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HiPerfClient
The
HiPerfClient sample simply creates a refresher using the WMI high performance
API. The client adds a set of
Win32_BasicHiPerf enumerators and instances to the refresher, enters a finite
loop that will refresh the values and outputs them to the console, and finally
removes the objects from the refresher and quits.
The
WMI high performance API is only supported on Windows 2000 platforms.
NOTE:
The HiPerfClient sample has
been designed to work with the HiPerfProvider sample. Please see the HiPerfProvider sample documentation for
instructions on building and using the provider sample. Make sure the provider is properly built and
registered before using the HiPerfClient sample.
Building the Client Application
The application can be
built from the command line using NMAKE, or it can be built using Microsoft
Visual C++.
From the command line
in the sample installation directory, type the following:
NMAKE /f "Makefile"
From Microsoft Visual
C++:
1.
Select File + Open Workspace
2.
Select the SamplCli.dsp file
General Notes
Things
to remember when you're building your own WMI client application:
1.
If you want your client to
run on NT and non-DCOM versions of Windows 95, manually load the ole32.dll and
see if CoInitializeSecurity() exists. This routine won’t exist on Windows 95
installations that don’t have DCOM installed separately. If this routine
doesn't exist, the asynchronous routines in this sample won’t work because of
mismatched security level problems. The synchronous techniques will still work.
2.
If you don’t care about
non-DCOM versions of Windows 95, you can define _WIN32_DCOM so that CoInitializeSecurity() is available for
implicit linking. Don't use _WIN32_WINNT to get this prototype since it won't
compile under the Windows 95/98 operating systems.
3.
In any case, the
CoInitializeSecurity() call (in InitInstance()) is required to work around a
security problem when WMI trying to call a Sink object but won't identify
itself. The CoInitializeSecurity() call turns off the authentication
requirement.
4.
WMI interfaces are defined
in wbemcli.h and wbemprov.h found in the wbem\include directory. You may #include both these files by
including just wbemidl.h located in the same directory.
5.
WMI interface CLSIDs are
defined in wbemuuid.lib. If you get unresolved externals in interfaces and
CLSIDs, this is what is missing.
6.
You'll need to link with
oleaut32.lib and ole32.lib to get the needed COM support.
7.
In the Link|Output
settings, specify 'wWinMainCRTStartup' as the entry point. This is per the
Unicode programming instructions.
8.
If you're using the makefiles, don't forget to set the Visual C++
environment variables. This is done by running VCVARS32.BAT.