lockfairness.py

from threading import RLock, Thread
import time

running = True

def long_lock_loop(mutex):
    while running:
        mutex.acquire()
        print "Long acquired"
        time.sleep(3)
        print "Long releasing"
        mutex.release()

def short_lock_loop(mutex):
    while running:
        mutex.acquire()
        print "Short acquired"
        mutex.release()
        time.sleep(3)

t_lock = RLock()
t1 = Thread(target=long_lock_loop, args=(t_lock,))
t2 = Thread(target=short_lock_loop, args=(t_lock,))

t1.start()
t2.start()

try:
    while True:
        time.sleep(60)
finally:
    running = False