Re: tecomp 0.6 released

On Dec 7, 4:51 pm, Andrew Reilly <andrew-newsp...@xxxxxxxxxxxx
users.org> wrote:
On Sun, 07 Dec 2008 09:02:12 -0800, Helmut wrote:
If you want garbage collection, you get some overhead for it (but it is
a rather small offset, nothing that grows with the code).

Some compilers/runtimes generate helper functions that know where the
pointers are, both in object records *and* in stack frames. This allows
exact, rather than conservative collection, I believe. This probably
introduces a code-proportional overhead. Of course this can probably be
data driven too: classic performance/size trade-off.

Cheers,

--
Andrew

Hello Andrew,

from my point of view you don't need code proportional information if
you want to do "exact" garbage collection. The only thing you need is
layout information about the objects (i.e. is an attribute of an
object an expanded type object or a pointer?). Conservative collection
does not need that information. It looks at each word on the stack as
a potential pointer to an object. Therefore it is possible to mark
objects as "referenced" because of an integer on the stack that by
coincidence interpreted as a pointer "points" to a dead object.

Regards
Helmut
.

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