[launchd-dev] Enforce a maximum time that a launchd process can live...

[Michael Ledford]

Hello,

I have a process I would like to used launchd to control. Its job is  
very simple; look for messages that are waiting in a SQLite database  
and send them synchronously with NSMutableURLRequest via HTTP. The  
problem I face is occasionally on production machines I have found  
that the networking request becomes stalled for some reason which  
causes the process to simply sit waiting.

I was hoping that launchd would be able to enforce a maximum time that  
a process can live using the ExitTimeout key. The documentation isn't  
very clear to me on this point. At first I took it as this is the  
maximum length of time the process would live before launchd would  
send it a SIGKILL. However, it was pointed out to me by someone they  
believe it is the time between launchd sending a SIGTERM and SIGKILL.  
This would only occur if the launchd process was stopped or removed  
and doesn't exit within the specified ExitTimeout causing a SIGKILL to  
be sent.

In the ideal world people would say, "Your problem is a bug and it  
needs to be fixed." However, in the real world where frameworks are  
not under my control this isn't an option. In this case I want to work  
around the problem. I want to specify a maximum amount of time that a  
process can live and then have it terminated if it exceeds that time.

Can I accomplish a process living for a certain amount of time and  
then being asked to terminate via launchd? If not, what other options  
do I have?

Thanks,
Michael