InvalidOperationException while dealing with ComponentLookup

Unity Engine
, ,
1

Hi,

I’m trying to write a piece of code based on the pattern I’ve seen elsewhere, but I’m getting a runtime error. My code looks similar to what I see in SnakeSystems.cs from EntitiesSamples.

I’ve a BeingSystem that works on Being IComponentData. In its OnUpdate I want to schedule a IJobEntity. The Execute method of that IJobEntity needs access to ComponentLookup, because I cannot do SystemAPI.GetComponent in the Execute method. My code looks like this

    [BurstCompile]
    [RequireMatchingQueriesForUpdate]
    [UpdateInGroup(typeof(FixedStepSimulationSystemGroup))]
    public partial struct BeingSystem : ISystem
    {
        ComponentLookup<Being> m_beingLookup;

        [BurstCompile]
        public void OnCreate(ref SystemState state)
        {
            state.RequireForUpdate<Being>();
            m_beingLookup = state.GetComponentLookup<Being>(true);
        }

        [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            m_beingLookup.Update(ref state);

            new BeingIdleJob
            {
                BeingLookup = m_beingLookup,
            }.ScheduleParallel();
        }
    }

    [BurstCompile]
    partial struct BeingIdleJob : IJobEntity
    {
        [ReadOnly]
        public AgentSpatialPartitioningSystem.Singleton Spatial;
        [ReadOnly]
        public ComponentLookup<Being> BeingLookup;

        public void Execute(Entity entity, ref Being being)
        {
        }
    }
}

When I run this code, I get

InvalidOperationException: The writeable ComponentTypeHandle<com.bluemathsoftware.dots.Being> BeingIdleJob.JobData.__TypeHandle.__com_bluemathsoftware_dots_Being_RW_ComponentTypeHandle is the same ComponentLookup<com.bluemathsoftware.dots.Being> as BeingIdleJob.JobData.BeingLookup, two containers may not be the same (aliasing).

What am I doing wrong?

2

You can’t have a lookup for the same type of component you are accessing as one of the Execute parameters.

3

That must be it. Dropping ref Being being from the signature or changing ref to in fixes the error.
Thanks!

4

this worked like a charm. thanks!