SAGE Notebook leaves dead processes on OS X

[williamstein]

The sage notebook restart often leaves "dead Python" process running.
This is especially bad on OS X, where there is a 100 process limit by
default (at least on my laptop).

Component: basic arithmetic

Issue created by migration from https://trac.sagemath.org/ticket/1

[williamstein]

comment:1

I finally decided to fix that bug under OS X where the SAGE notebook
spawns > 100 processes, which OS X doesn't like (i.e., when you hit
restart a lot). It took me 2 minutes to fix, so I wish I had done
it earlier.

I just inserted this line

        self.__sage._expect = None

in worksheet.py as line 661, so now its:
alarm(2)
try:
self.__sage._expect = None
del self.__sage
except AttributeError, msg:
print "WARNING: %s"%msg
except Exception, msg:
print msg
print "WARNING: Error deleting SAGE object!"
cancel_alarm()

I checked this into the standard darcs repository.