锁:可以保证线程同步和线程安全
1)Lock锁
方式1:Lock from threading import Thread, Lock import threading def run(lock, num): lock.acquire() # 获得锁 threadName = threading.current_thread().getName() # 取得当前线程的线程名 print("%s, Hello Num: %s" %(threadName, num)) lock.release() # 释放锁 if __name__ == '__main__': lock = Lock() # 创建一个共享锁实例 for num in range(20): Thread(name='Thread-%s' % str(num), target=run, args=(lock, num)).start() # 方式2 import threading import time data = 0 lock = threading.Lock() # 创建一个锁对象 def func(): global data print("%s acquire lock...\n" % threading.currentThread().getName()) if lock.acquire(): print("%s get lock...\n" % threading.currentThread().getName()) data += 1 # must lock time.sleep(2) # 其它操作 print("%s release lock...\n" % threading.currentThread().getName()) # 调用release()将释放锁 lock.release() startTime = time.time() t1 = threading.Thread(target=func) t2 = threading.Thread(target=func) t3 = threading.Thread(target=func) t1.start() t2.start() t3.start() t1.join() t2.join() t3.join() endTime = time.time() print("used time is", endTime - startTime)
2)Semaphore锁
from threading import Thread, Lock import threading import time def worker(s, i): s.acquire() print(threading.current_thread().name + " acquire") time.sleep(i) print(threading.current_thread().name + " release") s.release() if __name__ == "__main__": # 设置限制最多3个线程同时访问共享资源 s = threading.Semaphore(3) for i in range(5): t = Thread(target=worker, args=(s, i * 2)) t.start()