Why Android Activity onStop/onDestroy Is Delayed by 10 Seconds When an Infinite Animation Is Running

This article investigates a bug where an Android Activity's onStop and onDestroy methods are delayed by about 10 seconds after the Activity finishes. The root cause is an infinite RotateAnimation started on the previous page, which repeatedly invalidates the view hierarchy.

The animation's getTransformation method always returns true (the more flag) because the repeat count is INFINITE . Consequently, applyLegacyAnimation always calls parent.invalidate(...) , which posts new messages to the MessageQueue on every frame.

When the current Activity calls finish() , the system schedules an idle timeout message ( IDLE_TIMEOUT_MSG ) to trigger activityIdleInternalLocked after 10 seconds, which would normally invoke finishCurrentActivityLocked and destroy the Activity. However, the message queue never becomes empty because the animation continuously adds new messages, so the idle handler ( MessageQueue.IdleHandler ) never runs.

The article outlines the full call chain from ActivityThread through TransactionExecutor , MessageQueue.next() , and the idle handler execution, showing how the perpetual animation blocks the idle processing.

Three practical solutions are proposed: pause the animation in onPause , replace the legacy animation with a ValueAnimator , or release resources early in onPause when the Activity is finishing.