import threading
from contextlib import contextmanager

# Thread-local state to stored information on locks already acquired
_local = threading.local()

@contextmanager
def acquire(*locks):
  # Sort locks by object identifier
  locks = sorted(locks, key=lambda x: id(x))

  # Make sure lock order of previously acquired locks is not violated
  acquired = getattr(_local,'acquired',[])
  if acquired and max(id(lock) for lock in acquired) >= id(locks[0]):
    raise RuntimeError('Lock Order Violation')

  # Acquire all of the locks
  acquired.extend(locks)
  _local.acquired = acquired

  try:
    for lock in locks:
      lock.acquire()
    yield
  finally:
    # Release locks in reverse order of acquisition
    for lock in reversed(locks):
      lock.release()
    del acquired[-len(locks):]

import threading
x_lock = threading.Lock()
y_lock = threading.Lock()

def thread_1():
  while True:
    with acquire(x_lock, y_lock):
      print('Thread-1')

def thread_2():
  while True:
    with acquire(y_lock, x_lock):
      print('Thread-2')

t1 = threading.Thread(target=thread_1)
t1.daemon = True
t1.start()

t2 = threading.Thread(target=thread_2)
t2.daemon = True
t2.start()

import threading
x_lock = threading.Lock()
y_lock = threading.Lock()

def thread_1():

  while True:
    with acquire(x_lock):
      with acquire(y_lock):
        print('Thread-1')

def thread_2():
  while True:
    with acquire(y_lock):
      with acquire(x_lock):
        print('Thread-2')

t1 = threading.Thread(target=thread_1)
t1.daemon = True
t1.start()

t2 = threading.Thread(target=thread_2)
t2.daemon = True
t2.start()

Exception in thread Thread-1:
Traceback (most recent call last):
 File "/usr/local/lib/python3.3/threading.py", line 639, in _bootstrap_inner
  self.run()
 File "/usr/local/lib/python3.3/threading.py", line 596, in run
  self._target(*self._args, **self._kwargs)
 File "deadlock.py", line 49, in thread_1
  with acquire(y_lock):
 File "/usr/local/lib/python3.3/contextlib.py", line 48, in __enter__
  return next(self.gen)
 File "deadlock.py", line 15, in acquire
  raise RuntimeError("Lock Order Violation")
RuntimeError: Lock Order Violation
>>>

import threading

# The philosopher thread
def philosopher(left, right):
  while True:
    with acquire(left,right):
       print(threading.currentThread(), 'eating')

# The chopsticks (represented by locks)
NSTICKS = 5
chopsticks = [threading.Lock() for n in range(NSTICKS)]

# Create all of the philosophers
for n in range(NSTICKS):
  t = threading.Thread(target=philosopher,
             args=(chopsticks[n],chopsticks[(n+1) % NSTICKS]))
  t.start()