[Bf-committers] memory allocation and crashes

[Joe Eagar]

Tom M wrote:
> Would it be possible to change trying to allocate too much memory to
> keep it from crashing?
>
> If you are sculpting at a high level - pressing tabkey by accident can
> crash you since editmode uses more ram than sculpt mode.  Or if you
> accidentally add a level when you meant to change back to a higher
> level you had already created.
>
> Both of those have happened to me more than once alas, and I know
> other users have had similar occurences.
>
> LetterRip
Shouldn't be hard, just a matter of checking for NULL on entering 
editmode, then exiting if memory can't be allocated and throwing an 
error.  Or perhaps editmode could allocate in fixed-size blocks of 
memory.  Is this important for release do you think? Could be kindof 
iffy figuring out the best way to deal with it.

One thing that might be good would be to write a SIGSEGV handler that 
saves the undo buffer on crashes.   I think you'd have to write a 
special function in guardedalloc where it  would use a special 
pre-allocated "crash-safe" pool of memory if malloc returned NULL.  Then 
all the file writing code would use this for allocation.

Joe