Project n°9 - Philosophers

basics of threading a process, see how to create threads and discover mutexes.

Goals

Here are the things you need to know if you want to succeed this assignment:

One or more philosophers sit at a round table. There is a large bowl of spaghetti in the middle of the table.
The philosophers alternatively eat, think, or sleep.
1. While they are eating, they are not thinking nor sleeping;
2. while thinking, they are not eating nor sleeping;
3. and, of course, while sleeping, they are not eating nor thinking.
There are also forks on 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.
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.
Philosophers don’t speak with each other.
Philosophers don’t know if another philosopher is about to die.
No need to say that philosophers should avoid dying!

Rules

Program(s) should take the following arguments: 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 sim- ulation, 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.

Test

Here is the test values:

./philo 1 800 200 200 (die)
./philo 5 800 200 200 (no die)
./philo 5 800 200 200 10 > result.txt (stop after each philo eat 10 times)
./philo 4 410 200 200 (no die)
./philo 4 310 200 200 (die)

External functs

memset, printf, malloc, free, write, usleep, gettimeofday, pthread_create, pthread_detach, pthread_join, pthread_mutex_init, pthread_mutex_destroy, pthread_mutex_lock, pthread_mutex_unlock

MarJC5 / Philosophers