updated taxi simulator

control/simulation/taxi_sim.py

@@ -0,0 +1,61 @@
+import sys
+import random
+import collections
+import queue
+
+Event = collections.namedtuple('Event', 'time actor description')
+
+FIND_CUSTOMER_INTERVAL = 4
+TRIP_DURATION = 10
+
+
+def compute_delay(interval):
+    return int(random.expovariate(1/interval))
+
+
+def taxi_process(sim, ident):
+    trips = 3
+    for i in range(trips):
+        prowling_time = compute_delay(FIND_CUSTOMER_INTERVAL)
+        yield Event(sim.time + prowling_time, ident, 'customer picked up')
+
+        trip_time = compute_delay(TRIP_DURATION)
+        yield Event(sim.time + trip_time, ident, 'customer dropped off')
+
+
+class Simulator:
+
+    def __init__(self):
+        self.events = queue.PriorityQueue()
+        self.time = 0
+
+    def run(self, end_time):
+        taxis = [taxi_process(self, i) for i in range(3)]
+        while self.time < end_time:
+            for index, taxi in enumerate(taxis):
+                try:
+                    future_event = next(taxi)
+                except StopIteration:
+                    del taxis[index]  # remove taxi not in service
+                else:
+                    self.events.put(future_event)
+            if self.events.empty():
+                print('*** end of events ***')
+                break
+            event = self.events.get()
+            self.time = event.time
+            print('taxi:', event.actor, event)
+        else:
+            print('*** end of simulation time ***')
+
+
+def main(args):
+    if args:
+        end_time = int(args[0])
+    else:
+        end_time = 10
+    sim = Simulator()
+    sim.run(end_time)
+
+if __name__ == '__main__':
+    main(sys.argv[1:])