Philosophers

I never thought philosophy would be so deadly

42 project about inter-process communication. A program that can monitor multiple instances of itself, either processes or threads, using semaphores or mutexes.

Concept

One or more philosophers sit at a round table. There is a large bowl of spaghetti in the middle of the table. There are as many forks as philosophers. Because serving and eating spaghetti with only one fork is very inconvenient, a philosopher takes their right and their left forks to eat, one in each hand (they each have a fork, but they need two forks to eat). So they need to borrow their neighbor's fork to eat. The philosophers alternatively eat, think, or sleep. 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. No need to say that philosophers should avoid dying!

Philosophers don’t speak with each other.
Philosophers don’t know if another philosopher is about to die.

How to use it

Using make in the 42_Philosophers directory will create the philo executable.

You run it specifying, in order :

The number of philosophers
The time in milliseconds until a philosopher dies from starvation
The time in milliseconds it takes for a philosopher to eat
The time in milliseconds it takes for a philosopher to sleep
(Optional) The number of meals before the program stops

Output

The program outputs every action with a timestamp (in milliseconds) and the philosopher's number. For example, if Philosopher 2 starts eating 369 milliseconds after the beginning of the program, it will output :

369 2 is eating

Each philosopher has a number ranging from 1 to number_of_philosophers.

Examples

Test with ./philo 1 800 200 200, the philosopher should not eat and should die!
Test with ./philo 5 800 200 200, no one should die!
Test with ./philo 5 800 200 200 7, no one should die and the simulation should stop when all the philosopher has eaten at least 7 times each.
Test with ./philo 4 410 200 200, no one should die!
Test with ./philo 4 310 200 100, a philosopher should die!
Do not test with more than 200 philosophers
Do not test with time_to_die or time_to_eat under 60 ms
Test with 2 philosophers and check the different times (a death delayed by more than 10 ms is unacceptable)

Additional information

Philos does their works using threads as philosophers, and mutexes as forks. For more information you can read the en.subject.pdf. My code does not have memory leaks and it passes all the tests.