| 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 (vstinner) * |
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 (vstinner) * |
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 (vstinner) * |
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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