diff options
| -rw-r--r-- | Lib/multiprocessing/pool.py | 9 | ||||
| -rw-r--r-- | Misc/NEWS | 4 |
2 files changed, 11 insertions, 2 deletions
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py index 1f366f0..862a60e 100644 --- a/Lib/multiprocessing/pool.py +++ b/Lib/multiprocessing/pool.py @@ -295,6 +295,8 @@ class Pool(object): while pool._worker_handler._state == RUN and pool._state == RUN: pool._maintain_pool() time.sleep(0.1) + # send sentinel to stop workers + pool._taskqueue.put(None) debug('worker handler exiting') @staticmethod @@ -413,7 +415,6 @@ class Pool(object): if self._state == RUN: self._state = CLOSE self._worker_handler._state = CLOSE - self._taskqueue.put(None) def terminate(self): debug('terminating pool') @@ -447,7 +448,6 @@ class Pool(object): worker_handler._state = TERMINATE task_handler._state = TERMINATE - taskqueue.put(None) # sentinel debug('helping task handler/workers to finish') cls._help_stuff_finish(inqueue, task_handler, len(pool)) @@ -457,6 +457,11 @@ class Pool(object): result_handler._state = TERMINATE outqueue.put(None) # sentinel + # We must wait for the worker handler to exit before terminating + # workers because we don't want workers to be restarted behind our back. + debug('joining worker handler') + worker_handler.join() + # Terminate workers which haven't already finished. if pool and hasattr(pool[0], 'terminate'): debug('terminating workers') @@ -51,6 +51,10 @@ Core and Builtins Library ------- +- Issue #8428: Fix a race condition in multiprocessing.Pool when terminating + worker processes: new processes would be spawned while the pool is being + shut down. Patch by Charles-François Natali. + - Issue #7311: fix HTMLParser to accept non-ASCII attribute values. - Issue #10963: Ensure that subprocess.communicate() never raises EPIPE. |