[Python-Dev] Looking for master thesis ideas involving Python
cpr at emsoftware.com
Mon Nov 3 09:44:27 EST 2003
Michael Hudson wrote:
> Remove the ob_type field from all PyObjects. Make pymalloc mandatory,
> make it use type specific pools and store a pointer to the type object
> at the start of each pool.
> So instead of
> I think having each type in its own pools would also let you lose the
> gc_next & gc_prev fields.
> Combined with a non-refcount GC, you could hammer sizeof(PyIntObject)
> down to sizeof(long)!
Yes, this is a variant of an implementation technique used in early
Lisp and Lisp-like language systems with types (e.g., Harvard's EL-1)
back in the early 70's (at least--that's when I first encountered it).
In those systems, you'd use the "page #" (higher-order bits) of a
pointer to reference a type table.
Good idea, but perhaps less effective these days where memory isn't
quite so dear. (Back then, a large system was a PDP-10 with 256K 36-bit
words, or around 1MB.)
--Chris Ryland / Em Software, Inc. / www.emsoftware.com
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