diff options
| -rw-r--r-- | Lib/multiprocessing/util.py | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/Lib/multiprocessing/util.py b/Lib/multiprocessing/util.py index 3bb9546..7495813 100644 --- a/Lib/multiprocessing/util.py +++ b/Lib/multiprocessing/util.py @@ -290,14 +290,17 @@ def _exit_function(info=info, debug=debug, _run_finalizers=_run_finalizers, if current_process() is not None: # We check if the current process is None here because if - # it's None, any call to ``active_children()`` will throw an - # AttributeError (active_children winds up trying to get - # attributes from util._current_process). This happens in a - # variety of shutdown circumstances that are not well-understood - # because module-scope variables are not apparently supposed to - # be destroyed until after this function is called. However, - # they are indeed destroyed before this function is called. See - # issues #9775 and #15881. Also related: #4106, #9205, and #9207. + # it's None, any call to ``active_children()`` will throw + # an AttributeError (active_children winds up trying to + # get attributes from util._current_process). One + # situation where this can happen is if someone has + # manipulated sys.modules, causing this module to be + # garbage collected. The destructor for the module type + # then replaces all values in the module dict with None. + # For instance, after setuptools runs a test it replaces + # sys.modules with a copy created earlier. See issues + # #9775 and #15881. Also related: #4106, #9205, and + # #9207. for p in active_children(): if p._daemonic: |