线程 Virtualbox 中正常和调试运行的不同行为

Question

当运行脚本处于 PyCharm 的调试模式或在 Flask 应用程序中时，我遇到了一个奇怪的错误。我已将我的代码缩小到以下

import virtualbox
import threading

class ThreadExecutor(threading.Thread):
    def __init__(self):
        super().__init__()

    def run(self):
        vbox = virtualbox.VirtualBox()


if __name__ == '__main__':
    th = ThreadExecutor()
    th.start()

运行这作为一个模块不会产生任何错误并且执行得很好，但在调试模式下它会产生以下错误消息

Connected to pydev debugger (build 181.5087.37)
Exception in thread Thread-6:
Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\site-packages\vboxapi\__init__.py", line 449, in __init__
    None)
pywintypes.com_error: (-2147221008, 'CoInitialize has not been called.', None, None)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\threading.py", line 916, in _bootstrap_inner
    self.run()
  File "C:/Users/.../dev/debug.py", line 13, in run
    vbox = virtualbox.VirtualBox()
  File "C:\Program Files\Python36\lib\site-packages\virtualbox\library_ext\vbox.py", line 22, in __init__
    manager = virtualbox.Manager()
  File "C:\Program Files\Python36\lib\site-packages\virtualbox\__init__.py", line 143, in __init__
    self.manager = vboxapi.VirtualBoxManager(mtype, mparams)
  File "C:\Program Files\Python36\lib\site-packages\vboxapi\__init__.py", line 991, in __init__
    self.platform = PlatformMSCOM(dPlatformParams)
  File "C:\Program Files\Python36\lib\site-packages\vboxapi\__init__.py", line 455, in __init__
    print("Warning: CoInitializeSecurity failed: ", oXctp);
NameError: name 'oXctp' is not defined

进入 \vboxapi__init__.py 我们发现

try:
    pythoncom.CoInitializeSecurity(None,
                                   None,
                                   None,
                                   pythoncom.RPC_C_AUTHN_LEVEL_DEFAULT,
                                   pythoncom.RPC_C_IMP_LEVEL_IMPERSONATE,
                                   None,
                                   pythoncom.EOAC_NONE,
                                   None)
except:
    _, oXcpt, _ = sys.exc_info();
    if isinstance(oXcpt, pythoncom.com_error) and self.xcptGetStatus(oXcpt) == -2147417831: # RPC_E_TOO_LATE
        print("Warning: CoInitializeSecurity was already called");
    else:
        print("Warning: CoInitializeSecurity failed: ", oXctp);

导致此错误的原因是什么？ sys.exc_info() 在调试器中的线程内的行为是否不同？

Answer 1

在线程和 virtualbox 之间的交互中似乎存在一些已知但未解决的问题，请参阅 here。我建议改用多处理，因为我以前没有遇到过任何问题。

线程 Virtualbox 中正常和调试运行的不同行为

Different behaviour in normal and debug run in threaded Virtualbox

python

multithreading

virtualbox

pycharm

flask

线程 Virtualbox 中正常和调试 运行 的不同行为

Different behaviour in normal and debug run in threaded Virtualbox

python

multithreading

virtualbox

pycharm

flask

线程 Virtualbox 中正常和调试运行的不同行为