Application Won't Quit/Process Can't be Killed

[IJ Reilly]

I just had a unique OSX experience (for me, at least). An application became unresponsive, so I tried to force-quit it from the Dock. It would not quit. Then I tried to tried it from the force-quit dialog. Nothing. Then I opened the Activity Monitor and tried to quit the process. Again, the application window sat open. Then I pulled out my last trick and attempted to kill the process in Terminal. To my amazement, it just sat there. I tried to shut down, but it timed-out. In the end, I had to shut the Mac down with the power button, the first time in years that I've had to do this. Otherwise, OSX (10.4.7) seemed to be working fine -- I was able to quit all my other running application in an orderly fashion before shutting down.

Has anyone else ever experienced this phenomenon? What's the problem, and what's the cure?

 

[Foxglove9]

Has anyone else ever experienced this phenomenon? What's the problem, and what's the cure?

That's happened to me this year as well. Actually 2 or 3 times, also running 10.4.7. Not sure why it happened either. But I put the blame on Safari because it's the only application that crashes on me practically every other day now.

 

[IJ Reilly]

That's happened to me this year as well. Actually 2 or 3 times, also running 10.4.7. Not sure why it happened either. But I put the blame on Safari because it's the only application that crashes on me practically every other day now.

Safari wasn't the culprit -- it was Delicious Library. But I think OSX is the real culprit somehow. Any process should be killable. This one became immortal for some reason.

 

[Queso]

Basic Kill sends a Termination (15) signal to the process. If it doesn't work try sending more powerful Kill signals, such as an Interrupt with

Kill -2 <pid>

and if that STILL doesn't work, go all out with the SIGKILL option

Kill -9 <pid>

Bear in mind that Kill -9 should only be used as a last resort as it stops the process there and then. Therefore on some programs you could end up with data corruption (not good).

If that still doesn't get it, the process could be a child where you have to kill the parent to get rid of it (don't you just love UNIX terminology? ).

 

[IJ Reilly]

Yup, Unix introduced the concept of fratricide to computer users.

Thanks for the advice. When I feel courageous enough I'll fire up Delicious Library again is see what happens. I didn't see any other stalled processes.

Still, the question remains: how can this happen?

 

[ferruccio]

Restarting OSX from terminal

I've had this happen to me a couple of times. Suddenly no app would quit and OS X refused to shut down or restart. I didn't want to just kill the power to it. Issuing the following command in a terminal window seemed to work:

$ sudo shutdown -r now

 

[old-wiz]

Safari wasn't the culprit -- it was Delicious Library. But I think OSX is the real culprit somehow. Any process should be killable. This one became immortal for some reason.

*NIX systems have a concept called a zombie process. A zombie is a process whose parent process has died and gone away. When you try to kill a process, the mechanism has to report back to the parent of the process that you want to kill. Since the parent is gone, the process can't be killed. I used to run into it when I was doing software dev on *NIX. Only way out was to reboot the machine.

**edit...I got confused..It's Orphans and Zombies. Anyway, *NIX does allow situations where tasks can't be removed without rebooting. (It's been 4 years since I had to cope with this).