Allis Tauri added the comment: Thanks for the suggestion. method_to_typeid and create_method are documented features, so I don't see why not. It does the trick in a cleaner way than my workaround: a metaclass for MyClass that just checks the arguments before creating a new instance. It just seems to me somewhat counterintuitive.
Another issue that arises in my case is: when I try to pass a proxy of MyClass to a subprocess it looses its' _manager during pickling and thus the ability to create proxies for children returned by get_child. This is solved by reimplementing the (not-working: http://bugs.python.org/issue5862) __reduce__ method of BaseManager in MyManager and creating corresponding custom proxy for MyClass with __reduce__ method also reimplemented. So the working solution for the situation is: either 1.1) class ReturnProxy(type): def __call__(cls, *args, **kwargs): if not kwargs and args and isinstance(args[0], cls): return args[0] return super(ReturnProxy, cls).__call__(*args, **kwargs) class MyClass(object): __metaclass__ = ReturnProxy ###class body### or 1.2) Your solution with the second typeid registration. 2) class AutoProxyMeta(type): '''Metaclass that replicates multiprocessing.managers.MakeProxyType functionality, but allows proxy classes that use it to be pickable''' def __new__(cls, name, bases, attrs): dic = {} for meth in attrs.get('_exposed_', ()): exec '''def %s(self, *args, **kwds): return self._callmethod(%r, args, kwds)''' % (meth, meth) in dic dic.update(attrs) return super(AutoProxyMeta, cls).__new__(cls, name, bases, dic) class MyClassProxy(BaseProxy): __metaclass__ = AutoProxyMeta _exposed_ = ('get_child',) _method_to_typeid_ = dict(get_child='MyClass') #or: _method_to_typeid_ = dict(get_child='_MyClass') def __reduce__(self): _unpickle, (cls, token, serializer, kwds) = BaseProxy.__reduce__(self) kwds['manager'] = self._manager return _unpickle, (cls, token, serializer, kwds) class MyClassManager(UManager): def __reduce__(self): return (RebuildMyClassManager, (self._address, None, self._serializer)) WorkCounterManager.register('MyClass', MyClass, MyClassProxy) #optionally: WorkCounterManager.register('_MyClass', None, MyClassProxy, create_method=False) def RebuildMyClassManager(address, authkey, serializer): mgr = MyClassManager(address, authkey, serializer) mgr.connect() return mgr ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue20854> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
