A problem with startUp messages
rwithers12 at mediaone.net
Thu Jun 28 03:48:49 UTC 2001
Is there a signal handler being installed for SIGCHLD, in the vm? The default
action (SIG_DFL) is to ignore the signal. I thought the child PID goes
zombie as a result, but I couldn't find evidence in the man pages..
On Wed, 27 Jun 2001, Kevin
Fisher wrote: > Hi folks:
> I've been working with David Lewis, trying to figure out why OSProcess has
> been leaving behind <defunct> zombie processes. It turns out, the problem
> isn't with OSProcess at all...
> In my image, the SystemDictionary's StartUpList has UnixOSProcessAccessor
> later in the ordered collection, after SecurityManager. When the image gets
> restarted, only classes iterated over the StartUpList up to and including
> SecurityManager receive the startUp message. After that, SystemDictionary>>
> send:toClassesNamedIn:with: terminates prematurely, leaving several classes
> not restarted (including UnisOSProcessAccessor, the source of the OSProcess
> zombies). Actually I'm not sure it terminates at all, it seems to get stuck
> at SecurityManager.
> It looks as though SecurityManager class>>startUp never returns...but only
> during startup. Once the image is up and running, doing a SecurityManager
> startUp seems to work just fine...it's only during the startup that something
> funny happens. The trick is to put Transcript show: scaffolding around 'self
> default startUp' in SecurityManager class>>startUp...open a Transcript, save
> the image and quit, reload and watch what gets put in the Transcript. The
> first Transcript show: will appear, but the second does not. However, once
> the image is up, doing a SecurityManager startUp will show both Transcript
> show: 's. Perhaps some sort of deadlock is happening during the restart of
> the image?
> I'm a bit stumped at this point...any ideas? This is on the UNIX VM, with the
> latest changes in the 3.1 image.
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