ANN: Stackless Python 0.2
tim_one at email.msn.com
Tue Jun 29 09:15:15 CEST 1999
[Tim sez Python stores space for each code object's "Python stack" in a
runtime frame object]
[Toby J Sargeant]
> This might be completely irrelevant, but during the course of my
> masters, I considered doing this kind of thing to java in order to
> allow asynchronous threads to share stack frames (don't ask...).
Don't tell <wink>.
> My supervisor complained bitterly on the grounds that function
> invocations where orders of magnitude more common than object creation,
> and hence associating memory allocation/deallocation with every call was
> considered horrendously inefficient.
> It seems that this should affect Stackless Python equally as
No more so than Stackful Python: Python has always worked this way;
Stackless Python doesn't change this aspect.
> Does anyone have anything to add on the subject? I would imagine that
> frames could be allocated and managed in chunks to alleviate a lot of
> the memory management load...
The code is in Objects/frameobject.c, and easy to follow. frameobjects are
recycled via their own free list. Typically the total number of
frame-associated mallocs is proportional to the maximum depth of the call
stack, not to the number of calls made.
Setting up a Python frame remains expensive, but for other reasons.
115-lines-of-code-doesn't-run-in-one-cycle-malloc-or-not<wink>-ly y'rs -
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