# Objective
Create new `NonSendMarker` that does not depend on `NonSend`.
Required, in order to accomplish #17682. In that issue, we are trying to
replace `!Send` resources with `thread_local!` in order to unblock the
resources-as-components effort. However, when we remove all the `!Send`
resources from a system, that allows the system to run on a thread other
than the main thread, which is against the design of the system. So this
marker gives us the control to require a system to run on the main
thread without depending on `!Send` resources.
## Solution
Create a new `NonSendMarker` to replace the existing one that does not
depend on `NonSend`.
## Testing
Other than running tests, I ran a few examples:
- `window_resizing`
- `wireframe`
- `volumetric_fog` (looks so cool)
- `rotation`
- `button`
There is a Mac/iOS-specific change and I do not have a Mac or iOS device
to test it. I am doubtful that it would cause any problems for 2
reasons:
1. The change is the same as the non-wasm change which I did test
2. The Pixel Eagle tests run Mac tests
But it wouldn't hurt if someone wanted to spin up an example that
utilizes the `bevy_render` crate, which is where the Mac/iSO change was.
## Migration Guide
If `NonSendMarker` is being used from `bevy_app::prelude::*`, replace it
with `bevy_ecs::system::NonSendMarker` or use it from
`bevy_ecs::prelude::*`. In addition to that, `NonSendMarker` does not
need to be wrapped like so:
```rust
fn my_system(_non_send_marker: Option<NonSend<NonSendMarker>>) {
...
}
```
Instead, it can be used without any wrappers:
```rust
fn my_system(_non_send_marker: NonSendMarker) {
...
}
```
---------
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
# Objective
- Contributes to #15460
- Supersedes #8520
- Fixes#4906
## Solution
- Added a new `web` feature to `bevy`, and several of its crates.
- Enabled new `web` feature automatically within crates without `no_std`
support.
## Testing
- `cargo build --no-default-features --target wasm32v1-none`
---
## Migration Guide
When using Bevy crates which _don't_ automatically enable the `web`
feature, please enable it when building for the browser.
## Notes
- I added [`cfg_if`](https://crates.io/crates/cfg-if) to help manage
some of the feature gate gore that this extra feature introduces. It's
still pretty ugly, but I think much easier to read.
- Certain `wasm` targets (e.g.,
[wasm32-wasip1](https://doc.rust-lang.org/nightly/rustc/platform-support/wasm32-wasip1.html#wasm32-wasip1))
provide an incomplete implementation for `std`. I have not tested these
platforms, but I suspect Bevy's liberal use of usually unsupported
features (e.g., threading) will cause these targets to fail. As such,
consider `wasm32-unknown-unknown` as the only `wasm` platform with
support from Bevy for `std`. All others likely will need to be treated
as `no_std` platforms.
# Objective
- Contributes to #15460
- Reduce quantity and complexity of feature gates across Bevy
## Solution
- Used `target_has_atomic` configuration variable to automatically
detect impartial atomic support and automatically switch to
`portable-atomic` over the standard library on an as-required basis.
## Testing
- CI
## Notes
To explain the technique employed here, consider getting `Arc` either
from `alloc::sync` _or_ `portable-atomic-util`. First, we can inspect
the `alloc` crate to see that you only have access to `Arc` _if_
`target_has_atomic = "ptr"`. We add a target dependency for this
particular configuration _inverted_:
```toml
[target.'cfg(not(target_has_atomic = "ptr"))'.dependencies]
portable-atomic-util = { version = "0.2.4", default-features = false }
```
This ensures we only have the dependency when it is needed, and it is
entirely excluded from the dependency graph when it is not. Next, we
adjust our configuration flags to instead of checking for `feature =
"portable-atomic"` to instead check for `target_has_atomic = "ptr"`:
```rust
// `alloc` feature flag hidden for brevity
#[cfg(not(target_has_atomic = "ptr"))]
use portable_atomic_util as arc;
#[cfg(target_has_atomic = "ptr")]
use alloc::sync as arc;
pub use arc::{Arc, Weak};
```
The benefits of this technique are three-fold:
1. For platforms without full atomic support, the functionality is
enabled automatically.
2. For platforms with atomic support, the dependency is never included,
even if a feature was enabled using `--all-features` (for example)
3. The `portable-atomic` feature no longer needs to virally spread to
all user-facing crates, it's instead something handled within
`bevy_platform_support` (with some extras where other dependencies also
need their features enabled).
# Objective
- Contributes to #16877
## Solution
- Initial creation of `bevy_platform_support` crate.
- Moved `bevy_utils::Instant` into new `bevy_platform_support` crate.
- Moved `portable-atomic`, `portable-atomic-util`, and
`critical-section` into new `bevy_platform_support` crate.
## Testing
- CI
---
## Showcase
Instead of needing code like this to import an `Arc`:
```rust
#[cfg(feature = "portable-atomic")]
use portable_atomic_util::Arc;
#[cfg(not(feature = "portable-atomic"))]
use alloc::sync::Arc;
```
We can now use:
```rust
use bevy_platform_support::sync::Arc;
```
This applies to many other types, but the goal is overall the same:
allowing crates to use `std`-like types without the boilerplate of
conditional compilation and platform-dependencies.
## Migration Guide
- Replace imports of `bevy_utils::Instant` with
`bevy_platform_support::time::Instant`
- Replace imports of `bevy::utils::Instant` with
`bevy::platform_support::time::Instant`
## Notes
- `bevy_platform_support` hasn't been reserved on `crates.io`
- ~~`bevy_platform_support` is not re-exported from `bevy` at this time.
It may be worthwhile exporting this crate, but I am unsure of a
reasonable name to export it under (`platform_support` may be a bit
wordy for user-facing).~~
- I've included an implementation of `Instant` which is suitable for
`no_std` platforms that are not Wasm for the sake of eliminating feature
gates around its use. It may be a controversial inclusion, so I'm happy
to remove it if required.
- There are many other items (`spin`, `bevy_utils::Sync(Unsafe)Cell`,
etc.) which should be added to this crate. I have kept the initial scope
small to demonstrate utility without making this too unwieldy.
---------
Co-authored-by: TimJentzsch <TimJentzsch@users.noreply.github.com>
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Fixes#16892
## Solution
- Removed `TypeRegistryPlugin` (`Name` is now automatically registered
with a default `App`)
- Moved `TaskPoolPlugin` to `bevy_app`
- Moved `FrameCountPlugin` to `bevy_diagnostic`
- Deleted now-empty `bevy_core`
## Testing
- CI
## Migration Guide
- `TypeRegistryPlugin` no longer exists. If you can't use a default
`App` but still need `Name` registered, do so manually with
`app.register_type::<Name>()`.
- References to `TaskPoolPlugin` and associated types will need to
import it from `bevy_app` instead of `bevy_core`
- References to `FrameCountPlugin` and associated types will need to
import it from `bevy_diagnostic` instead of `bevy_core`
## Notes
This strategy was agreed upon by Cart and several other members in
[Discord](https://discord.com/channels/691052431525675048/692572690833473578/1319137218312278077).
