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文件名称：定义一个Actor任务-python cookbook(第3版)高清中文完整版
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python cookbook 第3版 高清 中文完整版
12.10 定义一个Actor任务
问题
You’d like to define tasks with behavior similar to “actors” in the so-called “actor model.”
解决方案
The “actor model” is one of the oldest and most simple approaches to concurrency and
distributed computing. In fact, its underlying simplicity is part of its appeal. In a nutshell, an
actor is a concurrently executing task that simply acts upon messages sent to it. In response
to these messages, it may decide to send further messages to other actors. Communication
with actors is one way and asynchronous. Thus, the sender of a message does not know
when a message actually gets delivered, nor does it receive a response or acknowledgment
that the message has been processed. Actors are straightforward to define using a
combination of a thread and a queue. For example:
from queue import Queue from threading import Thread, Event
# Sentinel used for shutdown class ActorExit(Exception):
pass
class Actor:
def __init__(self):
self._mailbox = Queue()
def send(self, msg):
‘’’ Send a message to the actor ‘’’ self._mailbox.put(msg)
def recv(self):
‘’’ Receive an incoming message ‘’’ msg = self._mailbox.get() if msg is ActorExit:
raise ActorExit()
return msg