1 /* FileLockImpl.java -- FileLock associated with a FileChannelImpl. 2 Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.java.nio; 40 41 import gnu.java.nio.channels.FileChannelImpl; 42 43 import java.io.IOException; 44 import java.nio.channels.FileLock; 45 46 /** 47 * A FileLock associated with a FileChannelImpl. 48 * 49 * @author Michael Koch 50 * @since 1.4 51 */ 52 public final class FileLockImpl extends FileLock 53 { 54 /** 55 * Whether or not this lock is valid, false when channel is closed or 56 * release has been explicitly called. 57 */ 58 private boolean valid; 59 FileLockImpl(FileChannelImpl channel, long position, long size, boolean shared)60 public FileLockImpl (FileChannelImpl channel, long position, 61 long size, boolean shared) 62 { 63 super (channel, position, size, shared); 64 valid = true; 65 } 66 67 /** 68 * Releases this lock. 69 */ finalize()70 protected void finalize() 71 { 72 try 73 { 74 release(); 75 } 76 catch (IOException e) 77 { 78 // Ignore this. 79 } 80 } 81 82 /** 83 * Whether or not this lock is valid, false when channel is closed or 84 * release has been explicitly called. 85 */ isValid()86 public boolean isValid() 87 { 88 if (valid) 89 valid = channel().isOpen(); 90 return valid; 91 } 92 close()93 public void close() throws Exception 94 { 95 release(); 96 } 97 98 /** 99 * Releases the lock if it is still valid. Marks this lock as invalid. 100 */ release()101 public void release() throws IOException 102 { 103 if (isValid()) 104 { 105 valid = false; 106 ((FileChannelImpl) channel()).unlock(position(), size()); 107 } 108 } 109 } 110