Discovering services

[Tako Schotanus]

Aristid Breitkreuz wrote:
>> But, activating everything possible seems pretty scary to begin with - 
>> you might be launching apps left and right in essence. Could be 
>> slooooooow and have bizarre user-visible effects such as windows opening.
>>     
>
> When a service is activated by D-BUS, there should be no side effects
> like windows opening EVER. Windows might be opened after say a call of a
> method or when a service-providing program is started by the user but
> not, no, never, if a service is activated by D-BUS.
>
> If activating a service is slow... well do it asynchronously. There is
> more than one service to Introspect usually and there is no good
> alternative to starting the service IMO. At least once, caching is of
> course an option.
>   
But you don't want that either! Imagine that in a future we'll have 
dozens and dozens of DBus services, heck KDE4 will make use of DBus so I 
imagine there will be quite a few, and a tool just wants to show you a 
list of available services and start activating ALL of them!

Some services might be light-weight, but others might need to do a lot 
of work before they are even usable. The service might start browsing 
the network in search for printers/resources/services or it might start 
accessing slow drives or it might activate your webcam, etc. And there 
might still be other user-visible side-effects besides windows opening, 
dunno, because of the service that activated the webcam your file 
manager decides to put an icon for it on the desktop, for example.

I don't know but automatically activating services seems like a bad 
idea, in the same way that it would be a bad idea to activate all init.d 
services just to get at some meta info.

-Tako