timeout) throws IOException {
synchronized (this) {
if (!isOpen())
throw new ClosedSelectorException();
synchronized (publicKeys) {
synchronized (publicSelectedKeys) {
return doSelect(timeout);
}
}
}
}
public int select(long timeout)
throws IOException
{
if (timeout < 0)
throw new IllegalArgumentException("Negative timeout");
return lockAndDoSelect((timeout == 0) ? -1 : timeout);
}
public int select() throws IOException {
return select(0);
}
public int selectNow() throws IOException {
return lockAndDoSelect(0);
}
public void implCloseSelector() throws IOException {
wakeup();
synchronized (this) {
synchronized (publicKeys) {
synchronized (publicSelectedKeys) {
implClose();
}
}
}
}
protected abstract void implClose() throws IOException;
void putEventOps(SelectionKeyImpl sk, int ops) { }
protected final SelectionKey register(AbstractSelectableChannel ch,
int ops,
Object attachment)
{
if (!(ch instanceof SelChImpl))
throw new IllegalSelectorException();
SelectionKeyImpl k = new SelectionKeyImpl((SelChImpl)ch, this);
k.attach(attachment);
synchronized (publicKeys) {
implRegister(k);
}
k.interestOps(ops);
return k;
}
protected abstract void implRegister(SelectionKeyImpl ski);
void processDeregisterQueue() throws IOException {
// Precondition: Synchronized on this, keys, and selectedKeys
Set cks = cancelledKeys();
synchronized (cks) {
if (!cks.isEmpty()) {
Iterator i = cks.iterator();
while (i.hasNext()) {
SelectionKeyImpl ski = (SelectionKeyImpl)i.next();
try {
implDereg(ski);
} catch (SocketException se) {
IOException ioe = new IOException(
"Error deregistering key");
ioe.initCause(se);
throw ioe;
} finally {
i.remove();
}
}
}
}
}
protected abstract void implDereg(SelectionKeyImpl ski) throws IOException;
abstract public Selector wakeup();
}
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