PingThread.cpp

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#include "PingThread.h"
#include "cvd/thread.h"
#include "ros/ros.h"
#include <iostream>
#include <stdio.h>
#include "RosThread.h"
#include "tum_ardrone_gui.h"

PingThread::PingThread()
{
        line1[0] = '\0';
        line2[0] = '\0';
        keepRunning = true;
        measure = true;

        p500 = 25;
        p20000 = 50;

        rosThread = NULL;
        gui = NULL;
}

PingThread::~PingThread(void)
{


}

void PingThread::startSystem()
{
        keepRunning = true;
        start();
}

void PingThread::stopSystem()
{
        keepRunning = false;
        join();
}

double parsePingResult(std::string s)
{
        // 20008 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.075 ms
        int pos = s.find("time=");
        int found = 0;
        float ms;
        if(pos != std::string::npos)
                found = sscanf(s.substr(pos).c_str(),"time=%f",&ms);

        if(found == 1 && pos != std::string::npos)
                return ms;
        else
                return 10000;
}

void PingThread::run()
{
        std::cout << "Starting PING Thread" << std::endl;

        sprintf(pingCommand20000,"ping -c 1 -s 20000 -w 1 192.168.1.1");
        sprintf(pingCommand500,"ping -c 1 -s 500 -w 1 192.168.1.1");
        ros::Rate r(2.0);
        FILE *p;

        while(keepRunning)
        {
                if(measure)
                {
                        // ping twice, with a sleep in between
                        p = popen(pingCommand500,"r");
                        fgets(line1, 200, p);
                        fgets(line1, 200, p);
                        pclose(p);

                        // sleep 1s
                        r.sleep();
                        if(!keepRunning) break;
                        r.sleep();
                        if(!keepRunning) break;



                        p = popen(pingCommand20000,"r");
                        fgets(line2, 200, p);
                        fgets(line2, 200, p);
                        pclose(p);


                        // parse results which should be in line1 and line2
                        double res500 = parsePingResult(line1);
                        double res20000 = parsePingResult(line2);

                        std::cout << "new ping values: 500->" << res500 << " 20000->" << res20000 << std::endl;

                        // clip between 10 and 1000.
                        res500 = std::min(1000.0,std::max(10.0,res500));
                        res20000 = std::min(1000.0,std::max(10.0,res20000));

                        // update
                        p500 = 0.7 * p500 + 0.3 * res500;
                        p20000 = 0.7 * p20000 + 0.3 * res20000;

                        // send
                        snprintf(line1,200,"pings %d %d", (int)p500, (int)p20000);
                        if(rosThread != NULL) rosThread->publishCommand(line1);
                        if(gui != NULL) gui->setPings((int)p500, (int)p20000);

                        // sleep 1s
                        r.sleep();
                        if(!keepRunning) break;
                        r.sleep();
                        if(!keepRunning) break;
                }
                else
                {
                        r.sleep();
                        if(!keepRunning) break;
                        r.sleep();
                        if(!keepRunning) break;
                        r.sleep();
                        if(!keepRunning) break;
                        r.sleep();
                        if(!keepRunning) break;

                        // send
                        snprintf(line1,200,"pings %d %d", (int)p500Default, (int)p20000Default);
                        if(rosThread != NULL) rosThread->publishCommand(line1);
                        if(gui != NULL) gui->setPings((int)p500Default, (int)p20000Default);
                }
        }

        std::cout << "Exiting PING Thread" << std::endl;
}