Known samples for AndroidEnableMarshalMethods=true

[jonathanpeppers]

Android application type

.NET Android (net7.0-android, etc.)

Affected platform version

.NET 8 Preview 6

Description

We have turned off AndroidEnableMarshalMethods for .NET 8 due to too many issues surfaced during public testing. We plan on resolving those issues so it can be turned on for .NET 9.

This is just an issue of known examples that fail at runtime when AndroidEnableMarshalMethods=true:

• Release crash on unmanagedcallersonly framework code #7876
• [Marshal Methods] MAUI project infinite loop on startup #7893
• App becomes unresponsive when using plugin.fingerprint on net8-pre5 #8147
• ANR with MediaPlayer and AndroidEnableMarshalMethods #9064
• [Android, 9.0 Preview 5] Release configuration build results in a malfunctioning app (Preview 5 debug and Preview 4 release configurations work fine). #9115
• java.lang.UnsatisfiedLinkError: No implementation found for void crc64953c68cad4e91ae3.GlmApp.n_OnAppForegrounded() - is the library loaded, e.g. System.loadLibrary? #9209
• [regression/8.0.0-preview.6.8686] [Android] BitmapFactory.DecodeStreamAsync crashes the app on .NET 8-preview.6 in Release mode maui#16514
• Visual Studio 17.7.0 Pre2 / Dotnet 8 8.0.100-preview.5.23303.2 / MAUI 8.0.0-preview.5.8529 build error XAGJS7023 for Android maui#15947
• (maybe) [8.0.0-preview.5.8529] [Android] DeviceSensors produce an ANR at irregular intervals when built in Release mode. maui#15829
• (maybe) [regression/8.0.0] Android app crashes with an ANR on .NET 8 preview 6 maui#16418
• [MarshalMethods] .NET 9 Android crash: Fatal signal 11 (SIGSEGV), code 2 (SEGV_ACCERR), fault addr 0x7228361bf07b in tid 4437 (.NET TP Worker) #9717

Just linking them here for us to test later in future releases.

Note that even though we have closed the "duplicate" issues, they still represent actual known samples that should be considered for testing any marshal method fixes.

Steps to Reproduce

See links above.

Did you find any workaround?

No response

Relevant log output

No response

[tranb3r]

@grendello
Why did you enable marshal methods by default in net9-pre6? #8925
Did you test the known samples before releasing this feature again?
My sample #8147 is broken in net9-pre6, and once again, I have to manually disable marshal methods.

[grendello]

@tranb3r This is a very useful feature which gives a noticeable performance increase for huge majority of apps. The only known bad scenario we had was with Blazor apps, and those disable marshal methods by default. We enabled them in preview precisely for the reason of finding what else breaks and add it to the "disable" list if we can identify the issue. Note that marshal methods themselves are fine, the bug doesn't lie in their implementation as far as we can tell (we've had them around for nearly two years, they essentially implement in native code what is implemented in managed code when they are disabled) - the sole fact that they are that much faster triggers a race condition (at least in Blazor) of some sort. We haven't been able to determine what exactly trips up Blazor. If your sample has a pattern we can identify, we'd add it to the "disabled" list.

For the gain in 90% (or more) of apps out there, it is worth enabling the feature by default and disable it explicitly (or automatically, if the pattern is identified as explained above) for the remaining 10% (or less) apps.