palzap / 42-philosophers

Eat, Sleep, Spaghetti, repeat. This project is about learning how threads work by precisely timing a group of philosophers on when to pick up forks and eat spaghetti without dying from hunger.

Philosophers

Overview

The problem

• The problem involves a group of philosophers sitting at a round table.
• There is a large bowl of spaghetti in the middle of the table, and there are as many forks as philosophers.
• Philosophers alternate between eating, thinking, and sleeping. While eating, they cannot think or sleep; while thinking, they cannot eat or sleep; and while sleeping, they cannot eat or think.
• Philosophers take their right and left forks to eat, one in each hand.
• When a philosopher finishes eating, they put their forks back on the table and start sleeping. Once they wake up, they start thinking again.
• The simulation ends when a philosopher dies of starvation.
• Each philosopher needs to eat and should never starve.
• Philosophers cannot communicate with each other.
• Philosophers are not aware if another philosopher is about to die.

The rules

• You need to write two programs: one for the mandatory part and another for the bonus part (if you decide to do it)
• Global variables are forbidden
• Both programs must take the following arguments:
  • number_of_philosophers: the number of philosophers and forks
  • time_to_die (in milliseconds): if a philosopher doesn't start eating within this time since their last meal or the start of the simulation, they die
  • time_to_eat (in milliseconds): the time it takes for a philosopher to eat (must hold two forks during this time)
  • time_to_sleep (in milliseconds): the time a philosopher spends sleeping
  • number_of_times_each_philosopher_must_eat (optional): if all philosophers have eaten this many times, the simulation stops; if not specified, the simulation stops when a philosopher dies
• Each philosopher is assigned a number ranging from 1 to number_of_philosophers, and philosopher 1 sits next to philosopher number number_of_philosophers. Any other philosopher number N sits between philosopher number N - 1 and philosopher number N + 1
• The logs of the program must include state changes of each philosopher 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 Replace timestamp_in_ms with the current timestamp in milliseconds and X with the philosopher number.
• Each displayed state message should not be mixed up with another message
• A message announcing a philosopher's death should be displayed no more than 10 ms after the actual death
• Philosophers should avoid dying.

Evaluation

First submission

30/03/2023
125%