C Main Loop without 100% cpu

Question

#include 

int main() {
  while(!DONE) {
    /* check for stuff */
  }
  return 0;
}

The above code sample uses 100% cpu until DONE

Answer 1

What exactly are you checking for?

If you're checking something volatile that is changed by hardware or another process, just call sleep in your loop.

If you are waiting on a file descriptor or a network socket descriptor, you will want to use select or poll in your loop to wait for the descriptor to have data ready for consumption.