Avoid concurrent modification for pending partial layout views (ca98419f) · Commits · e / os / android_frameworks_base

core/java/android/view/View.java

+7 −1

Original line number	Diff line number	Diff line
		@@ -22369,7 +22369,13 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
		* Used to track views that need (at least) a partial relayout at their current size
		* during the next traversal.
		*/
		final List<View> mPartialLayoutViews = new ArrayList<View>();
		List<View> mPartialLayoutViews = new ArrayList<>();

		/**
		* Swapped with mPartialLayoutViews during layout to avoid concurrent
		* modification. Lazily assigned during ViewRootImpl layout.
		*/
		List<View> mEmptyPartialLayoutViews;

		/**
		* Used to track the identity of the current drag operation.

+13 −1

Original line number	Diff line number	Diff line
		@@ -1974,6 +1974,15 @@ public final class ViewRootImpl implements ViewParent,
		final List<View> partialLayoutViews = mAttachInfo.mPartialLayoutViews;
		final boolean didPartialLayout;
		if (!partialLayoutViews.isEmpty()) {
		// Measurement or layout of views may result in changes to the list
		// of partial-layout views. Swap in an "empty" list to prevent
		// concurrent modification of the list being traversed.
		if (mAttachInfo.mEmptyPartialLayoutViews == null) {
		mAttachInfo.mPartialLayoutViews = new ArrayList<>();
		} else {
		mAttachInfo.mPartialLayoutViews = mAttachInfo.mEmptyPartialLayoutViews;
		}

		final int count = partialLayoutViews.size();
		mInLayout = true;
		for (int i = 0; i < count; i++) {
		@@ -1992,9 +2001,12 @@ public final class ViewRootImpl implements ViewParent,
		}
		}
		mInLayout = false;
		partialLayoutViews.clear();
		didPartialLayout = true;
		triggerGlobalLayoutListener = true;

		// The traversal list becomes the new empty list.
		partialLayoutViews.clear();
		mAttachInfo.mEmptyPartialLayoutViews = partialLayoutViews;
		} else {
		didPartialLayout = false;
		}