The following problem was once used on an exam:Jurassic Park consists of a dinosaur museum...

The following problem was once used on an exam:

Jurassic Park consists of a dinosaur museum and a park for safari riding. There are m passengers and n single-passenger cars. Passengers wander around the museum for a while, then line up to take a ride in a safari car. When a car is available, it loads the one passenger it can hold and rides around the park for a random amount of time. If the n cars are all out riding passengers around, then a passenger who wants to ride waits; if a car is ready to load but there are no waiting passengers, then the car waits. Use semaphores to synchronize the m passenger processes and the n car processes.

The following skeleton code was found on a scrap of paper on the floor of the exam room. Grade it for correctness. Ignore syntax and missing variable declarations. Remember that P and V correspond to semWait and semSignal.

resource Jurassic_Park()
 sem car_avail := 0, car_taken := 0, car_filled := 0, passenger_released := 0
process passenger(i := 1 to num_passengers)
 do true -> nap(int(random(1000*wander_time)))
  P(car_avail); V(car_taken); P(car_filled)
  P(passenger_released)
 od
 end passenger
  process car(j := 1 to num_cars)
  do true -> V(car_avail); P(car_taken); V(car_filled)
  nap(int(random(1000*ride_time)))
  V(passenger_released)
   Od
 end car
end Jurassic_Park