multiprocessing.Process子在Linux上工作，但不能在Windows

Question

我試圖讓python-gasp在Windows上工作，但是當我做import gasp; gasp.begin_graphics()我得到以下回溯：

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 

任何想法，爲什麼我得到這個錯誤在Windows XP上，但不在Ubuntu Linux 9.04上？

它看起來像screen.updater是Updater(multiprocessing.Process)（def）的一個實例，如果有幫助。有問題的文件是在http://bazaar.launchpad.net/~gasp-dev/gasp-core/main/annotate/head%3A/gasp/backend.py

Answer 1

你Updater類有一個成員screen，其本身具有接收的multiprocessing.current_process()值的成員process。

當您撥打updater.start()時，它會嘗試更新更新器。這隻發生在Windows上，因爲Linux使用fork()代替酸洗。但是，當前進程對象不能被清理，並引發異常。

要解決此問題，您可以刪除process成員。