Example Program: Dining Philosophers

NUM_PHILOSOPHERS = 5; THINKMAX = 6; EATMAX = 2

def philosopher(n, forks, display):
    f1, f2 = n, (n+1)% NUM_PHILOSOPHERS
    display.setPhil(n, "thinking")
    while 1:  #infinite loop
        time.sleep(randint(0,THINKMAX))
        display.setPhil(n, "hungry")
        forks[f1].wait()
        display.setFork(f1,"inuse")
        time.sleep(1)
        forks[f2].wait()
        display.setFork(f2, "inuse"); display.setPhil(n, "eating")
        time.sleep(randint(1,EATMAX))
        display.setPhil(n, "thinking"); display.setFork(f2,"free")
        forks[f2].signal()
        display.setFork(f1,"free")
        forks[f1].signal()
        
d = DPDisplay(NUM_PHILOSOPHERS)
forks = []
for i in range(NUM_PHILOSOPHERS):
    forks.append(Semaphore(1)); d.setFork(i,"free")
for i in range(NUM_PHILOSOPHERS):
    thread.start_new_thread(philosopher, (i,forks, d))
d.pause()