Qtopia-interest Archive, March 2007
[MOQP] polling for files
Message 1 in thread
Hello,
I wonder why you still poll for files. In QtopiaCore4.2 you have this
rather nice class called QFileSystemWatcher, why don't you use this
Core functionality?
The files in question are
Settings/Trolltech/qpe.conf
Settings/Trolltech.conf
etc/default/Trolltech/qpe.conf
etc/default/Trolltech.conf
/var/run/stab
/var/state/pcmcia/stab
/var/lib/pcmcia/stab
/proc/mounts (well this doesn't work with inotify but use udev?)
$HOME
As outlined by Robert Love in his project Utopia, polling is evil,
specially on battery powered devices. Is there any reason you do not
use modern technology on a modern linux kernel?
kind regards
h.
PS: It is nice to see quicklauncher and qss don't have any timer
running and sleep nicely in select
PPS: Let us save battery power
--
[ signature omitted ]
Message 2 in thread
Holger Freyther wrote:
> Hello,
>
> I wonder why you still poll for files. In QtopiaCore4.2 you have this
> rather nice class called QFileSystemWatcher, why don't you use this
> Core functionality?
>
> The files in question are
> Settings/Trolltech/qpe.conf
> Settings/Trolltech.conf
> etc/default/Trolltech/qpe.conf
> etc/default/Trolltech.conf
> /var/run/stab
> /var/state/pcmcia/stab
> /var/lib/pcmcia/stab
> /proc/mounts (well this doesn't work with inotify but use udev?)
> $HOME
>
> As outlined by Robert Love in his project Utopia, polling is evil,
> specially on battery powered devices. Is there any reason you do not
> use modern technology on a modern linux kernel?
>
> kind regards
> h.
>
> PS: It is nice to see quicklauncher and qss don't have any timer
> running and sleep nicely in select
> PPS: Let us save battery power
>
>
>
> --
> To unsubscribe - send "unsubscribe" in the subject to
> qtopia-interest-request@xxxxxxxxxxxxx
>
>
Because this technology doesn't work unless you have a modern kernel ;)
we don't have inotify or dnotify on 2.4 kernels, and that's exactly
what's in the greenphone. There's ongoing work to make the polling more
phone friendly, but, there's not much else we can do unless there's a
way to get (working) notifications from the kernel on file change
(especially proc/mounts).
--
[ signature omitted ]
Message 3 in thread
Am 05.03.2007 um 22:49 schrieb Bill KING:
> Because this technology doesn't work unless you have a modern
> kernel ;)
> we don't have inotify or dnotify on 2.4 kernels, and that's exactly
> what's in the greenphone. There's ongoing work to make the polling
> more
> phone friendly, but, there's not much else we can do unless there's a
> way to get (working) notifications from the kernel on file change
> (especially proc/mounts).
Shouldn't the technology used (polling vs. inotify) be a secret of
the QFileSystemWatcher? So by using this class on ancient and
unmaintained kernels it could poll, on modern devices it could use
inotify automatically? And not to my suprise this is what
QFileSystemWatcher is doing. So there is no excuse in not using
QFileSystemWatcher :)
h.
Message 4 in thread
Holger Freyther wrote:
>
> Am 05.03.2007 um 22:49 schrieb Bill KING:
>
>> Because this technology doesn't work unless you have a modern kernel ;)
>> we don't have inotify or dnotify on 2.4 kernels, and that's exactly
>> what's in the greenphone. There's ongoing work to make the polling more
>> phone friendly, but, there's not much else we can do unless there's a
>> way to get (working) notifications from the kernel on file change
>> (especially proc/mounts).
>
> Shouldn't the technology used (polling vs. inotify) be a secret of
> the QFileSystemWatcher? So by using this class on ancient and
> unmaintained kernels it could poll, on modern devices it could use
> inotify automatically? And not to my suprise this is what
> QFileSystemWatcher is doing. So there is no excuse in not using
> QFileSystemWatcher :)
>
> h.
>
>
>
>
>
I kind of agree, but QFileSystemWatcher's very heavy for 2.4 kernels,
and by that's a huge chunk of the embedded world too. I'm not the one
working on this particular piece, but if I know the dev, he'll come up
with a solution that's rather swanky, and works rather well given the
rather poor choices for anything less than 2.6.13
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[ signature omitted ]
