Re: Graceful termination again

[Richard Frith-Macdonald]

On 23 Jan 2006, at 08:50, Roman Belenov wrote:

> I hacked a bit trying to implement logoff with graceful application
> termination on GNUstep and got some questions:
>
> 1) How to get a list of all running GNUstep applications ?
> launchedApplications seems to return only the list of apps launched  
> from the
> current one. For now I just use a list of message ports obtained by  
> examining
> corresponding subdirectory and treat everythying as a proxy for  
> application.

Well, the way workspace operations generally *should* work as I  
understand it, is that they should contact the workspace manager  
application and ask it to do the job for them.  There is partial  
support for this in the NSWorkspace class, but it has never been  
completed.  Basically, the idea is that the local NSWorkspace  
instance should first try to ask the workspace manager application to  
do jobs, and if no application is found, it should do the best it  
can.  In the case of launched tasks, this means that every  
application keeps track of any tasks it sees being launched, but  
since there is no workspace application launching all tasks, there is  
no central repository of all the information.
So, what you should ideally be doing is fixing that ...
Problem is that it was never completed because to make it useful  
there needs to be a workspace manager application and when I wrote it  
no such application existed.  Then later  Enrico wrote GWorkspace  
without much attention to integration with the NSWorkspace class, and  
we never got together to make it all work.

> 2) What is the correct way to check the result of sending terminate to
> application (from another one) ? Experiments show that if  
> application actually
> terminates, I get an exception caused by connection timeout.

Yes .. you expect the connection to go away when the app terminates.   
I don't think there is any realistic way you can be absolutely sure  
an app has completely gone away (though you could try registering a  
port using the name of the task ... if it works then the app has  
gone ... if it fails either the app is still running or another app  
with the same name has started).  It's probably best to just assume  
that loss of the connection to the app means that it has died.
Of course, in the case of the workspace manager application (which  
should generally have launched the app and be responsible for  
shutting it down too), you have an NSTask object corresponding to the  
launched application, so you can check the NSTask instance to see if  
the application is still running after it has been told to terminate.