DynamicComponentTypeHandle & safety system

[signal geyser]

I have this job and I'm running into an issue I do not fully understand.

I have this exception:

InvalidOperationException: The previously scheduled job HashDataJob reads from the ComponentTypeHandle<Sim.EventStorageSingleton> HashDataJob.JobData.DynamicComponentHandle. You must call JobHandle.Complete() on the job HashDataJob, before you can write to the ComponentTypeHandle<Sim.EventStorageSingleton> safely.

I thought it'd be due to the DynamicComponentTypeHandle, because I hadn't seen this before when using ComponentTypeHandle. So I wrote a version using ComponentTypeHandle instead (for the EventStorageSingleton only).

The error went away, but I got one for LocalTransform as well. I added a hard-coded version for that as well, and i had no more issues.

Then, I removed the hardcoded versions again, and there errors were gone, until I rebooted Unity (odd, I thought this was deterministic, but alright). Since then, I cannot reproduce the issue for the LocalTransform anymore (I do not understand that at all).

Now, only the exception related to Sim.EventStorageSingleton remains, which I started out with, and at least this I now reproduce this consistently. It is triggered from a CompleteDependencyBeforeRW<Sim.EventStorageSingleton>().

Is the dependency system expected to behave differently with DynamicComponentTypeHandle and ComponentTypeHandle ?

I also have this exception, which makes as little sense to me as the other one; the dependency has clearly been added to the list of dependencies, so I suspect this is also related to the dynamic component typehandle.

The system Sim.DesyncDetectionDataHashSystem reads Sim.EventStorageSingleton via HashDataJob but that type was not assigned to the Dependency property. To ensure correct behavior of other systems, the job or a dependency must be assigned to the Dependency property before returning from the OnUpdate method.

Perhaps the issues are related to codegen? Or there's a missing feature, or a bug? Or I misunderstand how this should work?

Some ideas to debug would be welcome. ^^'

[verbal blade]

you didn't show how you create type handles

my assumption is that you didn't register dependency to system with them

[signal geyser]

just like this

    for (int i = 0, l = _componentTypes.Length; i < l; i++)
    {
        _typeHandles[i] = state.EntityManager.GetDynamicComponentTypeHandle(_componentTypes[i]);
    }

my assumption is that you didn't register dependency to system with them
I don't know what you mean by this, I suppose I missed something; I'll dig through the documentation tomorrow then

[verbal blade]

jobs you schedule probably don't know about this dynamic type

[signal geyser]

I am suspecting something like that, but that's what the dynamic handle is for, isn't it?

[verbal blade]

No, you just break safety and safety system throwing because of it

There is either system state relattd overload to get dynamic handle

Or you can manually register dependecy

[signal geyser]

Alright, I hoped the system would do that for me when I schedule a job with the dynamic component type handle, but I can do that myself I suppose. I don't remember reading about this in the API 🤔

I'll dig a bit tomorrow, thanks

[signal geyser]

but isn't that what I did? state.EntityManager.GetDynamicComponentTypeHandle ?

[verbal blade]

it's not writing to system state

none of EntityManager methods are

[signal geyser]

ah that makes sense of course; however this seems to be the only way to create dynamic component type handles

you say manually register dependency but i dont recall seeing such a method

[verbal blade]

did you check SystemState?

or systemapi

[verbal blade]

you can take a look how query building works to see how it's done internally

[signal geyser]

if that's the issue, given all the things done when scheduling jobs, I must say I'm a bit surprised this hasnt been done for us already

[verbal blade]

it's not done because you use EntityManager

it's methods specifically meant to be not related to systems

[signal geyser]

I'm a little surprised but I think you were right
if I use state.GetComponentTypeHandle<EventStorageSingleton>(true);, I have no error,
but if I use state.EntityManager.GetComponentTypeHandle<EventStorageSingleton>(true);, I have an error even with a regular type handle

[verbal blade]

just take a look at state overload to see what is done

this is pretty much the whole idea behind thread safety

[signal geyser]

I don't know how I missed it, but there exists a GetDynamicComponentTypeHandle inside the state

I checked twice at least 🤦

im getting old 😂

it works, thanks for your patience

I hadn't realized there was a significant difference between the entitymanager and state variants. Mostly because we use Update(ref state) with both, so we're already telling the handles about the system.

[signal geyser]

And so the error message was a bit misleading, since it pointed me to the Dependency property and not to what I was doing wrong.

[verbal blade]

it is quite hard to figure where exactly you failed dependency

[signal geyser]

I'd like to mark the post as resolved but I don't find the option 🤔