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Author eshkrig
Recipients eshkrig
Date 2019-09-17.06:51:09
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1568703069.98.0.135749134145.issue38195@roundup.psfhosted.org>
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Hi!

I found a bug in the multiprocessing module.

The documentation (https://docs.python.org/3.6/library/multiprocessing.html) for the Queue.get method says:
"If timeout is a positive number, it blocks at most timeout seconds ..."

But the Queue.get method freezes if the process filling the queue terminates while reading data.

In the attachment is an example of a program (testqueue.py) that freezes after ~ 5-30 seconds.
After pressing <control>-<c>, the output is as follows:
Traceback (most recent call last):
  File "./testqueue.py", line 45, in <module>
    result = ps_queues[cpu].get(timeout=2)
  File "/usr/lib64/python3.6/multiprocessing/queues.py", line 108, in get
    res = self._recv_bytes()
  File "/usr/lib64/python3.6/multiprocessing/connection.py", line 216, in recv_bytes
    buf = self._recv_bytes(maxlength)
  File "/usr/lib64/python3.6/multiprocessing/connection.py", line 411, in _recv_bytes
    return self._recv(size)
  File "/usr/lib64/python3.6/multiprocessing/connection.py", line 379, in _recv
    chunk = read(handle, remaining)
KeyboardInterrupt

Please fix it.
History
Date User Action Args
2019-09-17 06:51:10eshkrigsetrecipients: + eshkrig
2019-09-17 06:51:09eshkrigsetmessageid: <1568703069.98.0.135749134145.issue38195@roundup.psfhosted.org>
2019-09-17 06:51:09eshkriglinkissue38195 messages
2019-09-17 06:51:09eshkrigcreate