Philosophers

Simulation of the dining philosophers problem.

Rules

• Several philosophers are sitting at a round table doing one of three things: eating, thinking, or sleeping.
• While eating, they are not thinking or sleeping, while sleeping, they are not eating or thinking and of course, while thinking, they are not eating or sleeping.
• The philosophers sit at a circular table with a large bowl of spaghetti in the center.
• There are some forks on the table.
• As spaghetti is difficult to serve and eat with a single fork, it is assumed that a philosopher must eat with two forks, one for each hand.
• The philosophers must never be starving.
• Every philosopher needs to eat.
• Philosophers don’t speak with each other.
• Philosophers don’t know when another philosopher is about to die.
• Each time a philosopher has finished eating, he will drop his forks and start sleeping.
• When a philosopher is done sleeping, he will start thinking.
• The simulation stops when a philosopher dies

Run the program

Compile with make.

Run with ./philo number_of_philosophers time_to_die time_to_eat time_to_sleep [number_of_times_each_philosopher_must_eat]

• number_of_philosophers: is the number of philosophers and also the number of forks. Must be between 1 and 100.
• time_to_die: is in milliseconds, if a philosopher doesn’t start eating ’time_to_die’ milliseconds after starting his last meal or the beginning of the simulation, it dies. Must be at least 50 milliseconds.
• time_to_eat: is in milliseconds and is the time it takes for a philosopher to eat. During that time he will need to keep the two forks. Must be at least 50 milliseconds.
• time_to_sleep: is in milliseconds and is the time the philosopher will spend sleeping. Must be at least 50 milliseconds.
• number_of_times_each_philosopher_must_eat: argument is optional, if all philosophers eat at least ’number_of_times_each_philosopher_must_eat’ the simulation will stop. If not specified, the simulation will stop only at the death of a philosopher.

This implementation treats every philosopher as a separate thread and protects every fork with a mutex. To ensure stability, it's not recommended to run the program with more than 100 philosophers or with time arguments lower than 60 ms.