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	/*
	* Copyright (c) 2000, 2013, 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
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.nio.ch;

	import java.io.FileDescriptor;
	import java.io.IOException;
	import java.net.*;
	import java.nio.channels.*;
	import java.nio.channels.spi.*;
	import java.util.*;
	import sun.net.NetHooks;
	import sun.net.ExtendedOptionsHelper;


	/**
	* An implementation of ServerSocketChannels
	*/

	class ServerSocketChannelImpl
	extends ServerSocketChannel
	implements SelChImpl
	{

	// Used to make native close and configure calls
	private static NativeDispatcher nd;

	// Our file descriptor
	private final FileDescriptor fd;
	private final int fdVal;

	// ID of native thread currently blocked in this channel, for signalling
	private volatile long thread = 0;

	// Lock held by thread currently blocked in this channel
	private final Object lock = new Object();

	// Lock held by any thread that modifies the state fields declared below
	// DO NOT invoke a blocking I/O operation while holding this lock!
	private final Object stateLock = new Object();

	// -- The following fields are protected by stateLock

	// Channel state, increases monotonically
	private static final int ST_UNINITIALIZED = -1;
	private static final int ST_INUSE = 0;
	private static final int ST_KILLED = 1;
	private int state = ST_UNINITIALIZED;

	// Binding
	private InetSocketAddress localAddress; // null => unbound

	// set true when exclusive binding is on and SO_REUSEADDR is emulated
	private boolean isReuseAddress;

	// Our socket adaptor, if any
	ServerSocket socket;

	// -- End of fields protected by stateLock


	ServerSocketChannelImpl(SelectorProvider sp) throws IOException {
	super(sp);
	this.fd = Net.serverSocket(true);
	this.fdVal = IOUtil.fdVal(fd);
	this.state = ST_INUSE;
	}

	ServerSocketChannelImpl(SelectorProvider sp,
	FileDescriptor fd,
	boolean bound)
	throws IOException
	{
	super(sp);
	this.fd = fd;
	this.fdVal = IOUtil.fdVal(fd);
	this.state = ST_INUSE;
	if (bound)
	localAddress = Net.localAddress(fd);
	}

	public ServerSocket socket() {
	synchronized (stateLock) {
	if (socket == null)
	socket = ServerSocketAdaptor.create(this);
	return socket;
	}
	}

	@Override
	public SocketAddress getLocalAddress() throws IOException {
	synchronized (stateLock) {
	if (!isOpen())
	throw new ClosedChannelException();
	return localAddress == null ? localAddress
	: Net.getRevealedLocalAddress(
	Net.asInetSocketAddress(localAddress));
	}
	}

	@Override
	public <T> ServerSocketChannel setOption(SocketOption<T> name, T value)
	throws IOException
	{
	if (name == null)
	throw new NullPointerException();
	if (!supportedOptions().contains(name))
	throw new UnsupportedOperationException("'" + name + "' not supported");
	synchronized (stateLock) {
	if (!isOpen())
	throw new ClosedChannelException();

	if (name == StandardSocketOptions.IP_TOS) {
	ProtocolFamily family = Net.isIPv6Available() ?
	StandardProtocolFamily.INET6 : StandardProtocolFamily.INET;
	Net.setSocketOption(fd, family, name, value);
	return this;
	}

	if (name == StandardSocketOptions.SO_REUSEADDR &&
	Net.useExclusiveBind())
	{
	// SO_REUSEADDR emulated when using exclusive bind
	isReuseAddress = (Boolean)value;
	} else {
	// no options that require special handling
	Net.setSocketOption(fd, Net.UNSPEC, name, value);
	}
	return this;
	}
	}

	@Override
	@SuppressWarnings("unchecked")
	public <T> T getOption(SocketOption<T> name)
	throws IOException
	{
	if (name == null)
	throw new NullPointerException();
	if (!supportedOptions().contains(name))
	throw new UnsupportedOperationException("'" + name + "' not supported");

	synchronized (stateLock) {
	if (!isOpen())
	throw new ClosedChannelException();
	if (name == StandardSocketOptions.SO_REUSEADDR &&
	Net.useExclusiveBind())
	{
	// SO_REUSEADDR emulated when using exclusive bind
	return (T)Boolean.valueOf(isReuseAddress);
	}
	// no options that require special handling
	return (T) Net.getSocketOption(fd, Net.UNSPEC, name);
	}
	}

	private static class DefaultOptionsHolder {
	static final Set<SocketOption<?>> defaultOptions = defaultOptions();

	private static Set<SocketOption<?>> defaultOptions() {
	HashSet<SocketOption<?>> set = new HashSet<SocketOption<?>>(2);
	set.add(StandardSocketOptions.SO_RCVBUF);
	set.add(StandardSocketOptions.SO_REUSEADDR);
	set.add(StandardSocketOptions.IP_TOS);
	set.addAll(ExtendedOptionsHelper.keepAliveOptions());
	return Collections.unmodifiableSet(set);
	}
	}

	@Override
	public final Set<SocketOption<?>> supportedOptions() {
	return DefaultOptionsHolder.defaultOptions;
	}

	public boolean isBound() {
	synchronized (stateLock) {
	return localAddress != null;
	}
	}

	public InetSocketAddress localAddress() {
	synchronized (stateLock) {
	return localAddress;
	}
	}

	@Override
	public ServerSocketChannel bind(SocketAddress local, int backlog) throws IOException {
	synchronized (lock) {
	if (!isOpen())
	throw new ClosedChannelException();
	if (isBound())
	throw new AlreadyBoundException();
	InetSocketAddress isa = (local == null) ? new InetSocketAddress(0) :
	Net.checkAddress(local);
	SecurityManager sm = System.getSecurityManager();
	if (sm != null)
	sm.checkListen(isa.getPort());
	NetHooks.beforeTcpBind(fd, isa.getAddress(), isa.getPort());
	Net.bind(fd, isa.getAddress(), isa.getPort());
	Net.listen(fd, backlog < 1 ? 50 : backlog);
	synchronized (stateLock) {
	localAddress = Net.localAddress(fd);
	}
	}
	return this;
	}

	public SocketChannel accept() throws IOException {
	synchronized (lock) {
	if (!isOpen())
	throw new ClosedChannelException();
	if (!isBound())
	throw new NotYetBoundException();
	SocketChannel sc = null;

	int n = 0;
	FileDescriptor newfd = new FileDescriptor();
	InetSocketAddress[] isaa = new InetSocketAddress[1];

	try {
	begin();
	if (!isOpen())
	return null;
	thread = NativeThread.current();
	for (;;) {
	n = accept(this.fd, newfd, isaa);
	if ((n == IOStatus.INTERRUPTED) && isOpen())
	continue;
	break;
	}
	} finally {
	thread = 0;
	end(n > 0);
	assert IOStatus.check(n);
	}

	if (n < 1)
	return null;

	IOUtil.configureBlocking(newfd, true);
	InetSocketAddress isa = isaa[0];
	sc = new SocketChannelImpl(provider(), newfd, isa);
	SecurityManager sm = System.getSecurityManager();
	if (sm != null) {
	try {
	sm.checkAccept(isa.getAddress().getHostAddress(),
	isa.getPort());
	} catch (SecurityException x) {
	sc.close();
	throw x;
	}
	}
	return sc;

	}
	}

	protected void implConfigureBlocking(boolean block) throws IOException {
	IOUtil.configureBlocking(fd, block);
	}

	protected void implCloseSelectableChannel() throws IOException {
	synchronized (stateLock) {
	if (state != ST_KILLED)
	nd.preClose(fd);
	long th = thread;
	if (th != 0)
	NativeThread.signal(th);
	if (!isRegistered())
	kill();
	}
	}

	public void kill() throws IOException {
	synchronized (stateLock) {
	if (state == ST_KILLED)
	return;
	if (state == ST_UNINITIALIZED) {
	state = ST_KILLED;
	return;
	}
	assert !isOpen() && !isRegistered();
	nd.close(fd);
	state = ST_KILLED;
	}
	}

	/**
	* Translates native poll revent set into a ready operation set
	*/
	public boolean translateReadyOps(int ops, int initialOps,
	SelectionKeyImpl sk) {
	int intOps = sk.nioInterestOps(); // Do this just once, it synchronizes
	int oldOps = sk.nioReadyOps();
	int newOps = initialOps;

	if ((ops & Net.POLLNVAL) != 0) {
	// This should only happen if this channel is pre-closed while a
	// selection operation is in progress
	// ## Throw an error if this channel has not been pre-closed
	return false;
	}

	if ((ops & (Net.POLLERR \| Net.POLLHUP)) != 0) {
	newOps = intOps;
	sk.nioReadyOps(newOps);
	return (newOps & ~oldOps) != 0;
	}

	if (((ops & Net.POLLIN) != 0) &&
	((intOps & SelectionKey.OP_ACCEPT) != 0))
	newOps \|= SelectionKey.OP_ACCEPT;

	sk.nioReadyOps(newOps);
	return (newOps & ~oldOps) != 0;
	}

	public boolean translateAndUpdateReadyOps(int ops, SelectionKeyImpl sk) {
	return translateReadyOps(ops, sk.nioReadyOps(), sk);
	}

	public boolean translateAndSetReadyOps(int ops, SelectionKeyImpl sk) {
	return translateReadyOps(ops, 0, sk);
	}

	// package-private
	int poll(int events, long timeout) throws IOException {
	assert Thread.holdsLock(blockingLock()) && !isBlocking();

	synchronized (lock) {
	int n = 0;
	try {
	begin();
	synchronized (stateLock) {
	if (!isOpen())
	return 0;
	thread = NativeThread.current();
	}
	n = Net.poll(fd, events, timeout);
	} finally {
	thread = 0;
	end(n > 0);
	}
	return n;
	}
	}

	/**
	* Translates an interest operation set into a native poll event set
	*/
	public void translateAndSetInterestOps(int ops, SelectionKeyImpl sk) {
	int newOps = 0;

	// Translate ops
	if ((ops & SelectionKey.OP_ACCEPT) != 0)
	newOps \|= Net.POLLIN;
	// Place ops into pollfd array
	sk.selector.putEventOps(sk, newOps);
	}

	public FileDescriptor getFD() {
	return fd;
	}

	public int getFDVal() {
	return fdVal;
	}

	public String toString() {
	StringBuffer sb = new StringBuffer();
	sb.append(this.getClass().getName());
	sb.append('[');
	if (!isOpen()) {
	sb.append("closed");
	} else {
	synchronized (stateLock) {
	InetSocketAddress addr = localAddress();
	if (addr == null) {
	sb.append("unbound");
	} else {
	sb.append(Net.getRevealedLocalAddressAsString(addr));
	}
	}
	}
	sb.append(']');
	return sb.toString();
	}

	/**
	* Accept a connection on a socket.
	*
	* @implNote Wrap native call to allow instrumentation.
	*/
	private int accept(FileDescriptor ssfd, FileDescriptor newfd,
	InetSocketAddress[] isaa)
	throws IOException
	{
	return accept0(ssfd, newfd, isaa);
	}

	// -- Native methods --

	// Accepts a new connection, setting the given file descriptor to refer to
	// the new socket and setting isaa[0] to the socket's remote address.
	// Returns 1 on success, or IOStatus.UNAVAILABLE (if non-blocking and no
	// connections are pending) or IOStatus.INTERRUPTED.
	//
	private native int accept0(FileDescriptor ssfd, FileDescriptor newfd,
	InetSocketAddress[] isaa)
	throws IOException;

	private static native void initIDs();

	static {
	IOUtil.load();
	initIDs();
	nd = new SocketDispatcher();
	}

	}

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