package kotlinx.coroutines

/**
 * A [Runnable] that's especially optimized for running in [Dispatchers.Default] on the JVM.
 *
 * Replacing a [SchedulerTask] with a [Runnable] should not lead to any change in observable behavior.
 *
 * An arbitrary [Runnable], once it is dispatched by [Dispatchers.Default], gets wrapped into a class that
 * stores the submission time, the execution context, etc.
 * For [Runnable] instances that we know are only going to be executed in dispatch procedures, we can avoid the
 * overhead of separately allocating a wrapper, and instead have the [Runnable] contain the required fields
 * on construction.
 *
 * When running outside the standard dispatchers, these new fields are just dead weight.
 */
internal expect abstract class SchedulerTask internal constructor() : Runnable