Do COMMON SHARED variables take up stack space?

sandmann999 · Sep 5, 2007

Hey everyone, I'm running into the OUT OF STACK SPACE error. I know what the error means and what the stack is, but I'm curious what I can do to clean up some space without using CLEAR (which is not an option by any means). I have a LOT of COMMON SHARED variables that pass between several modules in my game, such as MAIN.BAS, STATUS.BAS, FIGHT.BAS, etc... Do these COMMON SHARED variables take up stack space for every sub I go into?

Freestone · Sep 5, 2007

The memory diagrams show COMMON existing in DGROUP, outside of the stack:

http://support.microsoft.com/kb/45850

And the statement "To work around this problem, dimension the TYPEd array with DIM SHARED or put it in a COMMON SHARED statement" from the following KB implies that COMMON SHARED does not use the stack:

http://support.microsoft.com/kb/57711

QBasicMac · Sep 28, 2007

I see you have not responded yet. Maybe you want a simpler answer.

COMMON SHARED variables take up space before every other SUB or FUNCTION.

If you do
COMMON SHARED x(1000) as string
or just
DIM SHARED x(1000) as string
then the amount of storage needed to support that array will be unavailable to all SUB's and FUNCTION's or even MAIN even if the array is never used.

Does that answer your question?

Mac

sandmann999 · Oct 9, 2007

Thanks for the responses. Both explained a lot as to how stack space works. It turns out that my error was caused by small bug that I fixed that caused a recursion, but now I have a temporary code that pops up how much memory I have left (numeric, string, and stack) as the program's running and that helps a lot.

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Do COMMON SHARED variables take up stack space?

sandmann999

Programmer

Freestone

MIS

QBasicMac

Programmer

sandmann999

Programmer

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