Vfrdtyky

I'm working with a simple simulation with Simpy and Python.
My goal is to have a resource that can be 1 at the time, and count all the other processes that are waiting for that resource to be free.

Example :

 Person 1 comes, takes the resource. waiting is 0

 Person 2 arrives, waits. waiting is 1 

 Person 3 arrives, waits. waiting is 2

 Person 1 leaves, releasing resource, so now Person 2 takes it. waiting is 1 

This is my code so far:

import simpy



def env1(env):

    res = simpy.Resource(env,capacity=1)

    while True:  

        yield env.timeout(5)

        print("Arriving Person at ",(env.now))

        env.process(getResource(env, res))



def getResource(env,res):

        with res.request() as req:

            yield req

            print("Person using resource at ", env.now)

            yield env.timeout(20)

            print("Leaving at ", env.now)

Calling the Simulation

env = simpy.Environment()

env.process(env1(env))

env.run(until=500)

I've tried using .get_queue method , but it's always empty.
Using .queue seems to always add elements, but never removes them from the queue.
I've also tried using the put and release methods, but nothing seems to work.

I do not understand correctly how this methods work, and how to achieve this.
Any ideas?
Thanks!

After some research and trial/error, I've found the solution.
Basically, when you use "with res.request() as" statement, you let the put/release interaction to be done by itself, which helps to avoid errors.

In order to get the queue status, or interact with it, you only have to call it AFTER the with statement: (since the element will be inside the resource queue AFTER the with statement)

import simpy



def env1(env):

    res = simpy.Resource(env,capacity=1)

    while True:  

        yield env.timeout(5)

        print("Arriving Person at ",(env.now))

        env.process(getResource(env, res))



def getResource(env,res):

        with res.request() as req:

            print("QUEUE SIZE: ",len(res.queue))

            yield req

            print("Person using resource at ", env.now)

            yield env.timeout(20)

            print("Leaving at ", env.now)