python - 简单的过程 - 不能使用生成器发送方法？

Question

背景

据说 SimPy 进程是文档中的生成器，我希望它具有PE​​P 342中的send方法。

• 文档 » SimPy in 10 Minutes » 基本概念

流程由简单的 Python生成器描述。您可以将它们称为流程函数或流程方法，具体取决于它是普通函数还是类的方法。在它们的生命周期中，它们创建事件并产生它们以等待它们被触发。

我可以使用send将消息从另一个发电机发送到发电机，例如将充电站发电机注入 ev 发电机。

from typing import Dict, Optional, Generator
import time

def ev(env) -> Generator:
    while True:
        next_charging_station = yield
        print("next_charging_station[{}]".format(next_charging_station))
        
def dispathcer(env, ev) -> Generator:
    while True:
        time.sleep(3)
        print('Dispatching the next charging station')
        ev.send("new station")
        
process_ev = ev(env)
next(process_ev)

process_dispatcher = dispathcer(env, process_ev)

Dispatching the next charging station
next_charging_station[new station]
Dispatching the next charging station
next_charging_station[new station]

但是，SymPy 进程没有send方法。

import simpy
env = simpy.Environment()
                    
def ev(env):
    while True:
        next_charging_station = yield
        print("next_charging_station[{}]".format(next_charging_station))
        
def dispathcer(env, ev):
    while True:
        print('Dispatching the next charging station at %d' % (env.now))
        ev.send("new station")

rocess_ev = env.process(ev(env))
process_dispatcher = env.process(dispathcer(env, process_ev))
-----

Dispatching the next charging station at 0
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-12-ece25f162510> in <module>
      1 process_ev = env.process(ev(env))
----> 2 process_dispatcher = env.process(dispathcer(env, process_ev))

<ipython-input-11-b89aeb1a9073> in dispathcer(env, ev)
     11     while True:
     12         print('Dispatching the next charging station at %d' % (env.now))
---> 13         ev.send("hoge")

AttributeError: 'Process' object has no attribute 'send'

问题

如果这是按设计的（发送和可能关闭/抛出不可用）或者我误解了某些内容，请帮助了解此错误的原因。我想所有的同步都需要由 SimPy 环境通过其事件来完成，否则环境可能会丢失进程状态的跟踪，但不确定。

请告知是否有办法从另一个进程更新内存。例如，如何更改代码以将充电站进程动态注入 ev 进程。

import simpy
env = simpy.Environment()

def charging_station(env):
    print('Start charging at %d' % (env.now))
    charge_duration = 3
    yield env.timeout(charge_duration)
    return
                    
def ev(env):
    while True:
        print('Start driving at %d' % (env.now))
        driving_duration = 5
        yield env.timeout(driving_duration)

        print('Stop at a charging station at %d' % (env.now))

        # [Q] Instead of creating a charging process inside the ev process,
        # how to get it injected?
        yield env.process(charging_station(env))    # <----- 

env.process(ev(env))
env.run(until=20)

-----
Start driving at 0
Stop at a charging station at 5
Start charging at 5
Start driving at 8
Stop at a charging station at 13
Start charging at 13
Start driving at 16

如果可能的话，例如这样的东西。

def new_ev(env): # <---- how to implement?
    while True:
        next_charging_station = yield   # Get the next station process
        print('Start charging at %d' % (env.now))
        yield next_charging_station

        print('Start driving at %d' % (env.now))
        driving_duration = 5
        yield env.timeout(driving_duration)

它看起来只有在创建过程中才能注入进程。因此，一种方法可以将调度程序注入 ev 进程，然后从 ev 进程内部获取充电站。但是，希望将任何实例显式注入其中，而不是从其中提取。

import random
import simpy
env = simpy.Environment()

class Dispatcher(object):
    env = None
    def __init__(self, env):
        self.env = env
        print('Start dispatcher at time %d' % self.env.now)
        
        # Start the run process everytime an instance is created.
        #self.process = env.process(self.run())

    def run(self):
        while True:
            print('Start dispatcher at time %d' % self.env.now)
            yield self.env.timeout(1)
            
    def next_charger_station(self):
        return self._charge(random.randint(1, 1000), self.env)

    def _charge(self, id, env):
        print('station %s start charging at time %d' % (id, env.now))
        yield env.timeout(5)
        return

                    
def ev(env, dispatcher):
    while True:        
        print('EV stops at the new charging station at time %d' % (env.now))
        yield env.process(dispatcher.next_charger_station())
        
        print('EV start driving from the charging station at time %d' % (env.now))
        yield env.timeout(5)
            

dispatcher = Dispatcher(env)
process_ev = env.process(ev(env, dispatcher))
env.run(until=30)

标签： pythongeneratorsimpy