LoadedApk$ServiceDispatcher.mContext 泄漏

Question

经过多次轮换并且应用程序处于后台后，我收到此泄漏。这是堆栈跟踪，我无法理解原因。另外32474006字节保留的对象非常多。我有 10 个相同的泄漏。

\n

32474006 bytes retained by leaking objects\nDisplaying only 1 leak trace out of 10 with the same signature\nSignature: 329ec5b3be0cfe3ed2fc888129f5a6be93fb9\n\xe2\x94\xac\xe2\x94\x80\xe2\x94\x80\xe2\x94\x80\n\xe2\x94\x82 GC Root: Global variable in native code\n\xe2\x94\x82\n\xe2\x94\x9c\xe2\x94\x80 android.app.LoadedApk$ServiceDispatcher$DeathMonitor instance\n\xe2\x94\x82    Leaking: UNKNOWN\n\xe2\x94\x82    \xe2\x86\x93 LoadedApk$ServiceDispatcher$DeathMonitor.this$0\n\xe2\x94\x82                                               ~~~~~~\n\xe2\x94\x9c\xe2\x94\x80 android.app.LoadedApk$ServiceDispatcher instance\n\xe2\x94\x82    Leaking: UNKNOWN\n\xe2\x94\x82    \xe2\x86\x93 LoadedApk$ServiceDispatcher.mContext\n\xe2\x94\x82                                  ~~~~~~~~\n\xe2\x95\xb0\xe2\x86\x92 com.ics.homework.ui.MainActivity instance\n\xe2\x80\x8b     Leaking: YES (ObjectWatcher was watching this because com.ics.homework.ui.MainActivity received Activity#onDestroy() callback and Activity#mDestroyed is true)\n\xe2\x80\x8b     key = 8bcc50f8-ea3f-47d9-8dc3-904042a58df4\n\xe2\x80\x8b     watchDurationMillis = 60220\n\xe2\x80\x8b     retainedDurationMillis = 55216\n====================================\n0 LIBRARY LEAKS\n

\n

泄漏原因

\n

@AndroidEntryPoint\nclass MainActivity : AppCompatActivity(), NavController.OnDestinationChangedListener { \n\n....\n\noverride fun onStart() {\n    super.onStart()\n    findChromeCustomTabsNavigator(navController).bindCustomTabsService()\n}\n....\n}\n

\n

我尝试使用本教程实现 Chrome 自定义选项卡

\n

@Navigator.Name("chrome")\nclass ChromeCustomTabsNavigator(\nprivate val context: Context\n) : Navigator<ChromeCustomTabsNavigator.Destination>() {\n\n/**\n * Initialized when `findChromeCustomTabsNavigator().bindCustomTabsService()` is called.\n */\nprivate var session: CustomTabsSession? = null\n\nprivate val urisInProgress = mutableMapOf<Uri, Long>()\n\nprivate var connection :CustomTabsServiceConnection?= null\n\n/**\n * Prevent the user from repeatedly launching Chrome Custom Tabs for the same URL. Throttle\n * rapid repeats unless the URL has finished loading, or this timeout has passed (just in\n * case something went wrong with detecting that the page finished loading).\n * Feel free to change this value with [Fragment.findChromeCustomTabsNavigator.throttleTimeout()]\n * if you feel the need, or for testing purposes.\n * Defaults to two seconds.\n */\n@SuppressWarnings("WeakerAccess")\nvar throttleTimeout: Long = 2000L\n\nprivate val upIconBitmap: Bitmap by lazy {\n    AppCompatResources.getDrawable(context, R.drawable.ic_baseline_keyboard_backspace_24)?.toBitmap()!!\n}\n\noverride fun createDestination() =\n    Destination(this)\n\noverride fun navigate(\n    destination: Destination, args: Bundle?, navOptions: NavOptions?, navigatorExtras: Extras?\n): NavDestination? {\n    // The Navigation framework enforces the destination URL being non-null\n    val uri = args?.getParcelable<Uri>(KEY_URI)!!\n\n    if (!shouldAllowLaunch(uri)) return null\n\n    buildCustomTabsIntent(destination).launchUrl(context, uri)\n\n    return null // Do not add to the back stack, managed by Chrome Custom Tabs\n}\n\noverride fun popBackStack() = true // Managed by Chrome Custom Tabs\n\nprivate fun buildCustomTabsIntent(destination: Destination): CustomTabsIntent {\n    val builder = CustomTabsIntent.Builder()\n    val params = CustomTabColorSchemeParams.Builder()\n\n    session?.let { builder.setSession(it) }\n    builder.setColorScheme(destination.colorScheme)\n    if (destination.toolbarColor != 0) {\n        params.setToolbarColor(ContextCompat.getColor(context, destination.toolbarColor))\n    }\n    if (destination.navigationBarColor != 0) {\n        params.setNavigationBarColor(ContextCompat.getColor(context, destination.navigationBarColor))\n    }\n    builder.setDefaultColorSchemeParams(params.build())\n    builder.setStartAnimations(context, destination.enterAnim, destination.popEnterAnim)\n    builder.setExitAnimations(context, destination.popExitAnim, destination.exitAnim)\n    builder.setShowTitle(destination.showTitle)\n    if (destination.upInsteadOfClose) {\n        builder.setCloseButtonIcon(upIconBitmap)\n    }\n    if (destination.addDefaultShareMenuItem) {\n        builder.setShareState(CustomTabsIntent.SHARE_STATE_ON)\n    }\n    val customTabsIntent = builder.build()\n\n    // Adding referrer so websites know where their traffic came from, per Google\'s recommendations:\n    // https://medium.com/google-developers/best-practices-for-custom-tabs-5700e55143ee\n    customTabsIntent.intent.putExtra(\n        Intent.EXTRA_REFERRER, Uri.parse("android-app://" + context.packageName)\n    )\n    return customTabsIntent\n}\n\nprivate fun shouldAllowLaunch(uri: Uri): Boolean {\n    urisInProgress[uri]?.let { tabStartTime ->\n        // Have we launched this URI before recently?\n        if (System.currentTimeMillis() - tabStartTime > throttleTimeout) {\n            // Since we\'ve exceeded the throttle timeout, continue as normal, launching\n            // the destination and updating the time.\n            Timber.w("Throttle timeout for $uri exceeded. This means ChromeCustomTabsNavigator failed to accurately determine that the URL finished loading. If you see this error frequently, it could indicate a bug in ChromeCustomTabsNavigator.")\n        } else {\n            // The user has tried to repeatedly open the same URL in rapid succession. Let them chill.\n            // The tab probably just hasn\'t opened yet. Abort opening the tab a second time.\n            urisInProgress.remove(uri)\n            return false\n        }\n    }\n    urisInProgress[uri] = System.currentTimeMillis()\n    return true\n}\n\n/**\n * Boilerplate setup for Chrome Custom Tabs. This should suffice for most apps using Chrome\n * Custom Tabs with the Navigation component. It warms up Chrome in advance to save a few\n * milliseconds, and sets a [CustomTabsSession] for the [ChromeCustomTabsNavigator] so that\n * [CustomTabsSession.mayLaunchUrl] can be called from application code.\n */\nfun bindCustomTabsService() {\n    connection = object : CustomTabsServiceConnection() {\n        override fun onCustomTabsServiceConnected(name: ComponentName, client: CustomTabsClient) {\n            client.warmup(0L)\n            session = client.newSession(customTabsCallback)\n            //context.unbindService(this)\n        }\n\n        override fun onServiceDisconnected(name: ComponentName?) {}\n    }\n    CustomTabsClient.bindCustomTabsService(context, CUSTOM_TAB_PACKAGE_NAME, connection!!)\n}\n\nfun unBindCustomTabsService(){\n    if(connection !=null) return\n    context.unbindService(connection!!)\n}\n\n/**\n * Possibly pre-load one or more URLs. Note that\n * per https://developer.chrome.com/multidevice/android/customtabs#pre-render-content,\n * mayLaunchUrl should only be used if the odds are at least 50% of the user clicking\n * the link.\n * @see [CustomTabsSession.mayLaunchUrl] for more details on mayLaunchUrl.\n */\nfun mayLaunchUrl(url: Uri, extras: Bundle? = null, otherLikelyBundles: List<Bundle>? = null) {\n    session?.mayLaunchUrl(url, extras, otherLikelyBundles)\n}\n\nval customTabsCallback: CustomTabsCallback by lazy {\n    object : CustomTabsCallback() {\n        override fun onNavigationEvent(navigationEvent: Int, extras: Bundle?) {\n            when (navigationEvent) {\n                NAVIGATION_ABORTED, NAVIGATION_FAILED, NAVIGATION_FINISHED -> {\n                    // Navigation has finished. Remove the indication that page has not finished\n                    // loading, so we will allow the user to try to open the same page again.\n                    with(urisInProgress.entries) {\n                        remove(first())\n                    }\n                }\n            }\n        }\n    }\n}\n\ncompanion object {\n    private const val TAG = "ChromeTabsNavigator"\n    private const val CUSTOM_TAB_PACKAGE_NAME = "com.android.chrome"\n    const val KEY_URI = "uri"\n}\n\n@NavDestination.ClassType(Activity::class)\nclass Destination(navigator: Navigator<out NavDestination>) : NavDestination(navigator) {\n\n    var colorScheme: Int = 1\n\n    @ColorRes\n    var toolbarColor: Int = 0\n\n    @ColorRes\n    var navigationBarColor: Int = 0\n\n    @AnimRes\n    var enterAnim: Int = 0\n\n    @AnimRes\n    var exitAnim: Int = 0\n\n    @AnimRes\n    var popEnterAnim: Int = 0\n\n    @AnimRes\n    var popExitAnim: Int = 0\n\n    var showTitle: Boolean = false\n\n    var upInsteadOfClose: Boolean = false\n\n    var addDefaultShareMenuItem: Boolean = false\n\n    override fun onInflate(context: Context, attrs: AttributeSet) {\n        super.onInflate(context, attrs)\n\n        context.withStyledAttributes(attrs, R.styleable.ChromeCustomTabsNavigator, 0, 0) {\n            colorScheme = getInt(R.styleable.ChromeCustomTabsNavigator_colorScheme, 0)\n            toolbarColor = getResourceId(R.styleable.ChromeCustomTabsNavigator_toolbarColor, 0)\n            navigationBarColor =\n                getResourceId(R.styleable.ChromeCustomTabsNavigator_navigationBarColor, 0)\n            enterAnim = getResourceId(R.styleable.ChromeCustomTabsNavigator_enterAnim, 0)\n            exitAnim = getResourceId(R.styleable.ChromeCustomTabsNavigator_exitAnim, 0)\n            popEnterAnim = getResourceId(R.styleable.ChromeCustomTabsNavigator_popEnterAnim, 0)\n            popExitAnim = getResourceId(R.styleable.ChromeCustomTabsNavigator_popExitAnim, 0)\n            showTitle = getBoolean(R.styleable.ChromeCustomTabsNavigator_showTitle, false)\n            upInsteadOfClose =\n                getBoolean(R.styleable.ChromeCustomTabsNavigator_upInsteadOfClose, false)\n            addDefaultShareMenuItem =\n                getBoolean(R.styleable.ChromeCustomTabsNavigator_addDefaultShareMenuItem, false)\n        }\n    }\n}\n}\n/**\n * From https://proandroiddev.com/add-chrome-custom-tabs-to-the-android-navigation-component-75092ce20c6a\n */\nclass EnhancedNavHostFragment : NavHostFragment() {\n@SuppressLint("RestrictedApi")\noverride fun onCreateNavController(navController: NavController) {\n    super.onCreateNavController(navController)\n    context?.let { navController.navigatorProvider += ChromeCustomTabsNavigator(it) }\n}\n}\n

\n

扩展功能

\n

fun Fragment.findChromeCustomTabsNavigator(): ChromeCustomTabsNavigator =\nfindNavController().navigatorProvider.getNavigator(ChromeCustomTabsNavigator::class.java)\n\nfun AppCompatActivity.findChromeCustomTabsNavigator(navController: NavController): ChromeCustomTabsNavigator =\nnavController.navigatorProvider.getNavigator(ChromeCustomTabsNavigator::class.java)\n

\n

请注意，我在主要活动中绑定服务，因为我必须在抽屉以及一些片段中使用自定义选项卡。

\n

增强的NavHostFragment - 添加到主活动布局内部

\n

<androidx.fragment.app.FragmentContainerView\n            android:id="@+id/fragmentContainerView"\n            android:name="com.ics.homework.utils.EnhancedNavHostFragment"\n            android:layout_width="match_parent"\n            android:layout_height="match_parent"\n            app:defaultNavHost="true"\n            app:layout_constraintBottom_toBottomOf="parent"\n            app:layout_constraintEnd_toEndOf="parent"\n            app:layout_constraintStart_toStartOf="parent"\n            app:layout_constraintTop_toBottomOf="@id/toolbar"\n            app:navGraph="@navigation/main_nav_graph" />\n

\n

Answer 1

这看起来像是 Android 框架代码中的泄漏，您可以通过查看LoadedApk.java的源代码来弄清楚。

当单独的进程连接到进程中的服务时，将创建 ServiceDispatcher.DeathMonitor。这用于在连接的进程终止时通知 LoadedApk。

这里发生泄漏是因为服务被破坏，但不知何故，对 DeathMonitor 的本机引用没有被释放。这似乎意味着 IBinder.unleakToDeath() 没有被 LoadedApk 调用。

您应该尝试在最新的 Android 版本上重现并查看该错误是否仍然存在。如果是，请在 AOSP 中提交错误。

Answer 2

看起来泄漏是由线路引起的：

navController.addOnDestinationChangedListener(this)

在这里，您将活动的实例传递给控制器​​，但在活动被销毁时永远不会删除它，因此会发生泄漏。

我建议将侦听器添加到 中onResume，然后将其删除onPause。