Commit 269195b3 authored Jan 20, 2025 by wilsonshih

Prevent undisplayed splash screen from hanging in Shell.

A View's mAttachInfo field is assigned after
ViewRootImpl#performTraversals. Therefore, if the system server rapidly
requests to add two splash screen windows and then remove one during
the add sequence, the removal request might be ignored because the
traversal may not have occurred yet.
Instead of checking isAttachedToWindow, checking for the existence of
the root view's parent is more robust. This check is valid immediately
after WindowManagerGlobal#addView is called.

Flag: EXEMPT bugfix
Bug: 388221833
Test: hard-code to force create multiple splash screens in the system
server, to simulate what would happen when remove splash screen request
send to shell before the splash screen view added to the root view,
then found out the isAttachedToWindow could make the root view stay in
Shell if traversal hasn't happen.

Change-Id: I9a4f09685cbac409804e1086b027c6532c0367eb

parent 68673d19

libs/WindowManager/Shell/src/com/android/wm/shell/startingsurface/SplashscreenWindowCreator.java

+2 −1

Original line number	Diff line number	Diff line
		@@ -370,7 +370,8 @@ class SplashscreenWindowCreator extends AbsSplashWindowCreator {

		private void removeWindowInner(@NonNull View decorView, boolean hideView) {
		requestTopUi(false);
		if (!decorView.isAttachedToWindow()) {
		if (decorView.getParent() == null) {
		Slog.w(TAG, "This root view has no parent, never been added to a ViewRootImpl?");
		return;
		}
		if (hideView) {