Due: 10/1/2001 - Class Time

Write a multi-threaded C program that simulates the "Dining Philosophers" problem as discussed on page 283. You may take an approach similar to that of the book, or you may approach the problem differently - your choice. Regardless, the following guidelines need to be observed:

1. Philosophers
   • Each Philosopher is a thread
   • Each Philosopher will eat Breakfast, then Lunch, then Dinner
   • No Philosopher should start the 'next' meal until all Philosophers have completed the current meal
2. Chopsticks
• Arrange for a 'shared' array of int to represent the sticks
• A Philosopher is NOT allowed to grab both sticks 'simultaneously; i.e.
  • mutex lock the stick array
  • if ONE of the sticks you need is available - take it
  • unlock the stick array
  • usleep(100);
  • repeat the process for the other stick needed
  • IF you can't get BOTH sticks
    • give up the one that you are holding
    • usleep(500);
    • start the process over
  • IF you CAN get both sticks
    • simulate eating for sleep(a couple seconds);
    • give back both sticks
    • perform deep thought until you are awakened for the next meal; i.e. cond_wait(xxx,yyy)
3. Synchronization
   • main() is allow to coordinate the Philosopher activity if you want
   • keep the logic as simple as possible
   • don't depend on thr_yield() to 'accidentally' make things happen in the correct order. You MAY use thr_yield() to keep one Philosopher from hogging all the CPU time.
4. Output
   • log which Philosopher eats which meal (don't produce tons of output)
   • main() should log when 'breakfast' is finished, lunch is finished etc.
   • main() should not exit until all Philosopher threads have thr_exit()ed.
     
     
     You will use the 'script' command to capture all necessary information for handin.