Issue3272
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Created on 2008-07-03 16:48 by mishok13, last changed 2022-04-11 14:56 by admin. This issue is now closed.
Messages (2) | |||
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msg69207 - (view) | Author: Andrii V. Mishkovskyi (mishok13) | Date: 2008-07-03 16:48 | |
`multiprocessing` hangs, when `multiprocessing.Pool` methods `map`, `imap`, `imap_unordered`, `apply`, `apply_async`, `map_async` are called. Here is an example: Python 3.0b1+ (py3k:64686M, Jul 3 2008, 13:06:13) [GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from multiprocessing import Pool >>> Pool(processes=4).imap(lambda x: x, range(10)) <multiprocessing.pool.IMapIterator object at 0x83bcc8c> >>> Pool(processes=4).map(lambda x: x, range(10)) Exception in thread Thread-13: Traceback (most recent call last): File "/usr/local/lib/python3.0/threading.py", line 492, in _bootstrap_inner self.run() File "/usr/local/lib/python3.0/threading.py", line 447, in run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.0/multiprocessing/pool.py", line 225, in _handle_tasks put(task) File "/usr/local/lib/python3.0/pickle.py", line 1319, in dumps Pickler(f, protocol).dump(obj) File "/usr/local/lib/python3.0/multiprocessing/util.py", line 311, in _reduce_method if m.__self__ is None: AttributeError: 'function' object has no attribute '__self__' Process PoolWorker-28: Traceback (most recent call last): File "/usr/local/lib/python3.0/multiprocessing/process.py", line 232, in _bootstrap self.run() File "/usr/local/lib/python3.0/multiprocessing/process.py", line 88, in run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.0/multiprocessing/pool.py", line 57, in worker task = get() File "/usr/local/lib/python3.0/multiprocessing/queues.py", line 337, in get Process PoolWorker-27: Traceback (most recent call last): File "/usr/local/lib/python3.0/multiprocessing/process.py", line 232, in _bootstrap self.run() File "/usr/local/lib/python3.0/multiprocessing/process.py", line 88, in run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.0/multiprocessing/pool.py", line 57, in worker task = get() File "/usr/local/lib/python3.0/multiprocessing/queues.py", line 337, in get Process PoolWorker-26: Traceback (most recent call last): File "/usr/local/lib/python3.0/multiprocessing/process.py", line 232, in _bootstrap Process PoolWorker-25: Traceback (most recent call last): File "/usr/local/lib/python3.0/multiprocessing/process.py", line 232, in _bootstrap self.run() File "/usr/local/lib/python3.0/multiprocessing/process.py", line 88, in run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.0/multiprocessing/pool.py", line 57, in worker task = get() File "/usr/local/lib/python3.0/multiprocessing/queues.py", line 337, in get self.run() File "/usr/local/lib/python3.0/multiprocessing/process.py", line 88, in run self._target(*self._args, **self._kwargs) File "/usr/local/lib/python3.0/multiprocessing/pool.py", line 57, in worker task = get() File "/usr/local/lib/python3.0/multiprocessing/queues.py", line 339, in get return recv() KeyboardInterrupt racquire() KeyboardInterrupt racquire() KeyboardInterrupt racquire() KeyboardInterrupt Terminated The same happens on latest trunk of Python 2.6. Note, `map` and `apply` methods hang Python interpreter completely, so I have to use `kill` utility to exit Python. |
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msg80375 - (view) | Author: Jesse Noller (jnoller) * | Date: 2009-01-22 19:25 | |
This is now covered in the multiprocessing documentation: "Note Functionality within this package requires that the __main__ method be importable by the children. This is covered in Programming guidelines however it is worth pointing out here. This means that some examples, such as the multiprocessing.Pool examples will not work in the interactive interpreter." |
History | |||
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Date | User | Action | Args |
2022-04-11 14:56:36 | admin | set | github: 47522 |
2009-01-22 19:25:51 | jnoller | set | status: open -> closed resolution: fixed messages: + msg80375 |
2009-01-19 16:42:08 | jnoller | set | assignee: jnoller |
2008-07-03 16:48:37 | mishok13 | create |