python中多线程编程中EOFError报错问题

[fxmzssy]

最近学习python多进程编程时，发现一个问题，不知道是什么原因，请大家帮忙看看
python版本为2.7
我写了一个基于进程池的多进程处理消费者生产者模式的Python代码，如下

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from multiprocessing import Process, JoinableQueue, Pool
import time
import os

import MySQLdb

os.environ["PYTHONOPTIMIZE"] = '1'


def proxy(cls_instance):
    return cls_instance.process()


class ProdConsumProc(object):
    def __init__(self, queue,name):
        self.queue = queue
        self.name = name
 
    def producter(self):
        print "[%s]dealhour producter:begin...." % str(self.name)
        for row in range(10):
            self.queue.put(row)
            time.sleep(1)
        self.queue.join()

    def consumer(self):
        print "[%s]dealhour consumer:begin...." % str(self.name)
        while True:
            item = self.queue.get()
            print "[%s]consumer process username:%s" % (str(self.name),item)
            time.sleep(1)
            self.queue.task_done()


class BatchProc(object):
    def __init__(self, conscount,name):
        self.cusumnum = conscount
        self.name = name

    def process(self):
        taskqueue = JoinableQueue()
        for i in range(self.cusumnum):
            print "%s start consumer:begin...." % str(self.name)
            consumerservice = ProdConsumProc(taskqueue, self.name)
            consumer_p = Process(target=consumerservice.consumer, args=())
            consumer_p.daemon = True
            consumer_p.start()

        print "%s start producter:begin...." % str(self.name)
        productservice = ProdConsumProc(taskqueue, self.name)
        productservice.producter()


if __name__ == '__main__':
    pool = Pool(processes=3)
    for num in range(2):
        _kls = BatchProc(5, num)
        # pool.apply_async(self.func, args=(num,))
        pool.apply_async(proxy, args=(_kls, ))
    time.sleep(10)
    pool.close()
    pool.join()

这段代码运行一切，当我想给类ProdConsumProc初始化函数中增加一个数据库连接时（增加代码第20行），却出现了问题，代码如下：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from multiprocessing import Process, JoinableQueue, Pool
import time
import os

import MySQLdb

os.environ["PYTHONOPTIMIZE"] = '1'


def proxy(cls_instance):
    return cls_instance.process()


class ProdConsumProc(object):
    def __init__(self, queue,name):
        self.queue = queue
        self.name = name
        self.conn = MySQLdb.connect(host="173.23.2.16", user="user", passwd="1qsx", db="icp3.0", charset="utf8")

    def producter(self):
        print "[%s]dealhour producter:begin...." % str(self.name)
        for row in range(10):
            self.queue.put(row)
            time.sleep(1)
        self.queue.join()

    def consumer(self):
        print "[%s]dealhour consumer:begin...." % str(self.name)
        while True:
            item = self.queue.get()
            print "[%s]consumer process username:%s" % (str(self.name),item)
            time.sleep(1)
            self.queue.task_done()


class BatchProc(object):
    def __init__(self, conscount,name):
        self.cusumnum = conscount
        self.name = name

    def process(self):
        taskqueue = JoinableQueue()
        for i in range(self.cusumnum):
            print "%s start consumer:begin...." % str(self.name)
            consumerservice = ProdConsumProc(taskqueue, self.name)
            consumer_p = Process(target=consumerservice.consumer, args=())
            consumer_p.daemon = True
            consumer_p.start()

        print "%s start producter:begin...." % str(self.name)
        productservice = ProdConsumProc(taskqueue, self.name)
        productservice.producter()


if __name__ == '__main__':
    pool = Pool(processes=3)
    for num in range(2):
        _kls = BatchProc(5, num)
        # pool.apply_async(self.func, args=(num,))
        pool.apply_async(proxy, args=(_kls, ))
    time.sleep(10)
    pool.close()
    pool.join()

错误日志如下：
0 start consumer:begin....
1 start consumer:begin....
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "D:\Python27\lib\multiprocessing\forking.py", line 381, in main
self = load(from_parent)
File "D:\Python27\lib\pickle.py", line 1384, in load
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "D:\Python27\lib\multiprocessing\forking.py", line 381, in main
self = load(from_parent)
File "D:\Python27\lib\pickle.py", line 1384, in load
return Unpickler(file).load()
File "D:\Python27\lib\pickle.py", line 864, in load
dispatch[key](self)
File "D:\Python27\lib\pickle.py", line 886, in load_eof
return Unpickler(file).load()
File "D:\Python27\lib\pickle.py", line 864, in load
raise EOFError
EOFError
dispatch[key](self)
File "D:\Python27\lib\pickle.py", line 886, in load_eof
raise EOFError
EOFError

Process finished with exit code 0

后来我试着把这个数据库连接放在类的其他方法中（增加代码第23行和31行），程序又运行正常了，代码如下：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from multiprocessing import Process, JoinableQueue, Pool
import time
import os

import MySQLdb

os.environ["PYTHONOPTIMIZE"] = '1'


def proxy(cls_instance):
    return cls_instance.process()


class ProdConsumProc(object):
    def __init__(self, queue,name):
        self.queue = queue
        self.name = name
        #self.conn = MySQLdb.connect(host="173.23.2.16", user="user", passwd="1qsx", db="icp3.0", charset="utf8")

    def producter(self):
        self.conn = MySQLdb.connect(host="173.23.2.16", user="user", passwd="1qsx", db="icp3.0", charset="utf8")
        print "[%s]dealhour producter:begin...." % str(self.name)
        for row in range(10):
            self.queue.put(row)
            time.sleep(1)
        self.queue.join()

    def consumer(self):
        self.conn = MySQLdb.connect(host="173.23.2.16", user="user", passwd="1qsx", db="icp3.0", charset="utf8")
        print "[%s]dealhour consumer:begin...." % str(self.name)
        while True:
            item = self.queue.get()
            print "[%s]consumer process username:%s" % (str(self.name),item)
            time.sleep(1)
            self.queue.task_done()


class BatchProc(object):
    def __init__(self, conscount,name):
        self.cusumnum = conscount
        self.name = name

    def process(self):
        taskqueue = JoinableQueue()
        for i in range(self.cusumnum):
            print "%s start consumer:begin...." % str(self.name)
            consumerservice = ProdConsumProc(taskqueue, self.name)
            consumer_p = Process(target=consumerservice.consumer, args=())
            consumer_p.daemon = True
            consumer_p.start()

        print "%s start producter:begin...." % str(self.name)
        productservice = ProdConsumProc(taskqueue, self.name)
        productservice.producter()


if __name__ == '__main__':
    pool = Pool(processes=3)
    for num in range(2):
        _kls = BatchProc(5, num)
        # pool.apply_async(self.func, args=(num,))
        pool.apply_async(proxy, args=(_kls, ))
    time.sleep(10)
    pool.close()
    pool.join()

请各位大神看看是什么原因？多谢

[oyljerry]

eof 错误。文件加载有问题

[fxmzssy]

引用 1 楼 oyljerry 的回复:

eof 错误。文件加载有问题

为何放在初始化方法里不行，但是放到其他方法里就不报错了呢

[青青啊]

网上好多回答是把线程设置为0 但是会降低运行速度 怎么破

[带佳前行]

引用 3 楼 青青啊 的回复:

网上好多回答是把线程设置为0 但是会降低运行速度 怎么破

最后破了吗？