Python - Multiprocessing managers with class.md

Python - Multiprocessing managers with class

Demonstrate how to create a multiprocessing's manager server exposing a class.

Proxies

from multiprocessing.managers import BaseProxy


class GeneratorProxy(BaseProxy):
    """Manager's proxy for generators.
    """
    _exposed_ = ["__next__"]

    def __iter__(self):
        return self

    def __next__(self):
        return self._callmethod("__next__")

Server code: server.py

from multiprocessing.managers import BaseManager, BaseProxy
from proxies import GeneratorProxy


class App:
    """Exposed class.
    """
    def __init__(self, name: str):
        self.name = name

    def echo(self, data: str=''):
        print(f"{self.name}: {data}")

    def giveback(self, value):
        return value

    def split(self, data: str, by: str):
        for token in data.split(by):
            yield token


# Manager server class.
class Server(BaseManager): pass

# Registers the ``App`` class.
# The generator method ``App.split`` must be bound to the custom proxy ``GeneratorProxy``.
Server.register("App", App, method_to_typeid={"split": "App.split"})
Server.register("App.split", proxytype=GeneratorProxy)

# Creates and run a server instance.
server = Server(address=('', 50000), authkey=b"123")
server.get_server().serve_forever()

Client code: client.py

from multiprocessing.managers import BaseManager
from proxies import GeneratorProxy


# Manager
class Client(BaseManager): pass

# Registers the ``App`` class.
# The generator method ``App.split`` must be bound to the custom proxy ``GeneratorProxy``.
Client.register("App", method_to_typeid={"split": "App.split"})
Client.register("App.split", proxytype=GeneratorProxy)

# Connects to a remote server.
client = Client(address=('', 50000), authkey=b"123")
client.connect()

# Creates a new ``App`` instance remotely.
app = client.App(name="Client #1")

# Invokes the remotes ``App`` methods.
app.echo("Hello, World !")
print(app.giveback("Foobar"))
print(list(app.split(data="Hello,World !", by=",")))