Task<T>.await() schedules its continuation on the main thread

[petrcermak]

The Task<T>.await() extension function schedules its continuation on the main thread, which adds unnecessary latency:

addOnCompleteListener {
    val e = it.exception
    if (e == null) {
        @Suppress("UNCHECKED_CAST")
        if (it.isCanceled) deferred.cancel() else deferred.complete(it.result as T)
    } else {
        deferred.completeExceptionally(e)
    }
}

It would be better to avoid this by explicitly passing the direct executor to addOnCompleteListener instead:

addOnCompleteListener(directExecutor()) {
    val e = it.exception
    if (e == null) {
        @Suppress("UNCHECKED_CAST")
        if (it.isCanceled) deferred.cancel() else deferred.complete(it.result as T)
    } else {
        deferred.completeExceptionally(e)
    }
}