Le problème que j'ai rencontré était en essayant d'importer des globaux entre les modules, provoquant l'évaluation de la ligne ProcessPool () plusieurs fois.
globals.py
from processing import Manager, Lock
from pathos.multiprocessing import ProcessPool
from pathos.threading import ThreadPool
class SingletonMeta(type):
def __new__(cls, name, bases, dict):
dict['__deepcopy__'] = dict['__copy__'] = lambda self, *args: self
return super(SingletonMeta, cls).__new__(cls, name, bases, dict)
def __init__(cls, name, bases, dict):
super(SingletonMeta, cls).__init__(name, bases, dict)
cls.instance = None
def __call__(cls,*args,**kw):
if cls.instance is None:
cls.instance = super(SingletonMeta, cls).__call__(*args, **kw)
return cls.instance
def __deepcopy__(self, item):
return item.__class__.instance
class Globals(object):
__metaclass__ = SingletonMeta
"""
This class is a workaround to the bug: AssertionError: daemonic processes are not allowed to have children
The root cause is that importing this file from different modules causes this file to be reevalutated each time,
thus ProcessPool() gets reexecuted inside that child thread, thus causing the daemonic processes bug
"""
def __init__(self):
print "%s::__init__()" % (self.__class__.__name__)
self.shared_manager = Manager()
self.shared_process_pool = ProcessPool()
self.shared_thread_pool = ThreadPool()
self.shared_lock = Lock() # BUG: Windows: global name 'lock' is not defined | doesn't affect cygwin
Puis importez en toute sécurité depuis ailleurs dans votre code
from globals import Globals
Globals().shared_manager
Globals().shared_process_pool
Globals().shared_thread_pool
Globals().shared_lock
I want a pool to be able to call a function that has another pool inside
et comment cela interfère avec le fait que les ouvriers sont démonisés.