Re: Gen GC?

[Michael Livshin <mlivshin at bigfoot dot com>]

Han-Wen Nienhuys <hanwen@cs.uu.nl> writes:

> mlivshin@bigfoot.com writes:
> 
> > can you check where (code-wise) does Guile touch a lot of pages?
> 
> I'll have to think about this; I'm not sure how I can trace this.

<code>

#include <libguile/gc.h>

static void *
greet_sweep (void *dummy1, void *dummy2, void *dummy3)
{
   fprintf(stderr, "entering sweep\n");
}

static void *
wave_sweep_goodbye (void *dummy1, void *dummy2, void *dummy3)
{
   fprintf(stderr, "leaving sweep\n");
}

scm_c_hook_add (&scm_before_mark_c_hook, greet_sweep, 0, 0);
scm_c_hook_add (&scm_before_sweep_c_hook, wave_sweep_goodbye, 0, 0);

</code>

you'll need a recent CVS Guile for this, I'm afraid.

> What exactly is lazy sweeping?

it's when the GC doesn't doesn't sweep all the heap at once at the end 
of the collection, but rather does it on demand.  this can help avoid
touching a lot of pages unnessesarily.

-- 
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Please update your programs.