On Friday, 9 May 2014 at 21:05:18 UTC, Wyatt wrote:
But conversely, Manu, something has been bothering me: aren't
you restricted from using most libraries anyway, even in C++?
"Decent" or "acceptable" performance isn't anywhere near
"maximum", so shouldn't any library code that allocates in any
language be equally suspect? So from that standpoint, isn't
any library you use in any language going to _also_ be tuned
for performance in the hot path? Maybe I'm barking up the
wrong tree, but I don't recall seeing this point addressed.
More generally, I feel like we're collectively missing some
important context: What are you _doing_ in your 16.6ms
timeslice? I know _I'd_ appreciate a real example of what
you're dealing with without any hyperbole. What actually
_must_ be done in that timeframe? Why must collection run
inside that window? What must be collected when it runs in
that situation? (Serious questions.)
I'll try to guess: if you want something running at 60 Frames per
Second, 16.6ms is the time
you have to do everything between frames. This means that in that
timeframe
you have to:
-update your game state.
-possibly process all network I/O.
-prepare the rendering pipeline for the next frame.
Updating the game state can imply make computations on lots of
stuff: physics, animations, creation and deletion of entities and
particles, AI logic... pick your poison. At every frame you will
have an handful of objects being destroyed and a few resources
that might go forgotten. One frame would probably only need very
little objects collected. But given some times the amount of junk
can grow out of control easily. Your code will end up stuttering
at some point (because of random collections at random times),
and this can be really bad.
