Philosophers

I never thought philosophy would be so deadly

Table of contents

• About philosophers
• Mandatory part
• Bonus part
• How to run the simulation

About philosophers

This project simulates the dining philosophers problem that states that N philosophers seated around a circular table with a large bowl of spaghetti in the middle of the table. A philosopher may eat if he can pick up the two chopsticks on in each hand. The philosophers alternatively eat, think, or sleep. While they are eating, they are not thinking nor sleeping; while thinking, they are not eating nor sleeping; and, of course, while sleeping, they are not eating nor thinking. 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.

Mandatory part

• Each philosopher is a thread.
• There is one fork between each pair of philosophers. Therefore, if there are several philosophers, each philosopher has a fork on their left side and a fork on their right side.
• Forks states are protected from duplicating with a mutex for each of them.

Bonus part

• Each philosopher is a process.
• All the forks are put in the middle of the table.
• They have no states in memory but the number of available forks is represented by a semaphore.

How to run the simulation

1. Clone this repo and go to the cloned directoty

$> git clone https://github.com/cvine21/philosophers.git
$> cd philosophers/

2. Run the simulation:

Mandatory part:

$> cd philo && make

Program will be executed as follows:

$> ./philo arg1 arg2 arg3 arg4 arg5

Bonus part:

$> cd philo_bonus && make bonus

Program will be executed as follows:

$> ./philo_bonus arg1 arg2 arg3 arg4 arg5

• arg1: The number of philosophers and also the number of forks.
• arg2: 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.
• arg3: The time it takes for a philosopher to eat (in milliseconds). During that time, they will need to hold two forks.
• arg4: The time a philosopher will spend sleeping (in milliseconds).
• arg5 (optional argument): If all philosophers have eaten number_of_times_each_philosopher_must_eat times, the simulation stops. If not specified, the simulation stops when a philosopher dies.

Some cases for the mandatory part:

./philo 1 800 200 200     - the philosopher should not eat and should die.
./philo 5 800 200 200     - no one should die.
./philo 5 800 200 200 7   - no one should die and the simulation should stop when all the philospher everyone has eaten 7 times.
./philo 4 410 200 200     - no one should die.
./philo 4 310 200 100     - a philosopher should die.

bonus part:

./philo_bonus 1 800 200 200     - the philosopher should not eat and should die.
./philo_bonus 5 800 200 200     - no one should die.
./philo_bonus 5 800 200 200 7   - no one should die and the simulation should stop when all the philospher everyone has eaten 7 times.
./philo_bonus 4 410 200 200     - no one should die.
./philo_bonus 4 310 200 100     - a philosopher should die.