options :

- n_phi -> number_of_philosophers
- t_die -> time_to_die
- t_eat -> time_to_eat
- t_slp -> time_to_sleep
- n_eat -> [number_of_times_each_philosopher_must_eat]

thread :

• parts of a process that performs code simultaneously

• thread are light-weight-process (LWP) that happens inside a process (observe with command ps -eLf)

• a process can be single-threaded or multi-threaded

• different process have a different PID and different LWP, different thread in the same process have the same PID and different LWP

• thread vs process :

  process :

  • process is isolated, it doesn't share memory with any other process
  • process is less efficient in communication, it takes more times to create or terminate or switch
  • process speed is not impacted by speed of other process (untill it reach the limit of cpu)

  thread :

  • thread are not isolated, they share memory with the other threads
  • thread is more efficient in communication, it takes less times to create or terminate or switch
  • thread can become slow if the process does many concurrent tasks

• ressources :

  • https://www.baeldung.com/linux/process-vs-thread

mutex :

• mutual exclusion
• to prevent a part of the code to be performed simultaneously by threads
• the section of code wraped by a mutex can be access by only one thread at a time
• the section starts by unlocking a mutex, and end by locking it

external function :

• memset : fill memory with a constant byte
• printf : format and print data
• malloc : allocate dynamic memory
• free : free dynamic memory
• write : write to a file descriptor
• usleep : suspend execution for microseconds intervals
• gettimeofday: get time
• pthread_create : create a new thread
• pthread_join : wait for a thread to finish,
• pthread_detach : when a thread is detached it cannot be join, you cannot wait for it to teminate, it will release its ressources on its own when it has finish
• pthread_mutex_init : initialize a mutex
• pthread_mutex_destroy: destroy a mutex
• pthread_mutex_unlock : unlock a mutex
• pthread_mutex_lock : lock a mutex