philosophers

It is classic task about dining philosophers problem. For do this task, you need know some rules:

• One or more philosophers sit at a round table
• The philosophers alternatively eat, think, or sleep. While they are eating, they are not thinking nor sleeping; while thinking, they are not eating nor sleeping; and, of course, while sleeping, they are not eating nor thinking.
• There are also forks on the table. There are as many forks as philosophers.
• Because eating with only one fork is very inconvenient, a philosopher takes two forks to eat, one in each hand.
• When a philosopher has finished eating, they put their forks back on the table and start sleeping. Once awake, they start thinking again. The simulation stops when a philosopher dies of starvation.
• Every philosopher needs to eat and should never starve.
• Philosophers don’t speak with each other.
• Philosophers don’t know if another philosopher is about to die.
• No need to say that philosophers should avoid dying.

Programm take 4 or 5 arguments and looks like:

./philo number_of_philosophers time_to_die time_to_eat time_to_sleep number_of_times_each_philosopher_must_eat

• number_of_philosophers: The number of philosophers and also the number of forks.
• time_to_die (in milliseconds): If a philosopher didn’t start eating time_to_die milliseconds since the beginning of their last meal or the beginning of the simulation, they die.
• time_to_eat (in milliseconds): The time it takes for a philosopher to eat. During that time, they will need to hold two forks.
• time_to_sleep (in milliseconds): The time a philosopher will spend sleeping.
• number_of_times_each_philosopher_must_eat (optional argument): If all philosophers have eaten at least number_of_times_each_philosopher_must_eat times, the simulation stops. If not specified, the simulation stops when a philosopher dies.

In program runtime any state change of a philosopher must be formatted as follows:

timestamp_in_ms X has taken a fork
timestamp_in_ms X is eating
timestamp_in_ms X is sleeping
timestamp_in_ms X is thinking
timestamp_in_ms X died

timestamp_in_ms and X replace by:

• timestamp_in_ms - the current timestamp in milliseconds
• X - philosopher number (from 1 to number_of_philosopher)

Compilation:

make -C philo/

Example:

./philo 4 500 200 200
./philo 7 310 100 100 7

Docker

cd philo
docker build -t philo .
docker run philo 4 60 60 80