| Re: [AD] rest and yield_timeslice |
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Elias Pschernig wrote:
That's supposed to say *isn't* fully dependable, btw. In either case,
nanosleep seems to be the proper way to sleep in Unix. Allegro uses
enough "standard hacks" IMO, and I think it would be nice to use a
proper implementation where we can.
Nah, it sounds somehow like it does too much. Remember, we primarily
want to give up CPU with rest, and the nanosleep docs talk a lot about
real time mode and busy waiting.. all sounding like it does something
too much. "usleep" would be just what we want, but since it's not posix,
select is perfect.
From what I remember hearing, select waits for a file descriptor to
become available.. and by using select like we do causes it to wait for
stdin (or maybe stdout? I don't remember what was said). Small waits are
fine, but when you go for longer waits it'll be interrupted but
stdout/stdin events.
That's how I interpreted what I heard, anyway. If that turns out to not
be the case, then I suppose it won't matter too terribly. I just think
nanosleep would be a cleaner solution.
Well, to me, the highest priority is the cleaner and more logical API.
And I still don't see the problem with changing rest.. there's hardly
any code who would use negative numbers for rest, especially since the
docs don't even allow that. rest() might as well be freezing up with
them right now, or going back to the past, which would be the logical
thing to do with negative numbers probably :)
Heh, that's true. I'm just trying to minimize potential problems though.
I don't see a need for rest times in the billions, and negative numbers
can be delt with easilly enough.
Besides, it'd break the declaration: rest(long time) :P
Though we seem to have drifted away from how rest(0) should behave. ;)
As I mentioned, I think the behavior of rest is primarilly to pause
until the next function call, with a secondary concern being lowering
CPU usage. If you don't believe this is the case, then I would propse
that a function be made that would do high precision busy-looping. I
could create the function itself easilly enough if there was a
high-presicion timer in Allegro. And I could do that as well, but only
for Windows, Unix, and maybe DOS.
Actually, yeah.. this seems to be the perfect opportunity to start
prefixing. What you could do is rename rest to al_rest that takes an
unsigned int parameter. Have an inline rest(long) that calls al_rest for
compatibility (and I would also suggest this inline call filters out
negative times to be 0). Although I'm not completely convinced that
rest(0) shouldn't return immediately, I will concede that a function
named rest is better suited to resting the process as opposed to
something named al_wait which would do busy-looping.
- Kitty Cat