/jEdit/tags/jedit-4-2-pre14/org/gjt/sp/util/WorkThread.java

  1/*
  2 * WorkThread.java - Background thread that does stuff
  3 * Copyright (C) 2000 Slava Pestov
  4 *
  5 * This program is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU General Public License
  7 * as published by the Free Software Foundation; either version 2
  8 * of the License, or any later version.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, write to the Free Software
 17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 18 */
 19
 20package org.gjt.sp.util;
 21
 22/**
 23 * Services work requests in the background.
 24 * @author Slava Pestov
 25 * @version $Id: WorkThread.java 4543 2003-03-12 17:01:50Z spestov $
 26 */
 27public class WorkThread extends Thread
 28{
 29	public WorkThread(WorkThreadPool pool, ThreadGroup group, String name)
 30	{
 31		super(group, name);
 32		// so that jEdit doesn't exit with no views open automatically
 33		//setDaemon(true);
 34		setPriority(Thread.MIN_PRIORITY);
 35
 36		this.pool = pool;
 37	}
 38
 39	/**
 40	 * Sets if the current request can be aborted.
 41	 * @since jEdit 2.6pre1
 42	 */
 43	public void setAbortable(boolean abortable)
 44	{
 45		synchronized(abortLock)
 46		{
 47			this.abortable = abortable;
 48			if(aborted)
 49				stop(new Abort());
 50		}
 51	}
 52
 53	/**
 54	 * Returns if the work thread is currently running a request.
 55	 */
 56	public boolean isRequestRunning()
 57	{
 58		return requestRunning;
 59	}
 60
 61	/**
 62	 * Returns the status text.
 63	 */
 64	public String getStatus()
 65	{
 66		return status;
 67	}
 68
 69	/**
 70	 * Sets the status text.
 71	 * @since jEdit 2.6pre1
 72	 */
 73	public void setStatus(String status)
 74	{
 75		this.status = status;
 76		pool.fireProgressChanged(this);
 77	}
 78
 79	/**
 80	 * Returns the progress value.
 81	 */
 82	public int getProgressValue()
 83	{
 84		return progressValue;
 85	}
 86
 87	/**
 88	 * Sets the progress value.
 89	 * @since jEdit 2.6pre1
 90	 */
 91	public void setProgressValue(int progressValue)
 92	{
 93		this.progressValue = progressValue;
 94		pool.fireProgressChanged(this);
 95	}
 96
 97	/**
 98	 * Returns the progress maximum.
 99	 */
100	public int getProgressMaximum()
101	{
102		return progressMaximum;
103	}
104
105	/**
106	 * Sets the maximum progress value.
107	 * @since jEdit 2.6pre1
108	 */
109	public void setProgressMaximum(int progressMaximum)
110	{
111		this.progressMaximum = progressMaximum;
112		pool.fireProgressChanged(this);
113	}
114
115	/**
116	 * Aborts the currently running request, if allowed.
117	 * @since jEdit 2.6pre1
118	 */
119	public void abortCurrentRequest()
120	{
121		synchronized(abortLock)
122		{
123			if(abortable && !aborted)
124				stop(new Abort());
125			aborted = true;
126		}
127	}
128
129	public void run()
130	{
131		Log.log(Log.DEBUG,this,"Work request thread starting [" + getName() + "]");
132
133		for(;;)
134		{
135			doRequests();
136		}
137	}
138
139	// private members
140	private WorkThreadPool pool;
141	private Object abortLock = new Object();
142	private boolean requestRunning;
143	private boolean abortable;
144	private boolean aborted;
145	private String status;
146	private int progressValue;
147	private int progressMaximum;
148
149	private void doRequests()
150	{
151		WorkThreadPool.Request request;
152		for(;;)
153		{
154			request = pool.getNextRequest();
155			if(request == null)
156				break;
157			else
158			{
159				requestRunning = true;
160				pool.fireStatusChanged(this);
161				doRequest(request);
162				requestRunning = false;
163			}
164		}
165
166		pool.fireStatusChanged(this);
167
168		synchronized(pool.waitForAllLock)
169		{
170			// notify a running waitForRequests() method
171			pool.waitForAllLock.notifyAll();
172		}
173
174		synchronized(pool.lock)
175		{
176			// wait for more requests
177			try
178			{
179				pool.lock.wait();
180			}
181			catch(InterruptedException ie)
182			{
183				Log.log(Log.ERROR,this,ie);
184			}
185		}
186	}
187
188	private void doRequest(WorkThreadPool.Request request)
189	{
190		Log.log(Log.DEBUG,WorkThread.class,"Running in work thread: " + request);
191
192		try
193		{
194			request.run.run();
195		}
196		catch(Abort a)
197		{
198			Log.log(Log.ERROR,WorkThread.class,"Unhandled abort");
199		}
200		catch(Throwable t)
201		{
202			Log.log(Log.ERROR,WorkThread.class,"Exception "
203				+ "in work thread:");
204			Log.log(Log.ERROR,WorkThread.class,t);
205		}
206		finally
207		{
208			synchronized(abortLock)
209			{
210				aborted = abortable = false;
211			}
212			status = null;
213			progressValue = progressMaximum = 0;
214			pool.requestDone();
215			pool.fireStatusChanged(this);
216		}
217	}
218
219	public static class Abort extends Error
220	{
221		public Abort()
222		{
223			super("Work request aborted");
224		}
225	}
226}