implement new eventing system

SharedLibraryCore/Events/EventExtensions.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace SharedLibraryCore.Events;
+
+public static class EventExtensions
+{
+    public static Task InvokeAsync<TEventType>(this Func<TEventType, CancellationToken, Task> function,
+        TEventType eventArgType, CancellationToken token)
+    {
+        if (function is null)
+        {
+            return Task.CompletedTask;
+        }
+
+        return Task.WhenAll(function.GetInvocationList().Cast<Func<TEventType, CancellationToken, Task>>()
+            .Select(x => RunHandler(x, eventArgType, token)));
+    }
+
+    private static async Task RunHandler<TEventType>(Func<TEventType, CancellationToken, Task> handler,
+        TEventType eventArgType, CancellationToken token)
+    {
+        if (token == CancellationToken.None)
+        {
+            // special case to allow tasks like request after delay to run longer
+            await handler(eventArgType, token);
+        }
+
+        using var timeoutToken = new CancellationTokenSource(Utilities.DefaultCommandTimeout);
+        using var tokenSource =
+            CancellationTokenSource.CreateLinkedTokenSource(token, timeoutToken.Token);
+
+        try
+        {
+            await handler(eventArgType, tokenSource.Token);
+        }
+        catch (Exception)
+        {
+            // ignored
+        }
+    }
+}