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Re: A GC proposal

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jacobnavia <jacob@jacob.remcomp.fr> writes:

> Le 05/08/2016 à 22:50, Ben Bacarisse a écrit :
>> how do you determine what pointers need to be followed?  Obviously the
>> content of u, but then what?
>
> This is equivalent to figuring out embedded pointers in a data structure.
>
> The compiler leaves to the gc information about which pointers are at
> which offsets in the types of us1s2. The first points  to an s1
> structure that has a pointer to be followed at offset zero. The second
> points to a structure s2 with pointers to be followed at offset 8 and
> 16.

I know how that part works -- the point of the example was that run-time
information must be maintained needed for unions.  Languages that do
this "GC assist" usually have discriminated unions, but that's hard to
do in C (not impossible, I'm sure, but I can't see how right now).

You seem to be hoping for a method that avoids tracking any changing
type information at run-time, but I don't think that's possible without
crippling the language.

<snip>
> That eliminates false positives. It leaves the question of infinite
> loops in circular structures.

What collection algorithm are you thinking of using?  Handling circular
references comes for free in many GC algorithms.

<snip>
-- 
Ben.

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A GC proposal jacobnavia <jacob@jacob.remcomp.fr> - 2016-08-05 10:34 +0200
  Re: A GC proposal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-05 09:59 +0100
    Re: A GC proposal jacobnavia <jacob@jacob.remcomp.fr> - 2016-08-05 11:29 +0200
      Re: A GC proposal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-05 15:48 +0100
  Re: A GC proposal luser droog <luser.droog@gmail.com> - 2016-08-05 12:18 -0700
    Re: A GC proposal supercat@casperkitty.com - 2016-08-05 12:32 -0700
      Re: A GC proposal jacobnavia <jacob@jacob.remcomp.fr> - 2016-08-05 22:07 +0200
        Re: A GC proposal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-05 21:50 +0100
          Re: A GC proposal supercat@casperkitty.com - 2016-08-05 14:32 -0700
          Re: A GC proposal jacobnavia <jacob@jacob.remcomp.fr> - 2016-08-06 00:05 +0200
            Re: A GC proposal Melzzzzz <mel@zzzzz.com> - 2016-08-06 00:28 +0200
            Re: A GC proposal Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-08-06 01:47 +0100

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