review pass the last

lib/ruin_app/src/lib.rs

@@ -254,6 +254,7 @@ impl<M: Mountable> MountedApp<M> {
                 break;
             };
 
+            let mut should_flush_reactive_work = false;
             for event in iter::once(event).chain(ui.take_pending_events()) {
                 match event {
                     PlatformEvent::Configured {
@@ -268,7 +269,7 @@ impl<M: Mountable> MountedApp<M> {
                         );
                         let _ = viewport.set(configuration.actual_inner_size);
                         configure_serial.update(|value| *value = value.wrapping_add(1));
-                        current_reactor().flush_now();
+                        should_flush_reactive_work = true;
                     }
                     PlatformEvent::Pointer { window_id, event } if window_id == window.id() => {
                         Self::handle_pointer_event(
@@ -279,7 +280,7 @@ impl<M: Mountable> MountedApp<M> {
                             &mut input_state,
                             event,
                         )?;
-                        current_reactor().flush_now();
+                        should_flush_reactive_work = true;
                     }
                     PlatformEvent::Keyboard { window_id, event } if window_id == window.id() => {
                         Self::handle_keyboard_event(
@@ -289,7 +290,7 @@ impl<M: Mountable> MountedApp<M> {
                             &input_state,
                             event,
                         )?;
-                        current_reactor().flush_now();
+                        should_flush_reactive_work = true;
                     }
                     PlatformEvent::CloseRequested { window_id } if window_id == window.id() => {
                         tracing::debug!(
@@ -311,6 +312,9 @@ impl<M: Mountable> MountedApp<M> {
                     _ => {}
                 }
             }
+            if should_flush_reactive_work {
+                current_reactor().flush_now();
+            }
         }
 
         ui.shutdown()?;

lib/runtime/src/platform/macos_aarch64/driver.rs

@@ -99,7 +99,7 @@ pub struct Driver {
     pending_wakes: Cell<u64>,
     pending_timers: Cell<u64>,
     next_fd_token: Cell<u64>,
-    fd_waiters: RefCell<HashMap<FdKey, Vec<FdWaiter>>>,
+    fd_waiters: RefCell<HashMap<FdKey, FdWaiter>>,
 }
 
 /// Creates a new driver and its paired [`ThreadNotifier`].
@@ -241,17 +241,31 @@ impl Driver {
         completion: FdCompletion,
     ) -> io::Result<FdReadinessToken> {
         let key = FdKey { fd, interest };
-        let should_register = !self.fd_waiters.borrow().contains_key(&key);
+        let removed_stale_waiter = {
-        if should_register {
+            let mut waiters = self.fd_waiters.borrow_mut();
-            self.update_fd_interest(key, libc::EV_ADD | libc::EV_ENABLE)?;
+            match waiters.get(&key) {
+                Some(waiter) if !waiter.completion.is_interested() => {
+                    waiters.remove(&key);
+                    true
+                }
+                Some(_) => {
+                    return Err(io::Error::new(
+                        io::ErrorKind::AlreadyExists,
+                        "fd readiness already has a waiter for this interest",
+                    ));
+                }
+                None => false,
+            }
+        };
+        if removed_stale_waiter {
+            let _ = self.update_fd_interest(key, libc::EV_DELETE);
         }
 
         let token = self.allocate_fd_token();
+        self.update_fd_interest(key, libc::EV_ADD | libc::EV_ENABLE | libc::EV_ONESHOT)?;
         self.fd_waiters
             .borrow_mut()
-            .entry(key)
+            .insert(key, FdWaiter { token, completion });
-            .or_default()
-            .push(FdWaiter { token, completion });
         Ok(token)
     }
 
@@ -259,12 +273,9 @@ impl Driver {
         let mut empty_key = None;
         {
             let mut waiters = self.fd_waiters.borrow_mut();
-            for (key, entries) in waiters.iter_mut() {
+            for (key, entry) in waiters.iter() {
-                if let Some(index) = entries.iter().position(|entry| entry.token == token) {
+                if entry.token == token {
-                    entries.swap_remove(index);
+                    empty_key = Some(*key);
-                    if entries.is_empty() {
-                        empty_key = Some(*key);
-                    }
                     break;
                 }
             }
@@ -372,19 +383,13 @@ impl Driver {
 
     fn complete_fd_waiters(&self, fd: RawFd, interest: FdInterest, event: &libc::kevent) {
         let key = FdKey { fd, interest };
-        let waiters = self.fd_waiters.borrow_mut().remove(&key);
+        let waiter = self.fd_waiters.borrow_mut().remove(&key);
-        let Some(waiters) = waiters else {
+        let Some(waiter) = waiter else {
             return;
         };
 
-        let _ = self.update_fd_interest(key, libc::EV_DELETE);
+        let result = fd_event_result(event, interest);
-        let result = fd_event_result(event);
+        waiter.completion.complete(result);
-        for waiter in waiters {
-            waiter.completion.complete(match &result {
-                Ok(()) => Ok(()),
-                Err(error) => Err(io::Error::new(error.kind(), error.to_string())),
-            });
-        }
     }
 }
 
@@ -436,9 +441,14 @@ fn interest_from_filter(filter: i16) -> Option<FdInterest> {
     }
 }
 
-fn fd_event_result(event: &libc::kevent) -> io::Result<()> {
+fn fd_event_result(event: &libc::kevent, interest: FdInterest) -> io::Result<()> {
     if event.flags & libc::EV_ERROR != 0 && event.data != 0 {
         Err(io::Error::from_raw_os_error(event.data as i32))
+    } else if event.flags & libc::EV_EOF != 0 && interest == FdInterest::Writable {
+        Err(io::Error::new(
+            io::ErrorKind::BrokenPipe,
+            "fd write side reached EOF",
+        ))
     } else {
         Ok(())
     }

lib/runtime/src/sys/macos/fs.rs

@@ -21,6 +21,7 @@ use crate::platform::current::runtime::{ThreadHandle, current_thread_handle};
 type BlockingTask = Box<dyn FnOnce() + Send + 'static>;
 
 static BLOCKING_POOL: OnceLock<io::Result<BlockingPool>> = OnceLock::new();
+const BLOCKING_QUEUE_CAPACITY: usize = 1024;
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum ExecutionPath {
@@ -367,16 +368,20 @@ async fn offload<T: Send + 'static>(
 }
 
 struct BlockingPool {
-    sender: mpsc::Sender<BlockingTask>,
+    sender: mpsc::SyncSender<BlockingTask>,
 }
 
 impl BlockingPool {
     fn spawn(&self, task: BlockingTask) -> io::Result<()> {
-        self.sender.send(task).map_err(|_| {
+        self.sender.try_send(task).map_err(|error| match error {
-            io::Error::new(
+            mpsc::TrySendError::Full(_) => io::Error::new(
+                io::ErrorKind::WouldBlock,
+                "filesystem blocking worker queue is full",
+            ),
+            mpsc::TrySendError::Disconnected(_) => io::Error::new(
                 io::ErrorKind::BrokenPipe,
                 "filesystem blocking worker pool has stopped",
-            )
+            ),
         })
     }
 }
@@ -393,7 +398,7 @@ fn blocking_pool() -> io::Result<&'static BlockingPool> {
 }
 
 fn create_blocking_pool() -> io::Result<BlockingPool> {
-    let (sender, receiver) = mpsc::channel::<BlockingTask>();
+    let (sender, receiver) = mpsc::sync_channel::<BlockingTask>(BLOCKING_QUEUE_CAPACITY);
     let receiver = Arc::new(Mutex::new(receiver));
     let worker_count = std::thread::available_parallelism()
         .map(usize::from)

lib/runtime/src/sys/macos/net.rs

@@ -9,6 +9,7 @@ use std::net::{
 };
 use std::os::fd::{AsRawFd, FromRawFd, OwnedFd, RawFd};
 use std::pin::Pin;
+use std::sync::{Arc, Mutex, OnceLock, mpsc};
 use std::thread;
 use std::time::Duration;
 
@@ -16,10 +17,14 @@ use crate::op::completion::completion_for_current_thread;
 use crate::op::net::{AcceptedSocket, NetOp, ReceivedDatagram};
 
 const DEFAULT_LISTENER_BACKLOG: i32 = 1024;
+const DNS_QUEUE_CAPACITY: usize = 256;
 
 type RecvFuture = Pin<Box<dyn Future<Output = io::Result<Vec<u8>>> + 'static>>;
 type SendFuture = Pin<Box<dyn Future<Output = io::Result<usize>> + 'static>>;
 type ShutdownFuture = Pin<Box<dyn Future<Output = io::Result<()>> + 'static>>;
+type BlockingTask = Box<dyn FnOnce() + Send + 'static>;
+
+static DNS_POOL: OnceLock<io::Result<BlockingPool>> = OnceLock::new();
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum ExecutionPath {
@@ -391,16 +396,83 @@ async fn offload<T: Send + 'static>(
     work: impl FnOnce() -> io::Result<T> + Send + 'static,
 ) -> io::Result<T> {
     let (future, handle) = completion_for_current_thread::<io::Result<T>>();
-    let handle_for_thread = handle.clone();
+    if let Err(error) = dns_pool().and_then(|pool| {
-    if let Err(error) = thread::Builder::new()
+        pool.spawn(Box::new({
-        .name("ruin-runtime-net-offload".into())
+            let handle = handle.clone();
-        .spawn(move || handle_for_thread.complete(work()))
+            move || handle.complete(work())
-    {
+        }))
-        handle.complete(Err(io::Error::other(error)));
+    }) {
+        handle.complete(Err(error));
     }
     future.await
 }
 
+struct BlockingPool {
+    sender: mpsc::SyncSender<BlockingTask>,
+}
+
+impl BlockingPool {
+    fn spawn(&self, task: BlockingTask) -> io::Result<()> {
+        self.sender.try_send(task).map_err(|error| match error {
+            mpsc::TrySendError::Full(_) => io::Error::new(
+                io::ErrorKind::WouldBlock,
+                "DNS resolver blocking worker queue is full",
+            ),
+            mpsc::TrySendError::Disconnected(_) => io::Error::new(
+                io::ErrorKind::BrokenPipe,
+                "DNS resolver blocking worker pool has stopped",
+            ),
+        })
+    }
+}
+
+fn dns_pool() -> io::Result<&'static BlockingPool> {
+    match DNS_POOL.get_or_init(create_dns_pool) {
+        Ok(pool) => Ok(pool),
+        Err(error) => Err(io::Error::new(error.kind(), error.to_string())),
+    }
+}
+
+fn create_dns_pool() -> io::Result<BlockingPool> {
+    let (sender, receiver) = mpsc::sync_channel::<BlockingTask>(DNS_QUEUE_CAPACITY);
+    let receiver = Arc::new(Mutex::new(receiver));
+    let worker_count = std::thread::available_parallelism()
+        .map(usize::from)
+        .unwrap_or(2)
+        .clamp(2, 4);
+    let mut spawned = 0usize;
+    let mut last_error = None;
+
+    for index in 0..worker_count {
+        let receiver = Arc::clone(&receiver);
+        match thread::Builder::new()
+            .name(format!("ruin-runtime-dns-{index}"))
+            .spawn(move || {
+                loop {
+                    let task = {
+                        let receiver = receiver.lock().expect("DNS worker queue mutex poisoned");
+                        receiver.recv()
+                    };
+                    match task {
+                        Ok(task) => task(),
+                        Err(_) => break,
+                    }
+                }
+            }) {
+            Ok(_) => spawned += 1,
+            Err(error) => last_error = Some(error),
+        }
+    }
+
+    if spawned == 0 {
+        return Err(io::Error::other(last_error.expect(
+            "at least one DNS worker spawn should have been attempted",
+        )));
+    }
+
+    Ok(BlockingPool { sender })
+}
+
 async fn io_timeout<T>(
     timeout: Duration,
     future: impl Future<Output = io::Result<T>>,
@@ -531,7 +603,7 @@ impl RawSocketAddr {
                     sin_family: libc::AF_INET as libc::sa_family_t,
                     sin_port: addr.port().to_be(),
                     sin_addr: libc::in_addr {
-                        s_addr: u32::from_ne_bytes(addr.ip().octets()),
+                        s_addr: u32::from_be_bytes(addr.ip().octets()).to_be(),
                     },
                     sin_zero: [0; 8],
                 };

lib/ui/src/window.rs

@@ -34,6 +34,11 @@ pub enum WindowLifecycle {
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct WindowConfigured {
+    /// Current logical content size and platform presentation scale.
+    ///
+    /// Backends should emit a new configuration when either the logical size or
+    /// scale changes. This lets hosts relayout for size changes while renderers
+    /// can update drawable/text scale when a window moves between displays.
     pub actual_inner_size: UiSize,
     pub scale_factor: f32,
     pub visible: bool,

lib/ui_renderer_wgpu/src/lib.rs

@@ -369,6 +369,9 @@ impl WgpuSceneRenderer {
             format,
             width: width.max(1),
             height: height.max(1),
+            // RUIN prioritizes immediate resize/input feedback over frame pacing
+            // here. Keep latency to one frame and let callers opt into a more
+            // power-conservative policy once presentation settings are exposed.
             present_mode: wgpu::PresentMode::AutoNoVsync,
             desired_maximum_frame_latency: 1,
             alpha_mode: caps.alpha_modes[0],
@@ -795,9 +798,7 @@ fn fs_main(input: VertexOut) -> @location(0) vec4<f32> {
                     }
                 }
                 DisplayItem::Text(text) => {
-                    if (self.scale_factor - 1.0).abs() <= f32::EPSILON
+                    if text.glyphs.iter().all(|glyph| glyph.cache_key.is_some()) {
-                        && text.glyphs.iter().all(|glyph| glyph.cache_key.is_some())
-                    {
                         continue;
                     }
                     if let Some(uploaded) =
@@ -1070,9 +1071,6 @@ fn fs_main(input: VertexOut) -> @location(0) vec4<f32> {
         logical_size: UiSize,
         perf: &mut AtlasTextPerfStats,
     ) -> Option<UploadedAtlasText> {
-        if (self.scale_factor - 1.0).abs() > f32::EPSILON {
-            return None;
-        }
         let mut vertices = Vec::new();
         let mut clip_stack = Vec::new();
         let mut active_clip = ActiveClip::default();
@@ -1104,7 +1102,8 @@ fn fs_main(input: VertexOut) -> @location(0) vec4<f32> {
                     if active_clip.rect_active && logical_clip_rect.is_none() {
                         continue;
                     }
-                    let clip_rect = logical_clip_rect.map(rect_to_pixel_rect);
+                    let clip_rect = logical_clip_rect
+                        .map(|rect| scale_rect_to_pixel_rect(rect, self.scale_factor));
 
                     // Only iterate glyphs whose lines fall within the clip rect.
                     // For large text nodes (e.g. full Cargo.lock) this reduces
@@ -1115,7 +1114,10 @@ fn fs_main(input: VertexOut) -> @location(0) vec4<f32> {
                     perf.glyphs_clip_culled += (all_count - visible.len()) as u32;
 
                     for glyph in visible {
-                        let Some(cache_key) = glyph.cache_key else {
+                        let Some(cache_key) = glyph
+                            .cache_key
+                            .map(|cache_key| scale_glyph_cache_key(cache_key, self.scale_factor))
+                        else {
                             continue;
                         };
                         let resolved_color = resolve_glyph_color(glyph.color, text.default_color);
@@ -1124,9 +1126,12 @@ fn fs_main(input: VertexOut) -> @location(0) vec4<f32> {
                             continue;
                         };
 
-                        // Glyph positions are LOCAL; add text.origin for absolute screen coords.
+                        // Atlas glyphs are rasterized in device pixels while scene geometry remains
-                        let abs_x = (text.origin.x + glyph.position.x).round() as i32;
+                        // logical. Build and clip in device space, then convert back for vertices.
-                        let abs_y = (text.origin.y + glyph.position.y).round() as i32;
+                        let abs_x =
+                            ((text.origin.x + glyph.position.x) * self.scale_factor).round() as i32;
+                        let abs_y =
+                            ((text.origin.y + glyph.position.y) * self.scale_factor).round() as i32;
                         let glyph_rect = PixelRect {
                             left: abs_x + atlas_glyph.placement_left,
                             top: abs_y - atlas_glyph.placement_top,
@@ -1142,6 +1147,7 @@ fn fs_main(input: VertexOut) -> @location(0) vec4<f32> {
                             atlas_glyph.atlas_rect,
                             clip_rect,
                             logical_size,
+                            self.scale_factor,
                             resolved_color,
                             active_clip,
                         );
@@ -1872,6 +1878,7 @@ fn push_glyph_vertices(
     atlas_rect: AtlasRect,
     clip_rect: Option<PixelRect>,
     logical_size: UiSize,
+    scale_factor: f32,
     color: Color,
     clip: ActiveClip,
 ) {
@@ -1879,10 +1886,15 @@ fn push_glyph_vertices(
         return;
     };
 
-    let left = to_ndc_x(dest_rect.left as f32, logical_size.width.max(1.0));
+    let scale_factor = scale_factor.max(1.0);
-    let right = to_ndc_x(dest_rect.right as f32, logical_size.width.max(1.0));
+    let logical_left = dest_rect.left as f32 / scale_factor;
-    let top = to_ndc_y(dest_rect.top as f32, logical_size.height.max(1.0));
+    let logical_top = dest_rect.top as f32 / scale_factor;
-    let bottom = to_ndc_y(dest_rect.bottom as f32, logical_size.height.max(1.0));
+    let logical_right = dest_rect.right as f32 / scale_factor;
+    let logical_bottom = dest_rect.bottom as f32 / scale_factor;
+    let left = to_ndc_x(logical_left, logical_size.width.max(1.0));
+    let right = to_ndc_x(logical_right, logical_size.width.max(1.0));
+    let top = to_ndc_y(logical_top, logical_size.height.max(1.0));
+    let bottom = to_ndc_y(logical_bottom, logical_size.height.max(1.0));
 
     let color = color_to_f32(color);
     let clip_rect = clip_rect_array(clip);
@@ -1890,7 +1902,7 @@ fn push_glyph_vertices(
     vertices.extend_from_slice(&[
         TextVertex {
             position: [left, top],
-            world_position: [dest_rect.left as f32, dest_rect.top as f32],
+            world_position: [logical_left, logical_top],
             uv: [uv_rect.0, uv_rect.1],
             color,
             clip_rect,
@@ -1899,7 +1911,7 @@ fn push_glyph_vertices(
         },
         TextVertex {
             position: [left, bottom],
-            world_position: [dest_rect.left as f32, dest_rect.bottom as f32],
+            world_position: [logical_left, logical_bottom],
             uv: [uv_rect.0, uv_rect.3],
             color,
             clip_rect,
@@ -1908,7 +1920,7 @@ fn push_glyph_vertices(
         },
         TextVertex {
             position: [right, top],
-            world_position: [dest_rect.right as f32, dest_rect.top as f32],
+            world_position: [logical_right, logical_top],
             uv: [uv_rect.2, uv_rect.1],
             color,
             clip_rect,
@@ -1917,7 +1929,7 @@ fn push_glyph_vertices(
         },
         TextVertex {
             position: [right, top],
-            world_position: [dest_rect.right as f32, dest_rect.top as f32],
+            world_position: [logical_right, logical_top],
             uv: [uv_rect.2, uv_rect.1],
             color,
             clip_rect,
@@ -1926,7 +1938,7 @@ fn push_glyph_vertices(
         },
         TextVertex {
             position: [left, bottom],
-            world_position: [dest_rect.left as f32, dest_rect.bottom as f32],
+            world_position: [logical_left, logical_bottom],
             uv: [uv_rect.0, uv_rect.3],
             color,
             clip_rect,
@@ -1935,7 +1947,7 @@ fn push_glyph_vertices(
         },
         TextVertex {
             position: [right, bottom],
-            world_position: [dest_rect.right as f32, dest_rect.bottom as f32],
+            world_position: [logical_right, logical_bottom],
             uv: [uv_rect.2, uv_rect.3],
             color,
             clip_rect,
@@ -2484,12 +2496,22 @@ fn pixel_rect_tuple(rect: PixelRect) -> (i32, i32, i32, i32) {
     (rect.left, rect.top, rect.right, rect.bottom)
 }
 
+fn scale_glyph_cache_key(cache_key: CacheKey, scale_factor: f32) -> CacheKey {
+    CacheKey {
+        font_size_bits: (f32::from_bits(cache_key.font_size_bits) * scale_factor.max(1.0))
+            .to_bits(),
+        ..cache_key
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::{
-        ActiveClip, blend_rgba, build_text_vertices, build_vertices, clip_rect_array,
+        ActiveClip, AtlasRect, PixelRect, blend_rgba, build_text_vertices, build_vertices,
-        push_clip_state, rounded_clip_arrays, text_texture_key,
+        clip_rect_array, push_clip_state, push_glyph_vertices, rounded_clip_arrays,
+        scale_glyph_cache_key, text_texture_key,
     };
+    use cosmic_text::{CacheKey, CacheKeyFlags, SubpixelBin, fontdb};
     use ruin_ui::{ClipRegion, Color, Point, PreparedText, Rect, SceneSnapshot, UiSize};
 
     #[test]
@@ -2568,6 +2590,58 @@ mod tests {
         assert_ne!(first, different_pixel);
     }
 
+    #[test]
+    fn scale_glyph_cache_key_scales_font_size_only() {
+        let key = CacheKey {
+            font_id: fontdb::ID::dummy(),
+            glyph_id: 42,
+            font_size_bits: 13.0_f32.to_bits(),
+            x_bin: SubpixelBin::One,
+            y_bin: SubpixelBin::Two,
+            font_weight: fontdb::Weight::BOLD,
+            flags: CacheKeyFlags::FAKE_ITALIC,
+        };
+
+        let scaled = scale_glyph_cache_key(key, 2.0);
+
+        assert_eq!(f32::from_bits(scaled.font_size_bits), 26.0);
+        assert_eq!(scaled.font_id, key.font_id);
+        assert_eq!(scaled.glyph_id, key.glyph_id);
+        assert_eq!(scaled.x_bin, key.x_bin);
+        assert_eq!(scaled.y_bin, key.y_bin);
+        assert_eq!(scaled.font_weight, key.font_weight);
+        assert_eq!(scaled.flags, key.flags);
+    }
+
+    #[test]
+    fn scaled_atlas_vertices_convert_device_pixels_to_logical_space() {
+        let mut vertices = Vec::new();
+        push_glyph_vertices(
+            &mut vertices,
+            PixelRect {
+                left: 20,
+                top: 10,
+                right: 40,
+                bottom: 30,
+            },
+            AtlasRect {
+                x: 0,
+                y: 0,
+                width: 20,
+                height: 20,
+            },
+            None,
+            UiSize::new(100.0, 100.0),
+            2.0,
+            Color::rgb(0xFF, 0xFF, 0xFF),
+            ActiveClip::default(),
+        );
+
+        assert_eq!(vertices.len(), 6);
+        assert_eq!(vertices[0].world_position, [10.0, 5.0]);
+        assert_eq!(vertices[5].world_position, [20.0, 15.0]);
+    }
+
     #[test]
     fn nested_clip_with_empty_intersection_stays_clipped() {
         let mut clip_stack = Vec::new();