+ more threading support

+ removed "Commands" class
+ Deferred(Action<World> fn) function

samples/MyBattleground/Program.cs

@@ -27,10 +27,10 @@
 .RunIf(() => true)
 .RunIf((Res<GameStates> state, Res<GameStates> state1, Res<GameStates> state2, Query<Velocity> velQuery) => state.Value == GameStates.InGame);
 
-scheduler.AddSystem((Local<int> i32, Res<string> str, Commands commands) => {
+scheduler.AddSystem((Local<int> i32, Res<string> str, SchedulerState schedState) => {
 	Console.WriteLine(i32.Value++);
 
-	commands.AddResource(23ul);
+	schedState.AddResource(23ul);
 }, Stages.Startup);
 scheduler.AddSystem((Res<ulong> ul) => {
 	Console.WriteLine(ul.Value++);
@@ -83,13 +83,20 @@ Res<string> myText
 		Console.WriteLine("What: {0}", myText.Value);
 	}
 );
-scheduler.AddSystem((Commands commands) => {
-	var ff = commands.Entity()
+scheduler.AddSystem((World world) => {
+
+	world.BeginDeferred();
+	var ff = world.Entity()
 		.Set<Position>(default)
 		.Set<Velocity>(default);
-});
-scheduler.AddSystem((Commands commands) => {
-	commands.Merge();
+	world.EndDeferred();
+
+	world.Deferred(w => {
+		var ff = w.Entity()
+			.Set<Position>(default)
+			.Set<Velocity>(default)
+			.Set<Likes>();
+	});
 });
 scheduler.AddSystem((World world) => {
 	Console.WriteLine("entities in world {0}", world.EntityCount);
@@ -128,7 +135,7 @@ Res<string> myText
 // ecs.Entity<MyEvent>();
 
 ecs.Query<Position>()
-	.Each((EntityView ent) => {
+	.EachJob((EntityView ent, ref Position pos) => {
 
 		ent.Set(new MyEvent() { Value = 2 });
 
@@ -138,6 +145,8 @@ Res<string> myText
 		ref var v2 = ref ent.Get<MyEvent>();
 		v.Value += 1;
 
+		ent.Unset<MyEvent>();
+
 
 		// var ee = ent.World.Entity()
 		// 	.Set<MyEvent>(new MyEvent() { Value = 222 });

src/Query.cs

@@ -171,7 +171,7 @@ public QueryInternal GetEnumerator()
 
 	public void Each(QueryFilterDelegateWithEntity fn)
 	{
-		World.Lock();
+		World.BeginDeferred();
 
 		foreach (var arch in this)
 		{
@@ -187,6 +187,6 @@ public void Each(QueryFilterDelegateWithEntity fn)
 			}
 		}
 
-		World.Unlock();
+		World.EndDeferred();
 	}
 }

src/System.cs

@@ -56,7 +56,7 @@ public Scheduler(World world)
 			_systems[i] = new ();
 
 		AddSystemParam(world);
-		AddSystemParam(new Commands(world, this));
+		AddSystemParam(new SchedulerState(this));
 	}
 
 
@@ -117,7 +117,10 @@ internal Scheduler AddSystemParam<T>(T param) where T : ISystemParam
 		return this;
 	}
 
-	internal bool ResourceExists<T>() => _resources.ContainsKey(typeof(T));
+	internal bool ResourceExists<T>() where T : ISystemParam
+	{
+		return _resources.ContainsKey(typeof(T));
+	}
 }
 
 public interface IPlugin
@@ -219,27 +222,6 @@ void ISystemParam.New(object arguments)
 	}
 }
 
-partial class Commands : ISystemParam
-{
-	private readonly Scheduler? _scheduler;
-
-	public Commands() : this(null!) { }
-
-	public Commands(World world, Scheduler scheduler) : this(world)
-		=> _scheduler = scheduler;
-
-	void ISystemParam.New(object arguments)
-	{
-		World = (World) arguments;
-	}
-
-	public void AddResource<T>(T resource)
-		=> _scheduler?.AddResource(resource);
-
-	public bool ResourceExists<T>()
-		=> _scheduler?.ResourceExists<Res<T>>() ?? false;
-}
-
 public sealed class Res<T> : ISystemParam
 {
 	private T? _t;
@@ -278,25 +260,30 @@ void ISystemParam.New(object arguments)
 	}
 }
 
-// public sealed class SystemState : ISystemParam
-// {
-// 	private readonly Scheduler _scheduler;
+public sealed class SchedulerState : ISystemParam
+{
+	private readonly Scheduler _scheduler;
 
-// 	internal SystemState(Scheduler scheduler)
-// 	{
-// 		_scheduler = scheduler;
-// 	}
+	internal SchedulerState(Scheduler scheduler)
+	{
+		_scheduler = scheduler;
+	}
 
-// 	public SystemState()
-// 		=> throw new Exception("You are not allowed to initialixze this object by yourself!");
+	public SchedulerState()
+		=> throw new Exception("You are not allowed to initialixze this object by yourself!");
 
-// 	public void AddResource<T>(T resource)
-// 	{
-// 		_scheduler.AddResource(resource);
-// 	}
+	public void AddResource<T>(T resource)
+	{
+		_scheduler.AddResource(resource);
+	}
 
-// 	void ISystemParam.New(object arguments)
-// 	{
+	public bool ResourceExists<T>()
+	{
+		return _scheduler.ResourceExists<Res<T>>();
+	}
 
-// 	}
-// }
+	void ISystemParam.New(object arguments)
+	{
+
+	}
+}