[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kfm-devel
Subject:    Re: some thoughts on libkio
From:       Stephan Kulow <coolo () kde ! org>
Date:       1999-12-07 12:41:30
[Download RAW message or body]

Waldo Bastian wrote:
> 
> On Mon, 06 Dec 1999, Stephan Kulow wrote:
> > Simon Hausmann wrote:
> > >
> > > That means we will depend on a running server process in order to have a
> > > working kiojob? (like with kfm)
> >
> > No, the master slave should be restartable without notice. What I have
> > in
> > mind is:
> > app asks dcopserver
> > dcopserver asks kioslave (that's the slave without protocol specific
> > knowledge)
> > (kioslave may be started when not present)
> > kioslave forks, the new process dlopens kio_file.la if it's the first
> >   time invoked and waits for input by it's parent process
> > the kioslave sends back a ticket to the app
> > the app opens a socket (,crunches the address of it with the ticket) and
> > sends
> >   back to kioslave the address
> > kioslave pipes to the process and this one contacts the application.
> >
> > The application (in form of libkio) can get only one slave per protocol
> > and can ask this one to fork itself for further requests. There the
> > managing qualities of libkio come to work :)
> >
> > I'm not sure if this is the best solution, but this is what I found when
> > I thought about the problem :)
> 
> I would let the master slave do all the dlopening and forking.
> E.g:
> 1) Request comes in via DCOP
> 2) dlopen library if not already done
> 3) create communication socket
> 4) fork, child uses the communication socket from step 3)
> 5) reply to application via DCOP  to use the communication socket from
> step 3
It basicly doesn't matter for the API and is only an internal to the
io_daemon where the socket comes from. But in terms of responsobility
and cleaness I believe that it's better to have only one protocol in
one process.

> 
> The master slave would also be responsible for detecting the death of
> childs and closing libraries when no longer in use.
That's the point - libraries are exactly bound to the lifetime of it's
protocol daemons :)
> 
> I am not yet convinced that the savings are worth the trouble though.
> Typically we have about 5 slaves around. It would mean that the startup
> of 4 of those 5 would be somewhat faster and that we may win 4 x 400Kb
> = 1.6Mb of memory.
> 
Well, as each app will start a slave when the file dialog uses libkio
for
everything, it's basicly a bad idea not to share them.

Greetings, Stephan

-- 
As long as Linux remains a religion of freeware fanatics,
Microsoft have nothing to worry about.  
                       By Michael Surkan, PC Week Online

[prev in list] [next in list] [prev in thread] [next in thread]