If you are a 42 Student, do not copy/paste this project, it will be considered cheating and you will be grated -42.
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- Your project must be written in C.
- Your project must be written in accordance with the Norm.
If you have bonus files/functions, they are included in the norm check and you will receive a 0 if there is a norm error inside. - Your functions should not quit unexpectedly (segmentation fault, bus error, double free, etc) apart from undefined behaviors.
If this happens, your project will be considered non functional and will receive a 0 during the evaluation. - All heap allocated memory space must be properly freed when necessary. No leaks will be tolerated.
- If the subject requires it, you must submit a Makefile which will compile your source files to the required output
with the flags -Wall, -Wextra and -Werror, use cc, and your Makefile must not relink. - Your Makefile must at least contain the rules $(NAME), all, clean, fclean and re.
- To turn in bonuses to your project, you must include a rule bonus to your Makefile, which will add all the various headers,
librairies or functions that are forbidden on the main part of the project.
Bonuses must be in a different file _bonus.{c/h} if the subject does not specify anything else.
Mandatory and bonus part evaluation is done separately. - If your project allows you to use your libft, you must copy its sources and its associated Makefile in a libft folder with its associated Makefile. Your project’s Makefile must compile the library by using its Makefile, then compile the project.
- We encourage you to create test programs for your project even though this work won’t have to be submitted and won’t be graded.
It will give you a chance to easily test your work and your peers’ work. You will find those tests especially useful during your defence.
Indeed, during defence, you are free to use your tests and/or the tests of the peer you are evaluating. - Submit your work to your assigned git repository. Only the work in the git repository will be graded.
If Deepthought is assigned to grade your work, it will be done after your peer-evaluations.
If an error happens in any section of your work during Deepthought’s grading, the evaluation will stop.
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.
- 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.
- 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!
You have to write a program for the mandatory part and another one for the bonus part (if you decide to do the bonus part).
They both have to comply with the following rules:
- Global variables are forbidden!
- Your 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] - OPTIONAL)- 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.
- Each philosopher has a number ranging from 1 to number_of_philosophers.
- Philosopher number 1 sits next to philosopher number number_of_philosophers.
Any other philosopher number N sits between philosopher number N - 1 and philosopher number N + 1.
About the logs of your program:
- Any state change of a philosopher must be formatted as follows:
- timestamp_in_ms X has taken a fork
- timestamp_in_ms X is eating
- timestamp_in_ms X is sleeping
- timestamp_in_ms X is thinking
- timestamp_in_ms X died
Replace timestamp_in_ms with the current timestamp in milliseconds and X with the philosopher number.
- A displayed state message should not be mixed up with another message.
- A message announcing a philosopher died should be displayed no more than 10 ms
after the actual death of the philosopher. - Again, philosophers should avoid dying!
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| Program name | philo |
| Turn in files | Makefile, *.h, *.c, in directory philo/ |
| Makefile | NAME, all, clean, fclean, re |
| Arguments | number_of_philosophers / time_to_die / time_to_eat / time_to_sleep / [number_of_times_each_philosopher_must_eat] |
| External functions | 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 |
| Libft authorized | No |
| Description | Philosophers with threads and mutexes |
The specific rules for the mandatory part are:
- Each philosopher should be 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.
If there is only one philosopher, there should be only one fork on the table. - To prevent philosophers from duplicating forks, you should protect the forks state with a mutex for each of them.