Notifies the profiler that a transition from unmanaged code to managed code has occurred.
HRESULT UnmanagedToManagedTransition( [in] FunctionID functionId, [in] COR_PRF_TRANSITION_REASON reason);
If the value of reason is COR_PRF_TRANSITION_RETURN and functionId is not null, the function ID is that of the unmanaged function, and will never have been compiled using the just-in-time (JIT) compiler. Unmanaged functions have some basic information associated with them, such as a name and some metadata.
If the value of reason is COR_PRF_TRANSITION_CALL, it may be possible that the called function (that is, the managed function) has not yet been JIT-compiled.