实用:pyhon中异常的产生对多线程中影响

最新推荐文章于 2022-05-23 22:05:41 发布

原创最新推荐文章于 2022-05-23 22:05:41 发布 · 232 阅读

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#多线程 #python #异常处理

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这篇博客探讨了Python中异常如何影响多线程的运行情况，通过具体案例展示了异常处理在多线程环境中的行为和处理策略，对于理解和优化多线程程序具有实际指导意义。

import threading
import time

def foo1():
    try:
        1/0

    finally:
        print('foo1 fin')

def foo2():
    time.sleep(4)
    try:
        foo1()
    finally:
        print('foo2 fin')
    while True:
        time.sleep(1)

t = threading.Thread(target=foo2)
t.start()#子线程

while True:#主线程
    time.sleep(1)
    print('-------------')
    if t.is_alive():
        print('alive')
    else:
        print('dead')

运行结果:

-------------
alive
-------------
alive
-------------
alive
foo1 fin
foo2 fin
-------------
alive
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.5/threading.py", line 862, in run
    self._target(*self._args, **self._kwargs)
  File "/home/yzx/PycharmProjects/python/t32.py", line 14, in foo2
    foo1()
  File "/home/yzx/PycharmProjects/python/t32.py", line 6, in foo1
    1/0
ZeroDivisionError: division by zero

-------------
dead
-------------
dead
-------------
dead
-------------
dead
-------------
dead#一直持续打印dead,所以子进程产生异常中断了子进程,但并不影响主线程的继续执行

案例二:

import threading
import time

def foo1():
    try:
        1/0

    finally:
        print('foo1 fin')

def foo2():
    time.sleep(4)
    try:
        foo1()
    finally:
        print('foo2 fin')
    while True:
        time.sleep(1)

# t = threading.Thread(target=foo2)
# t.start()

while True:
    time.sleep(1)
    print('-------------')
    foo2()
    # if t.is_alive():
    #     print('alive')
    # else:
    #     print('dead')

运行结果:

-------------
foo1 fin
Traceback (most recent call last):
foo2 fin
  File "/home/yzx/PycharmProjects/python/t32.py", line 26, in <module>
    foo2()
  File "/home/yzx/PycharmProjects/python/t32.py", line 14, in foo2
    foo1()
  File "/home/yzx/PycharmProjects/python/t32.py", line 6, in foo1
    1/0
ZeroDivisionError: division by zero

Process finished with exit code 1  #主线程产生了小异常中断了主线程的执行,在生产环境中意味着当前程序主线程崩溃,为避免此类生产事故发生把一些不重要的代码放进子线程单独跑!