Merge pull request #3650 from QuartzLibrary/immediate-effect

`ImmediateEffect`

Author: gbj

or_poisoned/src/lib.rs

@@ -35,7 +35,7 @@ pub trait OrPoisoned {
     fn or_poisoned(self) -> Self::Inner;
 }
 
-impl<'a, T> OrPoisoned
+impl<'a, T: ?Sized> OrPoisoned
     for Result<RwLockReadGuard<'a, T>, PoisonError<RwLockReadGuard<'a, T>>>
 {
     type Inner = RwLockReadGuard<'a, T>;
@@ -45,7 +45,7 @@ impl<'a, T> OrPoisoned
     }
 }
 
-impl<'a, T> OrPoisoned
+impl<'a, T: ?Sized> OrPoisoned
     for Result<RwLockWriteGuard<'a, T>, PoisonError<RwLockWriteGuard<'a, T>>>
 {
     type Inner = RwLockWriteGuard<'a, T>;
@@ -55,7 +55,7 @@ impl<'a, T> OrPoisoned
     }
 }
 
-impl<'a, T> OrPoisoned for LockResult<MutexGuard<'a, T>> {
+impl<'a, T: ?Sized> OrPoisoned for LockResult<MutexGuard<'a, T>> {
     type Inner = MutexGuard<'a, T>;
 
     fn or_poisoned(self) -> Self::Inner {

reactive_graph/src/effect.rs

@@ -3,11 +3,13 @@
 #[allow(clippy::module_inception)]
 mod effect;
 mod effect_function;
+mod immediate;
 mod inner;
 mod render_effect;
 
 pub use effect::*;
 pub use effect_function::*;
+pub use immediate::*;
 pub use render_effect::*;
 
 /// Creates a new render effect, which immediately runs `fun`.

reactive_graph/src/effect/effect.rs

@@ -374,47 +374,16 @@ impl Effect<SyncStorage> {
     /// This spawns a task that can be run on any thread. For an effect that will be spawned on
     /// the current thread, use [`new`](Effect::new).
     pub fn new_sync<T, M>(
-        mut fun: impl EffectFunction<T, M> + Send + Sync + 'static,
+        fun: impl EffectFunction<T, M> + Send + Sync + 'static,
     ) -> Self
     where
         T: Send + Sync + 'static,
     {
-        let inner = cfg!(feature = "effects").then(|| {
-            let (mut rx, owner, inner) = effect_base();
-            let mut first_run = true;
-            let value = Arc::new(RwLock::new(None::<T>));
-
-            crate::spawn({
-                let value = Arc::clone(&value);
-                let subscriber = inner.to_any_subscriber();
-
-                async move {
-                    while rx.next().await.is_some() {
-                        if !owner.paused()
-                            && (subscriber.with_observer(|| {
-                                subscriber.update_if_necessary()
-                            }) || first_run)
-                        {
-                            first_run = false;
-                            subscriber.clear_sources(&subscriber);
-
-                            let old_value =
-                                mem::take(&mut *value.write().or_poisoned());
-                            let new_value = owner.with_cleanup(|| {
-                                subscriber.with_observer(|| {
-                                    run_in_effect_scope(|| fun.run(old_value))
-                                })
-                            });
-                            *value.write().or_poisoned() = Some(new_value);
-                        }
-                    }
-                }
-            });
-
-            ArenaItem::new_with_storage(Some(inner))
-        });
+        if !cfg!(feature = "effects") {
+            return Self { inner: None };
+        }
 
-        Self { inner }
+        Self::new_isomorphic(fun)
     }
 
     /// Creates a new effect, which runs once on the next “tick”, and then runs again when reactive values