[ python-Bugs-1061968 ] threads: segfault or Py_FatalError at exit

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Bugs item #1061968, was opened at 2004-11-07 16:30
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Category: Threads
Group: Python 2.4
Status: Open
Resolution: None
Priority: 9
Submitted By: Armin Rigo (arigo)
Assigned to: Nobody/Anonymous (nobody)
Summary: threads: segfault or Py_FatalError at exit

Initial Comment:
I couldn't reproduce this bug on any machine but mine, but after investigation it looks like a real locking bug in pystate.c which triggers under a certain timing.  Attached is a small example which triggers the problem repeatedly on my machine, together with the output I get with a Python interpreter where I inserted debug prints in pystate.c:zapthreads() and pystate.c:PyThreadState_Delete().  My problem is that zapthreads() gets called before the last C thread finishes to call PyGILState_Release().  The very final call that PyGILState_Release() makes to PyThreadState_Delete() -- *after* it releases all locks -- then occurs after zapthreads() has cleared everything.  Crash.

Can't fix it myself because I don't know anything about PyGILState_*() and the intent of the various locks...

Boosted to priority 9 because it looks like it should be fixed before 2.4b3.

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