def print_chopsticks_used():
mutex_chopsticks_used.wait()
print("[", end="")
for i in range(N_PHILOSOPHERS):
print(print_chopstick(chopsticks_used[i]), end="")
print(",", end="")
print("]")
mutex_chopsticks_used.signal()
def philosopher(i):
while True:
print("%i is thinking..." % i)
# time.sleep(i + 1)
print("%i is done thinking and ready to eat" % i)
print_chopsticks_used()
get_chopsticks(i)
print("%i is starting to eat" % i)
print_chopsticks_used()
# time.sleep(i + 1)
print("%i is done eating" % i)
put_chopsticks(i)
print_chopsticks_used()
watcher()
[Thread(philosopher, i) for i in range(N_PHILOSOPHERS)]
# rendezvous
# desired: (a1 and b1) < (a2 and b2)
from sync import Thread, Semaphore, watcher
sem1 = Semaphore(0)
sem2 = Semaphore(0)
def child1():
print("a1")
sem1.signal()
sem2.wait()
print("a2")
def child2():
print("b1")
sem2.signal()
sem1.wait()
print("b2")
watcher()
threada = Thread(child1)
threadb = Thread(child2)
from sync import Thread, Semaphore, watcher
mutex = Semaphore(1)
count = 0
def child1():
global count
mutex.wait()
print("a1")
count += 1
mutex.signal()
def child2():
global count
mutex.wait()
print("b1")
count += 1
mutex.signal()
watcher()
threada = Thread(child1)
threadb = Thread(child2)
threada.join()
threadb.join()
print(count)