Memory leak when integrating Unity with Flutter on Android using flutter_embed_unity

[quoctruongkt]

I'm encountering a memory leak issue on Android when integrating Unity into a Flutter app using the flutter_embed_unity plugin.

Environment:
Flutter version: 3.29.3

Plugin version: flutter_embed_unity 1.2.7

Platform: Android

Description:
When running Flutter or Unity independently, memory usage remains stable.

However, once Unity is embedded into the Flutter app, RAM usage increases continuously, even when the app is idle and no interaction occurs.

The issue only happens during integration, which suggests a possible leak or lifecycle management problem in the plugin or its Android embedding.

Steps to Reproduce:
Create a basic Flutter project.

Integrate Unity using flutter_embed_unity per documentation.

Launch the app on an Android device.

Monitor RAM usage in Android Studio or via adb shell dumpsys meminfo.

Observe memory increasing over time without user interaction.

Expected Behavior:
Memory usage should remain stable when the app is idle, similar to running Flutter or Unity standalone.

Actual Behavior:
Memory usage continues to grow indefinitely when Unity is embedded, leading to eventual performance degradation or crash.

[timbotimbo]

I haven't had time to try this yet.
But to double check, are you using Flutter 3.7.0 (2.5 years old) or is that a typo for 3.27.0?

[quoctruongkt]

I haven't had time to try this yet. But to double check, are you using Flutter 3.7.0 (2.5 years old) or is that a typo for 3.27.0?

Ah, thanks for pointing that out!

It was indeed a typo — I'm using Flutter 3.29.3.
Happy to provide more details if needed!

[timbotimbo]

The Flutter 3.32.3 hotfix includes a fix for a memory leak reported in 3.29.3 when using the impeller rendering engine.
It was reported to affect the videoplayer, which I believe is also using a kind of native view underneath.

Can you try either disabling impeller or running with Flutter 3.32.3?

It would be ideal if it was simply Flutter instead of having to find some hidden leak in the plugin.

[quoctruongkt]

The Flutter 3.32.3 hotfix includes a fix for a memory leak reported in 3.29.3 when using the impeller rendering engine. It was reported to affect the videoplayer, which I believe is also using a kind of native view underneath.

Can you try either disabling impeller or running with Flutter 3.32.3?

It would be ideal if it was simply Flutter instead of having to find some hidden leak in the plugin.

Thank you for your support!

I've upgraded to Flutter 3.32.3 as suggested, and the issue has been resolved. It looks like the memory leak was indeed related to the impeller engine in 3.29.3.

Really appreciate your help in pointing me in the right direction!