[maemo-developers] [maemo-developers] Re: Troubleshooting .desktop and .service file

[From: Eero Tamminen]

Hi,

ext Danny Milosavljevic wrote:
>> (One of the benefits of D-BUS is that other programs don't
>> need to know whether your app is running, they can just
>> send messages to it with D-BUS auto-invocation flag and
>> D-BUS takes care that only one instance of your application
>> is running.)
> 
> If you call that an "advantage"... It usually breaks one of the oldest and
> best UNIX conventions: that the process blocks the caller until the task
> is done.

I think you are a bit confused.  Nobody's removed good ol' exec
from the libc, so nothing's "broken".  :-)

Whether the D-BUS call is asynchronous or synchronous is controlled
with a flag used when sending the message.  (in CORBA everything
is by default synchronous because it's used mainly for "remote
procedure calls" whereas D-BUS is used more for delivering events
and events are usually async)

You know on desktop when you want to have another browser window,
you run Firefox which checks whether there's already a Firefox
running and then sends a message to that so that it opens another
window.  Sure, it already saves some time, but more is saved if
you don't need to start Firefox (or any other app) in the first
place, just send the message to the already running process
and D-BUS is the one checking whether something already runs...


	- Eero