CustomWidgetTests.InflateCustomView_ShouldNotLeakGlobalRefs test failing in CI

[simonrozsival]

Summary

The test Mono.Android.NET_Tests, Xamarin.Android.RuntimeTests.CustomWidgetTests.InflateCustomView_ShouldNotLeakGlobalRefs is failing across multiple CI configurations.

This test was added as a regression test for a JNI global reference leak when inflating custom .NET views via LayoutInflater.Inflate. Multiple fixes have been merged across dotnet/android and dotnet/java-interop, but the test continues to fail.

Background

The global ref leak was originally reported in:

• Repeated Activity recreation / switching leads to heavy GC pressure, OOM or process kill #10989 — Repeated Activity recreation/switching leads to heavy GC pressure, OOM or process kill
• Memory leak in LayoutInflater.Inflate method when using custom view in XML layout. #11101 — Memory leak in LayoutInflater.Inflate method when using custom view in XML layout

Fix attempts (all merged)

dotnet/android:

• [Mono.Android] fix global ref leak in TypeManager.Activate #11112 — fix global ref leak in TypeManager.Activate — fixed TypeManager.Activate not setting the Activatable flag after Java.Interop Unification, causing duplicate global refs in the constructor chain
• [release/10.0.1xx] [tests] Add regression test for global ref leak in LayoutInflater.Inflate #11134 — add regression test for global ref leak in LayoutInflater.Inflate (release/10.0.1xx)

dotnet/java-interop:

• [Java.Interop] fix global ref leak in ConstructPeer java-interop#1403 — fix global ref leak in ConstructPeer — fixed duplicate NewGlobalRef without disposing the old one
• [Java.Interop] Defer exception creation in TryLoadClassWithFallback to fix global ref leak java-interop#1410 — defer exception creation in TryLoadClassWithFallback to fix global ref leak

Submodule bumps bringing java-interop fixes into dotnet/android:

• Bump external/Java.Interop from 85919bb to 7b018fe #11125 — Bump Java.Interop (includes [Java.Interop] fix global ref leak in ConstructPeer java-interop#1403)
• Bump external/Java.Interop from 7b018fe to 69c9daa #11171 — Bump Java.Interop (includes [Java.Interop] Defer exception creation in TryLoadClassWithFallback to fix global ref leak java-interop#1410)

Closed (superseded) PRs

• Fix JNI global ref leak in TypeManager.Activate and ValueManager.ActivateViaReflection #11111, [Mono.Android] follow up remaining value manager activation fixes #11115, [TrimmableTypeMap] fix JavaPeerableProxy activation gref leak #11116 — earlier/alternative fix attempts, closed in favor of [Mono.Android] fix global ref leak in TypeManager.Activate #11112

Expected behavior

After all the above fixes, the global ref count should not grow when repeatedly inflating and GC-collecting custom views.

Actual behavior

The test still fails in CI, indicating that the global ref leak is not fully resolved or that there is a separate source of global ref growth.

[dartasen]

@jonathanpeppers Should we reopen an issue about gref leak if the current work isn't enough to fill in the gap between .NET 9 and .NET 10 behavior ?
Currently the original issues are closed as completed

[jonathanpeppers]

The issue fixed was specific to .NET 10.

I think this issue was more about the new test being "flaky".