# Objective
Fix#7440. Fix#7441.
## Solution
* Remove builder functions on `ScheduleBuildSettings` in favor of public fields, move docs to the fields.
* Add `use_shortnames` and use it in `get_node_name` to feed it through `bevy_utils::get_short_name`.
# Objective
Web builds do not support running on multiple threads right now. Defaulting to the multi-threaded executor has significant overhead without any benefit.
## Solution
Default to the single threaded executor on wasm32 builds.
# Objective
- other tools (bevy_mod_debugdump) would like to have access to the ambiguities so that they can do their own reporting/visualization
## Solution
- store `conflicting_systems` in `ScheduleGraph` after calling `build_schedule`
The solution isn't very pretty and as pointed out it https://github.com/bevyengine/bevy/pull/7522, there may be a better way of exposing this, but this is the quick and dirty way if we want to have this functionality exposed in 0.10.
# Objective
- it would be nice to be able to associate a `NodeId` of a system type set to the `NodeId` of the actual system (used in bevy_mod_debugdump)
## Solution
- make `system_type` return the type id of the system
- that way you can check if a `dyn SystemSet` is the system type set of a `dyn System`
- I don't know if this information is already present somewhere else in the scheduler or if there is a better way to expose it
# Objective
Fixes#7702.
## Solution
- Added an test that ensures that no error is returned if a system or set is inside two different sets that share the same base set.
- Added an check to only return an error if the two base sets are not equal.
# Objective
The `ScheduleGraph` should be expose so that crates like [bevy_mod_debugdump](https://github.com/jakobhellermann/bevy_mod_debugdump/blob/stageless/docs/README.md) can access useful information.
## Solution
- expose `ScheduleGraph`, `NodeId`, `BaseSetMembership`, `Dag`
- add accessor functions for sets and systems
## Changelog
- expose `ScheduleGraph` for use in third party tools
This does expose our use of `petgraph` as a graph library, so we can only change that as a breaking change.
# Objective
- Fixes#5432
- Fixes#6680
## Solution
- move code responsible for generating the `impl TypeUuid` from `type_uuid_derive` into a new function, `gen_impl_type_uuid`.
- this allows the new proc macro, `impl_type_uuid`, to call the code for generation.
- added struct `TypeUuidDef` and implemented `syn::Parse` to allow parsing of the input for the new macro.
- finally, used the new macro `impl_type_uuid` to implement `TypeUuid` for the standard library (in `crates/bevy_reflect/src/type_uuid_impl.rs`).
- fixes#6680 by doing a wrapping add of the param's index to its `TYPE_UUID`
Co-authored-by: dis-da-moe <84386186+dis-da-moe@users.noreply.github.com>
# Objective
The trait `Condition<>` is implemented for any type that can be converted into a `ReadOnlySystem` which takes no inputs and returns a bool. However, due to the current implementation, consumers of the trait cannot rely on the fact that `<T as Condition>::System` implements `ReadOnlySystem`. In cases such as the `not` combinator (added in #7559), we are required to add redundant `T::System: ReadOnlySystem` trait bounds, even though this should be implied by the `Condition<>` trait.
## Solution
Add a hidden associated type which allows the compiler to figure out that the `System` associated type implements `ReadOnlySystem`.
# Objective
The `SystemParamFunction` (and `ExclusiveSystemParamFunction`) trait is very cumbersome to use, due to it requiring four generic type parameters. These are currently all used as marker parameters to satisfy rust's trait coherence rules.
### Example (before)
```rust
pub fn pipe<AIn, Shared, BOut, A, AParam, AMarker, B, BParam, BMarker>(
mut system_a: A,
mut system_b: B,
) -> impl FnMut(In<AIn>, ParamSet<(AParam, BParam)>) -> BOut
where
A: SystemParamFunction<AIn, Shared, AParam, AMarker>,
B: SystemParamFunction<Shared, BOut, BParam, BMarker>,
AParam: SystemParam,
BParam: SystemParam,
```
## Solution
Turn the `In`, `Out`, and `Param` generics into associated types. Merge the marker types together to retain coherence.
### Example (after)
```rust
pub fn pipe<A, B, AMarker, BMarker>(
mut system_a: A,
mut system_b: B,
) -> impl FnMut(In<A::In>, ParamSet<(A::Param, B::Param)>) -> B::Out
where
A: SystemParamFunction<AMarker>,
B: SystemParamFunction<BMarker, In = A::Out>,
```
---
## Changelog
+ Simplified the `SystemParamFunction` and `ExclusiveSystemParamFunction` traits.
## Migration Guide
For users of the `SystemParamFunction` trait, the generic type parameters `In`, `Out`, and `Param` have been turned into associated types. The same has been done with the `ExclusiveSystemParamFunction` trait.
# Objective
- Improve readability of the run condition for systems only running in a certain state
## Solution
- Rename `state_equals` to `in_state` (see [comment by cart](https://github.com/bevyengine/bevy/pull/7634#issuecomment-1428740311) in #7634 )
- `.run_if(state_equals(variant))` now is `.run_if(in_state(variant))`
This breaks the naming pattern a bit with the related conditions `state_exists` and `state_exists_and_equals` but I could not think of better names for those and think the improved readability of `in_state` is worth it.
# Objective
Fixes#7632.
As discussed in #7634, it can be quite challenging for users to intuit the mental model of how states now work.
## Solution
Rather than change the behavior of the `OnUpdate` system set, instead work on making sure it's easy to understand what's going on.
Two things have been done:
1. Remove the `.on_update` method from our bevy of system building traits. This was special-cased and made states feel much more magical than they need to.
2. Improve the docs for the `OnUpdate` system set.
# Objective
Closes#7202
## Solution
~~Introduce a `not` helper to pipe conditions. Opened mostly for discussion. Maybe create an extension trait with `not` method? Please, advice.~~
Introduce `not(condition)` condition that inverses the result of the passed.
---
## Changelog
### Added
- `not` condition.
Small commit to remove an unused resource scoped within a single bevy_ecs unit test. Also rearranged the initialization to follow initialization conventions of surrounding tests. World/Schedule initialization followed by resource initialization.
This change was tested locally with `cargo test`, and `cargo fmt` was run.
Risk should be tiny as change is scoped to a single unit test and very tiny, and I can't see any way that this resource is being used in the test.
Thank you so much!
# Objective
Run conditions are a special type of system that do not modify the world, and which return a bool. Due to the way they are currently implemented, you can *only* use bare function systems as a run condition. Among other things, this prevents the use of system piping with run conditions. This make very basic constructs impossible, such as `my_system.run_if(my_condition.pipe(not))`.
Unblocks a basic solution for #7202.
## Solution
Add the trait `ReadOnlySystem`, which is implemented for any system whose parameters all implement `ReadOnlySystemParam`. Allow any `-> bool` system implementing this trait to be used as a run condition.
---
## Changelog
+ Added the trait `ReadOnlySystem`, which is implemented for any `System` type whose parameters all implement `ReadOnlySystemParam`.
+ Added the function `bevy::ecs::system::assert_is_read_only_system`.
# Objective
Implementing `States` manually is repetitive, so let's not.
One thing I'm unsure of is whether the macro import statement is in the right place.
# Objective
- There is a small perf cost for starting the multithreaded executor.
## Solution
- We can skip that cost when there are zero systems in the schedule. Overall not a big perf boost unless there are a lot of empty schedules that are trying to run, but it is something.
Below is a tracy trace of the run_fixed_update_schedule for many_foxes which has zero systems in it. Yellow is main and red is this pr. The time difference between the peaks of the humps is around 15us.
Huge thanks to @maniwani, @devil-ira, @hymm, @cart, @superdump and @jakobhellermann for the help with this PR.
# Objective
- Followup #6587.
- Minimal integration for the Stageless Scheduling RFC: https://github.com/bevyengine/rfcs/pull/45
## Solution
- [x] Remove old scheduling module
- [x] Migrate new methods to no longer use extension methods
- [x] Fix compiler errors
- [x] Fix benchmarks
- [x] Fix examples
- [x] Fix docs
- [x] Fix tests
## Changelog
### Added
- a large number of methods on `App` to work with schedules ergonomically
- the `CoreSchedule` enum
- `App::add_extract_system` via the `RenderingAppExtension` trait extension method
- the private `prepare_view_uniforms` system now has a public system set for scheduling purposes, called `ViewSet::PrepareUniforms`
### Removed
- stages, and all code that mentions stages
- states have been dramatically simplified, and no longer use a stack
- `RunCriteriaLabel`
- `AsSystemLabel` trait
- `on_hierarchy_reports_enabled` run criteria (now just uses an ad hoc resource checking run condition)
- systems in `RenderSet/Stage::Extract` no longer warn when they do not read data from the main world
- `RunCriteriaLabel`
- `transform_propagate_system_set`: this was a nonstandard pattern that didn't actually provide enough control. The systems are already `pub`: the docs have been updated to ensure that the third-party usage is clear.
### Changed
- `System::default_labels` is now `System::default_system_sets`.
- `App::add_default_labels` is now `App::add_default_sets`
- `CoreStage` and `StartupStage` enums are now `CoreSet` and `StartupSet`
- `App::add_system_set` was renamed to `App::add_systems`
- The `StartupSchedule` label is now defined as part of the `CoreSchedules` enum
- `.label(SystemLabel)` is now referred to as `.in_set(SystemSet)`
- `SystemLabel` trait was replaced by `SystemSet`
- `SystemTypeIdLabel<T>` was replaced by `SystemSetType<T>`
- The `ReportHierarchyIssue` resource now has a public constructor (`new`), and implements `PartialEq`
- Fixed time steps now use a schedule (`CoreSchedule::FixedTimeStep`) rather than a run criteria.
- Adding rendering extraction systems now panics rather than silently failing if no subapp with the `RenderApp` label is found.
- the `calculate_bounds` system, with the `CalculateBounds` label, is now in `CoreSet::Update`, rather than in `CoreSet::PostUpdate` before commands are applied.
- `SceneSpawnerSystem` now runs under `CoreSet::Update`, rather than `CoreStage::PreUpdate.at_end()`.
- `bevy_pbr::add_clusters` is no longer an exclusive system
- the top level `bevy_ecs::schedule` module was replaced with `bevy_ecs::scheduling`
- `tick_global_task_pools_on_main_thread` is no longer run as an exclusive system. Instead, it has been replaced by `tick_global_task_pools`, which uses a `NonSend` resource to force running on the main thread.
## Migration Guide
- Calls to `.label(MyLabel)` should be replaced with `.in_set(MySet)`
- Stages have been removed. Replace these with system sets, and then add command flushes using the `apply_system_buffers` exclusive system where needed.
- The `CoreStage`, `StartupStage, `RenderStage` and `AssetStage` enums have been replaced with `CoreSet`, `StartupSet, `RenderSet` and `AssetSet`. The same scheduling guarantees have been preserved.
- Systems are no longer added to `CoreSet::Update` by default. Add systems manually if this behavior is needed, although you should consider adding your game logic systems to `CoreSchedule::FixedTimestep` instead for more reliable framerate-independent behavior.
- Similarly, startup systems are no longer part of `StartupSet::Startup` by default. In most cases, this won't matter to you.
- For example, `add_system_to_stage(CoreStage::PostUpdate, my_system)` should be replaced with
- `add_system(my_system.in_set(CoreSet::PostUpdate)`
- When testing systems or otherwise running them in a headless fashion, simply construct and run a schedule using `Schedule::new()` and `World::run_schedule` rather than constructing stages
- Run criteria have been renamed to run conditions. These can now be combined with each other and with states.
- Looping run criteria and state stacks have been removed. Use an exclusive system that runs a schedule if you need this level of control over system control flow.
- For app-level control flow over which schedules get run when (such as for rollback networking), create your own schedule and insert it under the `CoreSchedule::Outer` label.
- Fixed timesteps are now evaluated in a schedule, rather than controlled via run criteria. The `run_fixed_timestep` system runs this schedule between `CoreSet::First` and `CoreSet::PreUpdate` by default.
- Command flush points introduced by `AssetStage` have been removed. If you were relying on these, add them back manually.
- Adding extract systems is now typically done directly on the main app. Make sure the `RenderingAppExtension` trait is in scope, then call `app.add_extract_system(my_system)`.
- the `calculate_bounds` system, with the `CalculateBounds` label, is now in `CoreSet::Update`, rather than in `CoreSet::PostUpdate` before commands are applied. You may need to order your movement systems to occur before this system in order to avoid system order ambiguities in culling behavior.
- the `RenderLabel` `AppLabel` was renamed to `RenderApp` for clarity
- `App::add_state` now takes 0 arguments: the starting state is set based on the `Default` impl.
- Instead of creating `SystemSet` containers for systems that run in stages, simply use `.on_enter::<State::Variant>()` or its `on_exit` or `on_update` siblings.
- `SystemLabel` derives should be replaced with `SystemSet`. You will also need to add the `Debug`, `PartialEq`, `Eq`, and `Hash` traits to satisfy the new trait bounds.
- `with_run_criteria` has been renamed to `run_if`. Run criteria have been renamed to run conditions for clarity, and should now simply return a bool.
- States have been dramatically simplified: there is no longer a "state stack". To queue a transition to the next state, call `NextState::set`
## TODO
- [x] remove dead methods on App and World
- [x] add `App::add_system_to_schedule` and `App::add_systems_to_schedule`
- [x] avoid adding the default system set at inappropriate times
- [x] remove any accidental cycles in the default plugins schedule
- [x] migrate benchmarks
- [x] expose explicit labels for the built-in command flush points
- [x] migrate engine code
- [x] remove all mentions of stages from the docs
- [x] verify docs for States
- [x] fix uses of exclusive systems that use .end / .at_start / .before_commands
- [x] migrate RenderStage and AssetStage
- [x] migrate examples
- [x] ensure that transform propagation is exported in a sufficiently public way (the systems are already pub)
- [x] ensure that on_enter schedules are run at least once before the main app
- [x] re-enable opt-in to execution order ambiguities
- [x] revert change to `update_bounds` to ensure it runs in `PostUpdate`
- [x] test all examples
- [x] unbreak directional lights
- [x] unbreak shadows (see 3d_scene, 3d_shape, lighting, transparaency_3d examples)
- [x] game menu example shows loading screen and menu simultaneously
- [x] display settings menu is a blank screen
- [x] `without_winit` example panics
- [x] ensure all tests pass
- [x] SubApp doc test fails
- [x] runs_spawn_local tasks fails
- [x] [Fix panic_when_hierachy_cycle test hanging](https://github.com/alice-i-cecile/bevy/pull/120)
## Points of Difficulty and Controversy
**Reviewers, please give feedback on these and look closely**
1. Default sets, from the RFC, have been removed. These added a tremendous amount of implicit complexity and result in hard to debug scheduling errors. They're going to be tackled in the form of "base sets" by @cart in a followup.
2. The outer schedule controls which schedule is run when `App::update` is called.
3. I implemented `Label for `Box<dyn Label>` for our label types. This enables us to store schedule labels in concrete form, and then later run them. I ran into the same set of problems when working with one-shot systems. We've previously investigated this pattern in depth, and it does not appear to lead to extra indirection with nested boxes.
4. `SubApp::update` simply runs the default schedule once. This sucks, but this whole API is incomplete and this was the minimal changeset.
5. `time_system` and `tick_global_task_pools_on_main_thread` no longer use exclusive systems to attempt to force scheduling order
6. Implemetnation strategy for fixed timesteps
7. `AssetStage` was migrated to `AssetSet` without reintroducing command flush points. These did not appear to be used, and it's nice to remove these bottlenecks.
8. Migration of `bevy_render/lib.rs` and pipelined rendering. The logic here is unusually tricky, as we have complex scheduling requirements.
## Future Work (ideally before 0.10)
- Rename schedule_v3 module to schedule or scheduling
- Add a derive macro to states, and likely a `EnumIter` trait of some form
- Figure out what exactly to do with the "systems added should basically work by default" problem
- Improve ergonomics for working with fixed timesteps and states
- Polish FixedTime API to match Time
- Rebase and merge #7415
- Resolve all internal ambiguities (blocked on better tools, especially #7442)
- Add "base sets" to replace the removed default sets.
# Objective
- Currently exclusive systems and applying buffers run outside of the multithreaded executor and just calls the funtions on the thread the schedule is running on. Stageless changes this to run these using tasks in a scope. Specifically It uses `spawn_on_scope` to run these. For the render thread this is incorrect as calling `spawn_on_scope` there runs tasks on the main thread. It should instead run these on the render thread and only run nonsend systems on the main thread.
## Solution
- Add another executor to `Scope` for spawning tasks on the scope. `spawn_on_scope` now always runs the task on the thread the scope is running on. `spawn_on_external` spawns onto the external executor than is optionally passed in. If None is passed `spawn_on_external` will spawn onto the scope executor.
- Eventually this new machinery will be able to be removed. This will happen once a fix for removing NonSend resources from the world lands. So this is a temporary fix to support stageless.
---
## Changelog
- add a spawn_on_external method to allow spawning on the scope's thread or an external thread
## Migration Guide
> No migration guide. The main thread executor was introduced in pipelined rendering which was merged for 0.10. spawn_on_scope now behaves the same way as on 0.9.
# Objective
- Trying to move some of the fixes from https://github.com/bevyengine/bevy/pull/7267 to make that one easier to review
- The MainThreadExecutor is how the render world runs nonsend systems on the main thread for pipelined rendering.
- The multithread executor for stageless wasn't using the MainThreadExecutor.
- MainThreadExecutor was declared in the old executor_parallel module that is getting deleted.
- The way the MainThreadExecutor was getting passed to the scope was actually unsound as the resource could be dropped from the World while the schedule was running
## Solution
- Move MainThreadExecutor to the new multithreaded_executor's file.
- Make the multithreaded executor use the MainThreadExecutor
- Clone the MainThreadExecutor onto the stack and pass that ref in
## Changelog
- Move MainThreadExecutor for stageless migration.
# Objective
I found several words in code and docs are incorrect. This should be fixed.
## Solution
- Fix several minor typos
Co-authored-by: Chris Ohk <utilforever@gmail.com>
# Objective
- Implement pipelined rendering
- Fixes#5082
- Fixes#4718
## User Facing Description
Bevy now implements piplelined rendering! Pipelined rendering allows the app logic and rendering logic to run on different threads leading to large gains in performance.
*tracy capture of many_foxes example*
To use pipelined rendering, you just need to add the `PipelinedRenderingPlugin`. If you're using `DefaultPlugins` then it will automatically be added for you on all platforms except wasm. Bevy does not currently support multithreading on wasm which is needed for this feature to work. If you aren't using `DefaultPlugins` you can add the plugin manually.
```rust
use bevy::prelude::*;
use bevy::render::pipelined_rendering::PipelinedRenderingPlugin;
fn main() {
App::new()
// whatever other plugins you need
.add_plugin(RenderPlugin)
// needs to be added after RenderPlugin
.add_plugin(PipelinedRenderingPlugin)
.run();
}
```
If for some reason pipelined rendering needs to be removed. You can also disable the plugin the normal way.
```rust
use bevy::prelude::*;
use bevy::render::pipelined_rendering::PipelinedRenderingPlugin;
fn main() {
App::new.add_plugins(DefaultPlugins.build().disable::<PipelinedRenderingPlugin>());
}
```
### A setup function was added to plugins
A optional plugin lifecycle function was added to the `Plugin trait`. This function is called after all plugins have been built, but before the app runner is called. This allows for some final setup to be done. In the case of pipelined rendering, the function removes the sub app from the main app and sends it to the render thread.
```rust
struct MyPlugin;
impl Plugin for MyPlugin {
fn build(&self, app: &mut App) {
}
// optional function
fn setup(&self, app: &mut App) {
// do some final setup before runner is called
}
}
```
### A Stage for Frame Pacing
In the `RenderExtractApp` there is a stage labelled `BeforeIoAfterRenderStart` that systems can be added to. The specific use case for this stage is for a frame pacing system that can delay the start of main app processing in render bound apps to reduce input latency i.e. "frame pacing". This is not currently built into bevy, but exists as `bevy`
```text
|-------------------------------------------------------------------|
| | BeforeIoAfterRenderStart | winit events | main schedule |
| extract |---------------------------------------------------------|
| | extract commands | rendering schedule |
|-------------------------------------------------------------------|
```
### Small API additions
* `Schedule::remove_stage`
* `App::insert_sub_app`
* `App::remove_sub_app`
* `TaskPool::scope_with_executor`
## Problems and Solutions
### Moving render app to another thread
Most of the hard bits for this were done with the render redo. This PR just sends the render app back and forth through channels which seems to work ok. I originally experimented with using a scope to run the render task. It was cuter, but that approach didn't allow render to start before i/o processing. So I switched to using channels. There is much complexity in the coordination that needs to be done, but it's worth it. By moving rendering during i/o processing the frame times should be much more consistent in render bound apps. See https://github.com/bevyengine/bevy/issues/4691.
### Unsoundness with Sending World with NonSend resources
Dropping !Send things on threads other than the thread they were spawned on is considered unsound. The render world doesn't have any nonsend resources. So if we tell the users to "pretty please don't spawn nonsend resource on the render world", we can avoid this problem.
More seriously there is this https://github.com/bevyengine/bevy/pull/6534 pr, which patches the unsoundness by aborting the app if a nonsend resource is dropped on the wrong thread. ~~That PR should probably be merged before this one.~~ For a longer term solution we have this discussion going https://github.com/bevyengine/bevy/discussions/6552.
### NonSend Systems in render world
The render world doesn't have any !Send resources, but it does have a non send system. While Window is Send, winit does have some API's that can only be accessed on the main thread. `prepare_windows` in the render schedule thus needs to be scheduled on the main thread. Currently we run nonsend systems by running them on the thread the TaskPool::scope runs on. When we move render to another thread this no longer works.
To fix this, a new `scope_with_executor` method was added that takes a optional `TheadExecutor` that can only be ticked on the thread it was initialized on. The render world then holds a `MainThreadExecutor` resource which can be passed to the scope in the parallel executor that it uses to spawn it's non send systems on.
### Scopes executors between render and main should not share tasks
Since the render world and the app world share the `ComputeTaskPool`. Because `scope` has executors for the ComputeTaskPool a system from the main world could run on the render thread or a render system could run on the main thread. This can cause performance problems because it can delay a stage from finishing. See https://github.com/bevyengine/bevy/pull/6503#issuecomment-1309791442 for more details.
To avoid this problem, `TaskPool::scope` has been changed to not tick the ComputeTaskPool when it's used by the parallel executor. In the future when we move closer to the 1 thread to 1 logical core model we may want to overprovide threads, because the render and main app threads don't do much when executing the schedule.
## Performance
My machine is Windows 11, AMD Ryzen 5600x, RX 6600
### Examples
#### This PR with pipelining vs Main
> Note that these were run on an older version of main and the performance profile has probably changed due to optimizations
Seeing a perf gain from 29% on many lights to 7% on many sprites.
<html>
<body>
<!--StartFragment--><google-sheets-html-origin>
| percent | | | Diff | | | Main | | | PR | |
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --
tracy frame time | mean | median | sigma | mean | median | sigma | mean | median | sigma | mean | median | sigma
many foxes | 27.01% | 27.34% | -47.09% | 1.58 | 1.55 | -1.78 | 5.85 | 5.67 | 3.78 | 4.27 | 4.12 | 5.56
many lights | 29.35% | 29.94% | -10.84% | 3.02 | 3.03 | -0.57 | 10.29 | 10.12 | 5.26 | 7.27 | 7.09 | 5.83
many animated sprites | 13.97% | 15.69% | 14.20% | 3.79 | 4.17 | 1.41 | 27.12 | 26.57 | 9.93 | 23.33 | 22.4 | 8.52
3d scene | 25.79% | 26.78% | 7.46% | 0.49 | 0.49 | 0.15 | 1.9 | 1.83 | 2.01 | 1.41 | 1.34 | 1.86
many cubes | 11.97% | 11.28% | 14.51% | 1.93 | 1.78 | 1.31 | 16.13 | 15.78 | 9.03 | 14.2 | 14 | 7.72
many sprites | 7.14% | 9.42% | -85.42% | 1.72 | 2.23 | -6.15 | 24.09 | 23.68 | 7.2 | 22.37 | 21.45 | 13.35
<!--EndFragment-->
</body>
</html>
#### This PR with pipelining disabled vs Main
Mostly regressions here. I don't think this should be a problem as users that are disabling pipelined rendering are probably running single threaded and not using the parallel executor. The regression is probably mostly due to the switch to use `async_executor::run` instead of `try_tick` and also having one less thread to run systems on. I'll do a writeup on why switching to `run` causes regressions, so we can try to eventually fix it. Using try_tick causes issues when pipeline rendering is enable as seen [here](https://github.com/bevyengine/bevy/pull/6503#issuecomment-1380803518)
<html>
<body>
<!--StartFragment--><google-sheets-html-origin>
| percent | | | Diff | | | Main | | | PR no pipelining | |
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --
tracy frame time | mean | median | sigma | mean | median | sigma | mean | median | sigma | mean | median | sigma
many foxes | -3.72% | -4.42% | -1.07% | -0.21 | -0.24 | -0.04 | 5.64 | 5.43 | 3.74 | 5.85 | 5.67 | 3.78
many lights | 0.29% | -0.30% | 4.75% | 0.03 | -0.03 | 0.25 | 10.29 | 10.12 | 5.26 | 10.26 | 10.15 | 5.01
many animated sprites | 0.22% | 1.81% | -2.72% | 0.06 | 0.48 | -0.27 | 27.12 | 26.57 | 9.93 | 27.06 | 26.09 | 10.2
3d scene | -15.79% | -14.75% | -31.34% | -0.3 | -0.27 | -0.63 | 1.9 | 1.83 | 2.01 | 2.2 | 2.1 | 2.64
many cubes | -2.85% | -3.30% | 0.00% | -0.46 | -0.52 | 0 | 16.13 | 15.78 | 9.03 | 16.59 | 16.3 | 9.03
many sprites | 2.49% | 2.41% | 0.69% | 0.6 | 0.57 | 0.05 | 24.09 | 23.68 | 7.2 | 23.49 | 23.11 | 7.15
<!--EndFragment-->
</body>
</html>
### Benchmarks
Mostly the same except empty_systems has got a touch slower. The maybe_pipelining+1 column has the compute task pool with an extra thread over default added. This is because pipelining loses one thread over main to execute systems on, since the main thread no longer runs normal systems.
<details>
<summary>Click Me</summary>
```text
group main maybe-pipelining+1
----- ------------------------- ------------------
busy_systems/01x_entities_03_systems 1.07 30.7±1.32µs ? ?/sec 1.00 28.6±1.35µs ? ?/sec
busy_systems/01x_entities_06_systems 1.10 52.1±1.10µs ? ?/sec 1.00 47.2±1.08µs ? ?/sec
busy_systems/01x_entities_09_systems 1.00 74.6±1.36µs ? ?/sec 1.00 75.0±1.93µs ? ?/sec
busy_systems/01x_entities_12_systems 1.03 100.6±6.68µs ? ?/sec 1.00 98.0±1.46µs ? ?/sec
busy_systems/01x_entities_15_systems 1.11 128.5±3.53µs ? ?/sec 1.00 115.5±1.02µs ? ?/sec
busy_systems/02x_entities_03_systems 1.16 50.4±2.56µs ? ?/sec 1.00 43.5±3.00µs ? ?/sec
busy_systems/02x_entities_06_systems 1.00 87.1±1.27µs ? ?/sec 1.05 91.5±7.15µs ? ?/sec
busy_systems/02x_entities_09_systems 1.04 139.9±6.37µs ? ?/sec 1.00 134.0±1.06µs ? ?/sec
busy_systems/02x_entities_12_systems 1.05 179.2±3.47µs ? ?/sec 1.00 170.1±3.17µs ? ?/sec
busy_systems/02x_entities_15_systems 1.01 219.6±3.75µs ? ?/sec 1.00 218.1±2.55µs ? ?/sec
busy_systems/03x_entities_03_systems 1.10 70.6±2.33µs ? ?/sec 1.00 64.3±0.69µs ? ?/sec
busy_systems/03x_entities_06_systems 1.02 130.2±3.11µs ? ?/sec 1.00 128.0±1.34µs ? ?/sec
busy_systems/03x_entities_09_systems 1.00 195.0±10.11µs ? ?/sec 1.00 194.8±1.41µs ? ?/sec
busy_systems/03x_entities_12_systems 1.01 261.7±4.05µs ? ?/sec 1.00 259.8±4.11µs ? ?/sec
busy_systems/03x_entities_15_systems 1.00 318.0±3.04µs ? ?/sec 1.06 338.3±20.25µs ? ?/sec
busy_systems/04x_entities_03_systems 1.00 82.9±0.63µs ? ?/sec 1.02 84.3±0.63µs ? ?/sec
busy_systems/04x_entities_06_systems 1.01 181.7±3.65µs ? ?/sec 1.00 179.8±1.76µs ? ?/sec
busy_systems/04x_entities_09_systems 1.04 265.0±4.68µs ? ?/sec 1.00 255.3±1.98µs ? ?/sec
busy_systems/04x_entities_12_systems 1.00 335.9±3.00µs ? ?/sec 1.05 352.6±15.84µs ? ?/sec
busy_systems/04x_entities_15_systems 1.00 418.6±10.26µs ? ?/sec 1.08 450.2±39.58µs ? ?/sec
busy_systems/05x_entities_03_systems 1.07 114.3±0.95µs ? ?/sec 1.00 106.9±1.52µs ? ?/sec
busy_systems/05x_entities_06_systems 1.08 229.8±2.90µs ? ?/sec 1.00 212.3±4.18µs ? ?/sec
busy_systems/05x_entities_09_systems 1.03 329.3±1.99µs ? ?/sec 1.00 319.2±2.43µs ? ?/sec
busy_systems/05x_entities_12_systems 1.06 454.7±6.77µs ? ?/sec 1.00 430.1±3.58µs ? ?/sec
busy_systems/05x_entities_15_systems 1.03 554.6±6.15µs ? ?/sec 1.00 538.4±23.87µs ? ?/sec
contrived/01x_entities_03_systems 1.00 14.0±0.15µs ? ?/sec 1.08 15.1±0.21µs ? ?/sec
contrived/01x_entities_06_systems 1.04 28.5±0.37µs ? ?/sec 1.00 27.4±0.44µs ? ?/sec
contrived/01x_entities_09_systems 1.00 41.5±4.38µs ? ?/sec 1.02 42.2±2.24µs ? ?/sec
contrived/01x_entities_12_systems 1.06 55.9±1.49µs ? ?/sec 1.00 52.6±1.36µs ? ?/sec
contrived/01x_entities_15_systems 1.02 68.0±2.00µs ? ?/sec 1.00 66.5±0.78µs ? ?/sec
contrived/02x_entities_03_systems 1.03 25.2±0.38µs ? ?/sec 1.00 24.6±0.52µs ? ?/sec
contrived/02x_entities_06_systems 1.00 46.3±0.49µs ? ?/sec 1.04 48.1±4.13µs ? ?/sec
contrived/02x_entities_09_systems 1.02 70.4±0.99µs ? ?/sec 1.00 68.8±1.04µs ? ?/sec
contrived/02x_entities_12_systems 1.06 96.8±1.49µs ? ?/sec 1.00 91.5±0.93µs ? ?/sec
contrived/02x_entities_15_systems 1.02 116.2±0.95µs ? ?/sec 1.00 114.2±1.42µs ? ?/sec
contrived/03x_entities_03_systems 1.00 33.2±0.38µs ? ?/sec 1.01 33.6±0.45µs ? ?/sec
contrived/03x_entities_06_systems 1.00 62.4±0.73µs ? ?/sec 1.01 63.3±1.05µs ? ?/sec
contrived/03x_entities_09_systems 1.02 96.4±0.85µs ? ?/sec 1.00 94.8±3.02µs ? ?/sec
contrived/03x_entities_12_systems 1.01 126.3±4.67µs ? ?/sec 1.00 125.6±2.27µs ? ?/sec
contrived/03x_entities_15_systems 1.03 160.2±9.37µs ? ?/sec 1.00 156.0±1.53µs ? ?/sec
contrived/04x_entities_03_systems 1.02 41.4±3.39µs ? ?/sec 1.00 40.5±0.52µs ? ?/sec
contrived/04x_entities_06_systems 1.00 78.9±1.61µs ? ?/sec 1.02 80.3±1.06µs ? ?/sec
contrived/04x_entities_09_systems 1.02 121.8±3.97µs ? ?/sec 1.00 119.2±1.46µs ? ?/sec
contrived/04x_entities_12_systems 1.00 157.8±1.48µs ? ?/sec 1.01 160.1±1.72µs ? ?/sec
contrived/04x_entities_15_systems 1.00 197.9±1.47µs ? ?/sec 1.08 214.2±34.61µs ? ?/sec
contrived/05x_entities_03_systems 1.00 49.1±0.33µs ? ?/sec 1.01 49.7±0.75µs ? ?/sec
contrived/05x_entities_06_systems 1.00 95.0±0.93µs ? ?/sec 1.00 94.6±0.94µs ? ?/sec
contrived/05x_entities_09_systems 1.01 143.2±1.68µs ? ?/sec 1.00 142.2±2.00µs ? ?/sec
contrived/05x_entities_12_systems 1.00 191.8±2.03µs ? ?/sec 1.01 192.7±7.88µs ? ?/sec
contrived/05x_entities_15_systems 1.02 239.7±3.71µs ? ?/sec 1.00 235.8±4.11µs ? ?/sec
empty_systems/000_systems 1.01 47.8±0.67ns ? ?/sec 1.00 47.5±2.02ns ? ?/sec
empty_systems/001_systems 1.00 1743.2±126.14ns ? ?/sec 1.01 1761.1±70.10ns ? ?/sec
empty_systems/002_systems 1.01 2.2±0.04µs ? ?/sec 1.00 2.2±0.02µs ? ?/sec
empty_systems/003_systems 1.02 2.7±0.09µs ? ?/sec 1.00 2.7±0.16µs ? ?/sec
empty_systems/004_systems 1.00 3.1±0.11µs ? ?/sec 1.00 3.1±0.24µs ? ?/sec
empty_systems/005_systems 1.00 3.5±0.05µs ? ?/sec 1.11 3.9±0.70µs ? ?/sec
empty_systems/010_systems 1.00 5.5±0.12µs ? ?/sec 1.03 5.7±0.17µs ? ?/sec
empty_systems/015_systems 1.00 7.9±0.19µs ? ?/sec 1.06 8.4±0.16µs ? ?/sec
empty_systems/020_systems 1.00 10.4±1.25µs ? ?/sec 1.02 10.6±0.18µs ? ?/sec
empty_systems/025_systems 1.00 12.4±0.39µs ? ?/sec 1.14 14.1±1.07µs ? ?/sec
empty_systems/030_systems 1.00 15.1±0.39µs ? ?/sec 1.05 15.8±0.62µs ? ?/sec
empty_systems/035_systems 1.00 16.9±0.47µs ? ?/sec 1.07 18.0±0.37µs ? ?/sec
empty_systems/040_systems 1.00 19.3±0.41µs ? ?/sec 1.05 20.3±0.39µs ? ?/sec
empty_systems/045_systems 1.00 22.4±1.67µs ? ?/sec 1.02 22.9±0.51µs ? ?/sec
empty_systems/050_systems 1.00 24.4±1.67µs ? ?/sec 1.01 24.7±0.40µs ? ?/sec
empty_systems/055_systems 1.05 28.6±5.27µs ? ?/sec 1.00 27.2±0.70µs ? ?/sec
empty_systems/060_systems 1.02 29.9±1.64µs ? ?/sec 1.00 29.3±0.66µs ? ?/sec
empty_systems/065_systems 1.02 32.7±3.15µs ? ?/sec 1.00 32.1±0.98µs ? ?/sec
empty_systems/070_systems 1.00 33.0±1.42µs ? ?/sec 1.03 34.1±1.44µs ? ?/sec
empty_systems/075_systems 1.00 34.8±0.89µs ? ?/sec 1.04 36.2±0.70µs ? ?/sec
empty_systems/080_systems 1.00 37.0±1.82µs ? ?/sec 1.05 38.7±1.37µs ? ?/sec
empty_systems/085_systems 1.00 38.7±0.76µs ? ?/sec 1.05 40.8±0.83µs ? ?/sec
empty_systems/090_systems 1.00 41.5±1.09µs ? ?/sec 1.04 43.2±0.82µs ? ?/sec
empty_systems/095_systems 1.00 43.6±1.10µs ? ?/sec 1.04 45.2±0.99µs ? ?/sec
empty_systems/100_systems 1.00 46.7±2.27µs ? ?/sec 1.03 48.1±1.25µs ? ?/sec
```
</details>
## Migration Guide
### App `runner` and SubApp `extract` functions are now required to be Send
This was changed to enable pipelined rendering. If this breaks your use case please report it as these new bounds might be able to be relaxed.
## ToDo
* [x] redo benchmarking
* [x] reinvestigate the perf of the try_tick -> run change for task pool scope
# Objective
Fixes#3310. Fixes#6282. Fixes#6278. Fixes#3666.
## Solution
Split out `!Send` resources into `NonSendResources`. Add a `origin_thread_id` to all `!Send` Resources, check it on dropping `NonSendResourceData`, if there's a mismatch, panic. Moved all of the checks that `MainThreadValidator` would do into `NonSendResources` instead.
All `!Send` resources now individually track which thread they were inserted from. This is validated against for every access, mutation, and drop that could be done against the value.
A regression test using an altered version of the example from #3310 has been added.
This is a stopgap solution for the current status quo. A full solution may involve fully removing `!Send` resources/components from `World`, which will likely require a much more thorough design on how to handle the existing in-engine and ecosystem use cases.
This PR also introduces another breaking change:
```rust
use bevy_ecs::prelude::*;
#[derive(Resource)]
struct Resource(u32);
fn main() {
let mut world = World::new();
world.insert_resource(Resource(1));
world.insert_non_send_resource(Resource(2));
let res = world.get_resource_mut::<Resource>().unwrap();
assert_eq!(res.0, 2);
}
```
This code will run correctly on 0.9.1 but not with this PR, since NonSend resources and normal resources have become actual distinct concepts storage wise.
## Changelog
Changed: Fix soundness bug with `World: Send`. Dropping a `World` that contains a `!Send` resource on the wrong thread will now panic.
## Migration Guide
Normal resources and `NonSend` resources no longer share the same backing storage. If `R: Resource`, then `NonSend<R>` and `Res<R>` will return different instances from each other. If you are using both `Res<T>` and `NonSend<T>` (or their mutable variants), to fetch the same resources, it's strongly advised to use `Res<T>`.
# Objective
- This pulls out some of the changes to Plugin setup and sub apps from #6503 to make that PR easier to review.
- Separate the extract stage from running the sub app's schedule to allow for them to be run on separate threads in the future
- Fixes#6990
## Solution
- add a run method to `SubApp` that runs the schedule
- change the name of `sub_app_runner` to extract to make it clear that this function is only for extracting data between the main app and the sub app
- remove the extract stage from the sub app schedule so it can be run separately. This is done by adding a `setup` method to the `Plugin` trait that runs after all plugin build methods run. This is required to allow the extract stage to be removed from the schedule after all the plugins have added their systems to the stage. We will also need the setup method for pipelined rendering to setup the render thread. See e3267965e1/crates/bevy_render/src/pipelined_rendering.rs (L57-L98)
## Changelog
- Separate SubApp Extract stage from running the sub app schedule.
## Migration Guide
### SubApp `runner` has conceptually been changed to an `extract` function.
The `runner` no longer is in charge of running the sub app schedule. It's only concern is now moving data between the main world and the sub app. The `sub_app.app.schedule` is now run for you after the provided function is called.
```rust
// before
fn main() {
let sub_app = App::empty();
sub_app.add_stage(MyStage, SystemStage::parallel());
App::new().add_sub_app(MySubApp, sub_app, move |main_world, sub_app| {
extract(app_world, render_app);
render_app.app.schedule.run();
});
}
// after
fn main() {
let sub_app = App::empty();
sub_app.add_stage(MyStage, SystemStage::parallel());
App::new().add_sub_app(MySubApp, sub_app, move |main_world, sub_app| {
extract(app_world, render_app);
// schedule is automatically called for you after extract is run
});
}
```
# Objective
A separate `tracing` span for running a system's commands is created, even if the system doesn't have commands. This is adding extra measuring overhead (see #4892) where it's not needed.
## Solution
Move the span into `ParallelCommandState` and `CommandQueue`'s `SystemParamState::apply`. To get the right metadata for the span, a additional `&SystemMeta` parameter was added to `SystemParamState::apply`.
---
## Changelog
Added: `SystemMeta::name`
Changed: Systems without `Commands` and `ParallelCommands` will no longer show a "system_commands" span when profiling.
Changed: `SystemParamState::apply` now takes a `&SystemMeta` parameter in addition to the provided `&mut World`.
# Objective
- fix new clippy lints before they get stable and break CI
## Solution
- run `clippy --fix` to auto-fix machine-applicable lints
- silence `clippy::should_implement_trait` for `fn HandleId::default<T: Asset>`
## Changes
- always prefer `format!("{inline}")` over `format!("{}", not_inline)`
- prefer `Box::default` (or `Box::<T>::default` if necessary) over `Box::new(T::default())`
# Objective
> System chaining is a confusing name: it implies the ability to construct non-linear graphs, and suggests a sense of system ordering that is only incidentally true. Instead, it actually works by passing data from one system to the next, much like the pipe operator.
> In the accepted [stageless RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/45-stageless.md), this concept is renamed to piping, and "system chaining" is used to construct groups of systems with ordering dependencies between them.
Fixes#6225.
## Changelog
System chaining has been renamed to system piping to improve clarity (and free up the name for new ordering APIs).
## Migration Guide
The `.chain(handler_system)` method on systems is now `.pipe(handler_system)`.
The `IntoChainSystem` trait is now `IntoPipeSystem`, and the `ChainSystem` struct is now `PipeSystem`.
# Objective
- Adding Debug implementations for App, Stage, Schedule, Query, QueryState.
- Fixes#1130.
## Solution
- Implemented std::fmt::Debug for a number of structures.
---
## Changelog
Also added Debug implementations for ParallelSystemExecutor, SingleThreadedExecutor, various RunCriteria structures, SystemContainer, and SystemDescriptor.
Opinions are sure to differ as to what information to provide in a Debug implementation. Best guess was taken for this initial version for these structures.
Co-authored-by: targrub <62773321+targrub@users.noreply.github.com>
# Background
Incremental implementation of #4299. The code is heavily borrowed from that PR.
# Objective
The execution order ambiguity checker often emits false positives, since bevy is not aware of invariants upheld by the user.
## Solution
Title
---
## Changelog
+ Added methods `SystemDescriptor::ignore_all_ambiguities` and `::ambiguous_with`. These allow you to silence warnings for specific system-order ambiguities.
## Migration Guide
***Note for maintainers**: This should replace the migration guide for #5916*
Ambiguity sets have been replaced with a simpler API.
```rust
// These systems technically conflict, but we don't care which order they run in.
fn jump_on_click(mouse: Res<Input<MouseButton>>, mut transforms: Query<&mut Transform>) { ... }
fn jump_on_spacebar(keys: Res<Input<KeyCode>>, mut transforms: Query<&mut Transform>) { ... }
//
// Before
#[derive(AmbiguitySetLabel)]
struct JumpSystems;
app
.add_system(jump_on_click.in_ambiguity_set(JumpSystems))
.add_system(jump_on_spacebar.in_ambiguity_set(JumpSystems));
//
// After
app
.add_system(jump_on_click.ambiguous_with(jump_on_spacebar))
.add_system(jump_on_spacebar);
```
# Objective
- Add ability to create nested spawns. This is needed for stageless. The current executor spawns tasks for each system early and runs the system by communicating through a channel. In stageless we want to spawn the task late, so that archetypes can be updated right before the task is run. The executor is run on a separate task, so this enables the scope to be passed to the spawned executor.
- Fixes#4301
## Solution
- Instantiate a single threaded executor on the scope and use that instead of the LocalExecutor. This allows the scope to be Send, but still able to spawn tasks onto the main thread the scope is run on. This works because while systems can access nonsend data. The systems themselves are Send. Because of this change we lose the ability to spawn nonsend tasks on the scope, but I don't think this is being used anywhere. Users would still be able to use spawn_local on TaskPools.
- Steals the lifetime tricks the `std:🧵:scope` uses to allow nested spawns, but disallow scope to be passed to tasks or threads not associated with the scope.
- Change the storage for the tasks to a `ConcurrentQueue`. This is to allow a &Scope to be passed for spawning instead of a &mut Scope. `ConcurrentQueue` was chosen because it was already in our dependency tree because `async_executor` depends on it.
- removed the optimizations for 0 and 1 spawned tasks. It did improve those cases, but made the cases of more than 1 task slower.
---
## Changelog
Add ability to nest spawns
```rust
fn main() {
let pool = TaskPool::new();
pool.scope(|scope| {
scope.spawn(async move {
// calling scope.spawn from an spawn task was not possible before
scope.spawn(async move {
// do something
});
});
})
}
```
## Migration Guide
If you were using explicit lifetimes and Passing Scope you'll need to specify two lifetimes now.
```rust
fn scoped_function<'scope>(scope: &mut Scope<'scope, ()>) {}
// should become
fn scoped_function<'scope>(scope: &Scope<'_, 'scope, ()>) {}
```
`scope.spawn_local` changed to `scope.spawn_on_scope` this should cover cases where you needed to run tasks on the local thread, but does not cover spawning Nonsend Futures.
## TODO
* [x] think real hard about all the lifetimes
* [x] add doc about what 'env and 'scope mean.
* [x] manually check that the single threaded task pool still works
* [x] Get updated perf numbers
* [x] check and make sure all the transmutes are necessary
* [x] move commented out test into a compile fail test
* [x] look through the tests for scope on std and see if I should add any more tests
Co-authored-by: Michael Hsu <myhsu@benjaminelectric.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
The [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) involves allowing exclusive systems to be referenced and ordered relative to parallel systems. We've agreed that unifying systems under `System` is the right move.
This is an alternative to #4166 (see rationale in the comments I left there). Note that this builds on the learnings established there (and borrows some patterns).
## Solution
This unifies parallel and exclusive systems under the shared `System` trait, removing the old `ExclusiveSystem` trait / impls. This is accomplished by adding a new `ExclusiveFunctionSystem` impl similar to `FunctionSystem`. It is backed by `ExclusiveSystemParam`, which is similar to `SystemParam`. There is a new flattened out SystemContainer api (which cuts out a lot of trait and type complexity).
This means you can remove all cases of `exclusive_system()`:
```rust
// before
commands.add_system(some_system.exclusive_system());
// after
commands.add_system(some_system);
```
I've also implemented `ExclusiveSystemParam` for `&mut QueryState` and `&mut SystemState`, which makes this possible in exclusive systems:
```rust
fn some_exclusive_system(
world: &mut World,
transforms: &mut QueryState<&Transform>,
state: &mut SystemState<(Res<Time>, Query<&Player>)>,
) {
for transform in transforms.iter(world) {
println!("{transform:?}");
}
let (time, players) = state.get(world);
for player in players.iter() {
println!("{player:?}");
}
}
```
Note that "exclusive function systems" assume `&mut World` is present (and the first param). I think this is a fair assumption, given that the presence of `&mut World` is what defines the need for an exclusive system.
I added some targeted SystemParam `static` constraints, which removed the need for this:
``` rust
fn some_exclusive_system(state: &mut SystemState<(Res<'static, Time>, Query<&'static Player>)>) {}
```
## Related
- #2923
- #3001
- #3946
## Changelog
- `ExclusiveSystem` trait (and implementations) has been removed in favor of sharing the `System` trait.
- `ExclusiveFunctionSystem` and `ExclusiveSystemParam` were added, enabling flexible exclusive function systems
- `&mut SystemState` and `&mut QueryState` now implement `ExclusiveSystemParam`
- Exclusive and parallel System configuration is now done via a unified `SystemDescriptor`, `IntoSystemDescriptor`, and `SystemContainer` api.
## Migration Guide
Calling `.exclusive_system()` is no longer required (or supported) for converting exclusive system functions to exclusive systems:
```rust
// Old (0.8)
app.add_system(some_exclusive_system.exclusive_system());
// New (0.9)
app.add_system(some_exclusive_system);
```
Converting "normal" parallel systems to exclusive systems is done by calling the exclusive ordering apis:
```rust
// Old (0.8)
app.add_system(some_system.exclusive_system().at_end());
// New (0.9)
app.add_system(some_system.at_end());
```
Query state in exclusive systems can now be cached via ExclusiveSystemParams, which should be preferred for clarity and performance reasons:
```rust
// Old (0.8)
fn some_system(world: &mut World) {
let mut transforms = world.query::<&Transform>();
for transform in transforms.iter(world) {
}
}
// New (0.9)
fn some_system(world: &mut World, transforms: &mut QueryState<&Transform>) {
for transform in transforms.iter(world) {
}
}
```
# Objective
Now that we can consolidate Bundles and Components under a single insert (thanks to #2975 and #6039), almost 100% of world spawns now look like `world.spawn().insert((Some, Tuple, Here))`. Spawning an entity without any components is an extremely uncommon pattern, so it makes sense to give spawn the "first class" ergonomic api. This consolidated api should be made consistent across all spawn apis (such as World and Commands).
## Solution
All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input:
```rust
// before:
commands
.spawn()
.insert((A, B, C));
world
.spawn()
.insert((A, B, C);
// after
commands.spawn((A, B, C));
world.spawn((A, B, C));
```
All existing instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api. A new `spawn_empty` has been added, replacing the old `spawn` api.
By allowing `world.spawn(some_bundle)` to replace `world.spawn().insert(some_bundle)`, this opened the door to removing the initial entity allocation in the "empty" archetype / table done in `spawn()` (and subsequent move to the actual archetype in `.insert(some_bundle)`).
This improves spawn performance by over 10%:
To take this measurement, I added a new `world_spawn` benchmark.
Unfortunately, optimizing `Commands::spawn` is slightly less trivial, as Commands expose the Entity id of spawned entities prior to actually spawning. Doing the optimization would (naively) require assurances that the `spawn(some_bundle)` command is applied before all other commands involving the entity (which would not necessarily be true, if memory serves). Optimizing `Commands::spawn` this way does feel possible, but it will require careful thought (and maybe some additional checks), which deserves its own PR. For now, it has the same performance characteristics of the current `Commands::spawn_bundle` on main.
**Note that 99% of this PR is simple renames and refactors. The only code that needs careful scrutiny is the new `World::spawn()` impl, which is relatively straightforward, but it has some new unsafe code (which re-uses battle tested BundlerSpawner code path).**
---
## Changelog
- All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input
- All instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api
- World and Commands now have `spawn_empty()`, which is equivalent to the old `spawn()` behavior.
## Migration Guide
```rust
// Old (0.8):
commands
.spawn()
.insert_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));
// Old (0.8):
commands.spawn_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));
// Old (0.8):
let entity = commands.spawn().id();
// New (0.9)
let entity = commands.spawn_empty().id();
// Old (0.8)
let entity = world.spawn().id();
// New (0.9)
let entity = world.spawn_empty();
```
# Objective
- Add unit tests for ambiguity detection reporting.
- Incremental implementation of #4299.
## Solution
- Refactor ambiguity detection internals to make it testable. As a bonus, this should make it easier to extend in the future.
## Notes
* This code was copy-pasted from #4299 and modified. Credit goes to @alice-i-cecile and @afonsolage, though I'm not sure who wrote what at this point.
# Objective
Take advantage of the "impl Bundle for Component" changes in #2975 / add the follow up changes discussed there.
## Solution
- Change `insert` and `remove` to accept a Bundle instead of a Component (for both Commands and World)
- Deprecate `insert_bundle`, `remove_bundle`, and `remove_bundle_intersection`
- Add `remove_intersection`
---
## Changelog
- Change `insert` and `remove` now accept a Bundle instead of a Component (for both Commands and World)
- `insert_bundle` and `remove_bundle` are deprecated
## Migration Guide
Replace `insert_bundle` with `insert`:
```rust
// Old (0.8)
commands.spawn().insert_bundle(SomeBundle::default());
// New (0.9)
commands.spawn().insert(SomeBundle::default());
```
Replace `remove_bundle` with `remove`:
```rust
// Old (0.8)
commands.entity(some_entity).remove_bundle::<SomeBundle>();
// New (0.9)
commands.entity(some_entity).remove::<SomeBundle>();
```
Replace `remove_bundle_intersection` with `remove_intersection`:
```rust
// Old (0.8)
world.entity_mut(some_entity).remove_bundle_intersection::<SomeBundle>();
// New (0.9)
world.entity_mut(some_entity).remove_intersection::<SomeBundle>();
```
Consider consolidating as many operations as possible to improve ergonomics and cut down on archetype moves:
```rust
// Old (0.8)
commands.spawn()
.insert_bundle(SomeBundle::default())
.insert(SomeComponent);
// New (0.9) - Option 1
commands.spawn().insert((
SomeBundle::default(),
SomeComponent,
))
// New (0.9) - Option 2
commands.spawn_bundle((
SomeBundle::default(),
SomeComponent,
))
```
## Next Steps
Consider changing `spawn` to accept a bundle and deprecate `spawn_bundle`.
# Objective
While using the ParallelExecutor, systems do not actually start until `prepare_systems` completes. In stages where there are large numbers of "empty" systems with very little work to do, this delay adds significant overhead, which can add up over many stages.
## Solution
Immediately and synchronously signal the start of systems that can run without dependencies inside `prepare_systems` instead of waiting for the first executor iteration after `prepare_systems` completes. Any system that is dependent on them still cannot run until after `prepare_systems` completes, but there are a large number of unconstrained systems in the base engine where this is a general benefit in almost every case.
## Performance
This change was tested against `many_foxes` in the default configuration. As this change is sensitive to the overhead around scheduling systems, the spans for measuring system timing, system overhead, and system commands were all commented out for these measurements.
The median stage timings between `main` and this PR are as follows:
|stage|main|this PR|
|:--|:--|:--|
|First|75.54 us|61.61 us|
|LoadAssets|51.05 us|42.32 us|
|PreUpdate|54.6 us|55.56 us|
|Update|61.89 us|51.5 us|
|PostUpdate|7.27 ms|6.71 ms|
|AssetEvents|47.82 us|35.95 us|
|Last|39.19 us|37.71 us|
|reserve_and_flush|57.83 us|48.2 us|
|Extract|1.41 ms|1.28 ms|
|Prepare|554.49 us|502.53 us|
|Queue|216.29 us|207.51 us|
|Sort|67.03 us|60.99 us|
|Render|1.73 ms|1.58 ms|
|Cleanup|33.55 us|30.76 us|
|Clear Entities|18.56 us|17.05 us|
|**full frame**|**11.9 ms**|**10.91 ms**|
For the first few stages, the benefit is small but cumulative over each. For PostUpdate in particular, this allows `parent_update` to run while prepare_systems is running, which is required for the animation and transform propagation systems, which dominate the time spent in the stage, but also frontloads the contention as the other "empty" systems are also running while `parent_update` is running. For Render, where there is just a single large exclusive system, the benefit comes from not waiting on a spuriously scheduled task on the task pool to kick off the system: it's immediately scheduled to run.
# Objective
This code is very disjoint, and the `stage.rs` file that it's in is already very long.
All I've done is move the code and clean up the compiler errors that result.
Followup to #5916, split out from #4299.
# Objective
Ambiguity sets are used to ignore system order ambiguities between groups of systems. However, they are not very useful: they are clunky, poorly integrated, and generally hampered by the difficulty using (or discovering) the ambiguity detector.
As a first step to the work in #4299, we're removing them.
## Migration Guide
Ambiguity sets have been removed.
# Objective
Rust 1.63 resolved [an issue](https://github.com/rust-lang/rust/issues/83701) that prevents you from combining explicit generic arguments with `impl Trait` arguments.
Now, we no longer need to use dynamic dispatch to work around this.
## Migration Guide
The methods `Schedule::get_stage` and `get_stage_mut` now accept `impl StageLabel` instead of `&dyn StageLabel`.
### Before
```rust
let stage = schedule.get_stage_mut::<SystemStage>(&MyLabel)?;
```
### After
```rust
let stage = schedule.get_stage_mut::<SystemStage>(MyLabel)?;
```
*This PR description is an edited copy of #5007, written by @alice-i-cecile.*
# Objective
Follow-up to https://github.com/bevyengine/bevy/pull/2254. The `Resource` trait currently has a blanket implementation for all types that meet its bounds.
While ergonomic, this results in several drawbacks:
* it is possible to make confusing, silent mistakes such as inserting a function pointer (Foo) rather than a value (Foo::Bar) as a resource
* it is challenging to discover if a type is intended to be used as a resource
* we cannot later add customization options (see the [RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/27-derive-component.md) for the equivalent choice for Component).
* dependencies can use the same Rust type as a resource in invisibly conflicting ways
* raw Rust types used as resources cannot preserve privacy appropriately, as anyone able to access that type can read and write to internal values
* we cannot capture a definitive list of possible resources to display to users in an editor
## Notes to reviewers
* Review this commit-by-commit; there's effectively no back-tracking and there's a lot of churn in some of these commits.
*ira: My commits are not as well organized :')*
* I've relaxed the bound on Local to Send + Sync + 'static: I don't think these concerns apply there, so this can keep things simple. Storing e.g. a u32 in a Local is fine, because there's a variable name attached explaining what it does.
* I think this is a bad place for the Resource trait to live, but I've left it in place to make reviewing easier. IMO that's best tackled with https://github.com/bevyengine/bevy/issues/4981.
## Changelog
`Resource` is no longer automatically implemented for all matching types. Instead, use the new `#[derive(Resource)]` macro.
## Migration Guide
Add `#[derive(Resource)]` to all types you are using as a resource.
If you are using a third party type as a resource, wrap it in a tuple struct to bypass orphan rules. Consider deriving `Deref` and `DerefMut` to improve ergonomics.
`ClearColor` no longer implements `Component`. Using `ClearColor` as a component in 0.8 did nothing.
Use the `ClearColorConfig` in the `Camera3d` and `Camera2d` components instead.
Co-authored-by: Alice <alice.i.cecile@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: devil-ira <justthecooldude@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
I noticed while working on #5366 that the documentation for label types wasn't working correctly. Having experimented with this for a few weeks, I believe that generating docs in macros is more effort than it's worth.
## Solution
Add more boilerplate, copy-paste and edit the docs across types. This also lets us add custom doctests for specific types. Also, we don't need `concat_idents` as a dependency anymore.
# Objective
- Closes#4954
- Reduce the complexity of the `{System, App, *}Label` APIs.
## Solution
For the sake of brevity I will only refer to `SystemLabel`, but everything applies to all of the other label types as well.
- Add `SystemLabelId`, a lightweight, `copy` struct.
- Convert custom types into `SystemLabelId` using the trait `SystemLabel`.
## Changelog
- String literals implement `SystemLabel` for now, but this should be changed with #4409 .
## Migration Guide
- Any previous use of `Box<dyn SystemLabel>` should be replaced with `SystemLabelId`.
- `AsSystemLabel` trait has been modified.
- No more output generics.
- Method `as_system_label` now returns `SystemLabelId`, removing an unnecessary level of indirection.
- If you *need* a label that is determined at runtime, you can use `Box::leak`. Not recommended.
## Questions for later
* Should we generate a `Debug` impl along with `#[derive(*Label)]`?
* Should we rename `as_str()`?
* Should we remove the extra derives (such as `Hash`) from builtin `*Label` types?
* Should we automatically derive types like `Clone, Copy, PartialEq, Eq`?
* More-ergonomic comparisons between `Label` and `LabelId`.
* Move `Dyn{Eq, Hash,Clone}` somewhere else.
* Some API to make interning dynamic labels easier.
* Optimize string representation
* Empty string for unit structs -- no debug info but faster comparisons
* Don't show enum types -- same tradeoffs as asbove.
Remove unnecessary calls to `iter()`/`iter_mut()`.
Mainly updates the use of queries in our code, docs, and examples.
```rust
// From
for _ in list.iter() {
for _ in list.iter_mut() {
// To
for _ in &list {
for _ in &mut list {
```
We already enable the pedantic lint [clippy::explicit_iter_loop](https://rust-lang.github.io/rust-clippy/stable/) inside of Bevy. However, this only warns for a few known types from the standard library.
## Note for reviewers
As you can see the additions and deletions are exactly equal.
Maybe give it a quick skim to check I didn't sneak in a crypto miner, but you don't have to torture yourself by reading every line.
I already experienced enough pain making this PR :)
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
- Currently, the `Extract` `RenderStage` is executed on the main world, with the render world available as a resource.
- However, when needing access to resources in the render world (e.g. to mutate them), the only way to do so was to get exclusive access to the whole `RenderWorld` resource.
- This meant that effectively only one extract which wrote to resources could run at a time.
- We didn't previously make `Extract`ing writing to the world a non-happy path, even though we want to discourage that.
## Solution
- Move the extract stage to run on the render world.
- Add the main world as a `MainWorld` resource.
- Add an `Extract` `SystemParam` as a convenience to access a (read only) `SystemParam` in the main world during `Extract`.
## Future work
It should be possible to avoid needing to use `get_or_spawn` for the render commands, since now the `Commands`' `Entities` matches up with the world being executed on.
We need to determine how this interacts with https://github.com/bevyengine/bevy/pull/3519
It's theoretically possible to remove the need for the `value` method on `Extract`. However, that requires slightly changing the `SystemParam` interface, which would make it more complicated. That would probably mess up the `SystemState` api too.
## Todo
I still need to add doc comments to `Extract`.
---
## Changelog
### Changed
- The `Extract` `RenderStage` now runs on the render world (instead of the main world as before).
You must use the `Extract` `SystemParam` to access the main world during the extract phase.
Resources on the render world can now be accessed using `ResMut` during extract.
### Removed
- `Commands::spawn_and_forget`. Use `Commands::get_or_spawn(e).insert_bundle(bundle)` instead
## Migration Guide
The `Extract` `RenderStage` now runs on the render world (instead of the main world as before).
You must use the `Extract` `SystemParam` to access the main world during the extract phase. `Extract` takes a single type parameter, which is any system parameter (such as `Res`, `Query` etc.). It will extract this from the main world, and returns the result of this extraction when `value` is called on it.
For example, if previously your extract system looked like:
```rust
fn extract_clouds(mut commands: Commands, clouds: Query<Entity, With<Cloud>>) {
for cloud in clouds.iter() {
commands.get_or_spawn(cloud).insert(Cloud);
}
}
```
the new version would be:
```rust
fn extract_clouds(mut commands: Commands, mut clouds: Extract<Query<Entity, With<Cloud>>>) {
for cloud in clouds.value().iter() {
commands.get_or_spawn(cloud).insert(Cloud);
}
}
```
The diff is:
```diff
--- a/src/clouds.rs
+++ b/src/clouds.rs
@@ -1,5 +1,5 @@
-fn extract_clouds(mut commands: Commands, clouds: Query<Entity, With<Cloud>>) {
- for cloud in clouds.iter() {
+fn extract_clouds(mut commands: Commands, mut clouds: Extract<Query<Entity, With<Cloud>>>) {
+ for cloud in clouds.value().iter() {
commands.get_or_spawn(cloud).insert(Cloud);
}
}
```
You can now also access resources from the render world using the normal system parameters during `Extract`:
```rust
fn extract_assets(mut render_assets: ResMut<MyAssets>, source_assets: Extract<Res<MyAssets>>) {
*render_assets = source_assets.clone();
}
```
Please note that all existing extract systems need to be updated to match this new style; even if they currently compile they will not run as expected. A warning will be emitted on a best-effort basis if this is not met.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
