class MMCC:
""" Simulation object tasked with conducting the MMCC system """
def run(self, total_servers: int, total_arrival: int) -> None:
""" Begin the simulation of a MMCC system. Process the information until
termination criteria is meet.
Params:
- total_servers :: The number of servers that can handle clients at
any one instance.
- total_arrival :: The total number of clients that can be handled
within the simulation.
"""
# Initialise the beginning parameters of the simulation
self.servers = Servers(total_servers) # Set up server handler
self.events = EventHandler() # Set up the event handler
startingEvent = Event("arrival", 0) # Construct the first event object
startingEvent.departure_time -= startingEvent.arrival_time # Reset times
startingEvent.arrival_time = 0 # Reset times
self.events.add(startingEvent) # Create the first event
# Begin iteration of events, record arrivals for checking
self.num_arrival = 0
while (self.num_arrival < total_arrival):
# Collect next event from the event handler
currentEvent = self.events.next()
# Update simulation time
self.sim_time = currentEvent.time()
if currentEvent.type == "arrival":
# Arrival event received
self.num_arrival += 1 # Record number of arrivals
# Create new arrival event
self.events.add(Event("arrival", currentEvent.time()))
# Check if any server is available
if not self.servers.isFree():
self.events.block(
currentEvent) # Arriving client is blocked
continue
# Begin serving the client.
currentEvent.servedBy(self.servers.allocate())
# All event handler to manage departure
self.events.add(currentEvent)
else:
# Departure event received
self.servers.deallocate(
currentEvent.servedBy()) # Free the server
self.events.depart(currentEvent) # Record departure
def blockingProbability(self) -> float:
""" Calculate the blocking probability for the previous simulation run.
Returns:
- float :: Probability of blocking
"""
return len(self.events.blocked) / self.num_arrival
def serverUtilisation(self) -> float:
""" Calculate the server utilisation for the previous simulation run.
Returns:
- float :: Server utilisation value
"""
return sum([e.serviceTime()
for e in self.events.departed]) / self.sim_time
def report(self) -> None:
""" Display the results of the simulation is a readible fashion. """
print("\tEvents Handled ::")
print("\t\tArrival:", self.num_arrival)
incomplete = self.num_arrival - (len(self.events.departed) +
len(self.events.blocked))
print("\t\tIncomplete events:", incomplete)
print("\t\tDeparture:", len(self.events.departed))
print("\t\tBlocked:", len(self.events.blocked))
print("\tBlocking rate:", self.blockingProbability())
print("\tServer Utilisation:", self.serverUtilisation())
class MMCC:
"""
Class to simulate M/M/C/C system
"""
def run(self, server_number: int, arrival_total: int):
"""
Run simulation with specified parameters
:param server_number: Number of servers
:param arrival_total: Number of events
"""
# Initialise Servers and EventHandler
self.servers = Servers(server_number)
self.events = EventHandler()
# Create and add initial event
starting_event = Event("arrival", 0)
starting_event.departure_time -= starting_event.arrival_time
starting_event.arrival_time = 0
self.events.add(starting_event)
# Run simulation until number of events handled
self.arrival_number = 0
while (self.arrival_number < arrival_total):
# Iterate to next event and update simulation time
current_event = self.events.next()
self.simulation_time = current_event.time()
# If arrival, update counter and add to appropriate list
if current_event.event_type == "arrival":
self.arrival_number += 1
self.events.add(Event("arrival", current_event.time()))
# If no servers free, block event
if not self.servers.is_free():
self.events.block(current_event)
continue
# Assign server to event
current_event.served_by(self.servers.allocate())
self.events.add(current_event)
# If departure, free server and depart
else:
self.servers.deallocate(current_event.served_by())
self.events.depart(current_event)
def blocking_probability(self) -> float:
"""
Obtain blocking probability of previous run
:return: Blocking probability
"""
return len(self.events.blocked) / self.arrival_number
def server_utilisation(self) -> float:
"""
Obtain server utilisation of previous run
:return: Server utilisation
"""
return sum([e.service_time()
for e in self.events.departed]) / self.simulation_time
