Question

我试图模拟一个缓冲区有限的队列，其中没有丢弃数据包但是仍在等待。因为我只是一名具有基本编码技能的学生，所以请耐心等待。

数据包以指数方式分布，每个数据包保持一个平均1250字节的数据包大小。我设法让代码工作在数据包到达+处理时间但我不能让数据包离开＆＃39;并模拟队列（到目前为止，它是无限缓冲区）我有什么办法可以模拟数据包离开和队列限制吗？

代码：

import random
import simpy

RANDOM_SEED = 42
NEW_CUSTOMERS = 100  # Total number of customers
INTERVAL_CUSTOMERS = 1  # Generate new customers roughly every x seconds
SIZE = 1250

def source(env, number, interval, port):
    """Source generates packet randomly"""
    for i in range(number):
        size =  int(random.expovariate(0.0008))
        packet = Packet(env, '%d' % i, size, port, time_in_port=1)
        env.process(packet)
        t = random.expovariate(1 / interval)
        yield env.timeout(t)

def Packet(env, id, size, port, time_in_port):
    arrive = env.now
    yield Queue.buffer.put(size)
    print('packet%s %s arriving at %lf' % (id, size, arrive))

    with port.request() as req:
        yield req

        tip = random.expovariate(1/time_in_port)
        yield env.timeout(tip)
        amount = size
        yield Queue.buffer.get(amount)
        print('packet%s %s finished processing at %lf' % (id, size, env.now))

class queue:     #THIS PART WON'T WORK
    def __init__(self, env):
        self.port = simpy.Resource(env, capacity=1)
        self.buffer = simpy.Container(env, init = 0, capacity=12500)
        self.mon_proc = env.process(self.monitor_tank(env))

    def monitor_tank(self, env):
        while True:
           if self.buffer.level > 12500:
             print('Full at %d' % env.now)


random.seed(RANDOM_SEED)
env = simpy.Environment()
Queue = queue(env)

port = simpy.Resource(env, capacity=1)
env.process(source(env, NEW_CUSTOMERS, INTERVAL_CUSTOMERS, port))
env.run()

队列类没有用（该程序根本没有运行）。如果只删除队列类并模拟数据包到达和处理时间，它将运行。非常感谢帮助我模拟数据包离开（使用接收器）和队列限制。感谢。

Answer 1

不熟悉详细信息，但您在self.monitor_tank(env)构造函数中对queue的调用将进入一个紧密的无限循环 - 它不是一个生成器，只是一个无休止的循环，所以python将在执行过程中陷入困境。

Answer 2

您好，我认为代码将解决您的问题或至少给您一个方向。在您的原始代码中，所有包的大小都相同，我在此包中建模，但更改为字节很简单。

我使用了一个缓冲区（容器）和一个服务器（资源）。

;)

import simpy
import random     

def arrival(env, buffer):
  #Arrival of the Package

  while True:
    print('Package ARRIVED at %.1f \n\t Buffer: %i' 
                      % (env.now, buffer.level))
    yield buffer.put(1) # Put the package in the buffer
    yield env.timeout(random.expovariate(1.0)) # time between arrivals
    env.process(processDeparture(env, buffer, server)) 

def processDeparture(env, buffer, server):
  #Processing and Departure of the Package

  while True:
    
    # request a Server to process thge package
    request = server.request()
    yield request

    yield buffer.get(1) # GET a package from the buffer

    # Processing time of the package
    processingTime = 2
    print('Package begin processing at %.1f'
                      % (env.now))
    yield env.timeout(processingTime)
    print('Package end processing at %.1f'
                      % (env.now))
    # release the server
    yield server.release(request)


random.seed(150)            
env = simpy.Environment()
buffer = simpy.Container(env, capacity=3, init=0)  # Create the Buffer 
server = simpy.Resource(env, capacity=1)           # Create the servers (resources)

env.process(arrival(env, buffer))         

env.run(until=30)                                # Execute the Model

Answer 3

我认为您代码中的这段代码是一个无限循环，并且正在阻止您的代码运行

function aws_set_language_cookie() {

    //To save the language in a cookie
    
    $current_language = get_locale();
    
    if ($current_language == "es_ES") {
        $result = setcookie('lang', $current_language, time() + (30 * DAY_IN_SECONDS), '/');


    } else {
        $result = setcookie('lang', $current_language, time() + (30 * DAY_IN_SECONDS), '/');
    }

    //To read the cookie and change the language based on the cookie
    
    if (isset($_COOKIE['lang']) && $_COOKIE['lang'] == "es_ES") {
        //need code to change website language to spanish here
    }
}

尝试注释掉这篇文章，或者添加一个 env.timeout 让它在每次循环时“休眠”一段时间

Simpy队列模拟

3 个答案: