Subj : meaning of error message?
To   : comp.programming.threads
From : Huub
Date : Sun Jun 05 2005 03:07 pm

Hi,

Using Slackware 10, kernel 2.6.11 and gcc-3.3.4, I'm trying to pass an 
argument with a thread, but get this error:

"error: invalid conversion from `void (*)(void*)' to `void*(*)(void*)' "

on the line "rc = pthread....".

This is the code (I changed it into a main() function to have it 
compilable).

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iostream>
#include <cstdlib>
#include <memory>
#include "MotorenAansturing.h"
#include "ftapi/ftapi.h"
#include <pthread.h>
#include <time.h>

using namespace std;
using namespace ftapi;

int motor1;
int snelheid1, snelheid2;
//char *snelheden[t];

string device("");
ft_if_conn connection = FT_IC_LIB_USB;
/* Set all interface outputs */
IfOutputs out;
/* Lezen van interface */
IfInputs in;


//Mastermodule mamo;

void MotorThread(void *threadid)
{
   cout << "Start MotorThread" << endl;
   int *id_ptr, task_id;
   time_t start;
   time_t current;
   id_ptr = (int *)threadid;
   task_id = *id_ptr;
   try
     {
       /* Open een verbinding naar de ft interface */
       auto_ptr<FtInterface> fti
	(ftGetIfFromFactory(device,
			    connection));
       FtMotorSpeed mSpeed1(task_id);
       FtMotorSpeed mSpeed2(task_id);
       out.data[FT_MASTER] = 0xFF;
       out.setMotorSpeed(FT_MASTER, FT_M1, mSpeed1);
       out.setMotorSpeed(FT_MASTER, FT_M2, mSpeed2);
       while (difftime(current, start) < 3.0)
	{
	  time(&current);
	  fti->writeAndReadAllData(out, in);
	}
     }
   catch (exception &x)
     {
       cout << x.what() << endl;
     }
}

int main(int argc, char *argv[])
{
   pthread_t threads[1];
   int rc, t;
   int *task_ids[1];
   t = 0;
   int motor1 = 1;
   int snelheid = 1;
   if (motor1 == -1 && snelheid == 1)
     {
       snelheid1 = -4;
     }
   else if (motor1 == 0 && snelheid == 1)
     {
       snelheid1 = 0;
     }
   else if (motor1 == 1 && snelheid == 1)
     {
       snelheid1 = 4;
     }
   rc = pthread_create(&threads[t], NULL, MotorThread,
		      (void *)task_ids[t]);
   pthread_exit(NULL);
   return EXIT_SUCCESS;
}

Thank you for helping.

Huub

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