Interop Performance Counters 

The Performance console .NET CLR Interop category includes counters that provide information about an application's interaction with COM components, COM+ services, and external type libraries. The following table describes these performance counters.

Performance counter	Description
# of CCWs	Displays the current number of COM callable wrappers (CCWs). A CCW is a proxy for a managed object being referenced from an unmanaged COM client. This counter indicates the number of managed objects referenced by unmanaged COM code.
# of marshaling	Displays the total number of times arguments and return values have been marshaled from managed to unmanaged code, and vice versa, since the application started. This counter is not incremented if the stubs are inlined. (Stubs are responsible for marshaling arguments and return values). Stubs are usually inlined if the marshaling overhead is small.
# of Stubs	Displays the current number of stubs created by the common language runtime. Stubs are responsible for marshaling arguments and return values from managed to unmanaged code, and vice versa, during a COM interop call or a platform invoke call.
# of TLB exports / sec	Reserved for future use.
# of TLB imports / sec	Reserved for future use.

See Also

Reference

Runtime Profiling

Other Resources

Performance Counters in the .NET Framework
Interoperating with Unmanaged Code