spawn fork 和 forkserver
fork 最快但是fork处理文件的时候有一些问题，如果需要利用mp.Manager().Queue()交换数据的情况，可能会发生死锁，死锁机制未找到To Do.
利用 spawn 和 mp.Queue() 结合的时候，mp.Queue()有一点bug，比如最后一个数据读不出来
Note When an object is put on a queue, the object is pickled and a background thread later flushes the pickled data to an underlying pipe. This has some consequences which are a little surprising, but should not cause any practical difficulties – if they really bother you then you can instead use a queue created with a manager. After putting an object on an empty queue there may be an infinitesimal delay before the queue’s empty() method returns False and get_nowait() can return without raising Queue.Empty. If multiple processes are enqueuing objects, it is possible for the objects to be received at the other end out-of-order. However, objects enqueued by the same process will always be in the expected order with respect to each other.
解决方案
在我的实践中 使用 spawn 和 mp.Manager().Queue()结合会是一个比较好的解决方案，但是运行速度较慢