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Re: [Emacs-diffs] master 8c909d7: * src/gfilenotify.c (Fgfile_add_watch)
From: |
Michael Albinus |
Subject: |
Re: [Emacs-diffs] master 8c909d7: * src/gfilenotify.c (Fgfile_add_watch): Decrease polling rate. |
Date: |
Thu, 24 Sep 2015 22:52:02 +0200 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) |
Stefan Monnier <address@hidden> writes:
>> * src/gfilenotify.c (Fgfile_add_watch): Decrease polling rate.
>
> Decreasing the rate means increasing the interval. From the "800 msec"
> comment I get the impression that the patch reduces the interval, and
> hence increases the rate.
>
> Which one is it? And why do we need/want to do that (i.e. could you
> add a comment pointing the to a discussion or something)?
It is the polling rate gio (glib) checks for changes of a file, once it
has been set up to be monitored, and there is no native library like
inotify or kqueue which send a changed event w/o need to poll. See
<https://developer.gnome.org/gio/stable/GFileMonitor.html#g-file-monitor-set-rate-limit>
I've changed this, because typically users of filemonitor.el use
(read-event nil nil 0.1) when they are waiting for a file notification event.
I don't believe it will be a performance issue, because most of the uses
Emacs is based on non-polling file notifications. Either inotify or
w32notify directly, of gfilenotify with built-in inotify or kqueue.
Maybe it's worth to make it configurable? Don't know.
> Stefan
Best regards, Michael.