Converted exclusive systems to parallel systems wherever possible (#2774)

Closes #2767.

Converted:
- `play_queued_audio_system`
- `change_window`

crates/bevy_audio/src/audio_output.rs

@@ -1,6 +1,6 @@
 use crate::{Audio, AudioSource, Decodable};
 use bevy_asset::{Asset, Assets};
-use bevy_ecs::world::World;
+use bevy_ecs::system::{NonSend, Res, ResMut};
 use bevy_reflect::TypeUuid;
 use bevy_utils::tracing::warn;
 use rodio::{OutputStream, OutputStreamHandle, Sink, Source};
@@ -85,16 +85,13 @@ where
 }
 
 /// Plays audio currently queued in the [`Audio`] resource through the [`AudioOutput`] resource
-pub fn play_queued_audio_system<Source: Asset>(world: &mut World)
+pub fn play_queued_audio_system<Source: Asset + Decodable>(
-where
+    audio_output: NonSend<AudioOutput<Source>>,
-    Source: Decodable,
+    audio_sources: Option<Res<Assets<Source>>>,
-{
+    mut audio: ResMut<Audio<Source>>,
-    let world = world.cell();
+    mut sinks: ResMut<Assets<AudioSink>>,
-    let audio_output = world.get_non_send::<AudioOutput<Source>>().unwrap();
+) {
-    let mut audio = world.get_resource_mut::<Audio<Source>>().unwrap();
+    if let Some(audio_sources) = audio_sources {
-    let mut sinks = world.get_resource_mut::<Assets<AudioSink>>().unwrap();
-
-    if let Some(audio_sources) = world.get_resource::<Assets<Source>>() {
         audio_output.try_play_queued(&*audio_sources, &mut *audio, &mut *sinks);
     };
 }

crates/bevy_audio/src/lib.rs

@@ -44,7 +44,6 @@ pub use audio_source::*;
 
 use bevy_app::prelude::*;
 use bevy_asset::AddAsset;
-use bevy_ecs::system::IntoExclusiveSystem;
 
 /// Adds support for audio playback to a Bevy Application
 ///
@@ -60,7 +59,7 @@ impl Plugin for AudioPlugin {
             .init_resource::<Audio<AudioSource>>()
             .add_system_to_stage(
                 CoreStage::PostUpdate,
-                play_queued_audio_system::<AudioSource>.exclusive_system(),
+                play_queued_audio_system::<AudioSource>,
             );
 
         #[cfg(any(feature = "mp3", feature = "flac", feature = "wav", feature = "vorbis"))]

crates/bevy_pbr/src/lib.rs

@@ -14,6 +14,8 @@ pub use material::*;
 pub use pbr_material::*;
 pub use render::*;
 
+use bevy_window::ModifiesWindows;
+
 pub mod prelude {
     #[doc(hidden)]
     pub use crate::{
@@ -86,7 +88,8 @@ impl Plugin for PbrPlugin {
                 CoreStage::PostUpdate,
                 assign_lights_to_clusters
                     .label(SimulationLightSystems::AssignLightsToClusters)
-                    .after(TransformSystem::TransformPropagate),
+                    .after(TransformSystem::TransformPropagate)
+                    .after(ModifiesWindows),
             )
             .add_system_to_stage(
                 CoreStage::PostUpdate,

crates/bevy_render/src/camera/mod.rs

@@ -12,6 +12,8 @@ use crate::{
     view::{ComputedVisibility, Visibility, VisibleEntities},
 };
 use bevy_app::{App, CoreStage, Plugin};
+use bevy_ecs::schedule::ParallelSystemDescriptorCoercion;
+use bevy_window::ModifiesWindows;
 
 #[derive(Default)]
 pub struct CameraPlugin;
@@ -32,11 +34,11 @@ impl Plugin for CameraPlugin {
             .register_type::<Camera2d>()
             .add_system_to_stage(
                 CoreStage::PostUpdate,
-                crate::camera::camera_system::<OrthographicProjection>,
+                crate::camera::camera_system::<OrthographicProjection>.after(ModifiesWindows),
             )
             .add_system_to_stage(
                 CoreStage::PostUpdate,
-                crate::camera::camera_system::<PerspectiveProjection>,
+                crate::camera::camera_system::<PerspectiveProjection>.after(ModifiesWindows),
             )
             .add_plugin(CameraTypePlugin::<Camera3d>::default())
             .add_plugin(CameraTypePlugin::<Camera2d>::default());

crates/bevy_text/src/lib.rs

@@ -31,6 +31,7 @@ use bevy_asset::AddAsset;
 use bevy_ecs::{entity::Entity, schedule::ParallelSystemDescriptorCoercion};
 use bevy_render::{RenderApp, RenderStage};
 use bevy_sprite::SpriteSystem;
+use bevy_window::ModifiesWindows;
 
 pub type DefaultTextPipeline = TextPipeline<Entity>;
 
@@ -46,7 +47,7 @@ impl Plugin for TextPlugin {
             .register_type::<HorizontalAlign>()
             .init_asset_loader::<FontLoader>()
             .insert_resource(DefaultTextPipeline::default())
-            .add_system_to_stage(CoreStage::PostUpdate, text2d_system);
+            .add_system_to_stage(CoreStage::PostUpdate, text2d_system.after(ModifiesWindows));
 
         if let Ok(render_app) = app.get_sub_app_mut(RenderApp) {
             render_app.add_system_to_stage(

crates/bevy_ui/src/lib.rs

@@ -31,6 +31,7 @@ use bevy_ecs::schedule::{ParallelSystemDescriptorCoercion, SystemLabel};
 use bevy_input::InputSystem;
 use bevy_math::Rect;
 use bevy_transform::TransformSystem;
+use bevy_window::ModifiesWindows;
 use update::{ui_z_system, update_clipping_system};
 
 use crate::prelude::CameraUi;
@@ -84,7 +85,9 @@ impl Plugin for UiPlugin {
             // add these stages to front because these must run before transform update systems
             .add_system_to_stage(
                 CoreStage::PostUpdate,
-                widget::text_system.before(UiSystem::Flex),
+                widget::text_system
+                    .before(UiSystem::Flex)
+                    .after(ModifiesWindows),
             )
             .add_system_to_stage(
                 CoreStage::PostUpdate,
@@ -94,7 +97,8 @@ impl Plugin for UiPlugin {
                 CoreStage::PostUpdate,
                 flex_node_system
                     .label(UiSystem::Flex)
-                    .before(TransformSystem::TransformPropagate),
+                    .before(TransformSystem::TransformPropagate)
+                    .after(ModifiesWindows),
             )
             .add_system_to_stage(
                 CoreStage::PostUpdate,

crates/bevy_window/src/lib.rs

@@ -21,7 +21,7 @@ pub mod prelude {
 }
 
 use bevy_app::prelude::*;
-use bevy_ecs::event::Events;
+use bevy_ecs::{event::Events, schedule::SystemLabel};
 
 pub struct WindowPlugin {
     pub add_primary_window: bool,
@@ -74,3 +74,6 @@ impl Plugin for WindowPlugin {
         }
     }
 }
+
+#[derive(Debug, Hash, PartialEq, Eq, Clone, SystemLabel)]
+pub struct ModifiesWindows;

crates/bevy_winit/src/lib.rs

@@ -12,8 +12,9 @@ pub use winit_windows::*;
 
 use bevy_app::{App, AppExit, CoreStage, Plugin};
 use bevy_ecs::{
-    event::{Events, ManualEventReader},
+    event::{EventWriter, Events, ManualEventReader},
-    system::IntoExclusiveSystem,
+    schedule::ParallelSystemDescriptorCoercion,
+    system::{NonSend, ResMut},
     world::World,
 };
 use bevy_math::{ivec2, DVec2, Vec2};
@@ -22,9 +23,9 @@ use bevy_utils::{
     Instant,
 };
 use bevy_window::{
-    CreateWindow, CursorEntered, CursorLeft, CursorMoved, FileDragAndDrop, ReceivedCharacter,
+    CreateWindow, CursorEntered, CursorLeft, CursorMoved, FileDragAndDrop, ModifiesWindows,
-    RequestRedraw, WindowBackendScaleFactorChanged, WindowCloseRequested, WindowCreated,
+    ReceivedCharacter, RequestRedraw, WindowBackendScaleFactorChanged, WindowCloseRequested,
-    WindowFocused, WindowMoved, WindowResized, WindowScaleFactorChanged, Windows,
+    WindowCreated, WindowFocused, WindowMoved, WindowResized, WindowScaleFactorChanged, Windows,
 };
 use winit::{
     dpi::PhysicalPosition,
@@ -42,18 +43,18 @@ impl Plugin for WinitPlugin {
         app.init_non_send_resource::<WinitWindows>()
             .init_resource::<WinitSettings>()
             .set_runner(winit_runner)
-            .add_system_to_stage(CoreStage::PostUpdate, change_window.exclusive_system());
+            .add_system_to_stage(CoreStage::PostUpdate, change_window.label(ModifiesWindows));
         let event_loop = EventLoop::new();
         handle_initial_window_events(&mut app.world, &event_loop);
         app.insert_non_send_resource(event_loop);
     }
 }
 
-fn change_window(world: &mut World) {
+fn change_window(
-    let world = world.cell();
+    winit_windows: NonSend<WinitWindows>,
-    let winit_windows = world.get_non_send::<WinitWindows>().unwrap();
+    mut windows: ResMut<Windows>,
-    let mut windows = world.get_resource_mut::<Windows>().unwrap();
+    mut window_dpi_changed_events: EventWriter<WindowScaleFactorChanged>,
-
+) {
     for bevy_window in windows.iter_mut() {
         let id = bevy_window.id();
         for command in bevy_window.drain_commands() {
@@ -88,9 +89,6 @@ fn change_window(world: &mut World) {
                     window.set_title(&title);
                 }
                 bevy_window::WindowCommand::SetScaleFactor { scale_factor } => {
-                    let mut window_dpi_changed_events = world
-                        .get_resource_mut::<Events<WindowScaleFactorChanged>>()
-                        .unwrap();
                     window_dpi_changed_events.send(WindowScaleFactorChanged { id, scale_factor });
                 }
                 bevy_window::WindowCommand::SetResolution {