Creating the Application's Performance Key

An application that supports performance counters must have a Performance subkey in a Services node. For development, an application writer can use Regedt32 to manually create the Performance key and the Library, Open, Collect, and Close values.

The following code shows the values under this key:

|

\HKEY_LOCAL_MACHINE
     \SYSTEM
          \CurrentControlSet
               \Services
                    \ApplicationName
                         \Performance
                              Library = DLL_Name
                              Open = Open_Function_Name
                              Collect = Collect_Function_Name
                              Close = Close_Function_Name
                              First Counter = 
                              First Help = 
                              Last Counter = 
                              Last Help = 

The Library, Open, Collect, and Close values provide the name of the application's performance DLL and the names of the exported functions in the DLL. When a performance monitoring application requests performance data, the Registry controller uses these values to determine the performance DLLs to load and the DLL functions to call. The Open and Close entries are optional.

You do not need to add manually the First Counter, First Help, Last Counter, and Last Help values. These are created automatically by the lodctr utility when you add counter names and descriptions to the Registry. These entries are explained in the following section.