http://www.perlmonks.org?node_id=564969

LittleGreyCat has asked for the wisdom of the Perl Monks concerning the following question:

Esteemed Monks,

a trivial question where I am 90% sure of the answer, but think it may be too obvious to be 100% clearly documented.

I have been asked if the 'wait' in 'Win32::ChangeNotify' is a true wait - i.e. sits waiting to be woken on an event using minimal CPU - or is an idle loop which repeatedly checks for the condition and uses significantly more CPU.

The documentation says that '$obj->wait($timeout)' from 'Win32::IPC' is the underlying 'wait' and that it "Waits for $obj to be signalled".

From this seems 90% certain that the process is waiting on an interrupt (which is allegedly handled quite well in Windows) but does leave the slight possibility that there is something lower down in an idle loop.

Can anyone take my certainty to 99%?
(100% defies Heisenberg)

Thanks

Dave R