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"""
Event Latency example
Covers:
- Resources: Store
Scenario:
This example shows how to separate the time delay of events between
processes from the processes themselves.
When Useful:
When modeling physical things such as cables, RF propagation, etc. it
better encapsulation to keep this propagation mechanism outside of the
sending and receiving processes.
Can also be used to interconnect processes sending messages
Example by:
Keith Smith
"""
import simpy
SIM_DURATION = 100
class Cable(object):
"""This class represents the propagation through a cable."""
def __init__(self, env, delay):
self.env = env
self.delay = delay
self.store = simpy.Store(env)
def latency(self, value):
yield self.env.timeout(self.delay)
self.store.put(value)
def put(self, value):
self.env.process(self.latency(value))
def get(self):
return self.store.get()
def sender(env, cable):
"""A process which randomly generates messages."""
while True:
# wait for next transmission
yield env.timeout(5)
cable.put('Sender sent this at %d' % env.now)
def receiver(env, cable):
"""A process which consumes messages."""
while True:
# Get event for message pipe
msg = yield cable.get()
print('Received this at %d while %s' % (env.now, msg))
# Setup and start the simulation
print('Event Latency')
env = simpy.Environment()
cable = Cable(env, 10)
env.process(sender(env, cable))
env.process(receiver(env, cable))
env.run(until=SIM_DURATION)
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