Created on 2011-06-15 13:24 by sbt, last changed 2012-05-25 20:15 by sbt. This issue is now closed.
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| File name | Uploaded | Description | Edit | |
| mp_remove_eintr_retry.patch | sbt, 2012-03-16 14:22 | review | ||
| Messages (8) | |||
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| msg138364 - (view) | Author: Richard Oudkerk (sbt) *  |
Date: 2011-06-15 13:24 | |
multiprocessing.util._eintr_retry is only used to wrap select.select, but it fails to recalculate timeouts. Also, it will never retry the function it wraps because of a missing "import errno". I think it would be better to just implement the retrying version of select directly. |
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| msg138674 - (view) | Author: STINNER Victor (haypo) * |
Date: 2011-06-19 23:29 | |
subprocess._communicate_with_select() retries select.select() on EINTR: it recomputes timeout before each call.
while self._read_set or self._write_set:
timeout = self._remaining_time(endtime)
if timeout is not None and timeout < 0:
raise TimeoutExpired(self.args, orig_timeout)
try:
(rlist, wlist, xlist) = \
select.select(self._read_set, self._write_set, [],
timeout)
except select.error as e:
if e.args[0] == errno.EINTR:
continue
raise
...
It has a similar code for select.poll().
asyncore.poll() handles EINTR: it just returns.
> I think it would be better to just implement the retrying version
> of select directly.
It would be nice to share more code between subprocess and multiprocessing, but I don't know where such code should be moved. Create a new module just for one function is stupid. Handling EINTR is a common problem when managing subprocesses.
subprocess has a _eintr_retry_call() function.
multiprocessing has a @_eintr_retry decorator handling supporting more error types (use except (EnvironmentError, select.error):).
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| msg156035 - (view) | Author: Richard Oudkerk (sbt) * |
Date: 2012-03-16 14:22 | |
_eintr_retry is currently unused. The attached patch removes it. If it is retained then we should at least add a warning that it does not recalculate timeouts. |
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| msg156088 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2012-03-16 21:47 | |
> _eintr_retry is currently unused. AFAICT it's still used in forking.py. |
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| msg157819 - (view) | Author: STINNER Victor (haypo) * |
Date: 2012-04-08 23:29 | |
SocketServer has been changed to restart select() on EINTR, but it doesn't recompute the timeout. |
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| msg157820 - (view) | Author: STINNER Victor (haypo) * |
Date: 2012-04-08 23:30 | |
> SocketServer has been changed to restart select() on EINTR, > but it doesn't recompute the timeout. See issue #7978. |
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| msg157821 - (view) | Author: Antoine Pitrou (pitrou) * |
Date: 2012-04-08 23:32 | |
Note that socketserver's timeout is not really important: it's just used for a polling loop, with a default of 0.5 seconds. |
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| msg161619 - (view) | Author: Richard Oudkerk (sbt) * |
Date: 2012-05-25 20:15 | |
_eintr_retry was removed by 99ef4501205b. |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2012-05-25 20:15:26 | sbt | set | status: open -> closed type: behavior messages: + msg161619 resolution: out of date stage: committed/rejected |
| 2012-04-08 23:32:07 | pitrou | set | messages: + msg157821 |
| 2012-04-08 23:30:21 | haypo | set | messages: + msg157820 |
| 2012-04-08 23:29:56 | haypo | set | messages: + msg157819 |
| 2012-03-16 21:47:17 | pitrou | set | messages:
+ msg156088 versions: + Python 3.3 |
| 2012-03-16 14:22:55 | sbt | set | files:
+ mp_remove_eintr_retry.patch keywords: + patch messages: + msg156035 |
| 2011-06-19 23:29:44 | haypo | set | messages: + msg138674 |
| 2011-06-19 23:17:56 | haypo | set | nosy:
+ pitrou, haypo |
| 2011-06-15 13:24:28 | sbt | create | |