Is SetDllImportResolver invoked multiple times normal?

[nathan130200]

I'm working on bindings for Expat to implement my own XMPP library. Then i provide a way to set an environment variable to manually point to correct expat library. Everything is working as excepted, expat is begin called and parsing is working, but...

I had placed an Debug.WriteLine to see what happens here:

    static nint TryResolveExpat(string name, Assembly assembly, DllImportSearchPath? searchPath = default)
    {
        if (name.Contains("libexpat", StringComparison.InvariantCultureIgnoreCase))
        {
            string libFile = Environment.GetEnvironmentVariable("EXPAT_LIBRARY_DIR");

            // fallback to default dll importer
            if (string.IsNullOrWhiteSpace(libFile))
                return default;

            // fallback to default dll importer
            if (!File.Exists(libFile))
                return default;

            Debug.WriteLine("Expat DLL Import Resolved: " + libFile);

            // attempt to load expat provided in env.
            return NativeLibrary.Load(libFile, assembly, searchPath);
        }

        // fallback to default dll importer
        return nint.Zero;
    }

And for my surprise is calling multiple times, my guess this is causing some memory leak loading many times into memory?

Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Using libexpat v2.5.0!
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll

The file in question
PInvoke.cs

1st: Get expat version (then next line you can see the version)
2nd: Is to invoke XML_CreateParser and return the parser pointer from unmanaged.
3rd~7th: calls is to set start/end handler, cdata open/close handler, comment handler and text handler.
8th... calls is sending data to parser (small chunks of 256 bytes for testing).

---

UPDATE: I've updated code to display address of returned nint pointer and its point to same library handle.

Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Using libexpat v2.5.0!
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)
Expat DLL Import Resolved: C:\vcpkg\installed\x64-windows\debug\bin\libexpatd.dll (at: 0000007FFC41FE0000)

But still this normal calling multipletimes even the library was resolved once?