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#Is it possible to use Commands or ParCommands in an AsyncComputeTask ?
formal creek
alternatively how would I send a signal from the detached task that i can then process
formal creek
I ended up using a resource with Arc<SegQueue<...>>, and then processing the results in a separate system. leaving open as I'm not sure this is actually a good way to do it
umbral skiff
how exactly do you want to use commands in a separate thread? aren't systems parallel by default?
formal creek
I have a non-blocking task created on the AsyncComputeTaskPool, that I then .detach() so I don't need to poll. I still want to apply the output of this function, though. If I had the ability to use Commands within this task that would work totally fine but it doesn't work. Using an Arc<SegQueue<...>> works but feels jank.
umbral skiff
what do you want to do with Commands? spawn an entity?
spring plank
Typically in these scenarios I build a list of calls to commands in the thread and then iterate through them in a system after the task is resolved.
formal creek
The task originally worked by returning data that would then be used to populate a component on an entity. Polling all of these tasks however quickly became an issue as polling a bunch of tasks that may or may not have finished is slow (and limiting the amount polled leads to stuttering as only the first N tasks get polled and then they all complete at once, causing stutter)
To solve this, I detach the task so it runs in the background (without having to be polled) and have it update a Queue that can then be applied with another system.
However, the ideal solution would be calling Commands directly from the task eliminating the need for an async queue
junior comet
The task originally worked by returning data that would then be used to populate...
Can you please share a small demonstration of this? I am chasing after this implementation as well, as part of the conversation in #networking . The use case is to use that async Task to perform an HTTP call and integrate the serialized result with the ECS system.
Here is what I'm looking at, personally: the current issue is that the compiler doesn't understand Task::poll method call on L39. Even though Task implements Future, the compiler doesn't want to hear it. So I imagine I'm just going about this in the wrong way.
FYI @peak temple
junior comet
Update: I got it to work! Thankfully, I was able to find a person on StackOverflow who posted the answer to their own question with such a minimal example: https://stackoverflow.com/questions/71504675/how-to-make-async-system-function-in-the-bevy-game-engine
peak temple
Actually bevy engine already has an example: https://github.com/bevyengine/bevy/blob/main/examples/async_tasks/async_compute.rs. I thought you knew it @junior comet 😄
I was using block_on too.
formal creek
Note for anybody else having issues with this, block_on can be quite slow, detaching the task and having it return results in an async queue is significantly faster