Philosophers is a 42 School project that introduces the basics of multi-threading and concurrent programming. Based on Edsger Dijkstra’s famous Dining Philosophers problem, the objective is to create a simulation where a number of philosophers sit around a table with a bowl of spaghetti and a limited number of forks.
The core challenge of this project is learning how to manage shared resources using threads and mutexes, while avoiding synchronization issues like deadlocks, data races, and starvation.
- A number of philosophers sit at a round table. There is a single fork between each pair of philosophers.
- A philosopher needs two forks (the one on their left and the one on their right) to eat.
- Philosophers alternate between three states: Eating, Sleeping, and Thinking.
- While eating, they hold their forks. When finished, they put them down and start sleeping. Once they wake up, they start thinking until they can grab forks again.
- If a philosopher doesn't start eating within
time_to_diemilliseconds since the beginning of their last meal (or the start of the simulation), they die of starvation, and the simulation stops immediately.
- One Thread per Philosopher: Each philosopher runs inside their own independent thread.
- Mutexes as Forks: Every fork is protected by a mutex to ensure that two philosophers cannot grab the exact same fork at the exact same time (preventing data races).
- State Protection: Crucial variables (like the time a philosopher last ate or the death state flag) are also protected by mutexes to prevent conflicting simultaneous read/write operations.
To compile the philo executable, run the following command at the root of the repository:
make