56bcbb0975
# Objective Resolves #3824. `unsafe` code should be the exception, not the norm in Rust. It's obviously needed for various use cases as it's interfacing with platforms and essentially running the borrow checker at runtime in the ECS, but the touted benefits of Bevy is that we are able to heavily leverage Rust's safety, and we should be holding ourselves accountable to that by minimizing our unsafe footprint. ## Solution Deny `unsafe_code` workspace wide. Add explicit exceptions for the following crates, and forbid it in almost all of the others. * bevy_ecs - Obvious given how much unsafe is needed to achieve performant results * bevy_ptr - Works with raw pointers, even more low level than bevy_ecs. * bevy_render - due to needing to integrate with wgpu * bevy_window - due to needing to integrate with raw_window_handle * bevy_utils - Several unsafe utilities used by bevy_ecs. Ideally moved into bevy_ecs instead of made publicly usable. * bevy_reflect - Required for the unsafe type casting it's doing. * bevy_transform - for the parallel transform propagation * bevy_gizmos - For the SystemParam impls it has. * bevy_assets - To support reflection. Might not be required, not 100% sure yet. * bevy_mikktspace - due to being a conversion from a C library. Pending safe rewrite. * bevy_dynamic_plugin - Inherently unsafe due to the dynamic loading nature. Several uses of unsafe were rewritten, as they did not need to be using them: * bevy_text - a case of `Option::unchecked` could be rewritten as a normal for loop and match instead of an iterator. * bevy_color - the Pod/Zeroable implementations were replaceable with bytemuck's derive macros. |
||
|---|---|---|
| .. | ||
| examples | ||
| src | ||
| Cargo.toml | ||
| README.md | ||
Bevy Tasks
A refreshingly simple task executor for bevy. :)
This is a simple threadpool with minimal dependencies. The main usecase is a scoped fork-join, i.e. spawning tasks from
a single thread and having that thread await the completion of those tasks. This is intended specifically for
bevy as a lighter alternative to rayon for this specific usecase. There are also utilities for
generating the tasks from a slice of data. This library is intended for games and makes no attempt to ensure fairness
or ordering of spawned tasks.
It is based on async-executor, a lightweight executor that allows the end user to manage their own threads.
async-executor is based on async-task, a core piece of async-std.
Usage
In order to be able to optimize task execution in multi-threaded environments, bevy provides three different thread pools via which tasks of different kinds can be spawned. (The same API is used in single-threaded environments, even if execution is limited to a single thread. This currently applies to WASM targets.) The determining factor for what kind of work should go in each pool is latency requirements:
-
For CPU-intensive work (tasks that generally spin until completion) we have a standard [
ComputeTaskPool] and an [AsyncComputeTaskPool]. Work that does not need to be completed to present the next frame should go to the [AsyncComputeTaskPool]. -
For IO-intensive work (tasks that spend very little time in a "woken" state) we have an [
IoTaskPool] whose tasks are expected to complete very quickly. Generally speaking, they should just await receiving data from somewhere (i.e. disk) and signal other systems when the data is ready for consumption. (likely via channels)