AssemblyLoadContext.LoadFromStream(Stream, Stream) is not implemented

[MaxwellDAssistek]

Android application type

Classic Xamarin.Android (MonoAndroid12.0, etc.), Android for .NET (net6.0-android, etc.)

Affected platform version

VS 2022

Description

Attempting to call LoadFromStream(Stream, Stream) raises a Not Implemented exception.

PR #5940 gave support for most AssemblyLoadContext functions, but it seems LoadFromStream including symbols was missed.

Steps to Reproduce

1. Call AssemblyLoadContext.LoadFromStream(Stream, Stream)

Did you find any workaround?

A workaround seems to be to write out the dll and pdb data to a temporary file and load it from there using AssemblyLoadContext.LoadFromAssemblyPath, or use embedded debug symbols in the loaded DLL (only applicable if you have control over the DLL build).

Relevant log output

No response

[grendello]

@MaxwellDAssistek could you please attach the full stack trace you get for this exception? Thanks!

Hi @MaxwellDAssistek. We have added the "need-info" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[MaxwellDAssistek]

Ahh, my bad, it seems that the real problem might be that the InputStream does not have querying the length implemented.

Here is a small snippet that demonstrates the issue:

        using (var resStream = FileSystem.OpenAppPackageFileAsync("MyModule.dll").Result)
        {
            var loadCtx = new AssemblyLoadContext("Module");

            var assem = loadCtx.LoadFromStream(resStream);
        }

A workaround seems to be copying the stream into a MemoryStream first, which does feel wasteful, but is a workaround.

Here is the full stacktrace:

{System.NotSupportedException: Specified method is not supported.
   at Android.Runtime.InputStreamInvoker.get_Length() in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.Runtime/InputStreamInvoker.cs:line 137
   at System.Runtime.Loader.AssemblyLoadContext.<LoadFromStream>g__ReadAllBytes|88_0(Stream stream)
   at System.Runtime.Loader.AssemblyLoadContext.LoadFromStream(Stream assembly, Stream assemblySymbols)
   at DynamicallyLoadedPagesRepro.MainPage.OnCounterClicked(Object sender, EventArgs e) in C:\Users\MaxwellDreytser\Projects\DynamicallyLoadedPagesRepro\DynamicallyLoadedPagesRepro\MainPage.xaml.cs:line 27
   at Microsoft.Maui.Controls.Button.Microsoft.Maui.Controls.Internals.IButtonElement.PropagateUpClicked() in D:\a\_work\1\s\src\Controls\src\Core\Button.cs:line 278
   at Microsoft.Maui.Controls.ButtonElement.ElementClicked(VisualElement visualElement, IButtonElement ButtonElementManager) in D:\a\_work\1\s\src\Controls\src\Core\ButtonElement.cs:line 85
   at Microsoft.Maui.Controls.Button.SendClicked() in D:\a\_work\1\s\src\Controls\src\Core\Button.cs:line 253
   at Microsoft.Maui.Controls.Button.Microsoft.Maui.IButton.Clicked() in D:\a\_work\1\s\src\Controls\src\Core\HandlerImpl\Button\Button.Impl.cs:line 22
   at Microsoft.Maui.Handlers.ButtonHandler.OnClick(IButton button, View v) in D:\a\_work\1\s\src\Core\src\Handlers\Button\ButtonHandler.Android.cs:line 151
   at Microsoft.Maui.Handlers.ButtonHandler.ButtonClickListener.OnClick(View v) in D:\a\_work\1\s\src\Core\src\Handlers\Button\ButtonHandler.Android.cs:line 166
   at Android.Views.View.IOnClickListenerInvoker.n_OnClick_Landroid_view_View_(IntPtr jnienv, IntPtr native__this, IntPtr native_v) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/obj/Release/net7.0/android-33/mcw/Android.Views.View.cs:line 2285
   at Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PPL_V(_JniMarshal_PPL_V callback, IntPtr jnienv, IntPtr klazz, IntPtr p0) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.Runtime/JNINativeWrapper.g.cs:line 121}