Re: [Pyobjc-dev] A better way to deal w/sig 10 & 11 exceptions

[Just v. R. <ju...@le...>]

bb...@ma... wrote:

> But there is now a better way to deal with sig 10/11.   I added a 
> Signals module to PyObjCTools.  When installed as follows....
> 
> from PyObjCTools import Signals
> Signals.dumpStackOnFatalSignal()
> 
> .... it will trap all fatal signals-- all signals that normally cause
> a core dump-- and attempt to dump the python stack before reverting
> the signal handler back to the default handler and resignaling.
> 
> I.e. if you invoke the above code and then your app crashes with 
> SIGBUS, it will dump the Python stack trace before croaking entirely.
> 
> It is likely an improvement, anyway...

That would be extremely useful. However, I can't get it to work when
there's a real crash. I don't get a Python stack trace when I patch your
demo like this:

Index: signal-demo.py
===================================================================
RCS file: /cvsroot/pyobjc/pyobjc/Examples/signal-demo.py,v
retrieving revision 1.1
diff -c -r1.1 signal-demo.py
*** signal-demo.py  4 Jun 2003 02:37:21 -0000   1.1
--- signal-demo.py  4 Jun 2003 08:06:48 -0000
***************
*** 13,19 ****
  ## the script again.
  
  def badness():
!     os.kill(os.getpid(), signal.SIGQUIT)
  
  class Foo:
      def baz(self):
--- 13,21 ----
  ## the script again.
  
  def badness():
!   import Foundation
!   o = Foundation.NSObject.alloc().init()
!   o.release()
  
  class Foo:
      def baz(self):


Could this ever work to begin with? It seems that upon such a crash the
state of the program is undefined, and executing Python code may no
longer work.

Just