Re: Debugging WMI Providers - COM Discussion Boards

I have WMI Studio which works as a activeX control on IE, instances/query is run from WMI Studio. I tired attaching the IE process and wmiprvse.exe process, when I execute the query on my WMI management class it runs as "LOCAL SERVICE" instead of "SYSTEM".

I tried attaching to both the instances, but could not debug. In visual studio after attaching the process I press F5 to run it.

Either debugger is not getting attached to the process or I am not placing debug pointer at the correct location. Is there a way that automatically it steps into the code, without me figuring out the locations where to place the debug point?

So...which process is your WMI provider loaded into?! Until you know that, you're going to have trouble debugging it!

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Hey, thanks for the prompt reponse(s).

I am using WMI CIM Studio supplied by MS for viewing instances of the my management class.

Though my management class is for touchscreen, but I am having same problem with the code from GWYN COLE's book "Developing WMI Solution" and compiled and regsitered it. The namespace is "WMIBook" and class is "SampleWINNet_Basket", there is method for enumeration.

I guess when I try to view the instances of Baskets in WMI Studio, I get a "WMI:Provider load failure". In order to figure the error, I am trying to get into debugging.

So, it sounds like WMI CIM Studio is trying to load your provider (I presume your provider is a DLL?), which means that the process trying to load your provider is Internet Explorer? In that case, you want to specify Internet Explorer as your debug executable and set breakpoints in your provider source code. I would suggest the Initialize method of IWbemProviderInit as a good place to start?

If that method's never reached, then it suggests that the system is having trouble locating your provider, which suggests that the registration of your management class is incorrect.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

My provider is a DLL, I tried attaching it to Internet Explorer but didn't work even after placing breakpoints in the Initialize method of IWbemProviderInit.

I am creating a new WMI Management object with its WMI provider, the class will only do enumeration. Let me check how it goes, I guess it will take me half an hour to try out all the above permutation and combinations. Will definitely get back.

I just Googled for "debug wmi provider dll". Found a couple of things:

From Wikipedia:

WinMgmt.exe: WinMgmt.exe is not a tool; it is the executable that implements the WMI Core service. Under the Windows NT family of operating systems, WMI runs as a service. On computers running Windows 98, Windows 95 or Windows Me, WMI runs as an application. Under the Windows NT family of operating systems, it is also possible to run this executable as an application, in which case, the executable runs in the current user context. For this, the WMI service must be stopped first. The executable supports some switches that can be useful when starting WMI as a service or as an application. WMI provider developers who may want to debug their providers essentially need to run the WMI service as an application.

From this CodeProject article[^]:

Debugging WMI provider critta 4:39 11 Jan '06

Step 1:
stop the Windows Management Instrumentation Service
(control panel-->administrative tools---> services, or Start-->Run--> services.msc)

Step 2:
In your VS click go to Build/Start Debug / Go, a dialog appears and asks for "Executable for Debug Session" here specify the path to the winmgmt.exe (should be under %systemroot%/system32/wbem.

That's it !

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Tried attaching it to winmgmt.exe, I get the following critical error and debugging stops.

"Debugging information for 'winmgmt.exe' cannot be found or does not match. No symbols loaded."

I tried again by creating a simple management class which only supports enumeration. Same problem "WMI:Provider load failure", the MOF file and Enumeration function code is below:

MOF File
---------
#pragma namespace("\\\\.\\root")

Instance of __Namespace
{
Name = "KI";
};

#pragma namespace("\\\\.\\root\\KI")

instance of __Win32Provider as $P
{
Name = "KI_Country";
ClsId = "{8A203B80-841D-4274-B753-8A30D8AB862D}";

ClientLoadableCLSID = NULL;
DefaultMachineName = NULL;
ImpersonationLevel = 1;
InitializationReentrancy = 0;
InitializeAsAdminFirst = FALSE;
PerLocaleInitialization = FALSE;
PerUserInitialization = TRUE;
Pure = TRUE;
UnloadTimeout = NULL;
HostingModel = "LocalServiceHost";
};

instance of __InstanceProviderRegistration
{
Provider = $P;
SupportsGet = TRUE;
SupportsEnumeration = TRUE;
};

[
dynamic: ToInstance,
provider("KI_Country"): ToInstance
]
class Country
{
[key] string Name;
uint8 Population;
};

Source code for method for enumeration
---------------------------------------
void CCKICountry::OnCountryInstances(CWbemInstanceList& instList, LPWBEMMETHODCTX ptrs)
{
// Create instance!
LPWBEMINSTANCE pInst = CreateWbemInstance(ptrs);

if (pInst)
{
CComVariant varCapacity(11);
varCapacity.ChangeType(VT_UI1);

// Set property
pInst->SetProperty(L"Name", L"Argentina");
pInst->SetProperty(L"Population", varCapacity);
instList.Add(pInst);

pInst->SetProperty(L"Name", L"Brazil");
pInst->SetProperty(L"Population", varCapacity);
instList.Add(pInst);
}
}

IDL definition
---------------
import "oaidl.idl";
import "ocidl.idl";
import "wbemprov.idl";

[
object,
uuid(7E9375F5-7033-4991-9602-1A406A8BDED5),
helpstring("ICKICountry Interface"),
pointer_default(unique)
]
interface ICKICountry : IUnknown{
};
[
uuid(8A203B80-841D-4274-B753-8A30D8AB862D),
version(1.0),
helpstring("Test4 1.0 Type Library")
]
library Test4Lib
{
importlib("stdole2.tlb");
[
uuid(397891B8-804F-45E6-9D8D-2AF808AE2B49),
helpstring("CKICountry Class")
]
coclass CKICountry
{
[default] interface IWbemProviderInit;
interface IWbemServices;
};
};

I was able to remove the error "WMI:Provider load failuer". The problem was with the CLSID, in the MOF I was using the wrong CLSID. rectified it and now I am not getting this error.

But I am still not able to get into the debugger, for debugging I have tried using "wmic.exe" from command line. E.g.,

>wmic /NAMESPACE:\\root\KI path "Country" get name

this returns me the result.

I have tried to attach to "wmic.exe" and "cmd.exe", both didn't work.

One thing I noted was that the breakpoint shows up as a empty ring with warning sign, the message being displayed in tool tip is "The breakpoint will not be currently hit. No symbols have been loaded for the document."

Any pointers?

As I've said before, you don't want to attach to a process. Here are Microsoft's instructions for debugging a DLL[^] - they're for Visual Studio 2003, but they apply to 2005 and 2008 as well.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Ooh...I tried the as mentioned in the "Microsoft's instructions for debugging a DLL".

I have specified "C:\WINDOWS\System32\Wbem\wmic.exe", when debugging is started it opens a command prompt. In the command prompt I type:

wmic:root\cli> /NAMESPACE:\\root\KI path "Country" get name

I get the output, but does not enter debugger. I think wmic.exe does not create the DLL, how do I figure which executable or DLL is hosting my DLL in process? Possibly point to that executable in project properties may help.

Hey, Got it working. Big Grin | :-D

Attached the process to "wmiprvse.exe" instead of specifying the command line. Now able to debug.

Thanks Stuart for all the help, your pointers helped me be on track.

Thanks once again.

Excellent

Now you've got the debugging working, you can get back to the primary problem - i.e. getting the provider working Smile | :)

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Hey Stuart,

Hope you enjoyed the weekend.

Now in my OnxxxInstance() method I am trying to set the WMI property EWFUsage which is defined as uint32. I keep getting error 0x80041005, the error seems to be related with the setting up of variant variable.

My code looks something like this in OnxxxInstance()

pInst->SetProperty<UINT32>(L"EWFUsage", 11);

I tried as below also:

CComVariant varValue(11);
varValue.ChangeType(VT_UI4);
pInst->SetProperty(L"EWFUsage",varValue);

krishiyengar wrote:
I keep getting error 0x80041005

What statement actually raises the error?

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

When I am setting the WMI property value, I get the error. The method SetProperty() raises the error.

void CTL_Memory::OnMemoryInstances(CWbemInstanceList& instList, LPWBEMMETHODCTX ptrs)
{


     // Create instance!
     LPWBEMINSTANCE pInst = CreateWbemInstance(ptrs);

     if (pInst)
     {
          CComVariant varValue(11ul);
          varValue.ChangeType(VT_UI8);

          //varValue.ullVal = 0l;
          pInst->SetProperty(L"EWFUsage",UINT32(11));

                        instList.Add(pInst);
            }
}

When I change the code to :

pInst->SetProperty(L"EWFUsage",int(11));

I.e., intead of casting it as UINT32 I cast it to int() then it works. My other property values are 64 bit, which data type casting will I be required to use?

__int64?

Look at the source code for the WMI Provider framework you're using - that should define the mappings between C++ types and VARIANT types.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

I checked the atlcomcli.h file, which defines the C++ to VARIANT mappings.

In order to support uint64 I have _ATL_SUPPORT_VT_I8 defined in stdAfx.h file, the code snippet from atlcomcli.h based on which I defined the directive is :

#if (_WIN32_WINNT >= 0x0501) || defined(_ATL_SUPPORT_VT_I8)
     CComVariant(__in LONGLONG nSrc) throw()
     {
          vt = VT_I8;
          llVal = nSrc;
     }
     CComVariant(__in ULONGLONG nSrc) throw()
     {
          vt = VT_UI8;
          ullVal = nSrc;
     }
#endif

In the code I tried using __int64 and LONGLONG but still I am getting the same error (0x80041005).

I'm thinking more of the code that implements the 'SetProperty' method

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

I just figured out that this method is in a header file I took from a book.

I am debugging the code and trying to figure out the reason.

Got it working, 64 bit integers are handled differently from 32 bit integers.

I tweaked the code to handle 64 bit integers as well and it worked.

Thanks for your time. Big Grin | :-D

how to get the name of propertie in actvieX control.

Eg:
"BackColor"
"Visible"
"Caption"

VIBIN

"Fool's run away,where angle's fear to tread"

You need to interrogate the control for its type information. This CodeProject article[^] has code that does that.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

Hello,

I am trying to simulate a SONY TV remote control to our Set Top box's (STB) remote control.
We use Serial Communication to communicate between the TV and the STB. We are using SONY TV RS232C Control Protocol Manual to send information thru our remote to the SONY TV.
To ensure serial communication I have used a SerialPort class of Microsoft.
Now we know interfaces as Ethernet, FireWire, and USB all that send data as a serial stream, the term "serial port" usually identifies hardware more or less compliant to the RS-232 standard, intended to interface with a modem or with a similar communication device.
But the Control Protocol doc specifies that it is RS232C complaint?
Will the same class support the serial communication?

I ask that as I feel that there is an error in the communication between my remote and the SONY TV?