From: Dmitry Antipov <dmantipov@yandex.ru>
To: Michael Welsh Duggan <md5i@md5i.com>
Cc: Emacs development discussions <emacs-devel@gnu.org>
Subject: Re: Pseudovectors initialization
Date: Tue, 26 Jun 2012 17:07:36 +0400 [thread overview]
Message-ID: <4FE9B418.4000709@yandex.ru> (raw)
In-Reply-To: <87wr2utfpl.fsf@maru.md5i.com>
On 06/26/2012 04:33 PM, Michael Welsh Duggan wrote:
> Is it really safe to memset to zero that which should default to Qnil?
No, of course.
All pseudo-vector objects has tricky layout:
pseudo_vector {
vectorlike_header;
Lisp_Object A; |
... | area visible by GC
Lisp_Object Z; |
non_lisp_object a; |
... | area invisible for GC
non_lisp_object z; |
};
Everything from area visible by GC is initialized to Qnil by
allocate_pseudovector, and ALLOCATE_PSEUDOVECTOR knows how to
evaluate this area's size. This patch zeroes just the rest,
i.e. area invisible for GC.
Dmitry
next prev parent reply other threads:[~2012-06-26 13:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-26 7:26 Pseudovectors initialization Dmitry Antipov
2012-06-26 9:17 ` John Wiegley
2012-06-26 11:02 ` Dmitry Antipov
2012-06-26 12:33 ` Michael Welsh Duggan
2012-06-26 13:07 ` Dmitry Antipov [this message]
2012-06-26 13:15 ` Stefan Monnier
2012-06-26 13:52 ` Nix
2012-06-27 17:04 ` Dan Nicolaescu
2012-06-27 17:26 ` Dmitry Antipov
2012-06-27 21:22 ` Stefan Monnier
2012-06-27 21:31 ` Andreas Schwab
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