diff --git a/Doc/ACKS.txt b/Doc/ACKS.txt index 26f7ea907f6..69735ca06c1 100644 --- a/Doc/ACKS.txt +++ b/Doc/ACKS.txt @@ -236,3 +236,4 @@ docs@python.org), and we'll be glad to correct the problem. * Moshe Zadka * Milan Zamazal * Cheng Zhang + * Chris McDonough diff --git a/Lib/multiprocessing/util.py b/Lib/multiprocessing/util.py index 30b7a85fa26..68d6c1f9c4a 100644 --- a/Lib/multiprocessing/util.py +++ b/Lib/multiprocessing/util.py @@ -247,6 +247,12 @@ def _run_finalizers(minpriority=None): Finalizers with highest priority are called first; finalizers with the same priority will be called in reverse order of creation. ''' + if _finalizer_registry is None: + # This function may be called after this module's globals are + # destroyed. See the _exit_function function in this module for more + # notes. + return + if minpriority is None: f = lambda p : p[0][0] is not None else: @@ -278,24 +284,40 @@ def is_exiting(): _exiting = False -def _exit_function(): +def _exit_function(info=info, debug=debug, _run_finalizers=_run_finalizers, + active_children=active_children, + current_process=current_process): + # We hold on to references to functions in the arglist due to the + # situation described below, where this function is called after this + # module's globals are destroyed. + global _exiting - info('process shutting down') - debug('running all "atexit" finalizers with priority >= 0') - _run_finalizers(0) + if not _exiting: + info('process shutting down') + debug('running all "atexit" finalizers with priority >= 0') + _run_finalizers(0) + 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. + for p in active_children(): + if p._daemonic: + info('calling terminate() for daemon %s', p.name) + p._popen.terminate() - for p in active_children(): - if p._daemonic: - info('calling terminate() for daemon %s', p.name) - p._popen.terminate() + for p in active_children(): + info('calling join() for process %s', p.name) + p.join() - for p in active_children(): - info('calling join() for process %s', p.name) - p.join() - - debug('running the remaining "atexit" finalizers') - _run_finalizers() + debug('running the remaining "atexit" finalizers') + _run_finalizers() atexit.register(_exit_function)