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* Copyright (c) 2008, 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.
*
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package sun.nio.ch;
import java.nio.channels.*;
import java.net.SocketAddress;
import java.net.SocketOption;
import java.net.StandardSocketOptions;
import java.net.InetSocketAddress;
import java.io.FileDescriptor;
import java.io.IOException;
import java.util.Set;
import java.util.HashSet;
import java.util.Collections;
import java.util.concurrent.Future;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import sun.net.NetHooks;
/**
* Base implementation of AsynchronousServerSocketChannel.
*/
abstract class AsynchronousServerSocketChannelImpl
extends AsynchronousServerSocketChannel
implements Cancellable, Groupable
{
protected final FileDescriptor fd;
// the local address to which the channel's socket is bound
protected volatile InetSocketAddress localAddress;
// need this lock to set local address
private final Object stateLock = new Object();
// close support
private ReadWriteLock closeLock = new ReentrantReadWriteLock();
private volatile boolean closed;
// set true when accept operation is cancelled
private volatile boolean acceptKilled;
// set true when exclusive binding is on and SO_REUSEADDR is emulated
private boolean isReuseAddress;
AsynchronousServerSocketChannelImpl(AsynchronousChannelGroupImpl group) {
super(group.provider());
this.fd = Net.serverSocket(true);
}
@Override
public final boolean isOpen() {
return !closed;
}
/**
* Marks beginning of access to file descriptor/handle
*/
final void begin() throws IOException {
closeLock.readLock().lock();
if (!isOpen())
throw new ClosedChannelException();
}
/**
* Marks end of access to file descriptor/handle
*/
final void end() {
closeLock.readLock().unlock();
}
/**
* Invoked to close file descriptor/handle.
*/
abstract void implClose() throws IOException;
@Override
public final void close() throws IOException {
// synchronize with any threads using file descriptor/handle
closeLock.writeLock().lock();
try {
if (closed)
return; // already closed
closed = true;
} finally {
closeLock.writeLock().unlock();
}
implClose();
}
/**
* Invoked by accept to accept connection
*/
abstract Future<AsynchronousSocketChannel>
implAccept(Object attachment,
CompletionHandler<AsynchronousSocketChannel,Object> handler);
@Override
public final Future<AsynchronousSocketChannel> accept() {
return implAccept(null, null);
}
@Override
@SuppressWarnings("unchecked")
public final <A> void accept(A attachment,
CompletionHandler<AsynchronousSocketChannel,? super A> handler)
{
if (handler == null)
throw new NullPointerException("'handler' is null");
implAccept(attachment, (CompletionHandler<AsynchronousSocketChannel,Object>)handler);
}
final boolean isAcceptKilled() {
return acceptKilled;
}
@Override
public final void onCancel(PendingFuture<?,?> task) {
acceptKilled = true;
}
@Override
public final AsynchronousServerSocketChannel bind(SocketAddress local, int backlog)
throws IOException
{
InetSocketAddress isa = (local == null) ? new InetSocketAddress(0) :
Net.checkAddress(local);
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkListen(isa.getPort());
try {
begin();
synchronized (stateLock) {
if (localAddress != null)
throw new AlreadyBoundException();
NetHooks.beforeTcpBind(fd, isa.getAddress(), isa.getPort());
Net.bind(fd, isa.getAddress(), isa.getPort());
Net.listen(fd, backlog < 1 ? 50 : backlog);
localAddress = Net.localAddress(fd);
}
} finally {
end();
}
return this;
}
@Override
public final SocketAddress getLocalAddress() throws IOException {
if (!isOpen())
throw new ClosedChannelException();
return Net.getRevealedLocalAddress(localAddress);
}
@Override
public final <T> AsynchronousServerSocketChannel setOption(SocketOption<T> name,
T value)
throws IOException
{
if (name == null)
throw new NullPointerException();
if (!supportedOptions().contains(name))
throw new UnsupportedOperationException("'" + name + "' not supported");
try {
begin();
if (name == StandardSocketOptions.SO_REUSEADDR &&
Net.useExclusiveBind())
{
// SO_REUSEADDR emulated when using exclusive bind
isReuseAddress = (Boolean)value;
} else {
Net.setSocketOption(fd, Net.UNSPEC, name, value);
}
return this;
} finally {
end();
}
}
@Override
@SuppressWarnings("unchecked")
public final <T> T getOption(SocketOption<T> name) throws IOException {
if (name == null)
throw new NullPointerException();
if (!supportedOptions().contains(name))
throw new UnsupportedOperationException("'" + name + "' not supported");
try {
begin();
if (name == StandardSocketOptions.SO_REUSEADDR &&
Net.useExclusiveBind())
{
// SO_REUSEADDR emulated when using exclusive bind
return (T)Boolean.valueOf(isReuseAddress);
}
return (T) Net.getSocketOption(fd, Net.UNSPEC, name);
} finally {
end();
}
}
private static class DefaultOptionsHolder {
static final Set<SocketOption<?>> defaultOptions = defaultOptions();
private static Set<SocketOption<?>> defaultOptions() {
HashSet<SocketOption<?>> set = new HashSet<>(2);
set.add(StandardSocketOptions.SO_RCVBUF);
set.add(StandardSocketOptions.SO_REUSEADDR);
if (Net.isReusePortAvailable()) {
set.add(StandardSocketOptions.SO_REUSEPORT);
}
return Collections.unmodifiableSet(set);
}
}
@Override
public final Set<SocketOption<?>> supportedOptions() {
return DefaultOptionsHolder.defaultOptions;
}
@Override
public final String toString() {
StringBuilder sb = new StringBuilder();
sb.append(this.getClass().getName());
sb.append('[');
if (!isOpen())
sb.append("closed");
else {
if (localAddress == null) {
sb.append("unbound");
} else {
sb.append(Net.getRevealedLocalAddressAsString(localAddress));
}
}
sb.append(']');
return sb.toString();
}
}