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():
    time.sleep(1) # Take that, performance! Ha!