Understanding the ViewTreeObserver leak
I am using LeakCanary 1.3.1-SNAPSHOT. I found a leak regarding the setup ViewTreeObserver.OnScrollChangedListener
and I fixed it like in the following code:
private ViewTreeObserver.OnScrollChangedListener scrollViewChangeListener;
@Override protected void onFinishInflate() {
super.onFinishInflate();
ButterKnife.inject(this);
scrollViewChangeListener = new ViewTreeObserver.OnScrollChangedListener() {
@Override public void onScrollChanged() {
EventDetailsView.this.onScrollChanged(scrollView.getScrollY());
}
};
scrollView.getViewTreeObserver()
.addOnScrollChangedListener(scrollViewChangeListener);
}
@Override public void onDetachedFromWindow() {
super.onDetachedFromWindow();
scrollView.getViewTreeObserver().removeOnScrollChangedListener(scrollViewChangeListener);
}
However LeakCanary still reports this as a leak, any idea why?
* com.couchsurfing.mobile.ui.events.detail.EventDetailsScreen$Presenter has leaked:
* GC ROOT android.view.inputmethod.InputMethodManager$1.this$0 (anonymous class extends com.android.internal.view.IInputMethodClient$Stub)
* references android.view.inputmethod.InputMethodManager.mCurRootView
* references com.android.internal.policy.impl.PhoneWindow$DecorView.mAttachInfo
* references android.view.View$AttachInfo.mTreeObserver
* references android.view.ViewTreeObserver.mOnScrollChangedListeners
* references android.view.ViewTreeObserver$CopyOnWriteArray.mData
* references java.util.ArrayList.array
* references array java.lang.Object[].[0]
* references com.couchsurfing.mobile.ui.events.detail.EventDetailsView$1.this$0 (anonymous class implements android.view.ViewTreeObserver$OnScrollChangedListener)
* references com.couchsurfing.mobile.ui.events.detail.EventDetailsView.presenter
* leaks com.couchsurfing.mobile.ui.events.detail.EventDetailsScreen$Presenter instance* Reference Key: 69d0a429-ae27-48fc-a8e0-033c920dd07c
* Device: LGE google Nexus 5 hammerhead
* Android Version: 5.1 API: 22 LeakCanary: 1.3.1-SNAPSHOT
* Durations: watch=5032ms, gc=165ms, heap dump=2932ms, analysis=29907ms* Details:
* Instance of android.view.inputmethod.InputMethodManager$1
| this$0 = android.view.inputmethod.InputMethodManager [id=0x130239c0]
| mDescriptor = java.lang.String [id=0x6f5e3f38]
| mObject = -1601862176
| mOwner = android.view.inputmethod.InputMethodManager$1 [id=0x13112da0]
* Instance of android.view.inputmethod.InputMethodManager
| static $staticOverhead = byte[] [id=0x6fe25d29;length=240;size=256]
| static CONTROL_START_INITIAL = 256
| static CONTROL_WINDOW_FIRST = 4
| static CONTROL_WINDOW_IS_TEXT_EDITOR = 2
| static CONTROL_WINDOW_VIEW_HAS_FOCUS = 1
| static DEBUG = false
| static DISPATCH_HANDLED = 1
| static DISPATCH_IN_PROGRESS = -1
| static DISPATCH_NOT_HANDLED = 0
| static HIDE_IMPLICIT_ONLY = 1
| static HIDE_NOT_ALWAYS = 2
| static INPUT_METHOD_NOT_RESPONDING_TIMEOUT = 2500
| static MSG_BIND = 2
| static MSG_DUMP = 1
| static MSG_FLUSH_INPUT_EVENT = 7
| static MSG_SEND_INPUT_EVENT = 5
| static MSG_SET_ACTIVE = 4
| static MSG_SET_USER_ACTION_NOTIFICATION_SEQUENCE_NUMBER = 9
| static MSG_TIMEOUT_INPUT_EVENT = 6
| static MSG_UNBIND = 3
| static NOT_AN_ACTION_NOTIFICATION_SEQUENCE_NUMBER = -1
| static PENDING_EVENT_COUNTER = java.lang.String [id=0x6f5bb948]
| static REQUEST_UPDATE_CURSOR_ANCHOR_INFO_NONE = 0
| static RESULT_HIDDEN = 3
| static RESULT_SHOWN = 2
| static RESULT_UNCHANGED_HIDDEN = 1
| static RESULT_UNCHANGED_SHOWN = 0
| static SHOW_FORCED = 2
| static SHOW_IMPLICIT = 1
| static TAG = java.lang.String [id=0x6f5a76e0]
| static sInstance = android.view.inputmethod.InputMethodManager [id=0x130239c0]
| mActive = true
| mBindSequence = 1523
| mClient = android.view.inputmethod.InputMethodManager$1 [id=0x13112da0]
| mCompletions = null
| mCurChannel = android.view.InputChannel [id=0x1304a850]
| mCurId = java.lang.String [id=0x1325dd80]
| mCurMethod = com.android.internal.view.IInputMethodSession$Stub$Proxy [id=0x1304a840]
| mCurRootView = com.android.internal.policy.impl.PhoneWindow$DecorView [id=0x12eac000]
| mCurSender = android.view.inputmethod.InputMethodManager$ImeInputEventSender [id=0x12c72850]
| mCurrentTextBoxAttribute = android.view.inputmethod.EditorInfo [id=0x133036c0]
| mCursorAnchorInfo = null
| mCursorCandEnd = 0
| mCursorCandStart = 0
| mCursorRect = android.graphics.Rect [id=0x13112d40]
| mCursorSelEnd = 0
| mCursorSelStart = 0
| mDummyInputConnection = android.view.inputmethod.BaseInputConnection [id=0x13112dc0]
| mFullscreenMode = false
| mH = android.view.inputmethod.InputMethodManager$H [id=0x13112de0]
| mHasBeenInactive = false
| mIInputContext = android.view.inputmethod.InputMethodManager$ControlledInputConnectionWrapper [id=0x13113310]
| mLastSentUserActionNotificationSequenceNumber = -1
| mMainLooper = android.os.Looper [id=0x12c76be0]
| mNextServedView = com.couchsurfing.mobile.ui.drawer.DrawerView [id=0x131f8c00]
| mNextUserActionNotificationSequenceNumber = 1
| mPendingEventPool = android.util.Pools$SimplePool [id=0x13110fe0]
| mPendingEvents = android.util.SparseArray [id=0x13112d80]
| mRequestUpdateCursorAnchorInfoMonitorMode = 0
| mServedConnecting = false
| mServedInputConnection = null
| mServedInputConnectionWrapper = null
| mServedView = com.couchsurfing.mobile.ui.drawer.DrawerView [id=0x131f8c00]
| mService = com.android.internal.view.IInputMethodManager$Stub$Proxy [id=0x13110fc0]
| mTmpCursorRect = android.graphics.Rect [id=0x13112d20]
| mViewToScreenMatrix = android.graphics.Matrix [id=0x13110fd0]
| mViewTopLeft = int[] [id=0x13112d60;length=2;size=24]
* Instance of com.android.internal.policy.impl.PhoneWindow$DecorView
| mActionMode = null
| mActionModePopup = null
| mActionModeView = null
| mBackgroundFallback = com.android.internal.widget.BackgroundFallback [id=0x12fdd8e0]
| mBackgroundPadding = android.graphics.Rect [id=0x12ffd9a0]
| mBarEnterExitDuration = 250
| mChanging = false
| mDefaultOpacity = -1
| mDownY = 0
| mDrawingBounds = android.graphics.Rect [id=0x12ffd980]
| mFeatureId = -1
| mFrameOffsets = android.graphics.Rect [id=0x12ffd9e0]
| mFramePadding = android.graphics.Rect [id=0x12ffd9c0]
| mHideInterpolator = android.view.animation.PathInterpolator [id=0x12ffdb00]
| mLastBottomInset = 144
| mLastHasBottomStableInset = true
| mLastHasTopStableInset = true
| mLastRightInset = 0
| mLastTopInset = 75
| mLastWindowFlags = -2122252032
| mMenuBackground = null
| mNavigationColorViewState = com.android.internal.policy.impl.PhoneWindow$ColorViewState [id=0x12ff2c70]
| mNavigationGuard = null
| mRootScrollY = 0
| mShowActionModePopup = null
| mShowInterpolator = android.view.animation.PathInterpolator [id=0x12ffda60]
| mStatusColorViewState = com.android.internal.policy.impl.PhoneWindow$ColorViewState [id=0x12ff2c40]
| mStatusGuard = null
| mWatchingForMenu = false
| this$0 = com.android.internal.policy.impl.PhoneWindow [id=0x12db9e00]
| mForeground = null
| mForegroundBoundsChanged = true
| mForegroundGravity = 119
| mForegroundInPadding = true
| mForegroundPaddingBottom = 0
| mForegroundPaddingLeft = 0
| mForegroundPaddingRight = 0
| mForegroundPaddingTop = 0
| mForegroundTintList = null
| mForegroundTintMode = null
| mHasForegroundTint = false
| mHasForegroundTintMode = false
| mMatchParentChildren = java.util.ArrayList [id=0x12ffd960]
| mMeasureAllChildren = false
| mOverlayBounds = android.graphics.Rect [id=0x12ffd940]
| mSelfBounds = android.graphics.Rect [id=0x12ffd920]
| mAnimationListener = null
| mCachePaint = null
| mChildAcceptsDrag = false
| mChildCountWithTransientState = 0
| mChildTransformation = null
| mChildren = android.view.View[] [id=0x130064c0;length=12]
| mChildrenCount = 3
| mCurrentDrag = null
| mCurrentDragView = null
| mDisappearingChildren = null
| mDragNotifiedChildren = null
| mFirstHoverTarget = null
| mFirstTouchTarget = null
| mFocused = android.widget.LinearLayout [id=0x12eac800]
| mGroupFlags = 2375763
| mHoveredSelf = false
| mInvalidateRegion = null
| mInvalidationTransformation = null
| mLastTouchDownIndex = 0
| mLastTouchDownTime = 137539724
| mLastTouchDownX = 605.0
| mLastTouchDownY = 1177.0
| mLayoutAnimationController = null
| mLayoutCalledWhileSuppressed = false
| mLayoutMode = 0
| mLayoutTransitionListener = android.view.ViewGroup$3 [id=0x12fdd850]
| mLocalPoint = null
| mNestedScrollAxes = 0
| mOnHierarchyChangeListener = null
| mPersistentDrawingCache = 2
| mPreSortedChildren = null
| mSuppressLayout = false
| mTempPoint = float[] [id=0x12c0a220;length=2;size=24]
| mTransition = null
| mTransitioningViews = null
| mVisibilityChangingChildren = null
| mAccessibilityCursorPosition = -1
| mAccessibilityDelegate = null
| mAccessibilityTraversalAfterId = -1
| mAccessibilityTraversalBeforeId = -1
| mAccessibilityViewId = -1
| mAnimator = null
| mAttachInfo = android.view.View$AttachInfo [id=0x12c4fcc0]
| mAttributes = null
| mBackground = android.graphics.drawable.ColorDrawable [id=0x13014f80]
| mBackgroundRenderNode = android.view.RenderNode [id=0x12c73740]
| mBackgroundResource = 0
| mBackgroundSizeChanged = false
| mBackgroundTint = null
| mBottom = 1920
| mCachingFailed = false
| mClipBounds = null
| mContentDescription = null
| mContext = com.couchsurfing.mobile.ui.MainActivity [id=0x12db9c80]
| mCurrentAnimation = null
| mDrawableState = null
| mDrawingCache = null
| mDrawingCacheBackgroundColor = 0
| mFloatingTreeObserver = null
| mGhostView = null
| mHasPerformedLongPress = false
| mID = -1
| mInputEventConsistencyVerifier = null
| mKeyedTags = null
| mLabelForId = -1
| mLastIsOpaque = true
| mLayerPaint = null
| mLayerType = 0
| mLayoutInsets = null
| mLayoutParams = android.view.WindowManager$LayoutParams [id=0x12f1f7e0]
| mLeft = 0
| mLeftPaddingDefined = true
| mListenerInfo = android.view.View$ListenerInfo [id=0x13109940]
| mMatchIdPredicate = null
| mMatchLabelForPredicate = null
| mMeasureCache = android.util.LongSparseLongArray [id=0x13400120]
| mMeasuredHeight = 1920
| mMeasuredWidth = 1080
| mMinHeight = 0
| mMinWidth = 0
| mNestedScrollingParent = null
| mNextFocusDownId = -1
| mNextFocusForwardId = -1
| mNextFocusLeftId = -1
| mNextFocusRightId = -1
| mNextFocusUpId = -1
| mOldHeightMeasureSpec = 1073743744
| mOldWidthMeasureSpec = 1073742904
| mOutlineProvider = android.view.ViewOutlineProvider$1 [id=0x6fcd7240]
| mOverScrollMode = 1
| mOverlay = null
| mPaddingBottom = 0
| mPaddingLeft = 0
| mPaddingRight = 0
| mPaddingTop = 0
| mParent = android.view.ViewRootImpl [id=0x13313400]
| mPendingCheckForLongPress = null
| mPendingCheckForTap = null
| mPerformClick = null
| mPrivateFlags = 25201976
| mPrivateFlags2 = 1611867680
| mPrivateFlags3 = 4
| mRecreateDisplayList = false
| mRenderNode = android.view.RenderNode [id=0x12ffd880]
| mResources = android.content.res.Resources [id=0x12c078e0]
| mRight = 1080
| mRightPaddingDefined = true
| mScrollCache = null
| mScrollX = 0
| mScrollY = 0
| mSendViewScrolledAccessibilityEvent = null
| mSendViewStateChangedAccessibilityEvent = null
| mSendingHoverAccessibilityEvents = false
| mStateListAnimator = null
| mSystemUiVisibility = 0
| mTag = null
| mTempNestedScrollConsumed = null
| mTop = 0
| mTouchDelegate = null
| mTouchSlop = 24
| mTransformationInfo = android.view.View$TransformationInfo [id=0x1349e7c0]
| mTransientStateCount = 0
| mTransitionName = null
| mUnscaledDrawingCache = null
| mUnsetPressedState = null
| mUserPaddingBottom = 0
| mUserPaddingEnd = -2147483648
| mUserPaddingLeft = 0
| mUserPaddingLeftInitial = 0
| mUserPaddingRight = 0
| mUserPaddingRightInitial = 0
| mUserPaddingStart = -2147483648
| mVerticalScrollFactor = 0.0
| mVerticalScrollbarPosition = 0
| mViewFlags = 402655360
| mWindowAttachCount = 1
* Instance of android.view.View$AttachInfo
| mAccessibilityFetchFlags = 0
| mAccessibilityFocusDrawable = null
| mAccessibilityWindowId = 2147483647
| mApplicationScale = 1.0
| mCanvas = null
| mContentInsets = android.graphics.Rect [id=0x13364ee0]
| mDebugLayout = false
| mDisabledSystemUiVisibility = 0
| mDisplay = android.view.Display [id=0x12f75b50]
| mDisplayState = 2
| mDrawingTime = 137551407
| mForceReportNewAttributes = false
| mGivenInternalInsets = android.view.ViewTreeObserver$InternalInsetsInfo [id=0x13364f40]
| mGlobalSystemUiVisibility = 0
| mHandler = android.view.ViewRootImpl$ViewRootHandler [id=0x13364d00]
| mHardwareAccelerated = true
| mHardwareAccelerationRequested = true
| mHardwareRenderer = android.view.ThreadedRenderer [id=0x13323dc0]
| mHasNonEmptyGivenInternalInsets = false
| mHasSystemUiListeners = true
| mHasWindowFocus = true
| mHighContrastText = false
| mIWindowId = null
| mIgnoreDirtyState = false
| mInTouchMode = true
| mInvalidateChildLocation = int[] [id=0x13370060;length=2;size=24]
| mKeepScreenOn = false
| mKeyDispatchState = android.view.KeyEvent$DispatcherState [id=0x13364fc0]
| mOverscanInsets = android.graphics.Rect [id=0x13364ec0]
| mOverscanRequested = false
| mPanelParentWindowToken = null
| mPendingAnimatingRenderNodes = null
| mPoint = android.graphics.Point [id=0x133582f0]
| mRecomputeGlobalAttributes = false
| mRootCallbacks = android.view.ViewRootImpl [id=0x13313400]
| mRootView = com.android.internal.policy.impl.PhoneWindow$DecorView [id=0x12eac000]
| mScalingRequired = false
| mScrollContainers = java.util.ArrayList [id=0x13364fa0]
| mSession = android.view.IWindowSession$Stub$Proxy [id=0x13358290]
| mSetIgnoreDirtyState = true
| mStableInsets = android.graphics.Rect [id=0x13364f20]
| mSystemUiVisibility = 0
| mTempArrayList = java.util.ArrayList [id=0x133701a0]
| mTmpInvalRect = android.graphics.Rect [id=0x133700c0]
| mTmpLocation = int[] [id=0x13370080;length=2;size=24]
| mTmpMatrix = android.graphics.Matrix [id=0x133582d0]
| mTmpOutline = android.graphics.Outline [id=0x13370180]
| mTmpRectList = java.util.ArrayList [id=0x13370120]
| mTmpTransformLocation = float[] [id=0x133700a0;length=2;size=24]
| mTmpTransformRect = android.graphics.RectF [id=0x133700e0]
| mTmpTransformRect1 = android.graphics.RectF [id=0x13370100]
| mTmpTransformation = android.view.animation.Transformation [id=0x13370140]
| mTransparentLocation = int[] [id=0x13370040;length=2;size=24]
| mTreeObserver = android.view.ViewTreeObserver [id=0x133656c0]
| mTurnOffWindowResizeAnim = false
| mUnbufferedDispatchRequested = false
| mUse32BitDrawingCache = true
| mViewRequestingLayout = null
| mViewRootImpl = android.view.ViewRootImpl [id=0x13313400]
| mViewScrollChanged = false
| mViewVisibilityChanged = false
| mVisibleInsets = android.graphics.Rect [id=0x13364f00]
| mWindow = android.view.ViewRootImpl$W [id=0x13364e80]
| mWindowId = null
| mWindowLeft = 0
| mWindowToken = android.view.ViewRootImpl$W [id=0x13364e80]
| mWindowTop = 0
| mWindowVisibility = 0
* Instance of android.view.ViewTreeObserver
| mAlive = true
| mOnComputeInternalInsetsListeners = null
| mOnDrawListeners = null
| mOnEnterAnimationCompleteListeners = null
| mOnGlobalFocusListeners = null
| mOnGlobalLayoutListeners = android.view.ViewTreeObserver$CopyOnWriteArray [id=0x1315a300]
| mOnPreDrawListeners = android.view.ViewTreeObserver$CopyOnWriteArray [id=0x13345760]
| mOnScrollChangedListeners = android.view.ViewTreeObserver$CopyOnWriteArray [id=0x12fd3220]
| mOnTouchModeChangeListeners = java.util.concurrent.CopyOnWriteArrayList [id=0x133a1420]
| mOnWindowAttachListeners = null
| mOnWindowFocusListeners = null
| mOnWindowShownListeners = null
| mWindowShown = false
* Instance of android.view.ViewTreeObserver$CopyOnWriteArray
| mAccess = android.view.ViewTreeObserver$CopyOnWriteArray$Access [id=0x12fa1960]
| mData = java.util.ArrayList [id=0x12fd3240]
| mDataCopy = null
| mStart = false
* Instance of java.util.ArrayList
| static $staticOverhead = byte[] [id=0x6fcffb29;length=16;size=32]
| static MIN_CAPACITY_INCREMENT = 12
| static serialVersionUID = 8683452581122892189
| array = java.lang.Object[] [id=0x13094a40;length=12]
| size = 1
| modCount = 1
* Array of java.lang.Object[]
| [0] = com.couchsurfing.mobile.ui.events.detail.EventDetailsView$1 [id=0x12fa1950]
| [1] = null
| [2] = null
| [3] = null
| [4] = null
| [5] = null
| [6] = null
| [7] = null
| [8] = null
| [9] = null
| [10] = null
| [
+3
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2 answers
Try changing the code that removes the listener to run before the view is actually detached from the window, for example:
@Override public void onDetachedFromWindow() {
scrollView.getViewTreeObserver().removeOnScrollChangedListener(scrollViewChangeListener);
super.onDetachedFromWindow();
}
The reason is that after detaching from the window, it getViewTreeObserver()
returns another instance (the "floating tree observer"), so you are not going to remove the listener from the same object where you added it.
UPDATE
Since you are using a ViewTreeObserver
child view the behavior is a little more complicated and one possible solution is to add OnAttachStateChangeListener
to yours scrollView
and add / remove yours OnScrollChangedListener
from there.
Anyway, due to the fact that there was a leak: getViewTreeObserver()
will not return the same instance after being View
detached from the window. The call removeOnScrollChangedListener()
may have no effect, keeping your original OnScrollChangedListener
one still attached to the old one ViewTreeObserver
and thus leaking yours Context
.
+6
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