Follow up to “Android graphics true facts”, or The Reason Android is Laggy
"""It’s because on iOS all UI rendering occurs in a dedicated UI thread with real-time priority. On the other hand, Android follows the traditional PC model of rendering occurring on the main thread with normal priority.""" <- AFAIK this is simply wrong: the events that are later described as blocking rendering are coming in on the main thread, not some special "dedicated" one. The reason things block is because of the way the event loop on that thread is managed (and in fact is directly caused by all of that activity operating on the main thread, which we even often call the "UI thread"), and has nothing to do with threading, and certainly has nothing to do with "real-time priority".<p>"""On iOS when an app is installing from the app store and you put your finger on the screen, the installation instantly pauses until all rendering is finished.""" <- This is certainly not true. The update of the display for the installation progress might (...might) stop, as that's happening in the UI (aka, "main") thread of SpringBoard (and the event loop management might ignore incoming events that are not related to the touch event until after the gesture completes), but the installation itself is being managed by a background daemon (installd) and will not stop because someone is touching the screen. The operating system is /not/ doing something hilariously insane here, throwing out all computation on the device because someone is accidentally touching it.