浅谈Python3多线程之间的执行顺序问题

from threading import Thread, Lock


# 由_acquire解锁执行后释放_release锁
def _print(_id: str, _acquire: Lock, _release: Lock) -> None:
  for i in range(10):
    _acquire.acquire()
    print(f"id:{_id}")
    _release.release()


if __name__ == '__main__':
  # 创建三个锁供3个线程使用
  mutex1 = Lock()
  mutex2 = Lock()
  mutex3 = Lock()
  # 定义三个线程A、B、C
  # 线程A需要mutex1解锁执行后释放mutex2
  # 线程B需要mutex2解锁执行后释放mutex3
  # 线程C需要mutex3解锁执行后释放mutex1
  # 元组中第一位是自定义的线程ID，第二位是解锁需要的锁，第三位是释放的锁
  threads = [Thread(target=_print, args=[i[0], i[1], i[2]]) for i in
        [('A', mutex1, mutex2), ('B', mutex2, mutex3), ('C', mutex3, mutex1)]]
  # 把mutex2和mutex3这两把锁先用了以便阻塞线程2和线程3的执行
  mutex2.acquire()
  mutex3.acquire()
  # 接下来只有线程A可以先执行是因为mutex1并没有被占用
  # 线程B和线程C需要分别等待着锁2和锁3的释放才能继续执行
  [thr.start() for thr in threads]
  [thr.join() for thr in threads]

#coding=utf-8
import threading
import time

class MyThread(threading.Thread):
  def run(self):
    for i in range(3):
      time.sleep(1)
      msg = "I'm "+self.name+' @ '+str(i) #name属性中保存的是当前线程的名字
      print(msg)


if __name__ == '__main__':
  t = MyThread()
  t.start()

#coding=utf-8
import threading
import time

class MyThread(threading.Thread):
  def run(self):
    for i in range(3):
      time.sleep(1)
      msg = "I'm "+self.name+' @ '+str(i)
      print(msg)
def test():
  for i in range(5):
    t = MyThread()
    t.start()
if __name__ == '__main__':
  test()

  I'm Thread-1 @ 0
  I'm Thread-2 @ 0
  I'm Thread-5 @ 0
  I'm Thread-3 @ 0
  I'm Thread-4 @ 0
  I'm Thread-3 @ 1
  I'm Thread-4 @ 1
  I'm Thread-5 @ 1
  I'm Thread-1 @ 1
  I'm Thread-2 @ 1
  I'm Thread-4 @ 2
  I'm Thread-5 @ 2
  I'm Thread-2 @ 2
  I'm Thread-1 @ 2
  I'm Thread-3 @ 2