001 /* AbstractInterruptibleChannel.java --
002 Copyright (C) 2002, 2004 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.spi;
039
040 import java.io.IOException;
041 import java.nio.channels.AsynchronousCloseException;
042 import java.nio.channels.Channel;
043 import java.nio.channels.ClosedByInterruptException;
044 import java.nio.channels.InterruptibleChannel;
045
046
047 /**
048 * @author Michael Koch
049 * @since 1.4
050 */
051 public abstract class AbstractInterruptibleChannel
052 implements Channel, InterruptibleChannel
053 {
054 private boolean closed;
055
056 /**
057 * Initializes the channel.
058 */
059 protected AbstractInterruptibleChannel()
060 {
061 }
062
063 /**
064 * Marks the beginning of an I/O operation that might block indefinitely.
065 */
066 protected final void begin()
067 {
068 }
069
070 /**
071 * Closes the channel.
072 *
073 * @exception IOException If an error occurs
074 */
075 public final void close() throws IOException
076 {
077 if (! closed)
078 {
079 closed = true;
080 implCloseChannel();
081 }
082 }
083
084 /**
085 * Marks the end of an I/O operation that might block indefinitely.
086 *
087 * @param completed true if the task completed successfully,
088 * false otherwise
089 *
090 * @exception AsynchronousCloseException If the channel was asynchronously
091 * closed.
092 * @exception ClosedByInterruptException If the thread blocked in the
093 * I/O operation was interrupted.
094 */
095 protected final void end(boolean completed)
096 throws AsynchronousCloseException
097 {
098 // FIXME: check more here.
099
100 if (closed) throw new AsynchronousCloseException();
101 }
102
103 /**
104 * Closes the channel.
105 *
106 * @exception IOException If an error occurs
107 */
108 protected abstract void implCloseChannel() throws IOException;
109
110 /**
111 * Tells whether or not this channel is open.
112 *
113 * @return true if the channel is open, false otherwise
114 */
115 public final boolean isOpen()
116 {
117 return ! closed;
118 }
119 }