1. uwsgi 的锁

来源：https://stackoverflow.com/questions/42325105/flask-processing-requests-1-by-1

如果使用的是 uwsgi，那么可以使用下面的锁

@app.route("/",methods=['POST'])
def main_process():
    uwsgi.lock()
    # Critical section
    # heavy process here to run alone
    uwsgi.unlock()
    return "Done"

根据 https://github.com/unbit/uwsgi/issues/2309 的说法，uwsgi 的锁是全局进程锁，在 core/lock.c 中可以看到锁操作是在共享内存中进行的。

官方文档：https://uwsgi-docs.readthedocs.io/en/latest/Locks.html

uWSGI supports a configurable number of locks you can use to synchronize worker processes. Lock 0 (zero) is always available, but you can add more with the locks option. If your app has a lot of critical areas, holding and releasing the same lock over and over again can kill performance.

def use_lock_zero_for_important_things():
    uwsgi.lock() # Implicit parameter 0
    # Critical section
    uwsgi.unlock() # Implicit parameter 0

def use_another_lock():
    uwsgi.lock(1)
    time.sleep(1) # Take that, performance! Ha!
    uwsgi.unlock(1)

2. python 层面的线程锁

import threading

mutex = threading.RLock()

try:
    mutex.acquire()
    print("hello world")
except Exception as e:
    pass
finally:
    mutex.release()

flask lock 锁

1. uwsgi 的锁

2. python 层面的线程锁