lock = threading.Lock() subThread01 = threading.Thread(target=add) subThread02 = threading.Thread(target=sub) subThread01.start() subThread02.start() subThread01.join() subThread02.join() print("num result : %s" % num) with语句 由于threading.Lock()对象中实现了enter__()与__exit()方...
import threading def worker(lock, num): # 使用 with 语句自动获取和释放锁 with lock: print(f"Worker {num} is working...") def main(): lock = threading.Lock() threads = [] # 创建 5 个线程 for i in range(5): t = threading.Thread(target=worker, args=(lock, i)) threads.append(...
下面是一个示例,演示了如何因未释放锁而导致的阻塞情况。 importthreadingimporttime# 创建一个锁lock=threading.Lock()# 未释放的锁defblock_thread():lock.acquire()print("Lock acquired by block_thread")time.sleep(5)# 模拟长时间操作# lock.release() # 此处未释放锁defother_thread():time.sleep(1)pr...
由于threading.Lock()对象中实现了enter__()与__exit()方法,故我们可以使用with语句进行上下文管理形式的加锁解锁操作: importthreading num =0defadd():withlock:# 自动加锁globalnumforiinrange(10_000_000): num +=1# 自动解锁defsub():withlock:# 自动加锁globa
import threading num = 0 def add(): with lock: # 自动加锁 global num ...
4. 线程multiprocessing和Threading都有锁(Lock)这个模块,而且都能达到下面的要求。 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 fromthreadingimportThread,Lock a=1 deffunc1(lock): with lock: foriinrange(100000):
以下代码片段显示了使用 with lock: 来防止 Python 中的竞争条件。 from threading import Thread, Lock counter = 0 def increase(by, lock): global counter with lock: local_counter = counter local_counter += by counter = local_counter print(f'counter={counter}') lock = Lock() t1 = Thread(...
withlock=0 nolock=0 count=10000 lock=threading.Lock() def inwithlock(): global withlock for i in range(count): lock.acquire() withlock+=1 lock.release() def dewithlock(): global withlock for i in range(count): lock.acquire() withlock-=1 lock.release() def innolock(): global...
importthreadinglock=threading.Lock()withlock:# 这里写自己的代码pass with语句会在这个代码块执行前自动获取锁,在执行结束后自动释放锁。 3. 为何要使用锁?¶ 你现在肯定还是一脸懵逼,这么麻烦,我不用锁不行吗?有的时候还真不行。 那么为了说明锁存在的意义。我们分别来看下,不用锁的情形有怎样的问题。
lock = threading.Lock() # 线程工作的函数 def update_counter(name): global counter print(f"{name}: 准备更新计数器。") # 请求锁 lock.acquire() try: print(f"{name}: 已获得锁。") current_counter = counter print(f"{name}: 当前计数器值为 {current_counter}。") ...