Python 线程同步

使用Thread对象的Lock和RLock可以实现简单的线程同步，这两个对象都有acquire方法和release方法。对于每次只允许一个线程操作的数据，可以将操作放到acquire和release方法之间。多线程的优势在于可以同时运行多个任务，但当线程需要共享数据时，可能存在数据不同步的问题。



 示例一

<pre class="brush:cpp;toolbar:false">import threading
from time import sleep
from datetime import datetime

class MyThread(threading.Thread):
    def __init__(self, func, args, name=''):
        threading.Thread.__init__(self)
        self.name = name
        self.func = func
        self.args = args
    def getResult(self):
        return  self.res

def run(self):
        #调用类内的方法
        print('*********MyThread Run Start**********')
        print('param:---->' + self.name)
        #完成之后可以调用传入的方法
        threadLock.acquire()
        print_time(self.name,2,3)
        threadLock.release()
        self.res = self.func(*self.args)
        print('*********MyThread Run End**********')

def print_time(threadName, delay, counter):
    while counter:
        sleep(delay)
        print(f'{threadName}:{get_date_str(datetime.now())}')
        counter -= 1

def get_date_str(dt):
    return datetime.strftime(dt, '%Y-%m-%d %H-%M-%S')
def subthread(thid, sec):
    print(f'subthread-线程{thid},Start at {get_date_str(datetime.now())} ,sleep{sec} s')
    sleep(sec)
    print(f'subthread-线程{thid},End at {get_date_str(datetime.now())} ,sleep{sec} s')
def main():
    print('-' * 10 + 'ALL START:' + get_date_str(datetime.now()) + '-' * 10)
    threads.append(MyThread(subthread, (1, 2), subthread.__name__ + '线程一'))
    threads.append(MyThread(subthread, (2, 3), subthread.__name__+ '线程二'))
    for i in range(len(threads)):
        threads[i].start()
    for i in threads:
        i.join()  # 线程全部结束之后主线程才会退出
    print('-' * 10 + 'ALL End:' + get_date_str(datetime.now()) + '-' * 10)

if __name__ == '__main__':
 threadLock = threading.Lock()
 threads = []
 main()</pre>

 


 示例二

<pre class="brush:bash;toolbar:false">import threading
from time import sleep
from datetime import datetime

class MyThread(threading.Thread):
    def __init__(self, threadID, name, counter):
        threading.Thread.__init__(self)
        self.name = name
        self.threadID = threadID
        self.counter = counter

def run(self):
        # 调用类内的方法
        print('*********MyThread Start**********')
        print('param:---->' + self.name)
        # 完成之后可以调用传入的方法
        threadLock.acquire()
        print_time(self.name,self.counter,3)
        threadLock.release()
        print('*********MyThread End**********')

def get_date_str(dt):
    return datetime.strftime(dt, '%Y-%m-%d %H-%M-%S')

def print_time(threadName, delay, counter):
    while counter:
        sleep(delay)
        print(f'{threadName}:{get_date_str(datetime.now())}')
        counter -= 1

def main():
    print('-' * 10 + 'ALL START:' + get_date_str(datetime.now()) + '-' * 10)

threads.append(MyThread(1, 'thread-1', 1))
    threads.append(MyThread(2, 'thread-2', 2))

for i in range(len(threads)):
        threads[i].start()
    for i in threads:
        i.join()  # 线程全部结束之后主线程才会退出
    print('-' * 10 + 'ALL End:' + get_date_str(datetime.now()) + '-' * 10)

if __name__ == '__main__':
 threadLock = threading.Lock()
 threads = []
 main()</pre>