* Re: [Emacs-diffs] master 9d8d065: Add support for finalizers
[not found] ` <E1YSZvy-0004vW-Tc@vcs.savannah.gnu.org>
@ 2015-03-03 17:03 ` Stefan Monnier
2015-03-03 17:08 ` Daniel Colascione
0 siblings, 1 reply; 4+ messages in thread
From: Stefan Monnier @ 2015-03-03 17:03 UTC (permalink / raw)
To: emacs-devel; +Cc: Daniel Colascione
Was this discussed on emacs-devel and I missed it?
Question: why use a doubly-linked list, unlike pretty much everything
else in our code base?
Stefan
> + DEFVAR_BOOL ("gc-precise-p", gc_precise_p,
This name is wrong. "-p" stands for "predicate" and a predicate is
a function that returns a boolean, whereas this is a variable/constant.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Emacs-diffs] master 9d8d065: Add support for finalizers
2015-03-03 17:03 ` [Emacs-diffs] master 9d8d065: Add support for finalizers Stefan Monnier
@ 2015-03-03 17:08 ` Daniel Colascione
2015-03-03 18:18 ` Stefan Monnier
0 siblings, 1 reply; 4+ messages in thread
From: Daniel Colascione @ 2015-03-03 17:08 UTC (permalink / raw)
To: Stefan Monnier, emacs-devel
[-- Attachment #1: Type: text/plain, Size: 761 bytes --]
On 03/03/2015 09:03 AM, Stefan Monnier wrote:
> Was this discussed on emacs-devel and I missed it?
No.
> Question: why use a doubly-linked list, unlike pretty much everything
> else in our code base?
We remove finalizers from the middle of the list in unchain_finalizer.
We could just rebuild the list as we scan it, but when we'd have to
touch every node. Or we could maintain auxiliary state, but then in
run_finalizers we'd have to scan the whole list instead of the part
we're running.
>> + DEFVAR_BOOL ("gc-precise-p", gc_precise_p,
>
> This name is wrong. "-p" stands for "predicate" and a predicate is
> a function that returns a boolean, whereas this is a variable/constant.
I've also seen it for boolean-valued variables.
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Emacs-diffs] master 9d8d065: Add support for finalizers
2015-03-03 17:08 ` Daniel Colascione
@ 2015-03-03 18:18 ` Stefan Monnier
2015-03-03 18:23 ` Daniel Colascione
0 siblings, 1 reply; 4+ messages in thread
From: Stefan Monnier @ 2015-03-03 18:18 UTC (permalink / raw)
To: Daniel Colascione; +Cc: emacs-devel
>> Question: why use a doubly-linked list, unlike pretty much everything
>> else in our code base?
> We remove finalizers from the middle of the list in unchain_finalizer.
> We could just rebuild the list as we scan it, but when we'd have to
> touch every node. Or we could maintain auxiliary state, but then in
> run_finalizers we'd have to scan the whole list instead of the part
> we're running.
You can remove them from the middle of the list with a singly-linked
list as well, by keeping a "double-indirection" pointer. That's what we
do for markers.
It's not ideal, but it's no worse than using doubly-linked lists.
>>> + DEFVAR_BOOL ("gc-precise-p", gc_precise_p,
>> This name is wrong. "-p" stands for "predicate" and a predicate is
>> a function that returns a boolean, whereas this is a variable/constant.
> I've also seen it for boolean-valued variables.
Oh, yes, you're not the only one introducing such horrors, but we should
still avoid making things worse in this respect.
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Emacs-diffs] master 9d8d065: Add support for finalizers
2015-03-03 18:18 ` Stefan Monnier
@ 2015-03-03 18:23 ` Daniel Colascione
0 siblings, 0 replies; 4+ messages in thread
From: Daniel Colascione @ 2015-03-03 18:23 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
[-- Attachment #1: Type: text/plain, Size: 1335 bytes --]
On 03/03/2015 10:18 AM, Stefan Monnier wrote:
>>> Question: why use a doubly-linked list, unlike pretty much everything
>>> else in our code base?
>> We remove finalizers from the middle of the list in unchain_finalizer.
>> We could just rebuild the list as we scan it, but when we'd have to
>> touch every node. Or we could maintain auxiliary state, but then in
>> run_finalizers we'd have to scan the whole list instead of the part
>> we're running.
>
> You can remove them from the middle of the list with a singly-linked
> list as well, by keeping a "double-indirection" pointer. That's what we
> do for markers.
> It's not ideal, but it's no worse than using doubly-linked lists.
Yes, of course. That's why I should wait a few seconds before sending
emails. :-) That scheme still complicates iteration, though. Besides:
it's a Lisp_Misc. We're not going to make it any smaller by leaving out
the extra links.
>>>> + DEFVAR_BOOL ("gc-precise-p", gc_precise_p,
>>> This name is wrong. "-p" stands for "predicate" and a predicate is
>>> a function that returns a boolean, whereas this is a variable/constant.
>> I've also seen it for boolean-valued variables.
>
> Oh, yes, you're not the only one introducing such horrors, but we should
> still avoid making things worse in this respect.
Fixed.
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-03-03 18:23 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20150302233934.18904.59563@vcs.savannah.gnu.org>
[not found] ` <E1YSZvy-0004vW-Tc@vcs.savannah.gnu.org>
2015-03-03 17:03 ` [Emacs-diffs] master 9d8d065: Add support for finalizers Stefan Monnier
2015-03-03 17:08 ` Daniel Colascione
2015-03-03 18:18 ` Stefan Monnier
2015-03-03 18:23 ` Daniel Colascione
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.