CoroutineDispatcher

It's important to understand that in Kotlin, while you can create threads and thread pools easily, you don't access or control them directly. What you do is create a CoroutineDispatcher, which is basically an orchestrator that distributes coroutines among threads based on availability, load, and configuration.

In our current case, for example, we will create a CoroutineDispatcher that has only one thread, so all the coroutines that we attach to it will be running in that specific thread. To do so, we create a ThreadPoolDispatcher – which extends CoroutineDispatcher – with only one thread.

Let's open the MainActivity.kt file that was generated previously – it's in the main package of the app, co.starcarr.rssreader – and update it so that it creates such a dispatcher on the class level:

class MainActivity : AppCompatActivity() {
  val netDispatcher = newSingleThreadContext(name = "ServiceCall")
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)  
  }
}