42b74874e4
1 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Alice Cecile
|
27d02de375 |
Unify and simplify command and system error handling (#18351)
# Objective - ECS error handling is a lovely flagship feature for Bevy 0.16, all in the name of reducing panics and encouraging better error handling (#14275). - Currently though, command and system error handling are completely disjoint and use different mechanisms. - Additionally, there's a number of distinct ways to set the default/fallback/global error handler that have limited value. As far as I can tell, this will be cfg flagged to toggle between dev and production builds in 99.9% of cases, with no real value in more granular settings or helpers. - Fixes #17272 ## Solution - Standardize error handling on the OnceLock global error mechanisms ironed out in https://github.com/bevyengine/bevy/pull/17215 - As discussed there, there are serious performance concerns there, especially for commands - I also think this is a better fit for the use cases, as it's truly global - Move from `SystemErrorContext` to a more general purpose `ErrorContext`, which can handle observers and commands more clearly - Cut the superfluous setter methods on `App` and `SubApp` - Rename the limited (and unhelpful) `fallible_systems` example to `error_handling`, and add an example of command error handling ## Testing Ran the `error_handling` example. ## Notes for reviewers - Do you see a clear way to allow commands to retain &mut World access in the per-command custom error handlers? IMO that's a key feature here (allowing the ad-hoc creation of custom commands), but I'm not sure how to get there without exploding complexity. - I've removed the feature gate on the default_error_handler: contrary to @cart's opinion in #17215 I think that virtually all apps will want to use this. Can you think of a category of app that a) is extremely performance sensitive b) is fine with shipping to production with the panic error handler? If so, I can try to gather performance numbers and/or reintroduce the feature flag. UPDATE: see benches at the end of this message. - ~~`OnceLock` is in `std`: @bushrat011899 what should we do here?~~ - Do you have ideas for more automated tests for this collection of features? ## Benchmarks I checked the impact of the feature flag introduced: benchmarks might show regressions. This bears more investigation. I'm still skeptical that there are users who are well-served by a fast always panicking approach, but I'm going to re-add the feature flag here to avoid stalling this out.  --------- Co-authored-by: Zachary Harrold <zac@harrold.com.au> |