RE: Functions and memory usage

[John Donovan <JohnD@...>]

Thanks everyone for your replies, it's very enlightening! One thing I forgot
to tell everyone is that I'm using dlmalloc, and after a bit of tweaking
works a treat. Strangely enough, before I implemented it, I used the
"native" malloc on this particular console, and the profile information
suggested it was the same algorithm.

> View memory as a stack, and forbid freeing anything until everything
> that was allocated after it has been freed.  You can be a bit more
> flexible than that - use a stack of states, and insist that each state
> frees all of the memory it allocated before it leaves.

That's the sort of approach my boss wants to take. I'm under the impression
that it's not going to be that simple. However, he wants this scripting
system to last for a good few games, so spending time now making it as
robust as possible is going to pay off. Any hints on how I might go about
this?

> I suppose you could force a collection on each state transition.  That
> might work.  You still need discipline, of course.  And a big stick. 

The thing is, I'd probably be the only person being beaten with that stick!
I have enough of that at the weekends (I'm a member of a Viking and
Anglo-Saxon reenactment group, nothing kinky)!

> Whichever language you use, patch its memory allocation 
> routines so you
> can produce a log of all allocation: where, how much, and who did it.
> We have an off-line graphical viewer that nicely shows where 
> fragmentation
> occurs, and who to blame.  It's much easier to do this in Lua than in
> C++.

That's pretty much what I'm doing at the moment. I'm just using .csv files
and Excel at the moment.

> You mean spend CPU time on something that's not directly related to
> the game?  Heresy! :-)

LOL! This is true. Especially as it may occur at any time during the game,
and take an indeterminate amount of time. Dropping frames at random
intervals is A Bad Thing on a console. Of course the graphics guys get all
the time they want, and the sound guys have a completely separate chip to
play around with *mumble mumble* :)

John Donovan
Programmer - Magenta Software Ltd.


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