Using QUdpSocket within a QThread

[db]

Hopefully someone can help with this problem. I have created a QThread to work in conjunction with a GUI app. When runing the executable everything works great. However, after shutting down the application and trying to restart it within 5 seconds or so I get the following error:

GThread-ERROR **: GThread system may only be initialized once.
aborting...
Segmentation fault

I thought from the way may code was written that everything (includeing the thread) are terminated, but it appears that the thread is still running. How do I get it to stop completely. Using RedHat EL 4


Thanks for the help.

Here is my code:

//  Main -----------------------------------------------------------------
 
int main(int argc, char *argv[])
{
   // creates class that contains packets and methods
   CHostIFTools * hostifTools = new CHostIFTools();
 
   // create threads to handle UDP recieves and tranmits
   CHostIF hostifReceive( hostifTools );
 
   // start independant threads
   hostifReceive.start();
 
   // create application class
   QApplication app(argc,argv);
   CHostIF * hostif = new CHostIF( 0, hostifTools );
 
   // display main widget
   hostif->show();
 
   // run application
   app.exec();
 
   // stop independant threads
   hostifReceive.quit();
 
   // wait for thread to finish
   hostifReceive.wait();
 
   // delay to ensure that threads are really terminated
   printf("Waiting for thread to shutdown");
   fflush(stdout);
 
   for (int sleepIdx=0; sleepIdx<5; sleepIdx++)
   {
      printf("..");
      fflush(stdout);
      sleep (1);
   }
   printf("done!!\n");
   fflush(stdout);
 
   // need to remove the tools class
   delete hostifTools;
 
   return 0;
}
 
 
//  Class definition ----------------------------------------------------------------------
 
class CHostIFReceive : public QThread
{
   public:
 
      // CHostIFReceive : class initialization method
      CHostIFReceive( CHostIFTools * tools=0 );
 
      // ~CHostIFReceive : class destrcutor method
      ~CHostIFReceive();
 
      // run : local implementation of the QThread run method
      void run();
 
      // stop : used to set the stop variable
      void quit();
 
   protected:
 
      // defines the tools class that is to be used
      CHostIFTools * hostifTools;
 
      // provides clean approch to terminting the thread
      volatile bool stopThreads;
};
 
//  Class code ----------------------------------------------------------------------------
 
CHostIFReceive::CHostIFReceive(CHostIFTools * tools)
   : QThread()
{
   // instantiate configuration tools class
   hostifTools = tools;
 
   // indicate thread is in a running state
   stopThreads = false;
}
 
void CHostIFReceive::run()
{
   // as long as thread has not been terminated
   while ( ! stopThreads )
   {
      // update the system value
      hostifTools->updateSystemInformation1();
 
      // wait for a little while
      sleep( 1 );
 
   }
}
 
void CHostIFReceive::quit()
{
   stopThreads = true;
   QThread::quit();
}

//  Main -----------------------------------------------------------------

int main(int argc, char *argv[])
{
   // creates class that contains packets and methods
   CHostIFTools * hostifTools = new CHostIFTools();

   // create threads to handle UDP recieves and tranmits
   CHostIF hostifReceive( hostifTools );

   // start independant threads
   hostifReceive.start();
   
   // create application class
   QApplication app(argc,argv);
   CHostIF * hostif = new CHostIF( 0, hostifTools );

   // display main widget
   hostif->show();
   
   // run application
   app.exec();

   // stop independant threads
   hostifReceive.quit();

   // wait for thread to finish
   hostifReceive.wait();

   // delay to ensure that threads are really terminated
   printf("Waiting for thread to shutdown");
   fflush(stdout);
   
   for (int sleepIdx=0; sleepIdx<5; sleepIdx++)
   {
      printf("..");
      fflush(stdout);
      sleep (1);
   }
   printf("done!!\n");
   fflush(stdout);
   
   // need to remove the tools class
   delete hostifTools;

   return 0;
}


//  Class definition ----------------------------------------------------------------------

class CHostIFReceive : public QThread
{
   public:

      // CHostIFReceive : class initialization method
      CHostIFReceive( CHostIFTools * tools=0 );

      // ~CHostIFReceive : class destrcutor method
      ~CHostIFReceive();

      // run : local implementation of the QThread run method
      void run();

      // stop : used to set the stop variable
      void quit();
      
   protected:

      // defines the tools class that is to be used
      CHostIFTools * hostifTools;

      // provides clean approch to terminting the thread
      volatile bool stopThreads;
};

//  Class code ----------------------------------------------------------------------------

CHostIFReceive::CHostIFReceive(CHostIFTools * tools)
   : QThread()
{
   // instantiate configuration tools class
   hostifTools = tools;

   // indicate thread is in a running state
   stopThreads = false;
}

void CHostIFReceive::run()
{
   // as long as thread has not been terminated
   while ( ! stopThreads )
   {
      // update the system value
      hostifTools->updateSystemInformation1();

      // wait for a little while
      sleep( 1 );

   }
}

void CHostIFReceive::quit()
{
   stopThreads = true;
   QThread::quit();
}

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