dbus_message_new_signal parameter description

Bogdan Lotko boguslaw.lotko at chello.at
Mon Jan 2 09:08:13 PST 2012


Thanks for the answer,

Please see my comment below

On 1/2/2012 17:15, Mike Gorse wrote:
> Signals are broadcasts and don't specify a destination--when you send 
> a signal, you aren't concerned with the foreign objects that are 
> listening for it. 
Yes, I know this. Exactly this is the reason why I think that the signal 
is emitted  "for"  foreign (listening) objects that expose according 
interface and not "from" an interface.
As I already wrote, my object that emits (broadcasts) signals also 
exposes its own interface (nothing to do with signals sent), so the 
phrase  "the interface the signal is emitted from" is somehow misleading 
for me.
Anyway it is only a formulation (and may be my English knowledge). :)

> The signal will be routed to all connections that have a match rule 
> which covers the signal.
>
> So I'd recommend using the interface that you're generally using for 
> the object emitting the signal, if you think that makes sense, and 
> setting up a match rule for it on the connection that needs to receive 
> it. Your other option is to use a method call instead (and it's 
> possible to designate a method call as not needing a reply).
>
> Hth,
> -Mike G-
>
> On Mon, 2 Jan 2012, Bogdan Lotko wrote:
>
>> Hello,
>>
>> in the interface parameter description of the 
>> dbus_message_new_signal() method
>> one can read: "the interface the signal is emitted from"
>>
>> How is it to understand?  I thought the signal will be emitted to 
>> (for) a foreign object with a given interface interface.
>> e.g. in my case the object emitting a signal puplished its own 
>> interface, but it is not the interface where the signal shall be send 
>> to.
>>
>> Thanks for your help
>>
>> Bogdan
>>
>>



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