001    /* SelectableChannel.java --
002       Copyright (C) 2002 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.nio.channels;
039    
040    import java.io.IOException;
041    import java.nio.channels.spi.AbstractInterruptibleChannel;
042    import java.nio.channels.spi.SelectorProvider;
043    
044    
045    /**
046     * @author Michael Koch
047     * @since 1.4
048     */
049    public 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    }