The goal of this project is to learn how to work with posix threads, mutexes, multiprocessing in UNIX systems and semaphores. Let's imagine a surtain number of philosophers sitting by the round table. We create separate thread/process for each philosopher. There is a large bowl of spaghetti in the middle of the table. 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. There are also forks on the table. There are as many forks as philosophers. Forks are represented by mutexes/semaphore 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.
macOS (x86).
pthread.h library is used to work with threading, semaphore.h and signal.h libraries are used for interprocess communication.
Source files are lintered by "42 Norminette" linter.
Visualizer to simplify logs visualization.
Mandatory part (multithreading, mutexes). Here philosophers can only take forks (mutexes) by their right and left hands.
host@name:~$ make
host@name:~$ ./philo/philo number_of_philosophers time_to_die time_to_eat time_to_sleep [number_of_times_each_philosopher_must_eat]Bonus part (multiprocessing, semaphore). In this case philosophers can take any fork from the forks pool (semaphore).
host@name:~$ make bonus
host@name:~$ ./philo_bonus/philo_bonus number_of_philosophers time_to_die time_to_eat time_to_sleep [number_of_times_each_philosopher_must_eat]Arguments
◦ 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.
Any state change of a philosopher must be formatted as follows:
◦ timestamp_in_ms philosopher_id has taken a fork
◦ timestamp_in_ms philosopher_id is eating
◦ timestamp_in_ms philosopher_id is sleeping
◦ timestamp_in_ms philosopher_id is thinking
◦ timestamp_in_ms philosopher_id died
Thus we can use Visualizer.
host@name:~$ ./philo/philo 5 800 200 200 3
host@name:~$ ./philo_bonus/philo_bonus 4 310 200 100