b78efd339d
7 Commits
| Author | SHA1 | Message | Date | |
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Oliver Maskery
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022c6b1d34
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Prevent creation of superfluous empty table (#16935)
# Objective - To fix a tiny bug in `bevy_ecs::storage::Tables` that, in one case, means it accidentally allocates an additional "empty" `Table`, resulting in two "empty" `Table`s: - The one pre-allocated empty table at index 0 whose index is designed to match up with `TableId::empty()` - One extra empty table, at some non-0 index, that does not match up with `TableId::empty()`. - This PR aims to prevent this extraneous `Table`, ensuring that entities with no components in table-storage reliably have their archetype's table ID be equal to `TableId::empty()`. ## Solution ### Background The issue occurs because: - `Tables` contains: - `tables: Vec<Table>` - The set of all `Table`s allocated in the world. - `table_ids: HashMap<Box<[ComponentId]>, TableId>` - An index to rapidly lookup the `Table` in `tables` by a set of `ComponentId`s. - When `Tables` is constructed it pre-populates the `tables` `Vec` with an empty `Table`. - This ensures that the first entry (index 0) is always the `Table` for entities with no components in table storage. - In particular, `TableId::empty()` is a utility that returns a `TableId` of `0`. - However, the `table_ids` map is not initialised to associate an empty `[ComponentId]` with `TableId` `0`. - This means, the first time a structural change tries to access a `Table` for an archetype with 0 table components: - `Tables::get_id_or_insert` is used to retrieve the target `Table` - The function attempts to lookup the entry in the `table_ids` `HashMap` whose key is the empty `ComponentId` set - The empty `Table` created at startup won't be found, because it was never inserted into `table_ids` - It will instead create a new table, insert it into the `HashMap` (preventing further instances of this issue), and return it. ### Changes - I considered simply initialising the `table_ids` `HashMap` to know about the pre-allocated `Table` - However, I ended up using the proposed solution discussed on Discord [#ecs-dev](https://discord.com/channels/691052431525675048/749335865876021248/1320430933152759958): - Make `Tables::get_id_or_insert` simply early-exit if the requested `component_ids` was empty. - This avoids unnecessarily hashing the empty slice and looking it up in the `HashMap`. - The `table_ids` `HashMap` is not exposed outside this struct, and is only used within `get_id_or_insert`, so it seems wasteful to defensively populate it with the empty `Table`. ## Testing This is my first Bevy contribution, so I don't really know the processes that well. That said: - I have introduced a little test that exercises the original issue and shows that it is now resolved. - I have run the `bevy_ecs` tests locally, so I have reasonable confidence I haven't broken that. - I haven't run any further test suites, mostly as when I tried to run test suites for the whole project it filled my entire SSD with >600GB of target directory output 😱😱😱 |
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Zachary Harrold
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1f2d0e6308
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Add no_std support to bevy_ecs (#16758)
# Objective - Contributes to #15460 ## Solution - Added the following features: - `std` (default) - `async_executor` (default) - `edge_executor` - `critical-section` - `portable-atomic` - Gated `tracing` in `bevy_utils` to allow compilation on certain platforms - Switched from `tracing` to `log` for simple message logging within `bevy_ecs`. Note that `tracing` supports capturing from `log` so this should be an uncontroversial change. - Fixed imports and added feature gates as required - Made `bevy_tasks` optional within `bevy_ecs`. Turns out it's only needed for parallel operations which are already gated behind `multi_threaded` anyway. ## Testing - Added to `compile-check-no-std` CI command - `cargo check -p bevy_ecs --no-default-features --features edge_executor,critical-section,portable-atomic --target thumbv6m-none-eabi` - `cargo check -p bevy_ecs --no-default-features --features edge_executor,critical-section` - `cargo check -p bevy_ecs --no-default-features` ## Draft Release Notes Bevy's core ECS now supports `no_std` platforms. In prior versions of Bevy, it was not possible to work with embedded or niche platforms due to our reliance on the standard library, `std`. This has blocked a number of novel use-cases for Bevy, such as an embedded database for IoT devices, or for creating games on retro consoles. With this release, `bevy_ecs` no longer requires `std`. To use Bevy on a `no_std` platform, you must disable default features and enable the new `edge_executor` and `critical-section` features. You may also need to enable `portable-atomic` and `critical-section` if your platform does not natively support all atomic types and operations used by Bevy. ```toml [dependencies] bevy_ecs = { version = "0.16", default-features = false, features = [ # Required for platforms with incomplete atomics (e.g., Raspberry Pi Pico) "portable-atomic", "critical-section", # Optional "bevy_reflect", "serialize", "bevy_debug_stepping", "edge_executor" ] } ``` Currently, this has been tested on bare-metal x86 and the Raspberry Pi Pico. If you have trouble using `bevy_ecs` on a particular platform, please reach out either through a GitHub issue or in the `no_std` working group on the Bevy Discord server. Keep an eye out for future `no_std` updates as we continue to improve the parity between `std` and `no_std`. We look forward to seeing what kinds of applications are now possible with Bevy! ## Notes - Creating PR in draft to ensure CI is passing before requesting reviews. - This implementation has no support for multithreading in `no_std`, especially due to `NonSend` being unsound if allowed in multithreading. The reason is we cannot check the `ThreadId` in `no_std`, so we have no mechanism to at-runtime determine if access is sound. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Vic <59878206+Victoronz@users.noreply.github.com> |
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SpecificProtagonist
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1a6b94c5e8
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Remove flush_and_reserve_invalid_assuming_no_entities (#16460)
# Objective `flush_and_reserve_invalid_assuming_no_entities` was made for the old rendering world (which was reset every frame) and is usused since the 0.15 retained rendering world, but wasn't removed yet. It is pub, but is undocumented apart from the safety comment. ## Solution Remove `flush_and_reserve_invalid_assuming_no_entities` and the safety invariants this method required for `EntityMeta`, `EntityLocation`, `TableId` and `TableRow`. This reduces the amount of unsafe code & safety invariants and makes #16047 easier. ## Alternatives - Document `flush_and_reserve_invalid_assuming_no_entities` and keep it unchanged - Document `flush_and_reserve_invalid_assuming_no_entities` and change it to be based on `EntityMeta::INVALID` ## Migration Guide - exchange `Entities::flush_and_reserve_invalid_assuming_no_entities` for `reserve` and `flush_as_invalid` and notify us if that's insufficient --------- Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com> |
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Zachary Harrold
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d70595b667
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Add core and alloc over std Lints (#15281)
# Objective - Fixes #6370 - Closes #6581 ## Solution - Added the following lints to the workspace: - `std_instead_of_core` - `std_instead_of_alloc` - `alloc_instead_of_core` - Used `cargo +nightly fmt` with [item level use formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A) to split all `use` statements into single items. - Used `cargo clippy --workspace --all-targets --all-features --fix --allow-dirty` to _attempt_ to resolve the new linting issues, and intervened where the lint was unable to resolve the issue automatically (usually due to needing an `extern crate alloc;` statement in a crate root). - Manually removed certain uses of `std` where negative feature gating prevented `--all-features` from finding the offending uses. - Used `cargo +nightly fmt` with [crate level use formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A) to re-merge all `use` statements matching Bevy's previous styling. - Manually fixed cases where the `fmt` tool could not re-merge `use` statements due to conditional compilation attributes. ## Testing - Ran CI locally ## Migration Guide The MSRV is now 1.81. Please update to this version or higher. ## Notes - This is a _massive_ change to try and push through, which is why I've outlined the semi-automatic steps I used to create this PR, in case this fails and someone else tries again in the future. - Making this change has no impact on user code, but does mean Bevy contributors will be warned to use `core` and `alloc` instead of `std` where possible. - This lint is a critical first step towards investigating `no_std` options for Bevy. --------- Co-authored-by: François Mockers <francois.mockers@vleue.com> |
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hshrimp
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35d10866b8
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Rename init_component & friends (#15454)
# Objective - Fixes #15451 ## Migration Guide - `World::init_component` has been renamed to `register_component`. - `World::init_component_with_descriptor` has been renamed to `register_component_with_descriptor`. - `World::init_bundle` has been renamed to `register_bundle`. - `Components::init_component` has been renamed to `register_component`. - `Components::init_component_with_descriptor` has been renamed to `register_component_with_descriptor`. - `Components::init_resource` has been renamed to `register_resource`. - `Components::init_non_send` had been renamed to `register_non_send`. |
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Clar Fon
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efda7f3f9c
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Simpler lint fixes: makes ci lints work but disables a lint for now (#15376)
Takes the first two commits from #15375 and adds suggestions from this comment: https://github.com/bevyengine/bevy/pull/15375#issuecomment-2366968300 See #15375 for more reasoning/motivation. ## Rebasing (rerunning) ```rust git switch simpler-lint-fixes git reset --hard main cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "rustfmt" cargo clippy --workspace --all-targets --all-features --fix cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "clippy" git cherry-pick e6c0b94f6795222310fb812fa5c4512661fc7887 ``` |
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Adam
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9bda913e36
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Remove redundent information and optimize dynamic allocations in Table (#12929)
# Objective - fix #12853 - Make `Table::allocate` faster ## Solution The PR consists of multiple steps: 1) For the component data: create a new data-structure that's similar to `BlobVec` but doesn't store `len` & `capacity` inside of it: "BlobArray" (name suggestions welcome) 2) For the `Tick` data: create a new data-structure that's similar to `ThinSlicePtr` but supports dynamic reallocation: "ThinArrayPtr" (name suggestions welcome) 3) Create a new data-structure that's very similar to `Column` that doesn't store `len` & `capacity` inside of it: "ThinColumn" 4) Adjust the `Table` implementation to use `ThinColumn` instead of `Column` The result is that only one set of `len` & `capacity` is stored in `Table`, in `Table::entities` ### Notes Regarding Performance Apart from shaving off some excess memory in `Table`, the changes have also brought noteworthy performance improvements: The previous implementation relied on `Vec::reserve` & `BlobVec::reserve`, but that redundantly repeated the same if statement (`capacity` == `len`). Now that check could be made at the `Table` level because the capacity and length of all the columns are synchronized; saving N branches per allocation. The result is a respectable performance improvement per every `Table::reserve` (and subsequently `Table::allocate`) call. I'm hesitant to give exact numbers because I don't have a lot of experience in profiling and benchmarking, but these are the results I got so far: *`add_remove_big/table` benchmark after the implementation:*  *`add_remove_big/table` benchmark in main branch (measured in comparison to the implementation):*  *`add_remove_very_big/table` benchmark after the implementation:*  *`add_remove_very_big/table` benchmark in main branch (measured in comparison to the implementation):*  cc @james7132 to verify --- ## Changelog - New data-structure that's similar to `BlobVec` but doesn't store `len` & `capacity` inside of it: `BlobArray` - New data-structure that's similar to `ThinSlicePtr` but supports dynamic allocation:`ThinArrayPtr` - New data-structure that's very similar to `Column` that doesn't store `len` & `capacity` inside of it: `ThinColumn` - Adjust the `Table` implementation to use `ThinColumn` instead of `Column` - New benchmark: `add_remove_very_big` to benchmark the performance of spawning a lot of entities with a lot of components (15) each ## Migration Guide `Table` now uses `ThinColumn` instead of `Column`. That means that methods that previously returned `Column`, will now return `ThinColumn` instead. `ThinColumn` has a much more limited and low-level API, but you can still achieve the same things in `ThinColumn` as you did in `Column`. For example, instead of calling `Column::get_added_tick`, you'd call `ThinColumn::get_added_ticks_slice` and index it to get the specific added tick. --------- Co-authored-by: James Liu <contact@jamessliu.com> |