Python - 在非线程中锁定全局变量

Question

I have global variable that I'd like to access from thread and from main program:

import thread
var = 0
def abc(lock):
    lock.acquire()
    var = 1
    lock.release()
lock = thread.allocate_lock()
thread.start_new_thread(abc, (lock))
while True:
    #should I put lock.acquire() here?
    var = 2
    #and should I put lock.realease() here?

I would imagine something like this. At least I do it that way with only threads (by the way - is it OK to pass lock into thread like that? I do that with all of them). If it is not possible the only way is to put main code into thread too?

Answer 1

Since there is GIL(Global Interpretation Lock) you can use a global variable to pass data between threads. Since threads shares the same memory and you cannot deadlock the application, you can safely use a global variable or pass the variable as an argument when thread is first created.