001/* SelectableChannel.java --
002   Copyright (C) 2002 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package java.nio.channels;
039
040import java.io.IOException;
041import java.nio.channels.spi.AbstractInterruptibleChannel;
042import java.nio.channels.spi.SelectorProvider;
043
044
045/**
046 * @author Michael Koch
047 * @since 1.4
048 */
049public abstract class SelectableChannel extends AbstractInterruptibleChannel
050{
051  /**
052   * Initializes the channel.
053   */
054  protected SelectableChannel()
055  {
056  }
057
058  /**
059   * Returns the lock of this channel.
060   */
061  public abstract Object blockingLock();
062
063  /**
064   * Adjusts this channel's blocking mode.
065   *
066   * @exception ClosedChannelException If this channel is closed.
067   * @exception IllegalBlockingModeException If block is true and this channel
068   * is registered with one or more selectors.
069   * @exception IOException If an error occurs.
070   */
071  public abstract SelectableChannel configureBlocking(boolean block)
072    throws IOException;
073
074  /**
075   * Tells whether this channel is blocking or not.
076   */
077  public abstract boolean isBlocking();
078
079  /**
080   * Tells whether or not this channel is currently registered with
081   * any selectors.
082   */
083  public abstract boolean isRegistered();
084
085  /**
086   * Retrieves the key representing the channel's registration with
087   * the given selector.
088   */
089  public abstract SelectionKey keyFor(Selector sel);
090
091  /**
092   * Returns the provider that created this channel.
093   */
094  public abstract SelectorProvider provider();
095
096  /**
097   * Registers this channel with the given selector,
098   * returning a selection key.
099   *
100   * @exception CancelledKeyException If this channel is currently registered
101   * with the given selector but the corresponding key has already been cancelled
102   * @exception ClosedChannelException If this channel is closed.
103   * @exception IllegalArgumentException If a bit in ops does not correspond
104   * to an operation that is supported by this channel, that is, if
105   * set & ~validOps() != 0.
106   * @exception IllegalBlockingModeException If block is true and this channel
107   * is registered with one or more selectors.
108   * @exception IllegalSelectorException If this channel was not created by
109   * the same provider as the given selector.
110   */
111  public final SelectionKey register(Selector sel, int ops)
112    throws ClosedChannelException
113  {
114    return register(sel, ops, null);
115  }
116
117  /**
118   * Registers this channel with the given selector,
119   * returning a selection key.
120   *
121   * @exception CancelledKeyException If this channel is currently registered
122   * with the given selector but the corresponding key has already been
123   * cancelled.
124   * @exception ClosedChannelException If this channel is closed.
125   * @exception IllegalArgumentException If a bit in ops does not correspond
126   * to an operation that is supported by this channel, that is, if
127   * set & ~validOps() != 0.
128   * @exception IllegalBlockingModeException If block is true and this channel
129   * is registered with one or more selectors.
130   * @exception IllegalSelectorException If this channel was not created by
131   * the same provider as the given selector.
132   */
133  public abstract SelectionKey register(Selector sel, int ops, Object att)
134    throws ClosedChannelException;
135
136  /**
137   * Returns a set of valid operations on this channel.
138   */
139  public abstract int validOps();
140}