Low Processor Usage Timing Function

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?

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

Code:

---

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;
  ...
}

---

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?