python - 调用递归函数时出现 WMI 意外 COM 错误 -2147352567

Question

我是 python 的新手，作为我正在创建的程序的一部分，我正在尝试使用 WMI 来获取所有正在运行的进程及其当前处理器利用率的列表。我还使用线程事件调度程序每 30 秒调用一次。

import wmi
from threading import Timer
import time

c = wmi.WMI()
time_to_sleep  = 30

def get_process_info():
    process_info = {}    
    try:
        for process in c.Win32_Process ():
                id = process.ProcessID
                for p in c.Win32_PerfRawData_PerfProc_Process (IDProcess=id):
                    n1, d1 = long (p.PercentProcessorTime), long (p.Timestamp_Sys100NS)
                    n0, d0 = process_info.get (id, (0, 0))
                    try:
                        percent_processor_time = (float (n1 - n0) / float (d1 - d0)) *100.0
                    except ZeroDivisionError:
                        percent_processor_time = 0.0
                    process_info[id] = (n1, d1)
                    print id, process.Caption, str(percent_processor_time)
    finally: 
        Timer(time_to_sleep, get_process_info, ()).start()
        time.sleep(time_to_sleep) #Sleep while it loops

get_process_info()

它第一次运行时执行得很好，但是第二次运行时却抛出错误:

Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Python27\lib\threading.py", line 551, in __bootstrap_inner
    self.run()
  File "C:\Python27\lib\threading.py", line 755, in run
    self.function(*self.args, **self.kwargs)
  File "C:\Users\Administrator\workspace\WorkflowTesting\Workflow\Workflow.py", line 32, in get_process_info
    for process in c.Win32_Process ():
  File "C:\Python27\lib\site-packages\wmi.py", line 817, in query
    return self._namespace.query (wql, self, fields)
  File "C:\Python27\lib\site-packages\wmi.py", line 1009, in query
    return [ _wmi_object (obj, instance_of, fields) for obj in self._raw_query(wql) ]
  File "C:\Python27\lib\site-packages\wmi.py", line 1003, in _raw_query
    handle_com_error ()
  File "C:\Python27\lib\site-packages\wmi.py", line 241, in handle_com_error
    raise klass (com_error=err)
x_wmi: <x_wmi: Unexpected COM Error (-2147352567, 'Exception occurred.', (0, u'SWbemServicesEx', None, None, 0, -2147221008), None)>

Answer 1

在没有线程的情况下使用下面的方法似乎更好:

import wmi
import time

time_to_sleep  = 30

c = wmi.WMI()
process_info = {}    

while True:
    for process in c.Win32_Process ():
            id = process.ProcessID
            for p in c.Win32_PerfRawData_PerfProc_Process (IDProcess=id):
                n1, d1 = long (p.PercentProcessorTime), long (p.Timestamp_Sys100NS)
                n0, d0 = process_info.get (id, (0, 0))
                try:
                    percent_processor_time = (float (n1 - n0) / float (d1 - d0)) *100.0
                except ZeroDivisionError:
                    percent_processor_time = 0.0
                process_info[id] = (n1, d1)
                print id, process.Caption, str(percent_processor_time)
    time.sleep(time_to_sleep)

我不确定 sleep 时间是否有其他影响，但目前看来效果不错。我会怀疑如果我需要完成其他操作可能会在一个单独的线程上执行它？