Project: bml_lib License: BSD Dependencies: bml_msgs bml_srvs rosjava Used by: bml_realizer All Packages

bml_lib/src/edu/wpi/hri/comm/MasterSpinner.java Go to the documentation of this file. /* * Software License Agreement (BSD License) * * Copyright (c) 2010, Worcester Polytechnic Institute * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * Neither the name of Worcester Polytechnic Institute. nor the names * of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ package edu.wpi.hri.comm; import java.util.ArrayList; import ros.Ros; import edu.wpi.hri.log.Logger; import edu.wpi.hri.log.Logger.LoggerLevel; public class MasterSpinner { private Thread master; private final Logger logger; private final ArrayList<Thread> oldMasters; private final Thread endThread; public MasterSpinner(Logger logger, boolean autoEnd) { oldMasters = new ArrayList<Thread>(); this.logger = logger.sub(Logger.Colors.SPINNER, "SPIN"); this.createMaster(); // wait for ROS Master to send a bad signal, which means we may have // more than one thread spinning at a time, not necessarily a bad thing final MasterSpinner self = this; this.endThread = new Thread() { @Override public void run() { Ros.getInstance().spin(); self.stop(); } }; if (autoEnd) this.endThread.start(); } public synchronized void startNewMaster() { oldMasters.add(master); this.createMaster(); } private void createMaster() { this.logger.debug(LoggerLevel.MASTER, "Creating a new Master Spinner"); // a master thread simply spins once until it's no longer the master master = new Thread() { @Override public void run() { while (this == master) { // I'm the master :) Ros.getInstance().spinOnce(); try { Thread.sleep(10); } catch (Exception e) { } } // I'm not the master :( } }; master.start(); } public synchronized void joinOldMasters() { // use a blocking wait until the stop method notifies this one while (this.master != null) { try { this.wait(10000); if (oldMasters.size() > 0) { Thread old = oldMasters.get(0); old.join(1000); if (!old.isAlive()) { this.logger.debug(LoggerLevel.MASTER, "Stopped an old Spinner"); oldMasters.remove(old); } } } catch (InterruptedException e) { this.logger.debug(LoggerLevel.ALL, "Interruption: "); this.logger.printThrowable(LoggerLevel.ALL, e); } } // then join each thread for (Thread ms : oldMasters) { try { ms.join(); this.logger.debug(LoggerLevel.MASTER, "Stopped an old Spinner"); } catch (InterruptedException e) { this.logger.debug(LoggerLevel.ALL, "Interruption: "); this.logger.printThrowable(LoggerLevel.ALL, e); } } this.oldMasters.clear(); } public synchronized void stop() { this.master = null; this.notifyAll(); } }

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bml_lib
Author(s): Aaron Holroyd (aholroyd (at) wpi (dot) edu)
autogenerated on Fri Sep 9 10:44:05 2011