Fix bug in event broadcasting

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Change Log
 
+## Unreleased
+
+- Fixed a bug in event propagation.
+- The behavior of the event queue has changed. The next event in the queue is handled only once the current event has finished broadcasting.
+- Changed `EventPtr` interface and relaxed `Send` and `Sync` bounds for `EventMut`.
+
 ## 0.2.2 - 2024-02-8
 
 - Update documentation

README.md

@@ -7,11 +7,11 @@ It aims to have a small but maximally expressive set of features that are easy a
 
 ## Features
 
-- In addition to the usual Entities, Components, and Systems, `evenio` introduces _events_ as a first-class citizen.
-Rather than restricting systems to run once every frame/update in a fixed order, systems are generalized as _event handlers_.
+- In addition to the usual Entities, Components, and Systems, `evenio` introduces events as a first-class citizen.
+Rather than restricting systems to run once every frame/update in a fixed order, systems are generalized as event handlers.
 The control flow of the entire program is then defined by the flow of events between systems.
 - Structural changes to the world (such as entity despawning, component additions/removals, etc.) are mediated by events, allowing systems to hook into their occurrence.
-- _Targeted events_ enable systems to efficiently filter events based on queries.
+- Targeted events enable systems to efficiently filter events based on queries.
 - Component types, event types, and systems are identified with generational indices, allowing them to be added and removed dynamically.
 - Execute systems in parallel with [Rayon].
 - Core of the library does not depend on Rust's type system.

src/archetype.rs

@@ -9,6 +9,7 @@ use core::cmp::Ordering;
 use core::ptr;
 use core::ptr::NonNull;
 
+use ahash::RandomState;
 use slab::Slab;
 
 use crate::assert::{assume_debug_checked, GetDebugChecked, UnwrapDebugChecked};
@@ -47,9 +48,12 @@ pub struct Archetypes {
 
 impl Archetypes {
     pub(crate) fn new() -> Self {
+        let mut map = HashMap::with_hasher(RandomState::new());
+        map.insert(vec![].into_boxed_slice(), ArchetypeIdx::EMPTY);
+
         Self {
             archetypes: Slab::from_iter([(0, Archetype::empty())]),
-            by_components: HashMap::from_iter([(vec![].into_boxed_slice(), ArchetypeIdx::EMPTY)]),
+            by_components: map,
         }
     }
 

src/assert.rs

@@ -1,7 +1,7 @@
 //! Utilities for runtime and compile-time assertions.
 
-use alloc::vec::Vec;
 use core::marker::PhantomData;
+use core::slice::SliceIndex;
 use core::{fmt, mem};
 
 use slab::Slab;
@@ -16,7 +16,7 @@ const _: () = assert!(
 
 /// Extension trait for checked array indexing with checks removed in release
 /// mode.
-pub(crate) trait GetDebugChecked {
+pub(crate) trait GetDebugChecked<Idx> {
     type Output: ?Sized;
 
     /// Gets a reference to the element at the given index.
@@ -28,7 +28,7 @@ pub(crate) trait GetDebugChecked {
     ///
     /// - `idx` must be in bounds.
     #[track_caller]
-    unsafe fn get_debug_checked(&self, idx: usize) -> &Self::Output;
+    unsafe fn get_debug_checked(&self, idx: Idx) -> &Self::Output;
     /// Gets a mutable reference to the element at the given index.
     ///
     /// If `idx` is not in bounds, a panic occurs in debug mode and Undefined
@@ -38,23 +38,24 @@ pub(crate) trait GetDebugChecked {
     ///
     /// - `idx` must be in bounds.
     #[track_caller]
-    unsafe fn get_debug_checked_mut(&mut self, idx: usize) -> &mut Self::Output;
+    unsafe fn get_debug_checked_mut(&mut self, idx: Idx) -> &mut Self::Output;
 }
 
-impl<T> GetDebugChecked for [T] {
-    type Output = T;
+impl<T, I> GetDebugChecked<I> for [T]
+where
+    I: SliceIndex<[T]>,
+{
+    type Output = I::Output;
 
-    #[inline]
-    unsafe fn get_debug_checked(&self, idx: usize) -> &Self::Output {
+    unsafe fn get_debug_checked(&self, idx: I) -> &Self::Output {
         #[cfg(debug_assertions)]
         return &self[idx];
 
         #[cfg(not(debug_assertions))]
         return self.get_unchecked(idx);
     }
 
-    #[inline]
-    unsafe fn get_debug_checked_mut(&mut self, idx: usize) -> &mut Self::Output {
+    unsafe fn get_debug_checked_mut(&mut self, idx: I) -> &mut Self::Output {
         #[cfg(debug_assertions)]
         return &mut self[idx];
 
@@ -63,22 +64,8 @@ impl<T> GetDebugChecked for [T] {
     }
 }
 
-impl<T> GetDebugChecked for Vec<T> {
-    type Output = T;
-
-    #[inline]
-    unsafe fn get_debug_checked(&self, idx: usize) -> &Self::Output {
-        self.as_slice().get_debug_checked(idx)
-    }
-
-    #[inline]
-    unsafe fn get_debug_checked_mut(&mut self, idx: usize) -> &mut Self::Output {
-        self.as_mut_slice().get_debug_checked_mut(idx)
-    }
-}
-
 // Don't use `Slab::get_unchecked` because there's a panicking branch. https://github.com/tokio-rs/slab/pull/74
-impl<T> GetDebugChecked for Slab<T> {
+impl<T> GetDebugChecked<usize> for Slab<T> {
     type Output = T;
 
     #[inline]

src/blob_vec.rs

@@ -27,9 +27,6 @@ impl BlobVec {
     /// - `drop` must be safe to call with elements of this `BlobVec` as
     ///   described by [`DropFn`]'s documentation.
     pub(crate) unsafe fn new(layout: Layout, drop: DropFn) -> Self {
-        // // SAFETY: `Layout` guarantees alignment is non-zero.
-        // let data = NonNull::new(layout.align() as *mut u8).unwrap_debug_checked();
-
         Self {
             elem_layout: pad_to_align(&layout),
             len: 0,