Coroutines on Android (part I): Getting the background

Fetching a webpage or interacting with an API both involve making a network request. Similarly, reading from a database or loading an image from disk involve reading a file. These sorts of things are what I call long running tasks — tasks that take far too long for your app to stop and wait for them! It can be hard to understand how fast a modern phone executes code compared to a network request. On a Pixel 2, a single CPU cycle takes just under 0.0000000004 seconds, a number that’s pretty hard to grasp in human terms. However, if you think of a network request as one blink of the eye, around 400 milliseconds (0.4 seconds), it’s easier to understand how fast the CPU operates. In one blink of an eye, or a somewhat slow network request, the CPU can execute over one billion cycles! On Android, every app has a main thread that is in charge of handling UI (like drawing views) and coordinating user interactions. If there is too much work happening on this thread, the app appears to hang or slow down, leading to an undesirable user experience. Any long running task should be done without blocking the main thread, so your app doesn’t display what’s called “jank,” like frozen animations, or respond slowly to touch events. <a href="https://medium.com/androiddevelopers/coroutines-on-android-part-i-getting-the-background-3e0e54d20bb">Read More</a>