无法在 SIMPY 中触发两个事件（python 中的模拟）

Question

最近我了解了 SIMPY，我认为它对为我的工作提供一些信息并为决策提供背景非常有帮助。请注意，我对使用 python 编程很陌生，我知道基础知识，但我正在学习。

问题： 我正在一个集装箱码头工作，我们有三种移动方式：

• 与船只相关的移动（大约每 120 秒产生一次移动。）
• 与仓库相关的移动（大约每 960 秒生成一次移动。）
• 与大门相关的动作（大约每 800 秒产生一次动作。）

所有这些动作都以所述间隔同时“生成”。 船只和仓库都有自己的运输工具。但是，上述所有步骤的目的地都是相同的。容器堆栈采用 FIFO 原则（先进先出），一次可以处理四个移动。一个动作大约需要 270 秒。

我想要实现的是通过更改资源数量（船舶和仓库的运输数量以及闸门移动）来查看对集装箱堆内业务的影响。

我获得了适用于其中一个流程（VESSEL）的基本模拟，我现在正在尝试添加仓库流程，但是我被卡住了。当我使用以下代码时，只会生成来自容器的移动：

def move_generator(env):

    while True:
        yield env.timeout(120)
        print("Vessel move generated at: %.1f" % (env.now))

    while True:
        yield env.timeout(960)
        print("Warehouse move generated at: %.1f" % (env.now)) 


import simpy
env = simpy.Environment()
env.process(move_generator(env))
    
env.run(until=3600)

以上代码的输出为：

Vessel move generated at: 120.0
Vessel move generated at: 240.0
Vessel move generated at: 360.0
Vessel move generated at: 480.0
Vessel move generated at: 600.0
Vessel move generated at: 720.0
Vessel move generated at: 840.0
Vessel move generated at: 960.0
Vessel move generated at: 1080.0
Vessel move generated at: 1200.0
Vessel move generated at: 1320.0
Vessel move generated at: 1440.0
Vessel move generated at: 1560.0
Vessel move generated at: 1680.0
Vessel move generated at: 1800.0
Vessel move generated at: 1920.0
Vessel move generated at: 2040.0
Vessel move generated at: 2160.0
Vessel move generated at: 2280.0
Vessel move generated at: 2400.0
Vessel move generated at: 2520.0
Vessel move generated at: 2640.0
Vessel move generated at: 2760.0
Vessel move generated at: 2880.0
Vessel move generated at: 3000.0
Vessel move generated at: 3120.0
Vessel move generated at: 3240.0
Vessel move generated at: 3360.0
Vessel move generated at: 3480.0

然而，期望的输出是：

Vessel move generated at: 120.0
Vessel move generated at: 240.0
Vessel move generated at: 360.0
Vessel move generated at: 480.0
Vessel move generated at: 600.0
Vessel move generated at: 720.0
Vessel move generated at: 840.0
Vessel move generated at: 960.0
Warehouse move generated at: 960.0
Vessel move generated at: 1080.0
Vessel move generated at: 1200.0
Vessel move generated at: 1320.0
Vessel move generated at: 1440.0
Vessel move generated at: 1560.0
Vessel move generated at: 1680.0
Vessel move generated at: 1800.0
Vessel move generated at: 1920.0
Warehouse move generated at: 1920.0
Vessel move generated at: 2040.0
Vessel move generated at: 2160.0
Vessel move generated at: 2280.0
Vessel move generated at: 2400.0
Vessel move generated at: 2520.0
Vessel move generated at: 2640.0
Vessel move generated at: 2760.0
Vessel move generated at: 2880.0
Warehouse move generated at: 2880.0
Vessel move generated at: 3000.0
Vessel move generated at: 3120.0
Vessel move generated at: 3240.0
Vessel move generated at: 3360.0
Vessel move generated at: 3480.0

我认为问题出在两个 while True 语句中，但我无法弄清楚如何正确处理这个问题。我一直在使用谷歌（可能不知道找到答案的正确术语）但没有成功。

Answer 1

正如您在评论中指出的那样，问题在于您使用 python，而不是 simpy。

while True:
  <do anything>

# already unreachable
while True:
  # also unreachable

对于您的示例，请尝试查看 https://simpy.readthedocs.io/en/latest/simpy_intro/shared_resources.html

for i in range(4):
    env.process(car(env, 'Car %d' % i, bcs, i*2, 5))
env.run()

您可以看到process 可以在run 之前被多次调用，从而实现您想要的“并行”工作。

import simpy


def vessel(env):
    while True:
        yield env.timeout(120)
        print("Vessel move generated at: %.1f" % (env.now))


def warehouse(env):
    while True:
        yield env.timeout(960)
        print("Warehouse move generated at: %.1f" % (env.now)) 


def main():
    env = simpy.Environment()
    env.process(vessel(env))
    env.process(warehouse(env))
    env.run(until=3600)

if __name__ == '__main__':
    main()

这给了

Vessel move generated at: 120.0
Vessel move generated at: 240.0
Vessel move generated at: 360.0
Vessel move generated at: 480.0
Vessel move generated at: 600.0
Vessel move generated at: 720.0
Vessel move generated at: 840.0
Warehouse move generated at: 960.0
Vessel move generated at: 960.0
Vessel move generated at: 1080.0
Vessel move generated at: 1200.0
Vessel move generated at: 1320.0
Vessel move generated at: 1440.0
Vessel move generated at: 1560.0
Vessel move generated at: 1680.0
Vessel move generated at: 1800.0
Warehouse move generated at: 1920.0
Vessel move generated at: 1920.0
Vessel move generated at: 2040.0
Vessel move generated at: 2160.0
Vessel move generated at: 2280.0
Vessel move generated at: 2400.0
Vessel move generated at: 2520.0
Vessel move generated at: 2640.0
Vessel move generated at: 2760.0
Warehouse move generated at: 2880.0
Vessel move generated at: 2880.0
Vessel move generated at: 3000.0
Vessel move generated at: 3120.0
Vessel move generated at: 3240.0
Vessel move generated at: 3360.0
Vessel move generated at: 3480.0