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ramalhoramalho
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taxi simulator using coroutines
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‎control/simulation/taxi_sim.py‎

Lines changed: 69 additions & 58 deletions
Original file line numberDiff line numberDiff line change
@@ -4,21 +4,23 @@
44
55
Sample run with two cars, random seed = 4::
66
7-
>>> main(num_taxis=2, seed=7)
8-
taxi: 0 Event(time=2, actor_id=0, action='pick up passenger')
7+
>>> main(num_taxis=2, seed=10)
8+
taxi: 0 Event(time=0, actor_id=0, action='leave garage')
9+
taxi: 0 Event(time=4, actor_id=0, action='pick up passenger')
10+
taxi: 0 Event(time=10, actor_id=0, action='drop off passenger')
11+
taxi: 1 Event(time=10, actor_id=1, action='leave garage')
912
taxi: 1 Event(time=11, actor_id=1, action='pick up passenger')
10-
taxi: 1 Event(time=12, actor_id=1, action='drop off passenger')
11-
taxi: 0 Event(time=13, actor_id=0, action='drop off passenger')
12-
taxi: 0 Event(time=15, actor_id=0, action='pick up passenger')
13-
taxi: 0 Event(time=16, actor_id=0, action='drop off passenger')
14-
taxi: 1 Event(time=16, actor_id=1, action='pick up passenger')
15-
taxi: 0 Event(time=17, actor_id=0, action='going home')
16-
taxi: 1 Event(time=24, actor_id=1, action='drop off passenger')
17-
taxi: 1 Event(time=25, actor_id=1, action='pick up passenger')
18-
taxi: 1 Event(time=31, actor_id=1, action='drop off passenger')
19-
taxi: 1 Event(time=32, actor_id=1, action='pick up passenger')
20-
taxi: 1 Event(time=33, actor_id=1, action='drop off passenger')
21-
taxi: 1 Event(time=34, actor_id=1, action='going home')
13+
taxi: 0 Event(time=14, actor_id=0, action='pick up passenger')
14+
taxi: 1 Event(time=28, actor_id=1, action='drop off passenger')
15+
taxi: 0 Event(time=32, actor_id=0, action='drop off passenger')
16+
taxi: 0 Event(time=33, actor_id=0, action='going home')
17+
taxi: 1 Event(time=33, actor_id=1, action='pick up passenger')
18+
taxi: 1 Event(time=35, actor_id=1, action='drop off passenger')
19+
taxi: 1 Event(time=38, actor_id=1, action='pick up passenger')
20+
taxi: 1 Event(time=42, actor_id=1, action='drop off passenger')
21+
taxi: 1 Event(time=44, actor_id=1, action='pick up passenger')
22+
taxi: 1 Event(time=75, actor_id=1, action='drop off passenger')
23+
taxi: 1 Event(time=76, actor_id=1, action='going home')
2224
*** end of events ***
2325
2426
"""
@@ -31,7 +33,7 @@
3133

3234
DEFAULT_NUMBER_OF_TAXIS = 3
3335
DEFAULT_END_TIME = 80
34-
FIND_PASSENGER_INTERVAL = 4
36+
SEARCH_INTERVAL = 4
3537
TRIP_DURATION = 10
3638

3739
Event = collections.namedtuple('Event', 'time actor_id action')
@@ -44,61 +46,65 @@ def compute_delay(interval):
4446

4547
def taxi_process(ident, trips, start_time=0):
4648
"""Yield to simulator issuing event at each state change"""
47-
time = start_time
49+
time = yield Event(start_time, ident, 'leave garage')
4850
for i in range(trips):
49-
prowling_ends = time + compute_delay(FIND_PASSENGER_INTERVAL)
51+
prowling_ends = time + compute_delay(SEARCH_INTERVAL)
5052
time = yield Event(prowling_ends, ident, 'pick up passenger')
5153

5254
trip_ends = time + compute_delay(TRIP_DURATION)
5355
time = yield Event(trip_ends, ident, 'drop off passenger')
5456

5557
yield Event(trip_ends + 1, ident, 'going home')
5658

57-
59+
# BEGIN TAXI_SIMULATOR
5860
class Simulator:
5961

6062
def __init__(self, actors):
6163
self.events = queue.PriorityQueue()
6264
self.actors = dict(actors)
6365

6466

65-
def run(self, end_time):
66-
"""Schedule and execute events until time is up"""
67-
for ident, actor in sorted(self.actors.items()):
68-
first_event = next(actor) # prime each coroutine
69-
self.events.put(first_event)
67+
def run(self, end_time): # <1>
68+
"""Schedule and display events until time is up"""
69+
# schedule the first event for each cab
70+
for _, actor in sorted(self.actors.items()): # <2>
71+
first_event = next(actor) # <3>
72+
self.events.put(first_event) # <4>
73+
74+
# main loop of the simulation
7075
time = 0
71-
while time < end_time:
72-
if self.events.empty():
76+
while time < end_time: # <5>
77+
if self.events.empty(): # <6>
7378
print('*** end of events ***')
7479
break
7580

7681
# get and display current event
77-
current_event = self.events.get()
78-
print('taxi:', current_event.actor_id,
82+
current_event = self.events.get() # <7>
83+
print('taxi:', current_event.actor_id, # <8>
7984
current_event.actor_id * ' ', current_event)
8085

8186
# schedule next action for current actor
82-
actor = self.actors[current_event.actor_id]
83-
time = current_event.time
87+
time = current_event.time # <9>
88+
actor = self.actors[current_event.actor_id] # <10>
8489
try:
85-
next_event = actor.send(time)
90+
next_event = actor.send(time) # <11>
8691
except StopIteration:
87-
del self.actors[current_event.actor_id]
92+
del self.actors[current_event.actor_id] # <12>
8893
else:
89-
self.events.put(next_event)
90-
else:
94+
self.events.put(next_event) # <14>
95+
else: # <15>
9196
msg = '*** end of simulation time: {} events pending ***'
9297
print(msg.format(self.events.qsize()))
93-
98+
# END TAXI_SIMULATOR
9499

95100
def main(end_time=DEFAULT_END_TIME, num_taxis=DEFAULT_NUMBER_OF_TAXIS,
96101
seed=None):
97102
"""Initialize random generator, build actors and run simulation"""
98103
if seed is not None:
99104
random.seed(seed) # get reproducible results
100105

101-
taxis = {i: taxi_process(i, (i+1)*2, i*10) for i in range(num_taxis)}
106+
taxis = {i: taxi_process(i, (i+1)*2, i*10)
107+
for i in range(num_taxis)}
102108
sim = Simulator(taxis)
103109
sim.run(end_time)
104110

@@ -125,34 +131,39 @@ def main(end_time=DEFAULT_END_TIME, num_taxis=DEFAULT_NUMBER_OF_TAXIS,
125131
"""
126132
Sample run:
127133
128-
$ clear; python3 taxi_sim.py -s 19
134+
# BEGIN TAXI_SAMPLE_RUN
135+
$ $ clear; python3 taxi_sim.py -t 3 -s 19
136+
taxi: 0 Event(time=0, actor_id=0, action='leave garage')
129137
taxi: 0 Event(time=5, actor_id=0, action='pick up passenger')
130-
taxi: 0 Event(time=13, actor_id=0, action='drop off passenger')
131-
taxi: 0 Event(time=16, actor_id=0, action='pick up passenger')
132-
taxi: 1 Event(time=17, actor_id=1, action='pick up passenger')
138+
taxi: 1 Event(time=10, actor_id=1, action='leave garage')
139+
taxi: 1 Event(time=13, actor_id=1, action='pick up passenger')
140+
taxi: 2 Event(time=20, actor_id=2, action='leave garage')
141+
taxi: 0 Event(time=21, actor_id=0, action='drop off passenger')
133142
taxi: 1 Event(time=21, actor_id=1, action='drop off passenger')
134-
taxi: 1 Event(time=22, actor_id=1, action='pick up passenger')
143+
taxi: 1 Event(time=23, actor_id=1, action='pick up passenger')
135144
taxi: 2 Event(time=23, actor_id=2, action='pick up passenger')
136-
taxi: 1 Event(time=26, actor_id=1, action='drop off passenger')
145+
taxi: 1 Event(time=25, actor_id=1, action='drop off passenger')
146+
taxi: 1 Event(time=27, actor_id=1, action='pick up passenger')
137147
taxi: 2 Event(time=27, actor_id=2, action='drop off passenger')
138-
taxi: 1 Event(time=28, actor_id=1, action='pick up passenger')
139148
taxi: 2 Event(time=29, actor_id=2, action='pick up passenger')
140-
taxi: 1 Event(time=30, actor_id=1, action='drop off passenger')
141-
taxi: 1 Event(time=32, actor_id=1, action='pick up passenger')
142-
taxi: 2 Event(time=33, actor_id=2, action='drop off passenger')
143-
taxi: 2 Event(time=34, actor_id=2, action='pick up passenger')
144-
taxi: 2 Event(time=35, actor_id=2, action='drop off passenger')
145-
taxi: 2 Event(time=36, actor_id=2, action='pick up passenger')
146-
taxi: 1 Event(time=41, actor_id=1, action='drop off passenger')
147-
taxi: 1 Event(time=42, actor_id=1, action='going home')
148-
taxi: 2 Event(time=44, actor_id=2, action='drop off passenger')
149-
taxi: 2 Event(time=46, actor_id=2, action='pick up passenger')
150-
taxi: 2 Event(time=60, actor_id=2, action='drop off passenger')
151-
taxi: 2 Event(time=67, actor_id=2, action='pick up passenger')
152-
taxi: 2 Event(time=73, actor_id=2, action='drop off passenger')
153-
taxi: 0 Event(time=74, actor_id=0, action='drop off passenger')
154-
taxi: 2 Event(time=74, actor_id=2, action='going home')
155-
taxi: 0 Event(time=75, actor_id=0, action='going home')
149+
taxi: 1 Event(time=31, actor_id=1, action='drop off passenger')
150+
taxi: 2 Event(time=31, actor_id=2, action='drop off passenger')
151+
taxi: 1 Event(time=33, actor_id=1, action='pick up passenger')
152+
taxi: 2 Event(time=33, actor_id=2, action='pick up passenger')
153+
taxi: 2 Event(time=36, actor_id=2, action='drop off passenger')
154+
taxi: 2 Event(time=37, actor_id=2, action='pick up passenger')
155+
taxi: 2 Event(time=40, actor_id=2, action='drop off passenger')
156+
taxi: 1 Event(time=42, actor_id=1, action='drop off passenger')
157+
taxi: 1 Event(time=43, actor_id=1, action='going home')
158+
taxi: 0 Event(time=44, actor_id=0, action='pick up passenger')
159+
taxi: 2 Event(time=44, actor_id=2, action='pick up passenger')
160+
taxi: 0 Event(time=49, actor_id=0, action='drop off passenger')
161+
taxi: 0 Event(time=50, actor_id=0, action='going home')
162+
taxi: 2 Event(time=58, actor_id=2, action='drop off passenger')
163+
taxi: 2 Event(time=65, actor_id=2, action='pick up passenger')
164+
taxi: 2 Event(time=71, actor_id=2, action='drop off passenger')
165+
taxi: 2 Event(time=72, actor_id=2, action='going home')
156166
*** end of events ***
167+
# END TAXI_SAMPLE_RUN
157168
158169
"""

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