pythonのthreadで排他制御

概要

pythonのthreadで排他制御やってみた。

衝突する方。

import threading
import time

counter = 5

class MyThread(threading.Thread):
    def __init__(self, name, sleep_time):
        threading.Thread.__init__(self)
        self.name = name
        self.sleep_time = sleep_time
    def run(self):
        global counter
        count = counter
        print (self.name + ': read counter ' + str(counter))
        print (self.name + ': do something')
        time.sleep(self.sleep_time)
        counter = count - 1
        print (self.name + ': write counter ' + str(counter))


thread1 = MyThread('a', 1)
thread2 = MyThread('b', 0.1)
thread1.start()
time.sleep(0.1)
thread2.start()
thread1.join()
thread2.join()
print ('counter: ' + str(counter))

排他制御

import threading
import time

counter = 5
lock = threading.Lock()

class MyThread(threading.Thread):
    def __init__(self, name, sleep_time):
        threading.Thread.__init__(self)
        self.name = name
        self.sleep_time = sleep_time
    def run(self):
        global counter
        global lock
        lock.acquire()
        count = counter
        print (self.name + ': read counter ' + str(counter))
        print (self.name + ': do something')
        time.sleep(self.sleep_time)
        counter = count - 1
        print (self.name + ': write counter ' + str(counter))
        lock.release()

thread1 = MyThread('a', 1)
thread2 = MyThread('b', 0.1)
thread1.start()
time.sleep(0.1)
thread2.start()
thread1.join()
thread2.join()
print ('counter: ' + str(counter))

以上。