釋放virtualbox時Win32異常

Question

我正在嘗試在線程中運行Virtualbox。 在while循環的第二次迭代中，th變量被重新分配，應用程序崩潰並生成Win32異常。 這似乎是由vbox和會話的發布引起的。 我的問題是如何正確手動釋放它們？

Win32 exception occurred releasing IUnknown at 0x035e40b8
Win32 exception occurred releasing IUnknown at 0x04babcb0

我的應用程序的基礎知識（來自pyvbox和virtualbox sdk的virtualbox）

import virtualbox
import threading
import time


class ThreadExecutor(threading.Thread):
    def __init__(self):
        self.vbox = None
        self.session = None
        self.vm = None
        super().__init__()

    def run(self):
        self.vbox = virtualbox.VirtualBox()
        self.session = virtualbox.Session()
        self.vm = self.vbox.find_machine("Ubuntu")
        self.vm.launch_vm_process(self.session, 'gui', '')

        time.sleep(30)
        if int(self.session.state) == 1:
            print('Boot failed!')
            return
        else:
            print('Powering down')
            self.session.console.power_down()
        print('Operation completed')
        return


if __name__ == '__main__':
    while True:
        print('Input')
        if input():
            th = ThreadExecutor()
            th.start()
            print('Thread started')

            time.sleep(5)
            while th.isAlive():
                print('App running')
                time.sleep(5)
            print('Execution finished')

Answer 1

為了可靠地釋放會話，您應該使用try / except / finally結構，如下所示：

try:
   #Your code
except:
   print("something unexpected happend")
finally:
   self.session.console.power_down()

Answer 2

我修改了代碼（沒有運行它）：

• 修復（不正確的東西）和一些重組
• 附加印刷

為了解決問題並進行調試（ 無意於對其進行任何修復 -至少不在此階段）。

code.py ：

#!/usr/bin/env python3

import sys
import virtualbox
import threading
import time


DEFAULT_DEBUG_MSG_INDENT = "    "


def debug(text, indent_count, indent=DEFAULT_DEBUG_MSG_INDENT, leading_eoln_count=0):
    print("{:s}{:s}[TID: {:06d}]: {:s}".format("\n" * leading_eoln_count, indent * indent_count, threading.get_ident(), text))


class ThreadExecutor(threading.Thread):
    def __init__(self):
        super().__init__()
        self.vbox = virtualbox.VirtualBox()
        self.session = virtualbox.Session()
        if not self.vbox or not self.session:
            raise RuntimeError("virtualbox initialization failed")
        self.vm = self.vbox.find_machine("Ubuntu")
        if not self.vm:
            raise ValueError("VM not found")

    def run(self):
        start_wait_time = 15
        debug("Starting VM...", 1)
        self.vm.launch_vm_process(self.session, "gui", "")
        debug("Sleeping {:d} secs...".format(start_wait_time), 1)
        time.sleep(start_wait_time)
        if int(self.session.state) == 1:
            debug("Boot failed!", 1)
            return
        else:
            debug("Powering down", 1)
            self.session.console.power_down()
        debug("Operation completed", 1)


def run(threaded=True):
    debug("RUNNING with{:s} threads".format("" if threaded else "out"), 0, leading_eoln_count=1)
    sleep_time = 5
    while input("{:s}Press ANY key followed by ENTER to continue, ENTER ONLY to queet: ".format(DEFAULT_DEBUG_MSG_INDENT)):
        th = ThreadExecutor()
        if threaded:
            debug("Starting thread...", 0)
            th.start()
            debug("Thread started", 1)
            time.sleep(sleep_time)
            while th.isAlive():
                debug("App running", 1)
                time.sleep(sleep_time)
        else:
            debug("Running...", 0)
            th.run()
        debug("Execution finished", 1)
    debug("Done", 0)


def main():
    run(threaded=False)
    run()


if __name__ == "__main__":
    print("Python {:s} on {:s}\n".format(sys.version, sys.platform))
    main()

而且有效！！！

輸出 ：

 (py35x64_test) e:\\Work\\Dev\\StackOverflow\\q051136288>"e:\\Work\\Dev\\VEnvs\\py35x64_test\\Scripts\\python.exe" code.py Python 3.5.4 (v3.5.4:3f56838, Aug 8 2017, 02:17:05) [MSC v.1900 64 bit (AMD64)] on win32 [TID: 036256]: RUNNING without threads Press ANY key followed by ENTER to continue, ENTER ONLY to queet: a [TID: 036256]: Running... [TID: 036256]: Starting VM... [TID: 036256]: Sleeping 15 secs... [TID: 036256]: Powering down [TID: 036256]: Operation completed [TID: 036256]: Execution finished Press ANY key followed by ENTER to continue, ENTER ONLY to queet: a [TID: 036256]: Running... [TID: 036256]: Starting VM... [TID: 036256]: Sleeping 15 secs... [TID: 036256]: Powering down [TID: 036256]: Operation completed [TID: 036256]: Execution finished Press ANY key followed by ENTER to continue, ENTER ONLY to queet: [TID: 036256]: Done [TID: 036256]: RUNNING with threads Press ANY key followed by ENTER to continue, ENTER ONLY to queet: a [TID: 036256]: Starting thread... [TID: 038520]: Starting VM... [TID: 036256]: Thread started [TID: 038520]: Sleeping 15 secs... [TID: 036256]: App running [TID: 036256]: App running [TID: 036256]: App running [TID: 038520]: Powering down [TID: 038520]: Operation completed [TID: 036256]: Execution finished Press ANY key followed by ENTER to continue, ENTER ONLY to queet: a [TID: 036256]: Starting thread... [TID: 028884]: Starting VM... [TID: 036256]: Thread started [TID: 028884]: Sleeping 15 secs... [TID: 036256]: App running [TID: 036256]: App running [TID: 036256]: App running [TID: 028884]: Powering down [TID: 028884]: Operation completed [TID: 036256]: Execution finished Press ANY key followed by ENTER to continue, ENTER ONLY to queet: [TID: 036256]: Done 

原始代碼被拋出（僅相關部分）：

pywintypes.com_error: (-2147221008, 'CoInitialize has not been called.', None, None)

我懷疑在初始化程序中移動virualbox init可能是行為更改的原因（盡管正如我所說，我只是移動了代碼，因為我認為初始化程序是正確的位置）-正確：將代碼移回運行再次觸發異常。

在對virtualbox和vboxapi代碼進行了簡短檢查之后，我認為這與發生CoInitializeEx的位置（線程）有關，但是我無法動彈 。

我還嘗試在主塊中手動調用該函數（ pythoncom.CoInitializeEx(0) ），但是僅import pythoncom會觸發在第^一次迭代中出現的異常。