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Laurence · Feb 18, 2008, 03:07 PM

On a windows machine I can hit CTRL-ALT-DEL and get to the task manager and kill off errant processes if necessary. Why is it that on every version of Mac OS X there is no equivalent. No matter how stable the OS is there are always times where some process locks the interface so the mouse moves, but you can't click on anything. Usually I just go to another machine, ssh in and kill off the processes I think are causing the issue until the system becomes responsive again. This doesn't happen constantly, however where I work it probably happens at least once a day. (There are over 150 people constantly using their Macs here) I've heard that its due to USB not having the ability to do a hardware interrupt, (the same reason ADB keyboards had a power button on them and USB keyboards don't, I think?) but Windows machines don't have this issue with USB keyboards. Any idea why force quit doesn't always work reliably?

Chuckit · Feb 18, 2008, 03:28 PM

If something has locked up the GUI, it can't present a GUI dialog. There used to be a useful program called EscapePod that could force quit without the GUI dialog, but I don't know if it works anymore — Ambrosia stopped development on it a while back and I haven't had a need for it in quite a while to check if it's working.

Big Mac · Feb 18, 2008, 03:30 PM

Well, OS X should never be locking up in the way you describe, but I do realize it happens rarely. Force quit is a user level mechanism that will only work if your user is running normally. We should have access to a NMI for those rare cases, but it's apparently something Apple doesn't care to implement in OS X. As Chuckit points out, Ambrosia used to offer EscapePod, which would kill the window server on keystroke. I have argued that such functionality should be built into the OS, but others disagree.

Laurence · Feb 18, 2008, 04:20 PM

Strange... The ambrosia site says the following...

"NOTE: escapepod is no longer needed (or functional) under MacOS X 10.3 and later; Apple built the functionality in escapepod into the operating system."

If similar functionality is really built-in then I would assume that someone would know about it. I guess I'll just keep using ssh to resolve these situations. I don't understand how Apple thinks its wise to do this as most people don't know about ssh and will just unplug the computer at this point... Even with a journaled file-system that's never good for anything.

vertigociel · Feb 18, 2008, 04:53 PM

I've noticed that the Force Quit dialogue that Command-Option-Escape brings up isn't that helpful, even when the process in question is user-owned. I usually go into Activity Monitor and force-quit from there, which works every time. You could also type "killall $PROCESS_NAME (e.g. Finder)" into Terminal, which does the same thing.

Big Mac · Feb 18, 2008, 05:15 PM

Yeah, the functionality is definitely not built into the OS. I think it's referring to a mechanism that was added to Tiger that restarts WindowServer if the OS realizes it has crashed, but that's not much help if the OS doesn't know there's a problem.

Curiosity · Feb 19, 2008, 02:15 AM

Originally Posted by vertigociel

I've noticed that the Force Quit dialogue that Command-Option-Escape brings up isn't that helpful, even when the process in question is user-owned. I usually go into Activity Monitor and force-quit from there, which works every time. You could also type "killall $PROCESS_NAME (e.g. Finder)" into Terminal, which does the same thing.

If you cannot get clicking things to do anything, how do you launch Activity Monitor?

Big Mac · Feb 19, 2008, 02:30 AM

I think vertigociel is saying that apps often don't respond to Force Quit and that he just uses Activity Monitor instead. It's true that Activity Monitor is much more useful than Force Quit.

Amorya · Feb 19, 2008, 09:39 AM

Originally Posted by Big Mac

Yeah, the functionality is definitely not built into the OS. I think it's referring to a mechanism that was added to Tiger that restarts WindowServer if the OS realizes it has crashed, but that's not much help if the OS doesn't know there's a problem.

It is. Hit command option escape. A dialog appears. Select process to force quit.

Now, what do you do if the GUI has locked and no dialog appears? Hit command option escape again, a few more times. This works even when in a fullscreen game that has locked.

Amorya

EndlessMac · Feb 20, 2008, 12:14 AM

Originally Posted by Laurence

On a windows machine I can hit CTRL-ALT-DEL and get to the task manager and kill off errant processes if necessary. Why is it that on every version of Mac OS X there is no equivalent.

As Amorya has said use OPTION-APPLE-ESCAPE which is pretty much the equivalent to Windows. I also find that force quiting from the dock not as reliable. If you can get the Activity Monitor opened then you can used that to quit applications too.

Big Mac · Feb 20, 2008, 01:27 AM

Originally Posted by Amorya

It is. Hit command option escape. A dialog appears. Select process to force quit.

Now, what do you do if the GUI has locked and no dialog appears? Hit command option escape again, a few more times. This works even when in a fullscreen game that has locked.

Amorya

That doesn't help if WindowServer is FUBAR.

dru · Feb 20, 2008, 05:05 AM

These used to work but I they're not working for me on Tiger:

Command-Option-Shift-Esc: Force quits the frontmost application without asking or showing a dialog.
Command-Option-Shift-Q: Immediately log out the current user.

C.A.T.S. CEO · Feb 20, 2008, 08:38 AM

Originally Posted by dru

These used to work but I they're not working for me on Tiger:

Command-Option-Shift-Esc: Force quits the frontmost application without asking or showing a dialog.
Command-Option-Shift-Q: Immediately log out the current user.

The last one works if you cut Option out.

Simon · Feb 20, 2008, 10:19 AM

Originally Posted by C.A.T.S. CEO

The last one works if you cut Option out.

Actually you need option to force the logout. If you don't use option you'll get a dialog.

Big Mac · Feb 21, 2008, 03:16 PM

Oh, I forgot to add that in my experience Windows doesn't necessarily handle crashed apps better than Force Quit. I've had apps refuse End Task multiple times.

Cadaver · Feb 23, 2008, 02:31 AM

I used to keep either a terminal window or SSH enabled on my machine when running 10.2 or 10.3, in case an app locked up the GUI and nothing would respond or launch. That way I could either get to the terminal window (would work since it was running and didn't need to launch) or SSH in from another computer and do a kill command on it. Never needed to do so with 10.4 save maybe a few times. Fortunately, I don't recall having to do so with 10.5 yet (no longer keep Terminal or SSH running, either).