001    /*
002     * SonarQube, open source software quality management tool.
003     * Copyright (C) 2008-2014 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * SonarQube is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * SonarQube is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public License
017     * along with this program; if not, write to the Free Software Foundation,
018     * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019     */
020    package org.sonar.process;
021    
022    import org.slf4j.LoggerFactory;
023    
024    /**
025     * This watchdog asks for graceful termination of process when the file
026     * <process_key>.stop is created in temp directory.
027     */
028    public class StopWatcher extends Thread {
029    
030      private final Stoppable stoppable;
031      private final ProcessCommands commands;
032      private boolean watching = true;
033      private final long delayMs;
034    
035      public StopWatcher(ProcessCommands commands, Stoppable stoppable) {
036        this(commands, stoppable, 500L);
037      }
038    
039      StopWatcher(ProcessCommands commands, Stoppable stoppable, long delayMs) {
040        super("Stop Watcher");
041        this.commands = commands;
042        this.stoppable = stoppable;
043        this.delayMs = delayMs;
044      }
045    
046      @Override
047      public void run() {
048        commands.prepare();
049        try {
050          while (watching) {
051            if (commands.askedForStop()) {
052              LoggerFactory.getLogger(getClass()).info("Stopping process");
053              stoppable.stopAsync();
054              watching = false;
055            } else {
056              try {
057                Thread.sleep(delayMs);
058              } catch (InterruptedException ignored) {
059                watching = false;
060              }
061            }
062          }
063        } finally {
064          commands.endWatch();
065        }
066      }
067    
068      public void stopWatching() {
069        watching = false;
070      }
071    }