ManagedProcesses.java

/*
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version. You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

package org.aitools.programd.util;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.aitools.programd.Core;
import org.apache.log4j.Logger;

/**
 * Controls processes that run in separate threads and need to be shut down before the bot exits.
 */
public class ManagedProcesses {

  /** The Core to which this is attached. */
  private Core _core;

  /** The registry of all processes. */
  private Map<String, ManagedProcess> registry = Collections.checkedMap(new HashMap<String, ManagedProcess>(),
      String.class, ManagedProcess.class);

  /**
   * Creates a ManagedProcesses object.
   * 
   * @param core the Core to which to attach this
   */
  public ManagedProcesses(Core core) {
    this._core = core;
  }

  /**
   * Returns a given process.
   * 
   * @param name the name of the process
   * @return the process assigned to the name
   */
  public ManagedProcess get(String name) {
    return this.registry.get(name);
  }

  /**
   * Shuts down all registered processes.
   */
  public void shutdownAll() {
    Logger logger = Logger.getLogger("programd");
    logger.info("Shutting down all ManagedProcesses.");
    for (ManagedProcess process : this.registry.values()) {
      logger.debug("Shutting down " + process);
      process.shutdown();
    }
    logger.info("Finished shutting down ManagedProcesses.");
  }

  /**
   * Adds a process to the registry and starts it.
   * 
   * @param process the process to add
   * @param name a name by which its thread will be identified
   */
  public void start(ManagedProcess process, String name) {
    this.registry.put(name, process);
    Thread botProcess = new Thread(process, name);

    // Set the thread as a daemon, in case the server terminates abnormally.
    botProcess.setDaemon(true);

    try {
      // Start the thread.
      botProcess.start();
    }
    catch (Throwable e) {
      this._core.getLogger().error("Error starting \"" + name + "\".", e);
    }
  }

  /**
   * Returns an iterator on the registry.
   * 
   * @return an iterator on the registry
   */
  public Collection<ManagedProcess> values() {
    return this.registry.values();
  }
}