Question

How long is the typical overhead added by calling a .dll written in C++ from a C# application using the following syntax?

[DllImport("abc.dll", EntryPoint = "xcFoo", CallingConvention = CallingConvention.Cdecl)]
public extern static Result Foo(out IntPtr session,
                [MarshalAs(UnmanagedType.FunctionPtr)]ObjectCallback callback, 
                UInt64 turnKey,
                string serverAddress, 
                string userId, 
                string password);

Is there a more efficient way to do it?

Answer 1

Check out this article on how to improve interop performance. What to do and what best to avoid.

http://msdn.microsoft.com/en-us/library/ms998551.aspx