[launchd-dev] Questions on mixed triggers and calendar triggers

[Iceberg-Dev]

I've read some WWDC sessions slides, the launchd.plist man page and  
I've already made some launchd plists but I'm wondering about the  
following points:

- is it possible to define different types of trigger for a launchd  
daemon or agents?

For instance, is it possible to launch a daemon both on schedule with  
StartCalendarInterval and a mach message? The idea being the process  
would be run at a specific time of the day but could also be launched  
"manually".

- is there a way to change the StartCalendarInterval values of a  
daemon launchd plist (while the launchd daemon is running) with some  
kind of launchd APIs instead of Foundation/CoreFoundation APIs? If  
you change these values, do you need to unload and then reload the  
plist (I would tend to believe so which would be an issue)?

- is it possible tell launchd to re-launch a schedule daemon if the  
daemon crashes and not only when the next trigger date is reached?