On 01.02.2013, at 21:05, Stéphane Rollandin <lecteur at zogotounga.net> wrote:

> Hello,
> 
> Studying Scratch code I stumbled upon the fact that EventSensor primitives such as #primMousePt send a #wait2ms message before answering.
> 
> In Squeak 2.8 #primMousePt was indeed a primitive; it still is in the InputSensor implementation.
> 
> So my question is: what is the rationale for loosing 2 milliseconds everytime one asks for mouse position ?
> 
> 
> Stef

In MVC you often have a busy loop. The wait ensures that Squeak is not hogging the whole system in that case. 

- Bert -