[comp.sys.atari.st.tech] How much stack space do system calls need

teexand@ioe.lon.ac.uk (Andrew Dawson) (10/31/90)

Is there a defined figure somewhere that specifies how much stack space is
needed for TOS/GEM calls? When writing TSRs and Desk Accessories I don't want to
waste more space than is really necessary. Obviously I need enough to
stack the call arguments plus the SR and return address, but how much more
is then required for the call itself - Rwabs() for instance, seems to need
quite a lot of space. Any ideas?


===============================================================================
Andrew Dawson, Computer Unit, Windeyer Building, University College & Middlesex
School of Medicine, Cleveland Street, London W1P 6DB, England.
JANET:    andrew@uk.ac.ucl.sm.uxm          EARN/BITNET: andrew@uxm.sm.ucl.ac.uk
INTERNET: andrew%uxm.sm.ucl.ac.uk@nsfnet-relay.ac.uk
UUCP:     ...!ukc!uxm.sm.ucl.ac.uk!andrew
===============================================================================

csbrod@medusa.informatik.uni-erlangen.de (Claus Brod ) (11/01/90)

teexand@ioe.lon.ac.uk (Andrew Dawson) writes:


>Is there a defined figure somewhere that specifies how much stack space is
>needed for TOS/GEM calls? When writing TSRs and Desk Accessories I don't want to
>waste more space than is really necessary. Obviously I need enough to
>stack the call arguments plus the SR and return address, but how much more

As far as I know, there is no defined upper limit for the stack space needed.
Note that there may be other TSRs installed and linked into several vectors.
When you call Rwabs() for some hard disk partition, for example, the hard
disk driver is invoked which might use lots of stack space.

----------------------------------------------------------------------
Claus Brod, Am Felsenkeller 2,			Things. Take. Time.
D-8772 Marktheidenfeld, West Germany		(Piet Hein)
csbrod@medusa.informatik.uni-erlangen.de
----------------------------------------------------------------------