%matplotlib inline
import matplotlib.pyplot as plt
import numpy as np

runningjobs = [] # the array of running jobs
numrunning = []
timestamp = 0

stagein = 2
processingtime = 300
stageout = 0

nextstart = timestamp + stagein

for i in range(0, 1000):
    if timestamp == nextstart:
        runningjobs.append(timestamp+300)
        nextstart = timestamp + stagein
        
    if len(runningjobs) > 0 and runningjobs[0] <= timestamp:
        runningjobs.pop(0)
        
    numrunning.append(len(runningjobs))
    timestamp += 1

plt.plot(numrunning)
plt.ylabel("Running Jobs")
plt.xlabel("Time (m)")