须要的！
为什么呢，以 python 的第三方协程实现 eventlet 为例子
看上面的代码：
from loguru import logger
import eventlet
# from eventlet.lock import Lock
# eventlet.monkey_patch()
var = 0
def foo(i):
global var
if var < 10:
eventlet.sleep(1)
var += 1
pool = eventlet.GreenPool()
for body in pool.imap(foo, [i for i in range(100)]):
pass
logger.debug(f'最初的 {var}')输入后果：
╰─➤ time python -u "/Users/ponponon/Desktop/code/me/ideaboom/test_evenetlet/need_lock_with_sleep.py"
2022-06-29 23:33:03.015 | DEBUG | __main__:<module>:23 - 最初的 100
python -u 0.24s user 0.06s system 20% cpu 1.439 total应用了锁之后，就失常了
from loguru import logger
import eventlet
from eventlet.lock import Lock
# eventlet.monkey_patch()
var = 0
lock=Lock()
def foo(i):
global var
with lock:
if var < 10:
eventlet.sleep(1)
var += 1
pool = eventlet.GreenPool()
for body in pool.imap(foo, [i for i in range(100)]):
pass
logger.debug(f'最初的 {var}')输入后果：
╰─➤ time python -u "/Users/ponponon/Desktop/code/me/ideaboom/test_evenetlet/need_lock_with_sleep.py"
2022-06-29 23:31:35.865 | DEBUG | __main__:<module>:25 - 最初的 10
python -u 0.27s user 0.04s system 2% cpu 10.351 total