python-windows-分布式进程问题：pickle模块不能序列化lambda函数

在跑廖雪峰的一段代码的时候出了两个问题，第一个问题，经过调研有解决方案，第二个是找到了问题的地方，但是没找到原因
问题1：
_pickle.PicklingError: Can't pickle <function <lambda> at 0x000002BAAEF12F28>: attribute lookup <lambda> on __main__ failed
代码如下：

import random
import time
import queue
from multiprocessing.managers import BaseManager

task_queue = queue.Queue()
result_queue = queue.Queue()


def re_task_queue():
    global task_queue
    return task_queue


def re_result_queue():
    global result_queue
    return result_queue


class QueueManager(BaseManager):
    pass

if __name__ == '__main__':

    QueueManager.register("get_task_queue", callable=lambda :task_queue)
    QueueManager.register("get_result_queue", callable=lambda :result_queue)
    manager = QueueManager(address=("127.0.0.1", 5000), authkey=b'abc')
    manager.start()

    task = manager.get_task_queue()
    result = manager.get_result_queue()

    for i in range(10):
        n = random.randint(0, 10000)
        print "Put task %d..." % n
        task.put(n)

    print "Try to get results..."
    for i in range(10):
        r = result.get(timeout=10)
        print "Result: %d" % r


    manager.shutdown()
    print "Master exit."

报错信息：

Traceback (most recent call last):
  File "C:/Users/v_wangweihong/Desktop/supervisor-easy-master/task_master.py", line 39, in <module>
    manager.start()
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\managers.py", line 524, in start
    self._process.start()
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\process.py", line 130, in start
    self._popen = Popen(self)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\forking.py", line 277, in __init__
    dump(process_obj, to_child, HIGHEST_PROTOCOL)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\forking.py", line 199, in dump
    ForkingPickler(file, protocol).dump(obj)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 224, in dump
    self.save(obj)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 425, in save_reduce
    save(state)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 655, in save_dict
    self._batch_setitems(obj.iteritems())
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 687, in _batch_setitems
    save(v)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 568, in save_tuple
    save(element)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 655, in save_dict
    self._batch_setitems(obj.iteritems())
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 687, in _batch_setitems
    save(v)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 568, in save_tuple
    save(element)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\pickle.py", line 754, in save_global
    (obj, module, name))
pickle.PicklingError: Can't pickle <function <lambda> at 0x00000000035899E8>: it's not found as __main__.<lambda>

解决办法：
pickle模块不能序列化lambda，需要自定义函数
修改后代码：

import random
import time
import queue
from multiprocessing.managers import BaseManager

task_queue = queue.Queue()
result_queue = queue.Queue()


def re_task_queue():
    global task_queue
    return task_queue


def re_result_queue():
    global result_queue
    return result_queue


class QueueManager(BaseManager):
    pass

if __name__ == '__main__':

    QueueManager.register("get_task_queue", callable=re_task_queue)
    QueueManager.register("get_result_queue", callable=re_result_queue)
    manager = QueueManager(address=("127.0.0.1", 5000), authkey=b'abc')
    manager.start()
    
    task = manager.get_task_queue()
    result = manager.get_result_queue()
    
    for i in range(10):
        n = random.randint(0, 10000)
        print "Put task %d..." % n
        task.put(n)
    
    print "Try to get results..."
    for i in range(10):
        r = result.get(timeout=10)
        print "Result: %d" % r
    
    
    manager.shutdown()
    print "Master exit."

问题2:
如果缺少以下这行代码会抛异常（EOFERROR）：
if __name__ == '__main__':

报错信息：

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\forking.py", line 380, in main
    prepare(preparation_data)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\forking.py", line 510, in prepare
    '__parents_main__', file, path_name, etc
  File "C:\Users\v_wangweihong\Desktop\supervisor-easy-master\task_master.py", line 39, in <module>
    manager.start()
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\managers.py", line 524, in start
    self._process.start()
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\process.py", line 130, in start
    self._popen = Popen(self)
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\forking.py", line 258, in __init__
    cmd = get_command_line() + [rhandle]
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\forking.py", line 358, in get_command_line
    is not going to be frozen to produce a Windows executable.''')
RuntimeError: 
            Attempt to start a new process before the current process
            has finished its bootstrapping phase.

            This probably means that you are on Windows and you have
            forgotten to use the proper idiom in the main module:

                if __name__ == '__main__':
                    freeze_support()
                    ...

            The "freeze_support()" line can be omitted if the program
            is not going to be frozen to produce a Windows executable.
Traceback (most recent call last):
  File "C:/Users/v_wangweihong/Desktop/supervisor-easy-master/task_master.py", line 39, in <module>
    manager.start()
  File "C:\Users\v_wangweihong\AppData\Local\Continuum\anaconda2\lib\multiprocessing\managers.py", line 528, in start
    self._address = reader.recv()
EOFError

很奇葩的问题：

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