2011-07-30

protecting the stack limits

7.22: adda/protecting the stack limits:

. how can one test for stack limits per platform?
if you test it once per platform
could the limit become smaller later?
it could depend on number of processes,
and current ram count ?
the user or an error could downgrade ram .
some help from addm:
. one thing that helps the stack problem
is assuming that user programs are addm code
rather than native code;
addm uses the c stack in a very limited way
and puts the user's stack entirely in the heap;
the user does call standard libraries
that in turn are native code;
but these can be designed to conserve stack space
(eg,
all recursive routines are finding some way to
serialize the large jobs;
eg, instead of giving gig's to quicksort,
the sorter breaks the job into mbyte sections,
and gives the quicksort's sections to mergesort ).
...
but can't the user can program natively? yes:
(see adda/natively coded extensions)
the user isn't restricted to addm,
so adda must be aware of some stack limits
and provide protections against overflow .