等待池中所有线程的初始化

Question

我有创建线程池的主线程。在调用函数之前，对池中的每个线程进行初始化。当所有线程都将被初始化时，如何等待？

例子：

from multiprocessing.pool import ThreadPool

def main():
    # in main thread
    pool = ThreadPool(processes=5, initializer=init_pool)

    # >>> here it is I want to wait for initialized

    pool.map_async(do_smth).get()

 def init_pool():
    # initialized new thread in pool
    pass

def do_smth():
    # do somethings
    pass

如果发生线程初始化异常，则必须不引起map_async

Answer 1

我会在您的do_smth() 函数中实现barrier 并跳过init_pool。但这只能从 Python 3.2 开始。

Barriers 有预定义的参与方数量，必须调用 Barrier 的 wait-function。当屏障记录正确数量的调用时，它会“丢弃”，调用方会同时返回到那里他们的工作。

类似的东西：

from multiprocessing.pool import ThreadPool
from threading import Barrier

b = Barrier(parties=5)

def main():
    # in main thread
    pool = ThreadPool(processes=5)

    pool.map_async(do_smth).get()

def do_smth():
    #initialize here
    b.wait() #call to the barrier
    # do somethings
    pass