title: When are slots processed in Qt?
body: <p>I am developing a consequent program which is very sensitive to time (based on delayed video streams), and since I'm not sure about how the signals and slots are implemented within Qt, I don't know <strong>when</strong> they are executed. Are they really executed in real time like callbacks would do, or are they processed before the next iteration of some kind of main loop?</p>
  
  <p>My question would be about timers in particular: when a timer times out (which must be another thread), does it connect to the signal "instantaneously" (next instruction for example) nearly like an interrupt would do, or does it wait for the end of some loop?</p>
  
  <p>Thanks for your insight,</p>
  
  <p>Regards,
  Mister Mystère</p>