serialportio.java

用于传感器网络的节点操作系统 TinyOS 结构设计非常有意思

/*
 * "Copyright (c) 2001 and The Regents of the University
 * of California.  All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose, without fee, and without written
 * agreement is hereby granted, provided that the above copyright
 * notice and the following two paragraphs appear in all copies of
 * this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY
 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
 * DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
 * DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE
 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 * CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT,
 * UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
 *
 * $\Id$
 */

/**
 * File: SerialPortIO.java
 *
 * Description:
 * The SerialPortIO handles the collection of packets
 * from a mote connected to the serial port.  The Constructor
 * takes in an already open input stream from which to read
 * data.
 *
 * @author <a href="mailto:[e-mail]">Bret Hull</a>
 */

package net.tinyos.sf;

import java.util.*;
import java.io.*;

public class SerialPortIO extends Thread {
    private static SerialPortIO   runningSerialPortIO = null;
    private Vector                m_vctPSForwarders = new Vector ();
    private boolean               m_bShutdown     = false;
    private boolean               m_bTerminated   = false;
    int                           m_nBytes        = 0;
    private DataSource            m_dataSource    = null;


    public synchronized static void InitSerialPortIO () {
        if (runningSerialPortIO == null) {
            runningSerialPortIO = new SerialPortIO();
            runningSerialPortIO.start();
        }
    }

    public static void RegisterPacketForwarder (ClientServicer cs) {
        InitSerialPortIO();
        if (runningSerialPortIO != null) {
            runningSerialPortIO.RegisterPSForwarder(cs);
        }
    }

    public static void UnregisterPacketForwarder (ClientServicer cs) {
        if (runningSerialPortIO != null) {
            runningSerialPortIO.UnregisterPSForwarder(cs);
        }
    }

    public static void WriteBytes (byte[] data) {
        InitSerialPortIO ();
        if (runningSerialPortIO != null) {
            runningSerialPortIO.WriteToSource(data);
        }
    }

    public SerialPortIO () {

    }

    public void run () {
        SerialForward.VERBOSE ("SerialPortIO: initializing");
	m_dataSource = SerialForward.dataSource;

	if (m_dataSource != null) {
	    boolean bStatus;
	    byte[] packet;

	    bStatus = m_dataSource.OpenSource();
            if (!bStatus && !m_bShutdown) { 
		SerialForward.VERBOSE("Unable to open data source");
	    }
	    
	    while (!m_bShutdown && bStatus) {
		packet = m_dataSource.ReadPacket();
		if (packet != null) {
		    UpdatePacketForwarders (packet);
		}
		else {
                    m_dataSource.CloseSource();
                    m_bShutdown = true;
		}
	    }
	}
	else {
            SerialForward.VERBOSE ("SerialPortIO: no data source selected");
	}
	
        SerialForward.VERBOSE ("SerialPortIO: closing data source");
        runningSerialPortIO = null;
    }

    private void ReadFileData () {
        /*ObjectInputStream ois = (ObjectInputStream) m_is;
        Object currentPckt;
        Object lastPckt = null;

        while (!m_bShutdown)
        {
            try { currentPckt = ois.readObject(); }
            catch (Exception e)
            {
                m_bShutdown = true;
                continue;
            }

            if (currentPckt instanceof DataPckt)
            {
                SerialForward.settings.nBytesRead += ((DataPckt) currentPckt).data.length;
                if (lastPckt == null)
                {
                  UpdatePacketForwarders (((DataPckt) currentPckt).data);
                }
                else
                {
                  SimulatePcktDelay ((DataPckt) currentPckt, (DataPckt) lastPckt);
                  UpdatePacketForwarders (((DataPckt) currentPckt).data);
                }
                lastPckt = currentPckt;
            }
        }*/
    }
/*
    private void SimulatePcktDelay (DataPckt currentPckt, DataPckt lastPckt)
    {
        long timeDelta = currentPckt.time.getTime() - lastPckt.time.getTime();
        if (timeDelta < 0) { return; }
        else
        {
            try { this.sleep(timeDelta); }
            catch (InterruptedException e) { }
        }
    }
*/
    public static void Shutdown () {
        if (runningSerialPortIO != null) {
            runningSerialPortIO.Terminate();
        }
    }

    private void Terminate () {
        if (!m_bTerminated) {
            m_bTerminated = true;
            m_bShutdown = true;

            this.interrupt();
            //m_dataSource.CloseSource();
            runningSerialPortIO = null;
        }
    }
    private synchronized void RegisterPSForwarder (ClientServicer cs) {
        m_vctPSForwarders.addElement (cs);
        SerialForward.IncrementClients();
        SerialForward.DEBUG ("SerialPortIO: Added listener to position: " + m_vctPSForwarders.size());
    }



    private synchronized void UnregisterPSForwarder (ClientServicer cs)  {
        SerialForward.DEBUG ("SerialPortIO: Removing packet stream forwarder");
        UnregisterForwarder (cs, m_vctPSForwarders);
    }

    private void UnregisterForwarder (ClientServicer cs, Vector vct) {

        if (!vct.removeElement(cs)) {
          SerialForward.DEBUG ("Unable to unregister listener");
          return;
        }
	// we always want to read from port even if we
	// have no clients...cause jason says so
	/*
        if (m_vctPSForwarders.isEmpty() && !m_bSourceSim)
        {
            // no more forwarders, shutdown
            m_bShutdown = true;
	}*/

    }

    private synchronized void UpdatePacketForwarders (byte[] packet)
    {
        SerialForward.IncrementPacketsRead ();
        ClientServicer currentCS;

	if (SerialForward.debugMode) {
	  String s = "Forwarding packet: ";
	  for (int i = 0; i < packet.length; i++) {
	    s += Integer.toHexString(packet[i] & 0xff) + " ";
	  }
	  SerialForward.VERBOSE(s);
	}


        for (int i = 0; i < m_vctPSForwarders.size(); i++) {
            currentCS = (ClientServicer) m_vctPSForwarders.elementAt(i);
	    SerialForward.DEBUG("Forwarding packet to "+currentCS);
            try { currentCS.output.write(packet); }
            catch (IOException e) {
                currentCS.Shutdown ();
                i--;
            }
        }
	/*
        if (m_vctPSForwarders.size() == 0)
        {
            m_bShutdown = true;
	    }*/
    }

    private boolean WriteToSource (byte[] packet) {
        if (m_dataSource != null) {
            m_dataSource.WritePacket(packet);
        }
        return true;
    }

}