Implement scheduling system with parallel execution support and dummy job systems

Nerfed.Editor/Program.cs

@@ -2,7 +2,9 @@
 using Nerfed.Editor.Systems;
 using Nerfed.Runtime;
 using Nerfed.Runtime.Components;
+using Nerfed.Runtime.Scheduling;
 using Nerfed.Runtime.Systems;
+using Nerfed.Runtime.Systems.Synthetic;
 using Nerfed.Runtime.Util;
 using System.Numerics;
 
@@ -12,10 +14,22 @@ internal class Program
 {
     private static readonly World world = new World();
     private static List<MoonTools.ECS.System> systems = new List<MoonTools.ECS.System>();
+    private static SystemScheduler scheduler;
     public static List<MoonTools.ECS.System> editorSystems = new List<MoonTools.ECS.System>();
+    private static bool enableDummySchedulerHarness;
+    private static bool enableParallelSystemExecution;
 
     private static void Main(string[] args)
     {
+        enableDummySchedulerHarness = args.Contains("--dummy-scheduler-test", StringComparer.OrdinalIgnoreCase);
+        enableParallelSystemExecution = args.Contains("--parallel-systems", StringComparer.OrdinalIgnoreCase);
+
+        scheduler = new SystemScheduler(new SystemSchedulerOptions
+        {
+            EnableParallelSystemExecution = enableParallelSystemExecution,
+            StrictDependencyValidation = true,
+        });
+
         Engine.OnInitialize += HandleOnInitialize;
         Engine.OnUpdate += HandleOnUpdate;
         Engine.OnRender += HandleOnRender;
@@ -27,7 +41,42 @@ internal class Program
     private static void HandleOnInitialize()
     {
         //systems.Add(new ParentSystem(world));
-        systems.Add(new LocalToWorldSystem(world));
+        LocalToWorldSystem localToWorldSystem = new LocalToWorldSystem(world);
+        systems.Add(localToWorldSystem);
+        scheduler.Register(localToWorldSystem, SystemSchedulePhase.Simulation);
+
+        if (enableDummySchedulerHarness)
+        {
+            DummyLongJobSharedState sharedState = new DummyLongJobSharedState();
+
+            // Producer starts long work, middle system burns time on main thread, consumer acts as a barrier.
+            DummyLongJobProducerSystem producer = new DummyLongJobProducerSystem(
+                world,
+                sharedState,
+                JobSystem.Default,
+                TimeSpan.FromMilliseconds(6),
+                DummyWorkloadMode.Compute,
+                JobDeadlineMode.FrameCritical);
+            systems.Add(producer);
+            scheduler.Register(producer, SystemSchedulePhase.Simulation);
+
+            DummyMainThreadWorkSystem mainThreadWork = new DummyMainThreadWorkSystem(
+                world,
+                TimeSpan.FromMilliseconds(2),
+                DummyWorkloadMode.Compute,
+                nameof(DummyMainThreadWorkSystem));
+            systems.Add(mainThreadWork);
+            scheduler.Register(mainThreadWork, SystemSchedulePhase.Simulation);
+
+            DummyLongJobConsumerSystem consumer = new DummyLongJobConsumerSystem(
+                world,
+                sharedState,
+                JobSystem.Default,
+                requireCompletion: true);
+            systems.Add(consumer);
+            scheduler.Register(consumer, SystemSchedulePhase.LateSimulation, nameof(DummyLongJobProducerSystem));
+        }
+
         editorSystems.Add(new EditorProfilerWindow(world));
         editorSystems.Add(new EditorHierarchyWindow(world));
 #if DEBUG
@@ -72,10 +121,9 @@ internal class Program
 
     private static void HandleOnUpdate()
     {
-        foreach (MoonTools.ECS.System system in systems)
+        using (new ProfilerScope("SystemScheduler.Execute"))
         {
-            using ProfilerScope scope = new(system.GetType().Name);
-            system.Update(Engine.Timestep);
+            scheduler.Execute(Engine.Timestep);
         }
 
         using (new ProfilerScope("EditorGui.Update"))