Low Processor Usage Timing Function

[pianorain]

I'm trying to write a function that puts the amount of time in seconds the program has been running into a global variable. I've got one, but it eats CPU time like crazy.

int main()
{
   curTime = 0;
   DWORD nThreadID;
   CreateThread(0, 0, TimeHandler, NULL, 0, &nThreadID);
   return 0;
}

DWORD WINAPI TimeHandler(void* a)
{
   time_t firstTime;
   firstTime = time(NULL);
   for(;;)
   {
      curTime = time(NULL) - firstTime;
   }
}

curTime is a global variable.

There must be a better way to do this. Any suggestions on how to decrease the amount of CPU time this takes, or maybe a totally different approach all together?

[Sang-drax]

You could always write a function, or, if variable behavior is desired:

class curTimeclass
{
   public:
   operator time_t()
   {
     return time()-starttime;
   }
   curTimeclass(): starttime(time(0)) {}
  private:
   time_t starttime;
};

curTimeclass curTime;

int main()
{
  ...
  cout << "Program run-time:" << curTime << endl;
  ...
}

[pianorain]

Thanks for your responses. Let me re-word my problem and try again. I've programmed a good bit in both C++ and VB. Basically what I want to do is a whole lot like an event in VB. I want to run a function every two seconds. However, if I try to do it by setting up an infinite loop that checks to see if the time has passed, it eats CPU time like crazy. What's a better way to do this?