PropertiesChanged signal

[Lennart Poettering]

On Sat, 08.05.10 17:42, Rémi Denis-Courmont (remi at remlab.net) wrote:

> 
> Le samedi 8 mai 2010 17:08:53 Lennart Poettering, vous avez écrit :
> > On Sat, 08.05.10 17:06, Rémi Denis-Courmont (remi at remlab.net) wrote:
> > > Le samedi 8 mai 2010 16:19:48 Lennart Poettering, vous avez écrit :
> > > > My recommendation for this would be to do something that has recently
> > > > been done in libudev to minimize wakeups in the monitoring clients
> > > > there: pass along pre-calculated bloom filters with the packets and
> > > > use BSD socket filters to test them and supress unmatched packets.
> > > 
> > > If I'm not mistaken, udev uses Netlink sockets with datagram semantics. I
> > > wonder how BPF is supposed to work with stream socket semantics, that
> > > DBus currently uses.
> > 
> > Probably by going for SOCK_SEQPACKET then.
> 
> As far as I know, SOCK_SEQPACKET means any single DBus message must fit in the 
> kernel-space socket buffer. Currently that defaults to 128kb on Linux. Not 
> sure what limit distros configure the dbus-daemon with, but the protocol 
> allows for much much large packets.

D-Bus enforces a configurable maximum message size anyway. We should be
able to tune SO_SNDBUF/SO_RCVBUF to the same value.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
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