内存泄漏

[bainian]

复现步骤：

1、build.gradle中添加‘leakcanary-android:2.9.1’检测库 2、FB自带demo中点击 “open custom view page”。 3、返回键退出。 4、报告有内存泄漏。

log：

┬─── │ GC Root: Input or output parameters in native code │ ├─ dalvik.system.PathClassLoader instance │ Leaking: NO (FlutterEngineCache↓ is not leaking and A ClassLoader is never leaking) │ ↓ ClassLoader.runtimeInternalObjects ├─ java.lang.Object[] array │ Leaking: NO (FlutterEngineCache↓ is not leaking) │ ↓ Object[645] ├─ io.flutter.embedding.engine.FlutterEngineCache class │ Leaking: NO (a class is never leaking) │ ↓ static FlutterEngineCache.instance │ ~~~~~~~~ ├─ io.flutter.embedding.engine.FlutterEngineCache instance │ Leaking: UNKNOWN │ Retaining 140 B in 4 objects │ ↓ FlutterEngineCache.cachedEngines │ ~~~~~~~~~~~~~ ├─ java.util.HashMap instance │ Leaking: UNKNOWN │ Retaining 128 B in 3 objects │ ↓ HashMap["flutter_boost_default_engine"] │ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ├─ io.flutter.embedding.engine.FlutterEngine instance │ Leaking: UNKNOWN │ Retaining 5.2 kB in 142 objects │ ↓ FlutterEngine.platformViewsController │ ~~~~~~~~~~~~~~~~~~~~~~~ ├─ io.flutter.plugin.platform.PlatformViewsController instance │ Leaking: UNKNOWN │ Retaining 680 B in 21 objects │ context instance of com.idlefish.flutterboost.example.tab.TabCustomViewActivity with mDestroyed = true │ ↓ PlatformViewsController.context │ ~~~~~~~ ╰→ com.idlefish.flutterboost.example.tab.TabCustomViewActivity instance ​ Leaking: YES (ObjectWatcher was watching this because com.idlefish.flutterboost.example.tab.TabCustomViewActivity ​ received Activity#onDestroy() callback and Activity#mDestroyed is true) ​ Retaining 45.0 kB in 773 objects ​ key = 67860805-c7c7-41f4-a33d-c548975d52ec ​ watchDurationMillis = 6707 ​ retainedDurationMillis = 1665 ​ mApplication instance of com.idlefish.flutterboost.example.MyApplication ​ mBase instance of android.app.ContextImpl

环境

Flutter Boost Version：4.2.0 Target Platform: Android Target OS version/browser: android 10 Devices: Android模拟器

flutter doctor -v：

[✓] Flutter (Channel stable, 3.0.5, on macOS 13.1 22C65 darwin-arm, locale zh-Hans-CN)
    • Flutter version 3.0.5 at /Users/zfn/workspace/flutter/sdk/google/flutter-3.0.5
    • Upstream repository https://github.com/flutter/flutter.git
    • FLUTTER_GIT_URL = https://gitee.com/mirrors/Flutter.git
    • Framework revision f1875d570e (7 months ago), 2022-07-13 11:24:16 -0700
    • Engine revision e85ea0e79c
    • Dart version 2.17.6
    • DevTools version 2.12.2
    • Pub download mirror https://pub.flutter-io.cn
    • Flutter download mirror https://storage.flutter-io.cn

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.1)
    • Android SDK at /Users/zfn/Library/Android/sdk
    • Platform android-33, build-tools 33.0.1
    • ANDROID_HOME = /Users/zfn/Library/Android/sdk
    • Java binary at: /Library/Java/JavaVirtualMachines/jdk1.8.0_321.jdk/Contents/Home/bin/java
    • Java version Java(TM) SE Runtime Environment (build 1.8.0_321-b07)
    • All Android licenses accepted.

[joechan-cq]

这个主要是普通Activity+FlutterBoostView的实现下，FlutterBoostView在onDestroy下并不会去触发PlatformViewsController.detach()方法，所以不会销毁其中的context。使用FlutterBoostActivity或FlutterBoostFragment应该都没问题

如果确认使用FlutterBoostView的Activity销毁时，没有其他Flutter页面，可以手动调用FlutterBoost.instance().getEngine().getPlatformViewsController().detach();

最好不要用FlutterBoostView吧，问题很多。