Accessing an attribute of a multiprocessing Proxy of a class

Question

I have a class that I want to share in a read-only fashion with children processes in a pool, so I prepared a proxy of a class but it didn\'t work. The following is a simpli

Answer 1

After spending few hours to reading the source codes, here is the simplest ways to implement the proxy class to expose all attributes and methods:

class TestProxy(NamespaceProxy):
    _exposed_ = tuple(dir(Test))

    def __getattr__(self, name):
        result = super().__getattr__(name)
        if isinstance(result, types.MethodType):
            def wrapper(*args, **kwargs):
                self._callmethod(name, args)
            return wrapper
        return result

BaseManager.register('Test', Test, TestProxy)

manager = BaseManager()
test = manager.Test()

Also, here is an auto proxy method:

def Proxy(target):
    dic = {'types': types}
    exec('''def __getattr__(self, key):
        result = self._callmethod('__getattribute__', (key,))
        if isinstance(result, types.MethodType):
            def wrapper(*args, **kwargs):
                self._callmethod(key, args)
            return wrapper
        return result''', dic)
    proxyName = target.__name__ + "Proxy"
    ProxyType = type(proxyName, (NamespaceProxy,), dic)
    ProxyType._exposed_ = tuple(dir(target))
    return ProxyType

TestProxy = Proxy(Test)
BaseManager.register('Test', Test, TestProxy)

manager = BaseManager()
test = manager.Test()