improve signal copy runtime

packages/core/src/arena.rs

@@ -91,7 +91,7 @@ impl VirtualDom {
     // Note: This will not remove any ids from the arena
     pub(crate) fn drop_scope(&mut self, id: ScopeId, recursive: bool) {
         self.dirty_scopes.remove(&DirtyScope {
-            height: self.scopes[id.0].height,
+            height: self.scopes[id.0].height(),
             id,
         });
 
@@ -110,10 +110,11 @@ impl VirtualDom {
         // Drop all the hooks once the children are dropped
         // this means we'll drop hooks bottom-up
         scope.hooks.get_mut().clear();
+        let context = scope.context();
 
         // Drop all the futures once the hooks are dropped
-        for task_id in scope.spawned_tasks.borrow_mut().drain() {
-            scope.tasks.remove(task_id);
+        for task_id in context.spawned_tasks.borrow_mut().drain() {
+            context.tasks.remove(task_id);
         }
 
         self.scopes.remove(id.0);

packages/core/src/create.rs

@@ -66,9 +66,9 @@ impl<'b> VirtualDom {
     ///
     /// This method pushes the ScopeID to the internal scopestack and returns the number of nodes created.
     pub(crate) fn create_scope(&mut self, scope: ScopeId, template: &'b VNode<'b>) -> usize {
-        self.scope_stack.push(scope);
+        self.runtime.scope_stack.borrow_mut().push(scope);
         let out = self.create(template);
-        self.scope_stack.pop();
+        self.runtime.scope_stack.borrow_mut().pop();
         out
     }
 
@@ -522,7 +522,7 @@ impl<'b> VirtualDom {
             .take()
             .map(|props| {
                 let unbounded_props: Box<dyn AnyProps> = unsafe { std::mem::transmute(props) };
-                self.new_scope(unbounded_props, component.name).id
+                self.new_scope(unbounded_props, component.name).context().id
             })
             .unwrap_or_else(|| component.scope.get().unwrap())
     }

packages/core/src/diff.rs

@@ -15,9 +15,8 @@ use DynamicNode::*;
 
 impl<'b> VirtualDom {
     pub(super) fn diff_scope(&mut self, scope: ScopeId) {
-        let scope_state = &mut self.scopes[scope.0];
-
-        self.scope_stack.push(scope);
+        self.runtime.scope_stack.borrow_mut().push(scope);
+        let scope_state = &mut self.get_scope(scope).unwrap();
         unsafe {
             // Load the old and new bump arenas
             let old = scope_state
@@ -47,7 +46,7 @@ impl<'b> VirtualDom {
                 (Aborted(l), Ready(r)) => self.replace_placeholder(l, [r]),
             };
         }
-        self.scope_stack.pop();
+        self.runtime.scope_stack.borrow_mut().pop();
     }
 
     fn diff_ok_to_err(&mut self, l: &'b VNode<'b>, p: &'b VPlaceholder) {
@@ -210,7 +209,7 @@ impl<'b> VirtualDom {
         self.diff_scope(scope_id);
 
         self.dirty_scopes.remove(&DirtyScope {
-            height: self.scopes[scope_id.0].height,
+            height: self.runtime.scope_contexts[scope_id.0].height,
             id: scope_id,
         });
     }
@@ -714,7 +713,12 @@ impl<'b> VirtualDom {
 
                     Component(comp) => {
                         let scope = comp.scope.get().unwrap();
-                        match unsafe { self.scopes[scope.0].root_node().extend_lifetime_ref() } {
+                        match unsafe {
+                            self.get_scope(scope)
+                                .unwrap()
+                                .root_node()
+                                .extend_lifetime_ref()
+                        } {
                             RenderReturn::Ready(node) => self.push_all_real_nodes(node),
                             RenderReturn::Aborted(_node) => todo!(),
                         }
@@ -915,7 +919,12 @@ impl<'b> VirtualDom {
             .expect("VComponents to always have a scope");
 
         // Remove the component from the dom
-        match unsafe { self.scopes[scope.0].root_node().extend_lifetime_ref() } {
+        match unsafe {
+            self.get_scope(scope)
+                .unwrap()
+                .root_node()
+                .extend_lifetime_ref()
+        } {
             RenderReturn::Ready(t) => self.remove_node(t, gen_muts),
             RenderReturn::Aborted(placeholder) => self.remove_placeholder(placeholder, gen_muts),
         };
@@ -936,7 +945,12 @@ impl<'b> VirtualDom {
             Some(Placeholder(t)) => t.id.get().unwrap(),
             Some(Component(comp)) => {
                 let scope = comp.scope.get().unwrap();
-                match unsafe { self.scopes[scope.0].root_node().extend_lifetime_ref() } {
+                match unsafe {
+                    self.get_scope(scope)
+                        .unwrap()
+                        .root_node()
+                        .extend_lifetime_ref()
+                } {
                     RenderReturn::Ready(t) => self.find_first_element(t),
                     _ => todo!("cannot handle nonstandard nodes"),
                 }
@@ -952,7 +966,12 @@ impl<'b> VirtualDom {
             Some(Placeholder(t)) => t.id.get().unwrap(),
             Some(Component(comp)) => {
                 let scope = comp.scope.get().unwrap();
-                match unsafe { self.scopes[scope.0].root_node().extend_lifetime_ref() } {
+                match unsafe {
+                    self.get_scope(scope)
+                        .unwrap()
+                        .root_node()
+                        .extend_lifetime_ref()
+                } {
                     RenderReturn::Ready(t) => self.find_last_element(t),
                     _ => todo!("cannot handle nonstandard nodes"),
                 }

packages/core/src/lib.rs

@@ -14,8 +14,10 @@ mod lazynodes;
 mod mutations;
 mod nodes;
 mod properties;
+mod runtime;
 mod scheduler;
 mod scope_arena;
+mod scope_context;
 mod scopes;
 mod virtual_dom;
 
@@ -31,6 +33,7 @@ pub(crate) mod innerlude {
     pub use crate::nodes::*;
     pub use crate::properties::*;
     pub use crate::scheduler::*;
+    pub use crate::scope_context::*;
     pub use crate::scopes::*;
     pub use crate::virtual_dom::*;
 
@@ -81,9 +84,11 @@ pub use crate::innerlude::{
 /// This includes types like [`Scope`], [`Element`], and [`Component`].
 pub mod prelude {
     pub use crate::innerlude::{
-        fc_to_builder, AnyValue, Component, Element, Event, EventHandler, Fragment,
-        IntoAttributeValue, LazyNodes, Properties, Scope, ScopeId, ScopeState, Scoped, TaskId,
-        Template, TemplateAttribute, TemplateNode, Throw, VNode, VirtualDom,
+        consume_context, current_scope_id, fc_to_builder, has_context, provide_context,
+        provide_root_context, schedule_update_any, suspend, throw, AnyValue, Component, Element,
+        Event, EventHandler, Fragment, IntoAttributeValue, LazyNodes, Properties, Scope, ScopeId,
+        ScopeState, Scoped, TaskId, Template, TemplateAttribute, TemplateNode, Throw, VNode,
+        VirtualDom,
     };
 }
 

packages/core/src/runtime.rs

@@ -0,0 +1,87 @@
+use std::cell::RefCell;
+
+use crate::{
+    innerlude::{DirtyScope, Scheduler, SchedulerMsg},
+    scope_context::ScopeContext,
+    scopes::{ScopeId, ScopeState},
+};
+use rustc_hash::FxHashSet;
+use slab::Slab;
+use std::{collections::BTreeSet, rc::Rc};
+
+thread_local! {
+    static RUNTIMES: RefCell<Vec<Runtime>> = RefCell::new(vec![]);
+}
+
+/// Pushes a new scope onto the stack
+pub(crate) fn push_runtime(runtime: Runtime) {
+    RUNTIMES.with(|stack| stack.borrow_mut().push(runtime));
+}
+
+/// Pops a scope off the stack
+pub(crate) fn pop_runtime() {
+    RUNTIMES.with(|stack| stack.borrow_mut().pop());
+}
+
+/// Runs a function with the current runtime
+pub(crate) fn with_runtime<F, R>(f: F) -> Option<R>
+where
+    F: FnOnce(&Runtime) -> R,
+{
+    RUNTIMES.with(|stack| {
+        let stack = stack.borrow();
+        stack.last().map(f)
+    })
+}
+
+/// Runs a function with the current scope
+pub(crate) fn with_current_scope<F, R>(f: F) -> Option<R>
+where
+    F: FnOnce(&ScopeContext) -> R,
+{
+    with_runtime(|runtime| {
+        runtime
+            .current_scope_id()
+            .and_then(|scope| runtime.get_context(scope).map(f))
+    })
+    .flatten()
+}
+
+pub struct Runtime {
+    pub(crate) scope_contexts: Slab<ScopeContext>,
+    pub(crate) scheduler: Rc<Scheduler>,
+
+    // While diffing we need some sort of way of breaking off a stream of suspended mutations.
+    pub(crate) scope_stack: RefCell<Vec<ScopeId>>,
+}
+
+impl Runtime {
+    pub(crate) fn new(scheduler: Rc<Scheduler>) -> Rc<Self> {
+        Rc::new(Self {
+            scheduler,
+
+            scope_contexts: Default::default(),
+
+            scope_stack: Default::default(),
+        })
+    }
+
+    /// Get the current scope id
+    pub fn current_scope_id(&self) -> Option<ScopeId> {
+        self.scope_stack.borrow().last().copied()
+    }
+
+    /// Get the state for any scope given its ID
+    ///
+    /// This is useful for inserting or removing contexts from a scope, or rendering out its root node
+    pub fn get_context(&self, id: ScopeId) -> Option<&ScopeContext> {
+        self.scope_contexts.get(id.0).map(|f| &*f)
+    }
+
+    /// Get the single scope at the top of the Runtime tree that will always be around
+    ///
+    /// This scope has a ScopeId of 0 and is the root of the tree
+    pub fn base_context(&self) -> &ScopeContext {
+        self.get_context(ScopeId(0)).unwrap()
+    }
+}

packages/core/src/scheduler/wait.rs

@@ -7,7 +7,7 @@ impl VirtualDom {
     /// This is precise, meaning we won't poll every task, just tasks that have woken up as notified to use by the
     /// queue
     pub(crate) fn handle_task_wakeup(&mut self, id: TaskId) {
-        let mut tasks = self.scheduler.tasks.borrow_mut();
+        let mut tasks = self.runtime.scheduler.tasks.borrow_mut();
 
         let task = match tasks.get(id.0) {
             Some(task) => task,
@@ -20,8 +20,8 @@ impl VirtualDom {
         // If the task completes...
         if task.task.borrow_mut().as_mut().poll(&mut cx).is_ready() {
             // Remove it from the scope so we dont try to double drop it when the scope dropes
-            let scope = &self.scopes[task.scope.0];
-            scope.spawned_tasks.borrow_mut().remove(&id);
+            let scope = &self.get_scope(task.scope).unwrap();
+            scope.context().spawned_tasks.borrow_mut().remove(&id);
 
             // Remove it from the scheduler
             tasks.try_remove(id.0);

packages/core/src/scope_arena.rs

@@ -13,35 +13,29 @@ impl VirtualDom {
         props: Box<dyn AnyProps<'static>>,
         name: &'static str,
     ) -> &ScopeState {
-        let parent = self.acquire_current_scope_raw();
+        let parent_id = self.runtime.current_scope_id();
+        let height = parent_id
+            .and_then(|parent_id| self.get_scope(parent_id).map(|f| f.context().height + 1))
+            .unwrap_or(0);
         let entry = self.scopes.vacant_entry();
-        let height = unsafe { parent.map(|f| (*f).height + 1).unwrap_or(0) };
         let id = ScopeId(entry.key());
 
-        entry.insert(Box::new(ScopeState {
-            parent,
-            id,
-            height,
-            name,
+        entry.insert(ScopeState {
+            runtime: self.runtime.clone(),
+            context_id: id,
+
             props: Some(props),
-            tasks: self.scheduler.clone(),
+
             node_arena_1: BumpFrame::new(0),
             node_arena_2: BumpFrame::new(0),
-            spawned_tasks: Default::default(),
-            suspended: Default::default(),
+
             render_cnt: Default::default(),
             hooks: Default::default(),
             hook_idx: Default::default(),
-            shared_contexts: Default::default(),
+
             borrowed_props: Default::default(),
             attributes_to_drop: Default::default(),
-        }))
-    }
-
-    fn acquire_current_scope_raw(&self) -> Option<*const ScopeState> {
-        let id = self.scope_stack.last().copied()?;
-        let scope = self.scopes.get(id.0)?;
-        Some(scope.as_ref())
+        })
     }
 
     pub(crate) fn run_scope(&mut self, scope_id: ScopeId) -> &RenderReturn {
@@ -51,10 +45,10 @@ impl VirtualDom {
         self.ensure_drop_safety(scope_id);
 
         let new_nodes = unsafe {
-            self.scopes[scope_id.0].previous_frame().bump_mut().reset();
-
             let scope = &self.scopes[scope_id.0];
-            scope.suspended.set(false);
+            scope.previous_frame().bump_mut().reset();
+
+            scope.context().suspended.set(false);
 
             scope.hook_idx.set(0);
 
@@ -77,18 +71,19 @@ impl VirtualDom {
         // And move the render generation forward by one
         scope.render_cnt.set(scope.render_cnt.get() + 1);
 
+        let context = scope.context();
         // remove this scope from dirty scopes
         self.dirty_scopes.remove(&DirtyScope {
-            height: scope.height,
-            id: scope.id,
+            height: context.height,
+            id: context.id,
         });
 
-        if scope.suspended.get() {
+        if context.suspended.get() {
             if matches!(allocated, RenderReturn::Aborted(_)) {
-                self.suspended_scopes.insert(scope.id);
+                self.suspended_scopes.insert(context.id);
             }
         } else if !self.suspended_scopes.is_empty() {
-            _ = self.suspended_scopes.remove(&scope.id);
+            _ = self.suspended_scopes.remove(&context.id);
         }
 
         // rebind the lifetime now that its stored internally

packages/core/src/scope_context.rs

@@ -0,0 +1,288 @@
+use crate::{
+    innerlude::{ErrorBoundary, Scheduler, SchedulerMsg},
+    runtime::{with_current_scope, with_runtime},
+    Element, ScopeId, TaskId,
+};
+use rustc_hash::FxHashSet;
+use std::{
+    any::{Any, TypeId},
+    cell::{Cell, RefCell},
+    fmt::Debug,
+    future::Future,
+    rc::Rc,
+    sync::Arc,
+};
+
+/// A component's state separate from its props.
+///
+/// This struct exists to provide a common interface for all scopes without relying on generics.
+pub struct ScopeContext {
+    pub(crate) name: &'static str,
+
+    pub(crate) id: ScopeId,
+    pub(crate) parent_id: Option<ScopeId>,
+
+    pub(crate) height: u32,
+    pub(crate) suspended: Cell<bool>,
+
+    pub(crate) shared_contexts: RefCell<Vec<(TypeId, Box<dyn Any>)>>,
+
+    pub(crate) tasks: Rc<Scheduler>,
+    pub(crate) spawned_tasks: RefCell<FxHashSet<TaskId>>,
+}
+
+impl ScopeContext {
+    pub fn name(&self) -> &str {
+        self.name
+    }
+
+    pub fn height(&self) -> u32 {
+        self.height
+    }
+
+    pub fn parent_id(&self) -> Option<ScopeId> {
+        self.parent_id
+    }
+
+    pub fn scope_id(&self) -> ScopeId {
+        self.id
+    }
+
+    /// Create a subscription that schedules a future render for the reference component
+    ///
+    /// ## Notice: you should prefer using [`Self::schedule_update_any`] and [`Self::scope_id`]
+    pub fn schedule_update(&self) -> Arc<dyn Fn() + Send + Sync + 'static> {
+        let (chan, id) = (self.tasks.sender.clone(), self.scope_id());
+        Arc::new(move || drop(chan.unbounded_send(SchedulerMsg::Immediate(id))))
+    }
+
+    /// Schedule an update for any component given its [`ScopeId`].
+    ///
+    /// A component's [`ScopeId`] can be obtained from `use_hook` or the [`ScopeState::scope_id`] method.
+    ///
+    /// This method should be used when you want to schedule an update for a component
+    pub fn schedule_update_any(&self) -> Arc<dyn Fn(ScopeId) + Send + Sync> {
+        let chan = self.tasks.sender.clone();
+        Arc::new(move |id| {
+            chan.unbounded_send(SchedulerMsg::Immediate(id)).unwrap();
+        })
+    }
+
+    /// Mark this scope as dirty, and schedule a render for it.
+    pub fn needs_update(&self) {
+        self.needs_update_any(self.scope_id());
+    }
+
+    /// Get the [`ScopeId`] of a mounted component.
+    ///
+    /// `ScopeId` is not unique for the lifetime of the [`crate::VirtualDom`] - a [`ScopeId`] will be reused if a component is unmounted.
+    pub fn needs_update_any(&self, id: ScopeId) {
+        self.tasks
+            .sender
+            .unbounded_send(SchedulerMsg::Immediate(id))
+            .expect("Scheduler to exist if scope exists");
+    }
+
+    /// Return any context of type T if it exists on this scope
+    pub fn has_context<T: 'static + Clone>(&self) -> Option<T> {
+        self.shared_contexts
+            .borrow()
+            .iter()
+            .find(|(k, _)| *k == TypeId::of::<T>())
+            .map(|(_, v)| v)?
+            .downcast_ref::<T>()
+            .cloned()
+    }
+
+    /// Try to retrieve a shared state with type `T` from any parent scope.
+    ///
+    /// Clones the state if it exists.
+    pub fn consume_context<T: 'static + Clone>(&self) -> Option<T> {
+        if let Some(this_ctx) = self.has_context() {
+            return Some(this_ctx);
+        }
+
+        let mut search_parent = self.parent_id;
+        with_runtime(|runtime| {
+            let mut result = None;
+            while let Some(parent_id) = search_parent {
+                let parent = runtime.get_context(parent_id).unwrap();
+                if let Some(shared) = parent
+                    .shared_contexts
+                    .borrow()
+                    .iter()
+                    .find(|(k, _)| *k == TypeId::of::<T>())
+                {
+                    result = shared.1.downcast_ref::<T>().cloned();
+                    break;
+                }
+                search_parent = parent.parent_id;
+            }
+            result
+        })
+        .flatten()
+    }
+
+    /// Expose state to children further down the [`crate::VirtualDom`] Tree. Requires `Clone` on the context to allow getting values down the tree.
+    ///
+    /// This is a "fundamental" operation and should only be called during initialization of a hook.
+    ///
+    /// For a hook that provides the same functionality, use `use_provide_context` and `use_context` instead.
+    ///
+    /// # Example
+    ///
+    /// ```rust, ignore
+    /// struct SharedState(&'static str);
+    ///
+    /// static App: Component = |cx| {
+    ///     cx.use_hook(|| cx.provide_context(SharedState("world")));
+    ///     render!(Child {})
+    /// }
+    ///
+    /// static Child: Component = |cx| {
+    ///     let state = cx.consume_state::<SharedState>();
+    ///     render!(div { "hello {state.0}" })
+    /// }
+    /// ```
+    pub fn provide_context<T: 'static + Clone>(&self, value: T) -> T {
+        let mut contexts = self.shared_contexts.borrow_mut();
+
+        // If the context exists, swap it out for the new value
+        for ctx in contexts.iter_mut() {
+            // Swap the ptr directly
+            if let Some(ctx) = ctx.1.downcast_mut::<T>() {
+                std::mem::swap(ctx, &mut value.clone());
+                return value;
+            }
+        }
+
+        // Else, just push it
+        contexts.push((TypeId::of::<T>(), Box::new(value.clone())));
+
+        value
+    }
+
+    /// Provide a context to the root and then consume it
+    ///
+    /// This is intended for "global" state management solutions that would rather be implicit for the entire app.
+    /// Things like signal runtimes and routers are examples of "singletons" that would benefit from lazy initialization.
+    ///
+    /// Note that you should be checking if the context existed before trying to provide a new one. Providing a context
+    /// when a context already exists will swap the context out for the new one, which may not be what you want.
+    pub fn provide_root_context<T: 'static + Clone>(&self, context: T) -> T {
+        with_runtime(|runtime| {
+            // Walk upwards until there is no more parent - and tada we have the root
+            let mut parent = runtime.get_context(self.scope_id()).unwrap();
+            while let Some(next_parent) = parent.parent_id {
+                parent = runtime.get_context(next_parent).unwrap();
+            }
+            debug_assert_eq!(parent.scope_id(), ScopeId(0));
+
+            parent.provide_context(context)
+        })
+        .expect("Runtime to exist")
+    }
+
+    /// Pushes the future onto the poll queue to be polled after the component renders.
+    pub fn push_future(&self, fut: impl Future<Output = ()> + 'static) -> TaskId {
+        let id = self.tasks.spawn(self.id, fut);
+        self.spawned_tasks.borrow_mut().insert(id);
+        id
+    }
+
+    /// Spawns the future but does not return the [`TaskId`]
+    pub fn spawn(&self, fut: impl Future<Output = ()> + 'static) {
+        self.push_future(fut);
+    }
+
+    /// Spawn a future that Dioxus won't clean up when this component is unmounted
+    ///
+    /// This is good for tasks that need to be run after the component has been dropped.
+    pub fn spawn_forever(&self, fut: impl Future<Output = ()> + 'static) -> TaskId {
+        // The root scope will never be unmounted so we can just add the task at the top of the app
+        let id = self.tasks.spawn(ScopeId(0), fut);
+
+        // wake up the scheduler if it is sleeping
+        self.tasks
+            .sender
+            .unbounded_send(SchedulerMsg::TaskNotified(id))
+            .expect("Scheduler should exist");
+
+        self.spawned_tasks.borrow_mut().insert(id);
+
+        id
+    }
+
+    /// Informs the scheduler that this task is no longer needed and should be removed.
+    ///
+    /// This drops the task immediately.
+    pub fn remove_future(&self, id: TaskId) {
+        self.tasks.remove(id);
+    }
+
+    /// Inject an error into the nearest error boundary and quit rendering
+    ///
+    /// The error doesn't need to implement Error or any specific traits since the boundary
+    /// itself will downcast the error into a trait object.
+    pub fn throw(&self, error: impl Debug + 'static) -> Option<()> {
+        if let Some(cx) = self.consume_context::<Rc<ErrorBoundary>>() {
+            cx.insert_error(self.scope_id(), Box::new(error));
+        }
+
+        // Always return none during a throw
+        None
+    }
+
+    /// Mark this component as suspended and then return None
+    pub fn suspend(&self) -> Option<Element> {
+        self.suspended.set(true);
+        None
+    }
+}
+
+/// Schedule an update for any component given its [`ScopeId`].
+///
+/// A component's [`ScopeId`] can be obtained from `use_hook` or the [`ScopeState::scope_id`] method.
+///
+/// This method should be used when you want to schedule an update for a component
+pub fn schedule_update_any() -> Option<Arc<dyn Fn(ScopeId) + Send + Sync>> {
+    with_current_scope(|cx| cx.schedule_update_any())
+}
+
+/// Get the current scope id
+pub fn current_scope_id() -> Option<ScopeId> {
+    with_runtime(|rt| rt.current_scope_id()).flatten()
+}
+
+/// Consume context from the current scope
+pub fn consume_context<T: 'static + Clone>() -> Option<T> {
+    with_current_scope(|cx| cx.consume_context::<T>()).flatten()
+}
+
+/// Check if the current scope has a context
+pub fn has_context<T: 'static + Clone>() -> Option<T> {
+    with_current_scope(|cx| cx.has_context::<T>()).flatten()
+}
+
+/// Provide context to the current scope
+pub fn provide_context<T: 'static + Clone>(value: T) -> Option<T> {
+    with_current_scope(|cx| cx.provide_context(value))
+}
+
+/// Provide a context to the root scope
+pub fn provide_root_context<T: 'static + Clone>(value: T) -> Option<T> {
+    with_current_scope(|cx| cx.provide_root_context(value))
+}
+
+/// Suspends the current component
+pub fn suspend() -> Option<Element<'static>> {
+    with_current_scope(|cx| {
+        cx.suspend();
+    });
+    None
+}
+
+/// Throw an error into the nearest error boundary
+pub fn throw(error: impl Debug + 'static) -> Option<()> {
+    with_current_scope(|cx| cx.throw(error)).flatten()
+}

packages/core/src/scopes.rs

@@ -2,16 +2,17 @@ use crate::{
     any_props::AnyProps,
     any_props::VProps,
     bump_frame::BumpFrame,
+    innerlude::ErrorBoundary,
     innerlude::{DynamicNode, EventHandler, VComponent, VText},
-    innerlude::{ErrorBoundary, Scheduler, SchedulerMsg},
     lazynodes::LazyNodes,
     nodes::{IntoAttributeValue, IntoDynNode, RenderReturn},
+    runtime::Runtime,
+    scope_context::ScopeContext,
     AnyValue, Attribute, AttributeValue, Element, Event, Properties, TaskId,
 };
 use bumpalo::{boxed::Box as BumpBox, Bump};
-use rustc_hash::FxHashSet;
 use std::{
-    any::{Any, TypeId},
+    any::Any,
     cell::{Cell, RefCell, UnsafeCell},
     fmt::{Arguments, Debug},
     future::Future,
@@ -66,26 +67,17 @@ pub struct ScopeId(pub usize);
 ///
 /// This struct exists to provide a common interface for all scopes without relying on generics.
 pub struct ScopeState {
+    pub(crate) runtime: Rc<Runtime>,
+    pub(crate) context_id: ScopeId,
+
     pub(crate) render_cnt: Cell<usize>,
-    pub(crate) name: &'static str,
 
     pub(crate) node_arena_1: BumpFrame,
     pub(crate) node_arena_2: BumpFrame,
 
-    pub(crate) parent: Option<*const ScopeState>,
-    pub(crate) id: ScopeId,
-
-    pub(crate) height: u32,
-    pub(crate) suspended: Cell<bool>,
-
     pub(crate) hooks: RefCell<Vec<Box<UnsafeCell<dyn Any>>>>,
     pub(crate) hook_idx: Cell<usize>,
 
-    pub(crate) shared_contexts: RefCell<Vec<(TypeId, Box<dyn Any>)>>,
-
-    pub(crate) tasks: Rc<Scheduler>,
-    pub(crate) spawned_tasks: RefCell<FxHashSet<TaskId>>,
-
     pub(crate) borrowed_props: RefCell<Vec<*const VComponent<'static>>>,
     pub(crate) attributes_to_drop: RefCell<Vec<*const Attribute<'static>>>,
 
@@ -93,6 +85,10 @@ pub struct ScopeState {
 }
 
 impl<'src> ScopeState {
+    pub(crate) fn context(&self) -> &ScopeContext {
+        self.runtime.get_context(self.context_id).unwrap()
+    }
+
     pub(crate) fn current_frame(&self) -> &BumpFrame {
         match self.render_cnt.get() % 2 {
             0 => &self.node_arena_1,
@@ -111,7 +107,7 @@ impl<'src> ScopeState {
 
     /// Get the name of this component
     pub fn name(&self) -> &str {
-        self.name
+        self.context().name
     }
 
     /// Get the current render since the inception of this component
@@ -174,7 +170,7 @@ impl<'src> ScopeState {
     /// assert_eq!(base.height(), 0);
     /// ```
     pub fn height(&self) -> u32 {
-        self.height
+        self.context().height
     }
 
     /// Get the Parent of this [`Scope`] within this Dioxus [`crate::VirtualDom`].
@@ -193,9 +189,9 @@ impl<'src> ScopeState {
     ///
     /// assert_eq!(base.parent(), None);
     /// ```
-    pub fn parent(&self) -> Option<ScopeId> {
+    pub fn parent_id(&self) -> Option<ScopeId> {
         // safety: the pointer to our parent is *always* valid thanks to the bump arena
-        self.parent.map(|p| unsafe { &*p }.id)
+        self.context().parent_id()
     }
 
     /// Get the ID of this Scope within this Dioxus [`crate::VirtualDom`].
@@ -212,15 +208,14 @@ impl<'src> ScopeState {
     /// assert_eq!(base.scope_id(), 0);
     /// ```
     pub fn scope_id(&self) -> ScopeId {
-        self.id
+        self.context().scope_id()
     }
 
     /// Create a subscription that schedules a future render for the reference component
     ///
     /// ## Notice: you should prefer using [`Self::schedule_update_any`] and [`Self::scope_id`]
     pub fn schedule_update(&self) -> Arc<dyn Fn() + Send + Sync + 'static> {
-        let (chan, id) = (self.tasks.sender.clone(), self.scope_id());
-        Arc::new(move || drop(chan.unbounded_send(SchedulerMsg::Immediate(id))))
+        self.context().schedule_update()
     }
 
     /// Schedule an update for any component given its [`ScopeId`].
@@ -229,61 +224,31 @@ impl<'src> ScopeState {
     ///
     /// This method should be used when you want to schedule an update for a component
     pub fn schedule_update_any(&self) -> Arc<dyn Fn(ScopeId) + Send + Sync> {
-        let chan = self.tasks.sender.clone();
-        Arc::new(move |id| {
-            chan.unbounded_send(SchedulerMsg::Immediate(id)).unwrap();
-        })
+        self.context().schedule_update_any()
     }
 
     /// Mark this scope as dirty, and schedule a render for it.
     pub fn needs_update(&self) {
-        self.needs_update_any(self.scope_id());
+        self.context().needs_update()
     }
 
     /// Get the [`ScopeId`] of a mounted component.
     ///
     /// `ScopeId` is not unique for the lifetime of the [`crate::VirtualDom`] - a [`ScopeId`] will be reused if a component is unmounted.
     pub fn needs_update_any(&self, id: ScopeId) {
-        self.tasks
-            .sender
-            .unbounded_send(SchedulerMsg::Immediate(id))
-            .expect("Scheduler to exist if scope exists");
+        self.context().needs_update_any(id)
     }
 
     /// Return any context of type T if it exists on this scope
     pub fn has_context<T: 'static + Clone>(&self) -> Option<T> {
-        self.shared_contexts
-            .borrow()
-            .iter()
-            .find(|(k, _)| *k == TypeId::of::<T>())
-            .map(|(_, v)| v)?
-            .downcast_ref::<T>()
-            .cloned()
+        self.context().has_context()
     }
 
     /// Try to retrieve a shared state with type `T` from any parent scope.
     ///
     /// Clones the state if it exists.
     pub fn consume_context<T: 'static + Clone>(&self) -> Option<T> {
-        if let Some(this_ctx) = self.has_context() {
-            return Some(this_ctx);
-        }
-
-        let mut search_parent = self.parent;
-        while let Some(parent_ptr) = search_parent {
-            // safety: all parent pointers are valid thanks to the bump arena
-            let parent = unsafe { &*parent_ptr };
-            if let Some(shared) = parent
-                .shared_contexts
-                .borrow()
-                .iter()
-                .find(|(k, _)| *k == TypeId::of::<T>())
-            {
-                return shared.1.downcast_ref::<T>().cloned();
-            }
-            search_parent = parent.parent;
-        }
-        None
+        self.context().consume_context()
     }
 
     /// Expose state to children further down the [`crate::VirtualDom`] Tree. Requires `Clone` on the context to allow getting values down the tree.
@@ -308,21 +273,7 @@ impl<'src> ScopeState {
     /// }
     /// ```
     pub fn provide_context<T: 'static + Clone>(&self, value: T) -> T {
-        let mut contexts = self.shared_contexts.borrow_mut();
-
-        // If the context exists, swap it out for the new value
-        for ctx in contexts.iter_mut() {
-            // Swap the ptr directly
-            if let Some(ctx) = ctx.1.downcast_mut::<T>() {
-                std::mem::swap(ctx, &mut value.clone());
-                return value;
-            }
-        }
-
-        // Else, just push it
-        contexts.push((TypeId::of::<T>(), Box::new(value.clone())));
-
-        value
+        self.context().provide_context(value)
     }
 
     /// Provide a context to the root and then consume it
@@ -333,52 +284,31 @@ impl<'src> ScopeState {
     /// Note that you should be checking if the context existed before trying to provide a new one. Providing a context
     /// when a context already exists will swap the context out for the new one, which may not be what you want.
     pub fn provide_root_context<T: 'static + Clone>(&self, context: T) -> T {
-        let mut parent = self;
-
-        // Walk upwards until there is no more parent - and tada we have the root
-        while let Some(next_parent) = parent.parent {
-            parent = unsafe { &*next_parent };
-            debug_assert_eq!(parent.scope_id(), ScopeId(0));
-        }
-
-        parent.provide_context(context)
+        self.context().provide_root_context(context)
     }
 
     /// Pushes the future onto the poll queue to be polled after the component renders.
     pub fn push_future(&self, fut: impl Future<Output = ()> + 'static) -> TaskId {
-        let id = self.tasks.spawn(self.id, fut);
-        self.spawned_tasks.borrow_mut().insert(id);
-        id
+        self.context().push_future(fut)
     }
 
     /// Spawns the future but does not return the [`TaskId`]
     pub fn spawn(&self, fut: impl Future<Output = ()> + 'static) {
-        self.push_future(fut);
+        self.context().spawn(fut);
     }
 
     /// Spawn a future that Dioxus won't clean up when this component is unmounted
     ///
     /// This is good for tasks that need to be run after the component has been dropped.
     pub fn spawn_forever(&self, fut: impl Future<Output = ()> + 'static) -> TaskId {
-        // The root scope will never be unmounted so we can just add the task at the top of the app
-        let id = self.tasks.spawn(ScopeId(0), fut);
-
-        // wake up the scheduler if it is sleeping
-        self.tasks
-            .sender
-            .unbounded_send(SchedulerMsg::TaskNotified(id))
-            .expect("Scheduler should exist");
-
-        self.spawned_tasks.borrow_mut().insert(id);
-
-        id
+        self.context().spawn_forever(fut)
     }
 
     /// Informs the scheduler that this task is no longer needed and should be removed.
     ///
     /// This drops the task immediately.
     pub fn remove_future(&self, id: TaskId) {
-        self.tasks.remove(id);
+        self.context().remove_future(id);
     }
 
     /// Take a lazy [`crate::VNode`] structure and actually build it with the context of the efficient [`bumpalo::Bump`] allocator.
@@ -481,7 +411,7 @@ impl<'src> ScopeState {
     /// fn(Scope<Props>) -> Element;
     /// async fn(Scope<Props<'_>>) -> Element;
     /// ```
-    pub fn component<P>(
+    pub fn component<P: 'static>(
         &'src self,
         component: fn(Scope<'src, P>) -> Element<'src>,
         props: P,
@@ -564,8 +494,7 @@ impl<'src> ScopeState {
 
     /// Mark this component as suspended and then return None
     pub fn suspend(&self) -> Option<Element> {
-        self.suspended.set(true);
-        None
+        self.context().suspend()
     }
 
     /// Store a value between renders. The foundational hook for all other hooks.

packages/core/src/virtual_dom.rs

@@ -9,6 +9,7 @@ use crate::{
     mutations::Mutation,
     nodes::RenderReturn,
     nodes::{Template, TemplateId},
+    runtime::Runtime,
     scopes::{ScopeId, ScopeState},
     AttributeValue, Element, Event, Scope,
 };
@@ -174,24 +175,24 @@ use std::{any::Any, cell::Cell, collections::BTreeSet, future::Future, rc::Rc};
 /// }
 /// ```
 pub struct VirtualDom {
+    pub(crate) scopes: Slab<ScopeState>,
+
+    pub(crate) dirty_scopes: BTreeSet<DirtyScope>,
+
     // Maps a template path to a map of byteindexes to templates
     pub(crate) templates: FxHashMap<TemplateId, FxHashMap<usize, Template<'static>>>,
-    pub(crate) scopes: Slab<Box<ScopeState>>,
-    pub(crate) dirty_scopes: BTreeSet<DirtyScope>,
-    pub(crate) scheduler: Rc<Scheduler>,
 
     // Every element is actually a dual reference - one to the template and the other to the dynamic node in that template
     pub(crate) elements: Slab<ElementRef>,
 
-    // While diffing we need some sort of way of breaking off a stream of suspended mutations.
-    pub(crate) scope_stack: Vec<ScopeId>,
+    pub(crate) mutations: Mutations<'static>,
+
+    pub(crate) runtime: Rc<Runtime>,
 
     // Currently suspended scopes
     pub(crate) suspended_scopes: FxHashSet<ScopeId>,
 
     pub(crate) rx: futures_channel::mpsc::UnboundedReceiver<SchedulerMsg>,
-
-    pub(crate) mutations: Mutations<'static>,
 }
 
 impl VirtualDom {
@@ -251,16 +252,16 @@ impl VirtualDom {
     /// ```
     pub fn new_with_props<P: 'static>(root: fn(Scope<P>) -> Element, root_props: P) -> Self {
         let (tx, rx) = futures_channel::mpsc::unbounded();
+        let scheduler = Scheduler::new(tx);
         let mut dom = Self {
             rx,
-            scheduler: Scheduler::new(tx),
-            templates: Default::default(),
+            runtime: Runtime::new(scheduler),
             scopes: Default::default(),
+            dirty_scopes: Default::default(),
+            templates: Default::default(),
             elements: Default::default(),
-            scope_stack: Vec::new(),
-            dirty_scopes: BTreeSet::new(),
-            suspended_scopes: FxHashSet::default(),
             mutations: Mutations::default(),
+            suspended_scopes: Default::default(),
         };
 
         let root = dom.new_scope(
@@ -281,7 +282,7 @@ impl VirtualDom {
     ///
     /// This is useful for inserting or removing contexts from a scope, or rendering out its root node
     pub fn get_scope(&self, id: ScopeId) -> Option<&ScopeState> {
-        self.scopes.get(id.0).map(|f| f.as_ref())
+        self.scopes.get(id.0)
     }
 
     /// Get the single scope at the top of the VirtualDom tree that will always be around
@@ -301,10 +302,10 @@ impl VirtualDom {
 
     /// Manually mark a scope as requiring a re-render
     ///
-    /// Whenever the VirtualDom "works", it will re-render this scope
+    /// Whenever the Runtime "works", it will re-render this scope
     pub fn mark_dirty(&mut self, id: ScopeId) {
         if let Some(scope) = self.get_scope(id) {
-            let height = scope.height;
+            let height = scope.height();
             self.dirty_scopes.insert(DirtyScope { height, id });
         }
     }
@@ -501,10 +502,11 @@ impl VirtualDom {
                 if sync.template.get().name.rsplit_once(':').unwrap().0
                     == template.name.rsplit_once(':').unwrap().0
                 {
-                    let height = scope.height;
+                    let context = scope.context();
+                    let height = context.height;
                     self.dirty_scopes.insert(DirtyScope {
                         height,
-                        id: scope.id,
+                        id: context.id,
                     });
                 }
             }

packages/signals/Cargo.toml

@@ -9,3 +9,4 @@ edition = "2018"
 [dependencies]
 dioxus-core = { workspace = true }
 slab = { workspace = true }
+bumpalo = { version = "3.6" }

packages/signals/src/copy.rs

@@ -0,0 +1,301 @@
+use std::{
+    cell::{Cell, Ref, RefCell, RefMut},
+    marker::PhantomData,
+    rc::Rc,
+};
+
+use bumpalo::Bump;
+
+/// # Example
+///
+/// ```compile_fail
+/// let data = String::from("hello world");
+/// let store = Store::default();
+/// let owner = store.owner();
+/// let key = owner.insert(&data);
+/// drop(data);
+/// assert_eq!(*key.read(), "hello world");
+/// ```
+#[allow(unused)]
+fn compile_fail() {}
+
+#[test]
+fn reused() {
+    let store = Store::default();
+    let first_ptr;
+    {
+        let owner = store.owner();
+        first_ptr = owner.insert(1).raw.data.as_ptr();
+        drop(owner);
+    }
+    {
+        let owner = store.owner();
+        let second_ptr = owner.insert(1234).raw.data.as_ptr();
+        assert_eq!(first_ptr, second_ptr);
+        drop(owner);
+    }
+}
+
+#[test]
+fn leaking_is_ok() {
+    let data = String::from("hello world");
+    let store = Store::default();
+    let key;
+    {
+        // create an owner
+        let owner = store.owner();
+        // insert data into the store
+        key = owner.insert(data);
+        // don't drop the owner
+        std::mem::forget(owner);
+    }
+    assert_eq!(key.try_read().as_deref(), Some(&"hello world".to_string()));
+}
+
+#[test]
+fn drops() {
+    let data = String::from("hello world");
+    let store = Store::default();
+    let key;
+    {
+        // create an owner
+        let owner = store.owner();
+        // insert data into the store
+        key = owner.insert(data);
+        // drop the owner
+    }
+    assert!(key.try_read().is_none());
+}
+
+#[test]
+fn works() {
+    let store = Store::default();
+    let owner = store.owner();
+    let key = owner.insert(1);
+
+    assert_eq!(*key.read(), 1);
+}
+
+#[test]
+fn insert_while_reading() {
+    let store = Store::default();
+    let owner = store.owner();
+    let key;
+    {
+        let data: String = "hello world".to_string();
+        key = owner.insert(data);
+    }
+    let value = key.read();
+    owner.insert(&1);
+    assert_eq!(*value, "hello world");
+}
+
+#[test]
+#[should_panic]
+fn panics() {
+    let store = Store::default();
+    let owner = store.owner();
+    let key = owner.insert(1);
+    drop(owner);
+
+    assert_eq!(*key.read(), 1);
+}
+
+#[test]
+fn fuzz() {
+    fn maybe_owner_scope(
+        store: &Store,
+        valid_keys: &mut Vec<CopyHandle<String>>,
+        invalid_keys: &mut Vec<CopyHandle<String>>,
+        path: &mut Vec<u8>,
+    ) {
+        let branch_cutoff = 5;
+        let children = if path.len() < branch_cutoff {
+            rand::random::<u8>() % 4
+        } else {
+            rand::random::<u8>() % 2
+        };
+
+        for i in 0..children {
+            let owner = store.owner();
+            let key = owner.insert(format!("hello world {path:?}"));
+            valid_keys.push(key);
+            path.push(i);
+            // read all keys
+            println!("{:?}", path);
+            for key in valid_keys.iter() {
+                let value = key.read();
+                println!("{:?}", value);
+                assert!(value.starts_with("hello world"));
+            }
+            #[cfg(debug_assertions)]
+            for key in invalid_keys.iter() {
+                assert!(!key.validate());
+            }
+            maybe_owner_scope(store, valid_keys, invalid_keys, path);
+            invalid_keys.push(valid_keys.pop().unwrap());
+            path.pop();
+        }
+    }
+
+    for _ in 0..10 {
+        let store = Store::default();
+        maybe_owner_scope(&store, &mut Vec::new(), &mut Vec::new(), &mut Vec::new());
+    }
+}
+
+pub struct CopyHandle<T> {
+    raw: MemoryLocation,
+    #[cfg(debug_assertions)]
+    generation: u32,
+    _marker: PhantomData<T>,
+}
+
+impl<T: 'static> CopyHandle<T> {
+    #[inline(always)]
+    fn validate(&self) -> bool {
+        #[cfg(debug_assertions)]
+        {
+            self.raw.generation.get() == self.generation
+        }
+        #[cfg(not(debug_assertions))]
+        {
+            true
+        }
+    }
+
+    pub fn try_read(&self) -> Option<Ref<'_, T>> {
+        self.validate()
+            .then(|| {
+                Ref::filter_map(self.raw.data.borrow(), |any| {
+                    any.as_ref()?.downcast_ref::<T>()
+                })
+                .ok()
+            })
+            .flatten()
+    }
+
+    pub fn read(&self) -> Ref<'_, T> {
+        self.try_read().unwrap()
+    }
+
+    pub fn try_write(&self) -> Option<RefMut<'_, T>> {
+        self.validate()
+            .then(|| {
+                RefMut::filter_map(self.raw.data.borrow_mut(), |any| {
+                    any.as_mut()?.downcast_mut::<T>()
+                })
+                .ok()
+            })
+            .flatten()
+    }
+
+    pub fn write(&self) -> RefMut<'_, T> {
+        self.try_write().unwrap()
+    }
+}
+
+impl<T> Copy for CopyHandle<T> {}
+
+impl<T> Clone for CopyHandle<T> {
+    fn clone(&self) -> Self {
+        *self
+    }
+}
+
+#[derive(Clone, Copy)]
+struct MemoryLocation {
+    data: &'static RefCell<Option<Box<dyn std::any::Any>>>,
+    #[cfg(debug_assertions)]
+    generation: &'static Cell<u32>,
+}
+
+impl MemoryLocation {
+    #[allow(unused)]
+    fn drop(&self) {
+        let old = self.data.borrow_mut().take();
+        #[cfg(debug_assertions)]
+        if old.is_some() {
+            let new_generation = self.generation.get() + 1;
+            self.generation.set(new_generation);
+        }
+    }
+
+    fn replace<T: 'static>(&mut self, value: T) -> CopyHandle<T> {
+        let mut inner_mut = self.data.borrow_mut();
+
+        let raw = Box::new(value);
+        let old = inner_mut.replace(raw);
+        assert!(old.is_none());
+        CopyHandle {
+            raw: *self,
+            #[cfg(debug_assertions)]
+            generation: self.generation.get(),
+            _marker: PhantomData,
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct Store {
+    bump: &'static Bump,
+    recycled: Rc<RefCell<Vec<MemoryLocation>>>,
+}
+
+impl Default for Store {
+    fn default() -> Self {
+        Self {
+            bump: Box::leak(Box::new(Bump::new())),
+            recycled: Default::default(),
+        }
+    }
+}
+
+impl Store {
+    fn recycle(&self, location: MemoryLocation) {
+        location.drop();
+        self.recycled.borrow_mut().push(location);
+    }
+
+    fn claim(&self) -> MemoryLocation {
+        if let Some(location) = self.recycled.borrow_mut().pop() {
+            location
+        } else {
+            let data: &'static RefCell<_> = self.bump.alloc(RefCell::new(None));
+            MemoryLocation {
+                data,
+                #[cfg(debug_assertions)]
+                generation: self.bump.alloc(Cell::new(0)),
+            }
+        }
+    }
+
+    pub fn owner(&self) -> Owner {
+        Owner {
+            store: self.clone(),
+            owned: Default::default(),
+        }
+    }
+}
+
+pub struct Owner {
+    store: Store,
+    owned: Rc<RefCell<Vec<MemoryLocation>>>,
+}
+
+impl Owner {
+    pub fn insert<T: 'static>(&self, value: T) -> CopyHandle<T> {
+        let mut location = self.store.claim();
+        let key = location.replace(value);
+        self.owned.borrow_mut().push(location);
+        key
+    }
+}
+
+impl Drop for Owner {
+    fn drop(&mut self) {
+        for location in self.owned.borrow().iter() {
+            self.store.recycle(*location)
+        }
+    }
+}

packages/signals/src/lib.rs

@@ -1,70 +1,65 @@
 use std::{
     cell::{Ref, RefMut},
     fmt::Display,
-    marker::PhantomData,
     ops::{Add, Div, Mul, Sub},
+    sync::Arc,
 };
 
+mod copy;
 mod rt;
-
-use dioxus_core::ScopeState;
 pub use rt::*;
 
-pub fn use_init_signal_rt(cx: &ScopeState) {
-    cx.use_hook(|| {
-        let rt = claim_rt(cx.schedule_update_any());
-        cx.provide_context(rt);
-    });
-}
+use dioxus_core::{
+    prelude::{current_scope_id, schedule_update_any},
+    ScopeId, ScopeState,
+};
 
 pub fn use_signal<T: 'static>(cx: &ScopeState, f: impl FnOnce() -> T) -> Signal<T> {
-    cx.use_hook(|| {
-        let rt: &'static SignalRt = match cx.consume_context() {
-            Some(rt) => rt,
-            None => cx.provide_context(claim_rt(cx.schedule_update_any())),
-        };
-
-        let id = rt.init(f());
-        rt.subscribe(id, cx.scope_id());
-
-        struct SignalHook<T> {
-            signal: Signal<T>,
-        }
-
-        impl<T> Drop for SignalHook<T> {
-            fn drop(&mut self) {
-                self.signal.rt.remove(self.signal.id);
-            }
-        }
+    *cx.use_hook(|| Signal::new(f()))
+}
 
-        SignalHook {
-            signal: Signal {
-                id,
-                rt,
-                t: PhantomData,
-            },
-        }
-    })
-    .signal
+struct SignalData<T> {
+    subscribers: Vec<ScopeId>,
+    update_any: Arc<dyn Fn(ScopeId)>,
+    value: T,
 }
 
-pub struct Signal<T> {
-    id: usize,
-    rt: &'static SignalRt,
-    t: PhantomData<T>,
+pub struct Signal<T: 'static> {
+    inner: CopyValue<SignalData<T>>,
 }
 
 impl<T: 'static> Signal<T> {
+    pub fn new(value: T) -> Self {
+        Self {
+            inner: CopyValue::new(SignalData {
+                subscribers: Vec::new(),
+                update_any: schedule_update_any().expect("in a virtual dom"),
+                value,
+            }),
+        }
+    }
+
     pub fn read(&self) -> Ref<T> {
-        self.rt.read(self.id)
+        if let Some(current_scope_id) = current_scope_id() {
+            let mut inner = self.inner.write();
+            if !inner.subscribers.contains(&current_scope_id) {
+                inner.subscribers.push(current_scope_id);
+            }
+        }
+        Ref::map(self.inner.read(), |v| &v.value)
     }
 
     pub fn write(&self) -> RefMut<T> {
-        self.rt.write(self.id)
+        let inner = self.inner.write();
+        for &scope_id in &inner.subscribers {
+            (inner.update_any)(scope_id);
+        }
+
+        RefMut::map(inner, |v| &mut v.value)
     }
 
     pub fn set(&mut self, value: T) {
-        self.rt.set(self.id, value);
+        *self.write() = value;
     }
 
     pub fn with<O>(&self, f: impl FnOnce(&T) -> O) -> O {
@@ -72,23 +67,15 @@ impl<T: 'static> Signal<T> {
         f(&*write)
     }
 
-    pub fn update<O>(&self, _f: impl FnOnce(&mut T) -> O) -> O {
+    pub fn update<O>(&self, f: impl FnOnce(&mut T) -> O) -> O {
         let mut write = self.write();
-        _f(&mut *write)
+        f(&mut *write)
     }
 }
 
 impl<T: Clone + 'static> Signal<T> {
     pub fn get(&self) -> T {
-        self.rt.get(self.id)
-    }
-}
-
-impl<T: Clone + 'static> std::ops::Deref for Signal<T> {
-    type Target = dyn Fn() -> T;
-
-    fn deref(&self) -> &Self::Target {
-        self.rt.getter(self.id)
+        self.read().clone()
     }
 }
 
@@ -102,7 +89,7 @@ impl<T> Copy for Signal<T> {}
 
 impl<T: Display + 'static> Display for Signal<T> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        self.rt.with::<T, _>(self.id, |v| T::fmt(v, f))
+        self.with(|v| Display::fmt(v, f))
     }
 }
 

packages/signals/src/rt.rs

@@ -1,121 +1,65 @@
-use std::{any::Any, cell::RefCell, sync::Arc};
+use std::cell::{Ref, RefMut};
 
-use dioxus_core::ScopeId;
-use slab::Slab;
+use std::rc::Rc;
 
-thread_local! {
-    // we cannot drop these since any future might be using them
-    static RUNTIMES: RefCell<Vec<&'static SignalRt>> = RefCell::new(Vec::new());
-}
-
-/// Provide the runtime for signals
-///
-/// This will reuse dead runtimes
-pub fn claim_rt(update_any: Arc<dyn Fn(ScopeId)>) -> &'static SignalRt {
-    RUNTIMES.with(|runtimes| {
-        if let Some(rt) = runtimes.borrow_mut().pop() {
-            return rt;
-        }
+use dioxus_core::prelude::{consume_context, provide_root_context};
 
-        Box::leak(Box::new(SignalRt {
-            signals: RefCell::new(Slab::new()),
-            update_any,
-        }))
-    })
-}
+use crate::copy::{CopyHandle, Owner, Store};
 
-/// Push this runtime into the global runtime list
-pub fn reclam_rt(_rt: &'static SignalRt) {
-    RUNTIMES.with(|runtimes| {
-        runtimes.borrow_mut().push(_rt);
-    });
+fn current_store() -> Store {
+    match consume_context() {
+        Some(rt) => rt,
+        None => {
+            let store = Store::default();
+            provide_root_context(store).expect("in a virtual dom")
+        }
+    }
 }
 
-pub struct SignalRt {
-    pub(crate) signals: RefCell<Slab<Inner>>,
-    pub(crate) update_any: Arc<dyn Fn(ScopeId)>,
+fn current_owner() -> Rc<Owner> {
+    match consume_context() {
+        Some(rt) => rt,
+        None => {
+            let owner = Rc::new(current_store().owner());
+            provide_root_context(owner).expect("in a virtual dom")
+        }
+    }
 }
 
-impl SignalRt {
-    pub fn init<T: 'static>(&'static self, val: T) -> usize {
-        self.signals.borrow_mut().insert(Inner {
-            value: Box::new(val),
-            subscribers: Vec::new(),
-            getter: None,
-        })
-    }
+impl<T> Copy for CopyValue<T> {}
 
-    pub fn subscribe(&self, id: usize, subscriber: ScopeId) {
-        self.signals.borrow_mut()[id].subscribers.push(subscriber);
+impl<T> Clone for CopyValue<T> {
+    fn clone(&self) -> Self {
+        *self
     }
+}
 
-    pub fn get<T: Clone + 'static>(&self, id: usize) -> T {
-        self.signals.borrow()[id]
-            .value
-            .downcast_ref::<T>()
-            .cloned()
-            .unwrap()
-    }
+pub struct CopyValue<T: 'static> {
+    pub value: CopyHandle<T>,
+}
 
-    pub fn set<T: 'static>(&self, id: usize, value: T) {
-        let mut signals = self.signals.borrow_mut();
-        let inner = &mut signals[id];
-        inner.value = Box::new(value);
+impl<T: 'static> CopyValue<T> {
+    pub fn new(value: T) -> Self {
+        let owner = current_owner();
 
-        for subscriber in inner.subscribers.iter() {
-            (self.update_any)(*subscriber);
+        Self {
+            value: owner.insert(value),
         }
     }
 
-    pub fn remove(&self, id: usize) {
-        self.signals.borrow_mut().remove(id);
+    pub fn try_read(&self) -> Option<Ref<'_, T>> {
+        self.value.try_read()
     }
 
-    pub fn with<T: 'static, O>(&self, id: usize, f: impl FnOnce(&T) -> O) -> O {
-        let signals = self.signals.borrow();
-        let inner = &signals[id];
-        let inner = inner.value.downcast_ref::<T>().unwrap();
-        f(inner)
+    pub fn read(&self) -> Ref<'_, T> {
+        self.value.read()
     }
 
-    pub(crate) fn read<T: 'static>(&self, id: usize) -> std::cell::Ref<T> {
-        let signals = self.signals.borrow();
-        std::cell::Ref::map(signals, |signals| {
-            signals[id].value.downcast_ref::<T>().unwrap()
-        })
+    pub fn try_write(&self) -> Option<RefMut<'_, T>> {
+        self.value.try_write()
     }
 
-    pub(crate) fn write<T: 'static>(&self, id: usize) -> std::cell::RefMut<T> {
-        let signals = self.signals.borrow_mut();
-        std::cell::RefMut::map(signals, |signals| {
-            signals[id].value.downcast_mut::<T>().unwrap()
-        })
+    pub fn write(&self) -> RefMut<'_, T> {
+        self.value.write()
     }
-
-    pub(crate) fn getter<T: 'static + Clone>(&self, id: usize) -> &dyn Fn() -> T {
-        let mut signals = self.signals.borrow_mut();
-        let inner = &mut signals[id];
-        let r = inner.getter.as_mut();
-
-        if r.is_none() {
-            let rt = self;
-            let r = move || rt.get::<T>(id);
-            let getter: Box<dyn Fn() -> T> = Box::new(r);
-            let getter: Box<dyn Fn()> = unsafe { std::mem::transmute(getter) };
-
-            inner.getter = Some(getter);
-        }
-
-        let r = inner.getter.as_ref().unwrap();
-
-        unsafe { std::mem::transmute::<&dyn Fn(), &dyn Fn() -> T>(r) }
-    }
-}
-
-pub(crate) struct Inner {
-    pub value: Box<dyn Any>,
-    pub subscribers: Vec<ScopeId>,
-
-    // todo: this has a soundness hole in it that you might not run into
-    pub getter: Option<Box<dyn Fn()>>,
 }