I am confused with scrollViewDidScroll scrollViewWillEndDragging. Do they work as async way?
I found that at a moment, both scrollViewDidScroll and scrollViewWillEndDragging are triggered and not finished.
ps: NO BLOCK in my code
EDIT
I will use a property in scrollViewDidScroll, which will be updated at the end of scrollViewWillEndDragging. My question is whether scrollViewDidScroll and scrollViewWillEndDragging run as async way. If so I need use lock to prevent it.

