StackOverFlowException on sending CreateEntity

[No3371]

StackOverFlowException on sending CreateEntity

[No3371]

I've noticed, in latest documentation EntityReservationSystem is not mentioned at all, but I believe that's not related to this issue. It looks like something happened deep inside the command sending mechanics.

[No3371]

The provided logs is from local managed worker, running the worker in Unity will results in immediate crash. Unity's editor log file catches nothing after "CreateEntity sent!"

[jamiebrynes7]

Hey @No3371 I'm sorry you're running into this, can you post the implementation of EntityTemplates.CreateFishTemplate along with the schema for any components you've defined and added to this entity?

[No3371]

Sure.

        public static EntityTemplate CreateFishTemplate (string workerID, byte[] serializedArguments)
        {
            var template = new EntityTemplate();
            template.AddComponent(new Position.Snapshot(), WorkerTypeString);
            template.AddComponent(new W.C.Rotation2D.Snapshot(), WorkerTypeString);  // namespace simplified
            template.AddComponent(new W.F.Fish.Snapshot(), WorkerTypeString); // namespace simplified

            template.SetReadAccess(WorkerTypeString, "PlayerClient");

            return template;
        }

The schemas:

component Fish {
    id = 781;
    uint32 fish_type = 1;
}

component Rotation2D {
    id = 540;
    float degree = 1;
}

[No3371]

I was not sure what components are required for managed AI entities (the example project only got simulated players), so I only added Position. Did I miss anything?

[jamiebrynes7]

Hey @No3371, I managed to reproduce the problem and can see the issue:

        var eTemplate = EntityTemplates.CreateFishTemplate(AWorkerConnector.WorkerType, null);
        var request = new WorldCommands.CreateEntity.Request(eTemplate);
        for (int i = 0; i < spawned.Length; i++)
        {
            request.EntityId = reserved[i];
            spatialCommandSystem.SendCommand(request);
        }
        UnityEngine.Debug.Log("CreateEntity sent!");

Inside the WorldCommands.CreateEntity.Request(EntityTemplate template) constructor, we serialize the EntityTemplate into the binary format. This is native memory which is freed by the Worker SDK after Improbable.Worker.CInterop.Internal.CWorker.Connection_SendCreateEntityRequest is finished with it. This means if we reuse the Request object, the second time around you have memory corruption.

To fix, move the WorldCommands.CreateEntity.Request(EntityTemplate template) constructor into the for-loop:

        var eTemplate = EntityTemplates.CreateFishTemplate(AWorkerConnector.WorkerType, null);
        for (int i = 0; i < spawned.Length; i++)
        {
        	var request = new WorldCommands.CreateEntity.Request(eTemplate);
            request.EntityId = reserved[i];
            spatialCommandSystem.SendCommand(request);
        }
        UnityEngine.Debug.Log("CreateEntity sent!");

That being said, this should probably be handled more gracefully than hard-crashing the Editor! I'll raise a ticket to address that.

I've noticed, in latest documentation EntityReservationSystem is not mentioned at all

There's a small docs page on it here https://documentation.improbable.io/gdk-for-unity/docs/entity-reservation-system 😄

[No3371]

Thanks, will try the solution!

There's a small docs page on it here https://documentation.improbable.io/gdk-for-unity/docs/entity-reservation-system 😄

I see.
The ECS Workflow -> commands section does not mentions EntityReservationSystem, that's why I said that, sorry for the reckless comment!