Labeled asset handle getting prematurely dropped

[viridia]

I have a custom asset loader that parses an XML file. It creates multiple labeled assets, one for each element that has an "id" attribute. However I'm having a problem where some of the assets get prematurely unloaded.

Here's the scenario: I call server.load() to get an asset. I store the resulting handle into a component. Once I get an event that says that the asset is loaded, I call server.load() again to get a secondary asset (basically a stylesheet for the element) in the same file. I then store that handle into a different component. I have an asset event listener set up to listen for when the secondary asset is loaded.

What happens next is non-deterministic: sometimes it works, but mostly not. When it works, I get an event saying that the secondary asset is loaded. When it doesn't work, I get an "AssetEvent::Removed" event for the secondary asset, even though it was never loaded - that is, I never got an AssetEvent::Created or AssetEvent::Modified event for the secondary asset. Polling server.get_load_state() for the secondary asset returns Unloaded even though it was never loaded.

What's even more strange is that if I touch the asset file (hit save in VSCode), everything suddenly magically works - the secondary asset gets reloaded, I get the loaded event, and the polling loop sees that the asset is indeed loaded.

Am I doing something terribly wrong, or is this an actual bug? I've spent like two days on this :(

[dmyyy]

Non deterministic behavior smells like ambiguous system ordering. A couple things to try in no particular order

• Try storing the handles in a resource and seeing if that changes things

• Components are not added to entities right away - they are added the next time apply_deferred is called (wondering if that might be playing into the issue). There might be a race condition on the file finishing being loaded and the handle being added to the entity?

• Make sure the handle being stored isn't a weak handle

• Wait until asset v2 since these systems (and events are getting a rework)

• Use bevy_mod_debugdump to look at systems ordering

Edit: Consider filing a bug with a minimal repro?

[viridia]

Thanks, that was helpful. Chaining "apply_deferred" after creating the components seems to have mitigated the problem, although I'm not 100% certain that this is a robust fix.