Re: [exprimental patch] wakeup instead of polling for dns

Hi Jorge,

On Fri, Feb 10, 2012 at 01:40:10PM -0300, Jorge Arellano Cid wrote:
> Hi Johannes,
> 
> On Mon, Feb 06, 2012 at 09:45:44PM +0100, Johannes Hofmann wrote:
> > Hi,
> > 
> > attached experimental patch replaces the polling for DNS answers
> > with the wakeup mechanism fltk provides.
> > What do you think?
> 
>   Well dns resolving is delicate, but not sacred ;)
> 
>   AFAIS  the main advantage would be a near 0.1 second speedup on
> average  when  displaying  non dns-cached pages, (0.2 best case).
> Which is significative.
> 
>   Please let me know if there's another advantage I miss.

Well, I don't like the polling :-)
There might be an increased power consumption related to the
5 times/s timer, but I'm not sure whether it really matters.

> 
>   The  cost  is using an FLTK mechanism (awake) which we don't in
> the rest of the code.

Yes, plus we need to switch on locking for all fltk just for the dns
thing. That's the major drawback I think.

> 
>   It looks clean. It should be tested on different platforms/OS.
> 
>   BTW,  dns.c has code for a blocking server (not threaded). Does
> this  awake() call work OK when called from the same main thread?
> Is  this by design or by chance? Maybe it would be safer to avoid
> calling awake() in this case.

I didn't test it yet. I still want to try other approaches that
would avoid switching on the fltk threading stuff with the
Fl::lock() call.

Cheers,
Johannes