From: David Kastrup <dak@gnu.org>
To: emacs-devel@gnu.org
Subject: Re: t and nil in pure memory?
Date: Sun, 15 Nov 2009 21:25:12 +0100 [thread overview]
Message-ID: <87my2nsfh3.fsf@lola.goethe.zz> (raw)
In-Reply-To: jwvws1uh545.fsf-monnier+emacs@gnu.org
Stefan Monnier <monnier@iro.umontreal.ca> writes:
>>> Actually, it's even worse than that: (interned) symbols have a `next'
>>> field which points to the next symbol in the obarray (hash) bucket.
>>> So that's yet another reason why (pure)symbols can have pointers to non
>>> pure memory.
>> Can't the next pointers could be NULL.
>
> Of course: the last symbol in a bucket has a NULL there (as do
> non-interned symbols). Can't see why that would make a difference, tho.
>
>> Is the next pointer used for anything else other than GC?
>
> Yes, of course: it's used for the hash-lookup done in `intern' (and
> `intern-soft').
If one sorts the pure symbols to the end of the obarray bucket chain
before dumping, they can't possibly be followed by non-pure symbols in
their life time since intern adds to the front of a bucket chain.
--
David Kastrup
next prev parent reply other threads:[~2009-11-15 20:25 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-11 20:23 t and nil in pure memory? Dan Nicolaescu
2009-11-11 22:56 ` Stefan Monnier
2009-11-12 8:21 ` Tobias C. Rittweiler
2009-11-12 15:22 ` Stefan Monnier
2009-11-13 5:24 ` Dan Nicolaescu
2009-11-13 14:39 ` Stefan Monnier
2009-11-14 11:23 ` Richard Stallman
2009-11-15 20:25 ` David Kastrup [this message]
2009-11-16 1:26 ` Stefan Monnier
2009-11-16 8:24 ` David Kastrup
2009-11-17 7:57 ` Richard Stallman
2009-11-17 13:16 ` Stefan Monnier
2009-11-17 13:55 ` David Kastrup
2009-11-18 12:11 ` Richard Stallman
2009-11-18 15:52 ` Stefan Monnier
2009-11-18 17:53 ` Daniel Colascione
2009-11-18 18:19 ` Stefan Monnier
2009-11-19 16:23 ` Richard Stallman
2009-11-19 20:08 ` Stefan Monnier
2009-11-20 4:12 ` Richard Stallman
2009-11-20 5:47 ` Chong Yidong
2009-11-22 6:48 ` Sam Steingold
2009-11-22 8:14 ` David Kastrup
2009-11-19 21:05 ` Dan Nicolaescu
2009-11-15 21:08 ` Dan Nicolaescu
2009-11-16 1:34 ` Stefan Monnier
2009-11-18 18:53 ` Ken Raeburn
2009-11-18 19:03 ` Daniel Colascione
2009-11-18 19:18 ` Tom Tromey
2009-11-18 19:13 ` Tom Tromey
2009-11-23 3:05 ` Ken Raeburn
2009-11-23 5:31 ` Stephen J. Turnbull
2009-11-24 16:03 ` Ken Raeburn
2009-11-24 16:28 ` Stefan Monnier
2009-11-19 1:01 ` Stefan Monnier
2009-11-12 4:06 ` Eli Zaretskii
2009-11-13 4:55 ` Richard Stallman
2009-11-13 8:37 ` Eli Zaretskii
2009-11-14 11:23 ` Richard Stallman
2009-11-14 11:46 ` Eli Zaretskii
2009-11-15 22:38 ` Richard Stallman
2009-11-13 4:56 ` Richard Stallman
-- strict thread matches above, loose matches on Subject: below --
2009-11-20 7:28 A. Soare
2009-11-20 8:09 ` David Kastrup
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