Solving the famous 'dining philosophers' problem using threads and mutexes.

About the project

A project made in accordance with the philosophers project which is part of the Codam Core Curriculum. It is a version of the dining philosophers problem. One or more philosophers sit at a round table. There is a large bowl of spaghetti in the middle of the table. Philosophers need two forks to eat the spaghetti. There are as many forks as philosophers. The challenge is to write a program that lets the philosophers dine without starving. Each philosopher is a thread and the availability of each fork is protected by a mutex.

Getting started

Start by cloning the repository:

git clone https://github.com/fkoolhoven/philosophers.git

Go into the philo directory and compile by using make:

make

Usage

./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.

For example:

./philo 6 800 200 200 3 

will let 6 philosophers eat 3 times.

Or:

./philo 4 310 200 200

will let the simulation run until 1 philosopher starves.

Example output of

./philo 4 2000 350 800 5

Any state change of a philosopher is formatted as follows: [current timestamp in milliseconds] [philosopher number] [state]

Important learnings

1. Learned to create and join threads.
2. Learned about what causes race conditions.
3. Learned how to prevent race conditions using mutexes.
4. Additionally I worked on making the output as easy to read as possible, adding colors and appropriate (error) messages.

Contact

See my profile page for ways to contact me!