Require components viewed in Schedule to implement Sync.

CHANGELOG.md

@@ -27,6 +27,8 @@
 - `Entry::query()` no longer requires `V` and `F` to implement `Filter`.
 - `system::schedule::Schedule` now only requires a single parameter for indices.
 - `World::run_system()` now only requires a single parameter for schedule indices.
+### Fixed
+- `Schedule`s can now no longer access non-`Sync` components.
 
 ## 0.8.2 - 2023-04-02
 ### Fixed

src/system/schedule/mod.rs

@@ -1149,4 +1149,40 @@ mod tests {
             )>()
         );
     }
+
+    /// This test verifies that the schedule compiles just fine even when the registry contains a
+    /// non-`Sync` component, so long as the schedule itself doesn't borrow said component.
+    #[test]
+    fn registry_contains_non_sync_component() {
+        struct Foo;
+
+        impl System for Foo {
+            type Views<'a> = Views!();
+            type Filter = filter::None;
+            type ResourceViews<'a> = Views!();
+            type EntryViews<'a> = Views!();
+
+            fn run<'a, R, S, I, E>(
+                &mut self,
+                _query_results: Result<R, S, I, Self::ResourceViews<'a>, Self::EntryViews<'a>, E>,
+            ) where
+                R: registry::Registry,
+                I: Iterator<Item = Self::Views<'a>>,
+            {
+                unimplemented!()
+            }
+        }
+
+        assert_eq!(
+            TypeId::of::<
+                <(task::System<Foo>, task::Null) as Schedule<
+                    '_,
+                    (alloc::rc::Rc<A>, Registry),
+                    Resources!(),
+                    _,
+                >>::Stages,
+            >(),
+            TypeId::of::<((&mut task::System<Foo>, stage::Null), stages::Null)>()
+        );
+    }
 }

src/system/schedule/task/sealed.rs

@@ -27,7 +27,7 @@ where
     R: Registry,
 {
     /// The components viewed by this task.
-    type Views: Views<'a>;
+    type Views: Views<'a> + Send;
     /// A filter applied to the components viewed by this task.
     type Filter;
 
@@ -44,6 +44,7 @@ where
         + registry::ContainsViews<'a, S::EntryViews<'a>, EntryIndices>,
     Resources: 'a,
     Resources: ContainsViews<'a, S::ResourceViews<'a>, ResourceViewsIndices>,
+    S::Views<'a>: Send,
     S::EntryViews<'a>: view::Disjoint<S::Views<'a>, R, DisjointIndices> + Views<'a>,
 {
     type Views = S::Views<'a>;
@@ -68,6 +69,7 @@ where
         + registry::ContainsViews<'a, P::EntryViews<'a>, EntryIndices>,
     Resources: 'a,
     Resources: ContainsViews<'a, P::ResourceViews<'a>, ResourceViewsIndices>,
+    P::Views<'a>: Send,
     P::EntryViews<'a>: view::Disjoint<P::Views<'a>, R, DisjointIndices> + Views<'a>,
 {
     type Views = P::Views<'a>;

tests/trybuild/schedule/non_send_views.rs

@@ -0,0 +1,36 @@
+use brood::{query::{Views, filter, Result}, registry, World, Registry, system::{System, schedule}};
+// This import is technically unused, since the macro fails to compile before it would be consumed.
+// I'm leaving it here, though, for completeness; user code would use this module, and these tests
+// should do their best to simulate user code.
+#[allow(unused_imports)]
+use brood::system::schedule::task;
+use std::rc::Rc;
+
+struct A;
+
+struct Foo;
+
+impl System for Foo {
+    type Views<'a> = Views!(&'a Rc<A>);
+    type Filter = filter::None;
+    type ResourceViews<'a> = Views!();
+    type EntryViews<'a> = Views!();
+
+    fn run<'a, R, S, I, E>(
+        &mut self,
+        _query_results: Result<R, S, I, Self::ResourceViews<'a>, Self::EntryViews<'a>, E>,
+    ) where
+        R: registry::Registry,
+        I: Iterator<Item = Self::Views<'a>>,
+    {
+        unimplemented!()
+    }
+}
+
+fn main() {
+    let mut world = World::<Registry!(Rc<A>)>::new();
+
+    let schedule = schedule!(task::System(Foo));
+
+    world.run_schedule(&mut schedule);
+}

tests/trybuild/schedule/non_send_views.stderr

@@ -0,0 +1,21 @@
+error[E0277]: `Rc<A>` cannot be shared between threads safely
+  --> tests/trybuild/schedule/non_send_views.rs:35:24
+   |
+35 |     world.run_schedule(&mut schedule);
+   |           ------------ ^^^^^^^^^^^^^ `Rc<A>` cannot be shared between threads safely
+   |           |
+   |           required by a bound introduced by this call
+   |
+   = help: the trait `Sync` is not implemented for `Rc<A>`
+   = note: required for `&Rc<A>` to implement `Send`
+   = note: required because it appears within the type `(&Rc<A>, Null)`
+   = note: required for `brood::system::schedule::task::System<Foo>` to implement `brood::system::schedule::task::sealed::Task<'_, (Rc<A>, brood::registry::Null), brood::resource::Null, (registry::contains::Null, (registry::contains::Contained, registry::contains::Null), (registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), (resource::contains::Null, resource::contains::Null, resource::contains::Null, resource::contains::Null), (((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), view::disjoint::Null, ((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), view::disjoint::Null), ((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null)>`
+   = note: required for `(brood::system::schedule::task::System<Foo>, brood::system::schedule::task::Null)` to implement `schedule::stager::Cutoff<'_, (Rc<A>, brood::registry::Null), brood::resource::Null, schedule::claim::decision::Append, ((&Rc<A>, brood::query::view::Null), schedule::claim::Null), schedule::stager::Null, schedule::stager::Null, schedule::stager::Null, schedule::stager::Null, (brood::query::view::Null, schedule::claim::Null), schedule::stager::Null, schedule::stager::Null, schedule::stager::Null, ((registry::contains::Null, (registry::contains::Contained, registry::contains::Null), (registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), schedule::stage::Null), ((resource::contains::Null, resource::contains::Null, resource::contains::Null, resource::contains::Null), schedule::stage::Null), ((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), view::disjoint::Null, ((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), view::disjoint::Null), schedule::stage::Null), (((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), schedule::stage::Null)>`
+   = note: required for `(brood::system::schedule::task::System<Foo>, brood::system::schedule::task::Null)` to implement `schedule::scheduler::Scheduler<'_, (Rc<A>, brood::registry::Null), brood::resource::Null, ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), (((((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), ((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), (view::merge::Neither, (view::merge::Left, view::merge::Null))), schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), (((registry::contains::Null, (registry::contains::Contained, registry::contains::Null), (registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), schedule::stage::Null), schedule::stages::Null), (((resource::contains::Null, resource::contains::Null, resource::contains::Null, resource::contains::Null), schedule::stage::Null), schedule::stages::Null), (((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), view::disjoint::Null, ((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), view::disjoint::Null), schedule::stage::Null), schedule::stages::Null), ((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), schedule::stage::Null), schedule::stages::Null)>`
+   = note: required for `(brood::system::schedule::task::System<Foo>, brood::system::schedule::task::Null)` to implement `schedule::sealed::Sealed<'_, (Rc<A>, brood::registry::Null), brood::resource::Null, (((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), (((((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), ((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), (view::merge::Neither, (view::merge::Left, view::merge::Null))), schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), (((registry::contains::Null, (registry::contains::Contained, registry::contains::Null), (registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), schedule::stage::Null), schedule::stages::Null), (((resource::contains::Null, resource::contains::Null, resource::contains::Null, resource::contains::Null), schedule::stage::Null), schedule::stages::Null), (((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), view::disjoint::Null, ((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), view::disjoint::Null), schedule::stage::Null), schedule::stages::Null), ((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), schedule::stage::Null), schedule::stages::Null))>`
+   = note: required for `(brood::system::schedule::task::System<Foo>, brood::system::schedule::task::Null)` to implement `Schedule<'_, (Rc<A>, brood::registry::Null), brood::resource::Null, (((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::scheduler::Null), (((((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), ((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), (view::merge::Neither, (view::merge::Left, view::merge::Null))), schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), ((schedule::claim::Null, schedule::stager::Null), schedule::stages::Null), (((registry::contains::Null, (registry::contains::Contained, registry::contains::Null), (registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), schedule::stage::Null), schedule::stages::Null), (((resource::contains::Null, resource::contains::Null, resource::contains::Null, resource::contains::Null), schedule::stage::Null), schedule::stages::Null), (((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), view::disjoint::Null, ((registry::contains::NotContained, (&registry::contains::Contained, registry::contains::Null)), (brood::query::result::get::Index, registry::contains::Null), (brood::query::result::get::Index, brood::query::result::reshape::Null)), view::disjoint::Null), schedule::stage::Null), schedule::stages::Null), ((((registry::contains::NotContained, (registry::contains::NotContained, registry::contains::Null)), registry::contains::Null, brood::query::result::reshape::Null), schedule::stage::Null), schedule::stages::Null))>`
+note: required by a bound in `World::<R, Resources>::run_schedule`
+  --> src/world/mod.rs
+   |
+   |         S: Schedule<'a, R, Resources, Indices>,
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `World::<R, Resources>::run_schedule`