Async

await works like everywhere else in .NET, with one addition: code after an await that started on the main thread continues on the main thread, so it can use the API right away.

protected override async void OnStart()
{
    await Scheduler.Delay(TimeSpan.FromSeconds(5));
    Chat.BroadcastMessage("Five seconds after the start");
}

Task overloads

Functions that report their result through a callback in Lua have Task overloads with the same name:

var response = await HTTP.RequestAsync("https://api.example.com", "/status");
if (response.IsSuccess)
{
    Log.Info(response.Data);
}

var database = new Database(DatabaseEngine.SQLite, "db=server.db");
var affected = await database.ExecuteAsync("DELETE FROM sessions WHERE expires < ?", now);
var rows = await database.SelectAsync("SELECT name FROM players WHERE id = ?", playerId);
var name = rows[0]["name"] as string;

var file = new ScriptFile("data.json");
var content = await file.ReadAsync();

Database errors are thrown as DatabaseException. The Lua style overloads with a callback remain available.

Background work

Heavy computations can run on the thread pool with Task.Run. Calls into nanos world must go back to the main thread, either by awaiting from main thread code or with MainThread.InvokeAsync:

var result = await Task.Run(() => CalculateNavigation());
Chat.BroadcastMessage($"done: {result}");

caution

A task that is still running when its package unloads keeps the old assemblies alive. Stop long running work in OnStop, for example with a CancellationToken.