multiprocessing.Process子类可在Linux上运行，但不适用于Windows [英] multiprocessing.Process subclass works on Linux but not Windows

问题描述

我正在尝试在Windows上运行 python-gasp ，但是当我这样做时import gasp; gasp.begin_graphics()我得到以下回溯:

I'm trying to get python-gasp working on Windows, but when I do import gasp; gasp.begin_graphics() I get the following traceback:

  File "C:\Python26\lib\site-packages\gasp\backend.py", line 142, in create_screen

    screen.updater.start()

  File "C:\Python26\lib\multiprocessing\process.py", line 104, in start

    self._popen = Popen(self)

  File "C:\Python26\lib\multiprocessing\forking.py", line 239, in __init__

    dump(process_obj, to_child, HIGHEST_PROTOCOL)

  File "C:\Python26\lib\multiprocessing\forking.py", line 162, in dump

    ForkingPickler(file, protocol).dump(obj)

  File "C:\Python26\lib\pickle.py", line 224, in dump

    self.save(obj)

  File "C:\Python26\lib\pickle.py", line 331, in save

    self.save_reduce(obj=obj, *rv)

  File "C:\Python26\lib\pickle.py", line 419, in save_reduce

    save(state)

  File "C:\Python26\lib\pickle.py", line 286, in save

    f(self, obj) # Call unbound method with explicit self

  File "C:\Python26\lib\pickle.py", line 649, in save_dict

    self._batch_setitems(obj.iteritems())

  File "C:\Python26\lib\pickle.py", line 681, in _batch_setitems

    save(v)

  File "C:\Python26\lib\pickle.py", line 286, in save

    f(self, obj) # Call unbound method with explicit self

  File "C:\Python26\lib\pickle.py", line 725, in save_inst

    save(stuff)

  File "C:\Python26\lib\pickle.py", line 286, in save

    f(self, obj) # Call unbound method with explicit self

  File "C:\Python26\lib\pickle.py", line 649, in save_dict

    self._batch_setitems(obj.iteritems())

  File "C:\Python26\lib\pickle.py", line 681, in _batch_setitems

    save(v)

  File "C:\Python26\lib\pickle.py", line 331, in save

    self.save_reduce(obj=obj, *rv)

  File "C:\Python26\lib\pickle.py", line 396, in save_reduce

    save(cls)

  File "C:\Python26\lib\pickle.py", line 286, in save

    f(self, obj) # Call unbound method with explicit self

  File "C:\Python26\lib\pickle.py", line 748, in save_global

    (obj, module, name))

PicklingError: Can't pickle <class 'multiprocessing.process._MainProcess'>: it's not found as multiprocessing.process._MainProcess

有人知道为什么我在Windows XP而不是Ubuntu Linux 9.04上出现此错误吗?

Any idea why I'm getting this error on Windows XP but not on Ubuntu Linux 9.04?

看起来screen.updater是Updater(multiprocessing.Process)的实例(

It looks like screen.updater is an instance of Updater(multiprocessing.Process) (def), if that helps. The file in question is at http://bazaar.launchpad.net/~gasp-dev/gasp-core/main/annotate/head%3A/gasp/backend.py

推荐答案

您的Updater类具有成员screen，该成员本身具有成员process，该成员接收multiprocessing.current_process()的值.

Your Updater class has a member screen, which itself has a member process which receives the value of multiprocessing.current_process().

当您调用updater.start()时，它将尝试使更新程序腌制.这仅在Windows上发生，因为Linux使用fork()而不是酸洗.但是，不能对当前进程对象进行腌制，并且会引发异常.

When you call updater.start(), it tries to pickle the updater. This only happens on Windows because Linux uses fork() instead of pickling. However, the current-process object cannot be pickled and the exception is raised.

要解决此问题，您可以删除process成员.

To fix this, you can remove the process member.

这篇关于multiprocessing.Process子类可在Linux上运行，但不适用于Windows的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！