Re: Upcoming 1.3.2 release

[Greg Harvey <Greg.Harvey@thezone.net>]

Mikael Djurfeldt <mdj@mdj-pc.nada.kth.se> writes:

> Greg Badros <gjb@cs.washington.edu> writes:
> 
> > That sounds great;  we exchanged email a while back about ability to
> > register a C function to be invoked at start and end of garbage
> > collection.  Might that make it into 1.3.2?  It's definitely nice to be
> > able to provide feedback to the user of an interactive application about 
> > when garbage collection is occurring.
> 
> The new hooks have both Scheme level and C level interfaces.
> 
> If we add before-gc-hook and after-gc-hook before 1.3.2 we could warn
> now about %gc-thunk disappearing in 1.3.4.
> 
> Jim?
> 
> BTW Has Greg Harvey included these hooks in his sources?

after-gc-hook, yes. before-gc-hook, at least as a proper hook, is not
a good idea, since there's no memory left to do anything (if you try
to run almost any scheme code, you'll get a nice little infinite loop
thing going... there are a few problems in the current gc itself where
stuff like scm_error is being called, which evidences the exact same
thing; I've removed those, to). What it needs is a way to register
well behaved c functions with the gc, which isn't difficult to write,
but I haven't gotten around to it yet.

-- 
Greg