Created
March 12, 2018 08:17
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#!/usr/bin/env python | |
# -*- coding: utf-8 -*- | |
# Author: ficapy | |
# Create: '12/03/2018' | |
from threading import Lock, get_ident | |
class RLock: | |
def __init__(self): | |
self.lock = Lock() | |
self._owner = None | |
self._count = 0 | |
def acquire(self): | |
me = get_ident() | |
if self._owner == me: | |
self._count += 1 | |
return | |
rc = self.lock.acquire() | |
if rc: | |
self._owner = me | |
self._count = 1 | |
__enter__ = acquire | |
def release(self): | |
if self._owner != get_ident(): | |
raise RuntimeError() | |
self._count -= 1 | |
if self._count == 0: | |
self._owner = None | |
self.lock.release() | |
def __exit__(self, exc_type, exc_val, exc_tb): | |
self.release() | |
from collections import deque | |
class Condition: | |
def __init__(self): | |
self._lock = RLock() | |
self._waiters = deque() | |
def __enter__(self): | |
return self._lock.__enter__() | |
def __exit__(self, *args): | |
return self._lock.__exit__(*args) | |
def wait(self): | |
assert get_ident() == self._lock._owner | |
waiter = Lock() | |
self._waiters.append(waiter) | |
waiter.acquire() | |
self._lock.release() | |
waiter.acquire() | |
self._lock.acquire() | |
del waiter | |
def notify(self): | |
assert get_ident() == self._lock._owner | |
for waiter in self._waiters.copy(): | |
waiter.release() | |
self._waiters.remove(waiter) | |
class Semaphore: | |
def __init__(self, value=1): | |
self._lock = Condition() | |
self.value = value | |
def __enter__(self): | |
with self._lock: | |
if self.value == 0: | |
self._lock.wait() | |
else: | |
self.value -= 1 | |
def __exit__(self, exc_type, exc_val, exc_tb): | |
self.value += 1 | |
self._lock.notify() | |
class BoundedSemaphore(Semaphore): | |
def __init__(self, value=1): | |
super(BoundedSemaphore, self).__init__(value=value) | |
class Event: | |
def __init__(self): | |
self._cond = Condition() | |
self._flag = False | |
def set(self): | |
with self._cond: | |
self._flag = True | |
self._cond.notify() | |
def clear(self): | |
with self._cond: | |
self._flag = False | |
def wait(self): | |
with self._cond: | |
signaled = self._flag | |
if not signaled: | |
signaled = self._cond.wait() | |
return signaled |
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