From: Robert Pluim <rpluim@gmail.com>
To: Noam Postavsky <npostavs@gmail.com>
Cc: Emacs developers <emacs-devel@gnu.org>
Subject: Re: add-variable-watcher usage in lisp/frame.el
Date: Fri, 01 Jun 2018 12:31:22 +0200 [thread overview]
Message-ID: <87o9guu7b9.fsf@gmail.com> (raw)
In-Reply-To: <CAM-tV-_G=gRxft3=23u0jSwGQFBHh1TypL345viyYOMwT1Bu3g@mail.gmail.com> (Noam Postavsky's message of "Fri, 1 Jun 2018 05:55:46 -0400")
Noam Postavsky <npostavs@gmail.com> writes:
> On 1 June 2018 at 05:18, Robert Pluim <rpluim@gmail.com> wrote:
>> lisp/frame.el has:
>>
>> (mapc (lambda (var)
>> (add-variable-watcher var (symbol-function 'set-buffer-redisplay)))
>
>> Not using symbol-function makes this output (set-buffer-redisplay)
>> instead, which I think looks better, Iʼm wondering why symbol-function
>> was used?
>
> Passing a subr object tells the variable watcher mechanism to call the
> C function directly (without a possible GC call), which is closer to
> what happened in Emacs 25 (see diff of [1: d3faef9bae]). I don't know
> that it's really needed in this case though.
Thanks for the explanation. By all means lets avoid adding potential GC to code
thatʼs not expecting it.
Robert
prev parent reply other threads:[~2018-06-01 10:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-01 9:18 add-variable-watcher usage in lisp/frame.el Robert Pluim
2018-06-01 9:55 ` Noam Postavsky
2018-06-01 10:31 ` Robert Pluim [this message]
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