Sebastien Binet wrote:
hi there,
say I have this module
## farnsworth ##
__all__ = [
'mgr',
'maths',
]
from multiprocessing.managers import BaseManager
class MathsClass(object):
def add(self, x, y):
return x + y
def mul(self, x, y):
return x * y
class MyManager(BaseManager):
pass
MyManager.register('Maths', MathsClass)
def _setup():
print "creating a manager..."
mgr = MyManager()
print "starting the manager..."
mgr.start()
print "sciencing faster..."
maths = mgr.Maths()
print maths.add(4,3)
print maths.mul(7,8)
print "done with sciencing."
return (mgr, maths)
# exec at module import
mgr, maths = _setup()
# prevent hysteresis + clean-up
del _setup
## EOF ##
if I use it like so:
$ python -m farnsworth
creating a manager...
starting the manager...
sciencing faster...
7
56
done with sciencing.
all is fine, but if I try to use it thru an import:
$ python
py> import farnsworth.mgr as mgr
creating a manager...
starting the manager...
sciencing faster...
[stuck for some time... hitting ^C]
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "farnsworth.py", line 32, in <module>
mgr, maths = _setup()
File "farnsworth.py", line 25, in _setup
maths = mgr.Maths()
File "/usr/lib/python2.6/multiprocessing/managers.py", line 634, in
temp
token, exp = self._create(typeid, *args, **kwds)
File "/usr/lib/python2.6/multiprocessing/managers.py", line 532, in
_create
conn = self._Client(self._address, authkey=self._authkey)
File "/usr/lib/python2.6/multiprocessing/connection.py", line 140,
in Client
answer_challenge(c, authkey)
File "/usr/lib/python2.6/multiprocessing/connection.py", line 372,
in answer_challenge
message = connection.recv_bytes(256) # reject large
message
KeyboardInterrupt
is this a known limitation/feature of the multiprocessing module ?
is there a workaround (acquiring some import lock maybe) ?
cheers,
sebastien.
PS:
$ python
Python 2.6.4 (r264:75706, Oct 27 2009, 06:25:13)
[GCC 4.4.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
$ python -c 'import sys; print sys.version_info'
(2, 6, 4, 'final', 0)
$ uname -a
Linux farnsworth 2.6.31-ARCH #1 SMP PREEMPT Tue Nov 10 19:01:40 CET
2009 x86_64 Intel(R) Core(TM)2 Duo CPU T9400 @ 2.53GHz GenuineIntel
GNU/Linux
Since I don't see any other responses, I'll give my guess, even though
I'm not very experienced with the multiprocessing module.
It's my understanding that threads may not be created or destroyed
during an import. So you need to find a way to defer the creation till
the imports are done.
DaveA
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