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 }