Re: Making Event work for Win32

Graham Barr <[email protected]> writes:
>
>Ak, Event does rely on there being one place where all events can be waited upon,
>with the exception of signals as the will cause the poll to return anyway.

Tcl (and hence perl/Tk as I steal it) does this by messing with the "timeout" value to 
select/poll/WaitForMultipleObjects while polling the non-selectable
event types - that is:

sub get_events
{
  $timeout = 10mS; # say 
  foreach $source (@awkward_sources)
  {
   $timeout = 0 if ($source->queue_events);  # 
  } 
  select_or_poll_etc(@other_sources,$timeout);
  foreach $source (@other_sources)
   {
    $source->queue_events;
   } 
}

sub do_one_event
{
 my $wait = shift;
 while (1)
  {
   if (@queue)
    {
     my $event = shift(@queue);
     $event->process;
     return 1;
    }
   get_events();
   last unless $wait;
  }
 return 0;
}

The n-stage process makes it necessary to have a queue of 
events or you need to re-enter the "get_events" thing 
at the appropriate point - skipping the ones which have 
had their turn - to be "fair".

-- 
Nick Ing-Simmons <[email protected]>
Via, but not speaking for: Texas Instruments Ltd.