Python Manager.dict()锁定的工作方式:

Question

a managers.dict（）允许在过程中共享字典并执行线程安全操作。在我的情况下，每个协调器过程都使用m元素创建共享dict，而n工作过程读取到/从单个dict键读取。

managers.dict()是否有一个单锁或 m锁，一个锁一个？

？

除了共同的dict，当工人不必互相交流时，还有另一种方式与n工人共享m元素吗？

相关的python-manager-dict-is-ever-slow-comparpy-to-dict-dict

Answer 1

在一些尝试之后，我可以说每个经理人只有一个锁。这是证明这一点的代码：

import time
import multiprocessing as mp

def process_f(key, shared_dict):
        values = [i for i in range(64 * 1024 * 1024)]
        print "Writing {}...".format(key)
        a = time.time()
        shared_dict[key] = values
        b = time.time()
        print "released {} in {}ms".format(key, (b-a)*1000)

def main():
    process_manager = mp.Manager()
    n = 5
    keys = [i for i in range(n)]
    shared_dict = process_manager.dict({i: i * i for i in keys})
    pool = mp.Pool(processes=n)
    for i in range(n):
        pool.apply_async(process_f, (keys[i], shared_dict))
    time.sleep(20)

if __name__ == '__main__':
    main()

输出：

Writing 4...
Writing 3...
Writing 1...
Writing 2...
Writing 0...
released 4 in 3542.7968502ms
released 0 in 4416.22900963ms
released 1 in 6247.48706818ms
released 2 in 7926.97191238ms
released 3 in 9973.71196747ms
Process finished with exit code 0

写作时间的增加显示正在发生的等待。