GNU bug report logs - #77924
31.0.50; [Feature branch] Change marker implementation

Previous Next

Full log

Message #212 received at 77924 <at> debbugs.gnu.org (full text, mbox):

From: Gerd Möllmann <gerd.moellmann <at> gmail.com>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: pipcet <at> protonmail.com, monnier <at> iro.umontreal.ca, 77924 <at> debbugs.gnu.org,
 stefankangas <at> gmail.com
Subject: Re: bug#77924: 31.0.50; [Feature branch] Change marker implementation
Date: Fri, 25 Apr 2025 09:51:05 +0200

Sent from my iPhone

> On 25. Apr 2025, at 09:45, Eli Zaretskii <eliz <at> gnu.org> wrote:
> 
> 
>> 
>> From: Gerd Möllmann <gerd.moellmann <at> gmail.com>
>> Date: Fri, 25 Apr 2025 09:20:55 +0200
>> Cc: pipcet <at> protonmail.com, monnier <at> iro.umontreal.ca, 77924 <at> debbugs.gnu.org,
>> stefankangas <at> gmail.com
>> 
>> 
>>>> On 25. Apr 2025, at 09:01, Eli Zaretskii <eliz <at> gnu.org> wrote:
>>> 
>>> 
>>>> 
>>>> From: Gerd Möllmann <gerd.moellmann <at> gmail.com>
>>>> Cc: Eli Zaretskii <eliz <at> gnu.org>,  monnier <at> iro.umontreal.ca,
>>>> 77924 <at> debbugs.gnu.org,  stefankangas <at> gmail.com
>>>> Date: Thu, 24 Apr 2025 21:53:05 +0200
>>>> 
>>>> Pip Cet <pipcet <at> protonmail.com> writes:
>>>> 
>>>>> I think what we should do is mimic FOR_EACH_TAIL, and use
>>>>> FOR_EACH_MARKER like this:
>>>>> 
>>>>> struct Lisp_Marker *m;
>>>>> FOR_EACH_MARKER (b, m)
>>>>> {
>>>>>   /* do something with m */
>>>>> }
>>>> 
>>>> We need an if somewhere for the MARKERP, don't we?
>>> 
>>> Why is that needed, btw?  Can't we change the representation and/or
>>> the functions involved to avoid the need for such a test?
>> 
>> When markers are freed their entry in the market vector no longer contains a marker reference.
> 
> I understand, but why does this need to be tested inside the loop?
> Can't the loop itself know how many markers are in the vector, and
> stop when they are exhausted?

You are thinking of compacting the vector when a marker is freed? Then we would lose the O(1) deletion. As it is the entry is simply pushed on a free list. 

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.