DDR爱好者之家 Design By 杰米
领会下面这个示例吧,其实跟java中wait/nofity是一样一样的道理
import threading # 条件变量,用于复杂的线程间同步锁 """ 需求: 男:小姐姐,你好呀! 女:哼,想泡老娘不成""" class Boy(threading.Thread): def __init__(self, name, condition): super().__init__(name=name) self.condition = condition def run(self): with self.condition: print("{}:小姐姐,你好呀!".format(self.name)) self.condition.wait() self.condition.notify() print("{}:对呀,想泡你".format(self.name)) self.condition.wait() self.condition.notify() print("{}:切,长这么丑, 还这么吊...".format(self.name)) self.condition.wait() self.condition.notify() class Girl(threading.Thread): def __init__(self, name, condition): super().__init__(name=name) self.condition = condition def run(self): with self.condition: print("{}:哼,想泡老娘不成".format(self.name)) self.condition.notify() self.condition.wait() print("{}:滚蛋,门都没有!".format(self.name)) self.condition.notify() self.condition.wait() print("{}:关你鸟事!".format(self.name)) self.condition.notify() self.condition.wait() if __name__ == '__main__': condition = threading.Condition() boy_thread = Boy('男', condition) girl_thread = Girl('女', condition) boy_thread.start() girl_thread.start()
Condition的底层实现了__enter__和 __exit__协议.所以可以使用with上下文管理器
由Condition的__init__方法可知,它的底层也是维护了一个RLock锁
def __enter__(self): return self._lock.__enter__()
def __exit__(self, *args): return self._lock.__exit__(*args)
def __exit__(self, t, v, tb): self.release()
def release(self): """Release a lock, decrementing the recursion level. If after the decrement it is zero, reset the lock to unlocked (not owned by any thread), and if any other threads are blocked waiting for the lock to become unlocked, allow exactly one of them to proceed. If after the decrement the recursion level is still nonzero, the lock remains locked and owned by the calling thread. Only call this method when the calling thread owns the lock. A RuntimeError is raised if this method is called when the lock is unlocked. There is no return value. """ if self._owner != get_ident(): raise RuntimeError("cannot release un-acquired lock") self._count = count = self._count - 1 if not count: self._owner = None self._block.release()
至于wait/notify是如何操作的,还是有点懵.....
wait()方法源码中这样三行代码
waiter = _allocate_lock() #从底层获取了一把锁,并非Lock锁
waiter.acquire()
self._waiters.append(waiter) # 然后将这个锁加入到_waiters(deque)中
saved_state = self._release_save() # 这是释放__enter__时的那把锁"htmlcode">all_waiters = self._waiters waiters_to_notify = _deque(_islice(all_waiters, n))# 从_waiters中取出n个 if not waiters_to_notify: # 如果是None,结束 return for waiter in waiters_to_notify: # 循环release waiter.release() try: all_waiters.remove(waiter) #从_waiters中移除 except ValueError: pass大体意思: wait先从底层创建锁,acquire, 放到一个deque中,然后释放掉with锁, notify时,从deque取拿出锁,release
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。
DDR爱好者之家 Design By 杰米
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
DDR爱好者之家 Design By 杰米
暂无评论...
更新日志
2024年11月25日
2024年11月25日
- 凤飞飞《我们的主题曲》飞跃制作[正版原抓WAV+CUE]
- 刘嘉亮《亮情歌2》[WAV+CUE][1G]
- 红馆40·谭咏麟《歌者恋歌浓情30年演唱会》3CD[低速原抓WAV+CUE][1.8G]
- 刘纬武《睡眠宝宝竖琴童谣 吉卜力工作室 白噪音安抚》[320K/MP3][193.25MB]
- 【轻音乐】曼托凡尼乐团《精选辑》2CD.1998[FLAC+CUE整轨]
- 邝美云《心中有爱》1989年香港DMIJP版1MTO东芝首版[WAV+CUE]
- 群星《情叹-发烧女声DSD》天籁女声发烧碟[WAV+CUE]
- 刘纬武《睡眠宝宝竖琴童谣 吉卜力工作室 白噪音安抚》[FLAC/分轨][748.03MB]
- 理想混蛋《Origin Sessions》[320K/MP3][37.47MB]
- 公馆青少年《我其实一点都不酷》[320K/MP3][78.78MB]
- 群星《情叹-发烧男声DSD》最值得珍藏的完美男声[WAV+CUE]
- 群星《国韵飘香·贵妃醉酒HQCD黑胶王》2CD[WAV]
- 卫兰《DAUGHTER》【低速原抓WAV+CUE】
- 公馆青少年《我其实一点都不酷》[FLAC/分轨][398.22MB]
- ZWEI《迟暮的花 (Explicit)》[320K/MP3][57.16MB]