python threading开启的线程中用multiprocessing再开启多线程出现AttributeError

Question

一个简单的例子重现这个报错:

from multiprocessing.dummy import Pool as ThreadPool
import threading
def work():
    l = [1,2,3]
    pool = ThreadPool(3)
    pool.map(work2,l)
    pool.close()
    pool.join()
if __name__ == '__main__':
    t = threading.Thread(target=work)
    t.start()

错误信息：

    Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 504, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/eggeek/palendar/geodata/operation/praser.py", line 7, in work
    pool = ThreadPool(3)
  File "/usr/lib/python2.7/multiprocessing/dummy/__init__.py", line 150, in Pool
    return ThreadPool(processes, initializer, initargs)
  File "/usr/lib/python2.7/multiprocessing/pool.py", line 685, in __init__
    Pool.__init__(self, processes, initializer, initargs)
  File "/usr/lib/python2.7/multiprocessing/pool.py", line 136, in __init__
    self._repopulate_pool()
  File "/usr/lib/python2.7/multiprocessing/pool.py", line 199, in _repopulate_pool
    w.start()
  File "/usr/lib/python2.7/multiprocessing/dummy/__init__.py", line 73, in start
    self._parent._children[self] = None
AttributeError: 'Thread' object has no attribute '_children'

Answer 1

这是一个python的bug，参考 http://bugs.python.org/issue10015

可以按照里面的方法来绕过去，或者升级到python 2.7.5 或者 3.3.2

Answer 2

pool.map(work2,l)你这个里面的work2 没有声明，报错了，是不是代码没有上传全部

Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner

self.run()

File "/usr/lib/python2.7/threading.py", line 763, in run

self.__target(*self.__args, **self.__kwargs)

File "test.py", line 7, in work

pool.map(work2,l)

NameError: global name 'work2' is not defined