title: Why can't UI thread and Render thread run at the same time?
body: <p>I am a mediocore android developer for years. I like android but there's a big problem; frame drops. Even the most powerful ones can stutter so frequently while IOS devices can run at constant 60fps. I just can't understand why. I want to know it. So first thing i did was watching an I/O presentation about performance. And i didn't really understand one thing. Why can't ui and render thread run at the same time ? Yeah i know the basics like render thread can't know what to render while ui thread is doing it's thing but why can't render thread render the frame before? You can see the video here:
  <a href="https://youtu.be/9HtTL_RO2wI?t=491" rel="nofollow noreferrer">https://youtu.be/9HtTL_RO2wI?t=491</a>
  And here's a diagram what am i asking for:
  <img src="https://i.stack.imgur.com/ucbUh.png" alt="Dıagram"></p>
  
  <p>You get the idea. I don't know about low level things about android, can anyone explain this like i'm five.</p>