| /******************************************************************************* |
| * Copyright (c) 2004, 2005 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.update.internal.configurator; |
| |
| import java.io.*; |
| |
| /** |
| * Internal class. |
| */ |
| public class Locker_JavaIo implements Locker { |
| private File lockFile; |
| private RandomAccessFile lockRAF; |
| |
| public Locker_JavaIo(File lockFile) { |
| this.lockFile = lockFile; |
| } |
| |
| public synchronized boolean lock() throws IOException { |
| //if the lock file already exists, try to delete, |
| //assume failure means another eclipse has it open |
| if (lockFile.exists()) |
| lockFile.delete(); |
| if (lockFile.exists()) |
| return false; |
| |
| //open the lock file so other instances can't co-exist |
| lockRAF = new RandomAccessFile(lockFile, "rw"); //$NON-NLS-1$ |
| lockRAF.writeByte(0); |
| |
| return true; |
| } |
| |
| public synchronized void release() { |
| try { |
| if (lockRAF != null) { |
| lockRAF.close(); |
| lockRAF = null; |
| } |
| } catch (IOException e) { |
| //don't complain, we're making a best effort to clean up |
| } |
| if (lockFile != null) |
| lockFile.delete(); |
| } |
| } |