Merge pull request #277 from mahkoh/jorth/async-text

text: render text asynchronously

src/async_engine.rs

@@ -35,6 +35,8 @@ pub struct AsyncEngine {
     yield_stash: RefCell<VecDeque<Waker>>,
     stopped: Cell<bool>,
     now: Cell<Option<Time>>,
+    #[cfg(feature = "it")]
+    idle: Cell<Option<Waker>>,
 }
 
 impl AsyncEngine {
@@ -48,6 +50,8 @@ impl AsyncEngine {
             yield_stash: Default::default(),
             stopped: Cell::new(false),
             now: Default::default(),
+            #[cfg(feature = "it")]
+            idle: Default::default(),
         })
     }
 
@@ -91,7 +95,15 @@ impl AsyncEngine {
     pub fn dispatch(&self) {
         let mut stash = self.stash.borrow_mut();
         let mut yield_stash = self.yield_stash.borrow_mut();
-        while self.num_queued.get() > 0 {
+        loop {
+            if self.num_queued.get() == 0 {
+                #[cfg(feature = "it")]
+                if let Some(idle) = self.idle.take() {
+                    idle.wake();
+                    continue;
+                }
+                break;
+            }
             self.now.take();
             self.iteration.fetch_add(1);
             let mut phase = 0;
@@ -116,6 +128,22 @@ impl AsyncEngine {
         }
     }
 
+    #[cfg(feature = "it")]
+    pub async fn idle(&self) {
+        use std::{future::poll_fn, task::Poll};
+        let mut register = true;
+        poll_fn(|ctx| {
+            if register {
+                self.idle.set(Some(ctx.waker().clone()));
+                register = false;
+                Poll::Pending
+            } else {
+                Poll::Ready(())
+            }
+        })
+        .await
+    }
+
     fn push(&self, runnable: Runnable, phase: Phase) {
         self.queues[phase as usize].push(runnable);
         self.num_queued.fetch_add(1);

src/clientmem.rs

@@ -2,11 +2,14 @@ use {
     crate::{
         client::Client,
         cpu_worker::{AsyncCpuWork, CpuJob, CpuWork, CpuWorker},
+        gfx_api::{ShmMemory, ShmMemoryBacking},
         utils::vec_ext::VecExt,
     },
     std::{
         cell::Cell,
+        error::Error,
         mem::{ManuallyDrop, MaybeUninit},
+        ops::Deref,
         ptr,
         rc::Rc,
         sync::atomic::{compiler_fence, Ordering},
@@ -105,6 +108,7 @@ impl ClientMem {
         }
     }
 
+    #[expect(dead_code)]
     pub fn fd(&self) -> &Rc<OwnedFd> {
         &self.fd
     }
@@ -115,14 +119,17 @@ impl ClientMem {
 }
 
 impl ClientMemOffset {
+    #[expect(dead_code)]
     pub fn pool(&self) -> &ClientMem {
         &self.mem
     }
 
+    #[expect(dead_code)]
     pub fn offset(&self) -> usize {
         self.offset
     }
 
+    #[expect(dead_code)]
     pub fn ptr(&self) -> *const [Cell<u8>] {
         self.data
     }
@@ -263,3 +270,20 @@ impl CpuWork for CloseMemWork {
         None
     }
 }
+
+impl ShmMemory for ClientMemOffset {
+    fn len(&self) -> usize {
+        self.data.len()
+    }
+
+    fn safe_access(&self) -> ShmMemoryBacking {
+        match self.mem.sigbus_impossible() {
+            true => ShmMemoryBacking::Ptr(self.data),
+            false => ShmMemoryBacking::Fd(self.mem.fd.deref().clone(), self.offset),
+        }
+    }
+
+    fn access(&self, f: &mut dyn FnMut(&[Cell<u8>])) -> Result<(), Box<dyn Error + Sync + Send>> {
+        self.access(f).map_err(|e| e.into())
+    }
+}

src/compositor.rs

@@ -35,9 +35,9 @@ use {
         tasks::{self, idle},
         tracy::enable_profiler,
         tree::{
-            container_layout, container_render_data, float_layout, float_titles,
-            output_render_data, DisplayNode, NodeIds, OutputNode, TearingMode, VrrMode,
-            WorkspaceNode,
+            container_layout, container_render_positions, container_render_titles, float_layout,
+            float_titles, output_render_data, placeholder_render_textures, DisplayNode, NodeIds,
+            OutputNode, TearingMode, VrrMode, WorkspaceNode,
         },
         user_session::import_environment,
         utils::{
@@ -180,13 +180,15 @@ fn start_compositor2(
         input_device_handlers: Default::default(),
         theme: Default::default(),
         pending_container_layout: Default::default(),
-        pending_container_render_data: Default::default(),
+        pending_container_render_positions: Default::default(),
+        pending_container_render_title: Default::default(),
         pending_output_render_data: Default::default(),
         pending_float_layout: Default::default(),
         pending_float_titles: Default::default(),
         pending_input_popup_positioning: Default::default(),
         pending_toplevel_screencasts: Default::default(),
         pending_screencast_reallocs_or_reconfigures: Default::default(),
+        pending_placeholder_render_textures: Default::default(),
         dbus: Dbus::new(&engine, &ring, &run_toplevel),
         fdcloser: FdCloser::new(),
         logger: logger.clone(),
@@ -374,9 +376,19 @@ fn start_global_event_handlers(
             container_layout(state.clone()),
         ),
         eng.spawn2(
-            "container render",
+            "container render positions",
             Phase::PostLayout,
-            container_render_data(state.clone()),
+            container_render_positions(state.clone()),
+        ),
+        eng.spawn2(
+            "container titles",
+            Phase::PostLayout,
+            container_render_titles(state.clone()),
+        ),
+        eng.spawn2(
+            "placeholder textures",
+            Phase::PostLayout,
+            placeholder_render_textures(state.clone()),
         ),
         eng.spawn2(
             "output render",
@@ -577,7 +589,7 @@ fn create_dummy_output(state: &Rc<State>) {
         jay_workspaces: Default::default(),
         may_capture: Cell::new(false),
         has_capture: Cell::new(false),
-        title_texture: Cell::new(None),
+        title_texture: Default::default(),
         attention_requests: Default::default(),
         render_highlight: Default::default(),
     });

src/config/handler.rs

@@ -13,7 +13,7 @@ use {
         output_schedule::map_cursor_hz,
         scale::Scale,
         state::{ConnectorData, DeviceHandlerData, DrmDevData, OutputData, State},
-        theme::{Color, ThemeSized, DEFAULT_FONT},
+        theme::{Color, ThemeSized},
         tree::{
             move_ws_to_output, ContainerNode, ContainerSplit, FloatNode, Node, NodeVisitorBase,
             OutputNode, TearingMode, VrrMode, WsMoveConfig,
@@ -57,7 +57,7 @@ use {
     },
     libloading::Library,
     log::Level,
-    std::{cell::Cell, ops::Deref, rc::Rc, time::Duration},
+    std::{cell::Cell, ops::Deref, rc::Rc, sync::Arc, time::Duration},
     thiserror::Error,
     uapi::{c, fcntl_dupfd_cloexec, OwnedFd},
 };
@@ -1525,15 +1525,18 @@ impl ConfigProxyHandler {
     }
 
     fn handle_reset_font(&self) {
-        *self.state.theme.font.borrow_mut() = DEFAULT_FONT.to_string();
+        self.state
+            .theme
+            .font
+            .set(self.state.theme.default_font.clone());
     }
 
     fn handle_set_font(&self, font: &str) {
-        *self.state.theme.font.borrow_mut() = font.to_string();
+        self.state.theme.font.set(Arc::new(font.to_string()));
     }
 
     fn handle_get_font(&self) {
-        let font = self.state.theme.font.borrow_mut().clone();
+        let font = self.state.theme.font.get().to_string();
         self.respond(Response::GetFont { font });
     }
 

src/cpu_worker.rs

@@ -11,7 +11,7 @@ use {
             ptr_ext::MutPtrExt, queue::AsyncQueue, stack::Stack,
         },
     },
-    parking_lot::Mutex,
+    parking_lot::{Condvar, Mutex},
     std::{
         any::Any,
         cell::{Cell, RefCell},
@@ -113,18 +113,25 @@ enum Job {
 
 unsafe impl Send for Job {}
 
+#[derive(Default)]
+struct CompletedJobsExchange {
+    queue: VecDeque<CpuJobId>,
+    condvar: Option<Arc<Condvar>>,
+}
+
 struct CpuWorkerData {
     next: CpuJobIds,
     jobs_to_enqueue: AsyncQueue<Job>,
     new_jobs: Arc<Mutex<VecDeque<Job>>>,
     have_new_jobs: Rc<OwnedFd>,
-    completed_jobs_remote: Arc<Mutex<VecDeque<CpuJobId>>>,
+    completed_jobs_remote: Arc<Mutex<CompletedJobsExchange>>,
     completed_jobs_local: RefCell<VecDeque<CpuJobId>>,
     have_completed_jobs: Rc<OwnedFd>,
     pending_jobs: CopyHashMap<CpuJobId, Rc<PendingJobData>>,
     ring: Rc<IoUring>,
     _stop: OwnedFd,
     pending_job_data_cache: Stack<Rc<PendingJobData>>,
+    sync_wake_condvar: Arc<Condvar>,
 }
 
 linear_ids!(CpuJobIds, CpuJobId, u64);
@@ -172,12 +179,16 @@ impl Drop for PendingJob {
                 self.job_data.state.set(PendingJobState::Abandoned);
                 data.jobs_to_enqueue.push(Job::Cancel { id });
                 data.do_equeue_jobs();
-                let mut buf = 0u64;
-                while data.pending_jobs.contains(&id) {
-                    if let Err(e) = uapi::read(data.have_completed_jobs.raw(), &mut buf) {
-                        panic!("Could not wait for job completions: {}", ErrorFmt(e));
-                    }
+                loop {
                     data.dispatch_completions();
+                    if !data.pending_jobs.contains(&id) {
+                        break;
+                    }
+                    let mut remote = data.completed_jobs_remote.lock();
+                    while remote.queue.is_empty() {
+                        remote.condvar = Some(data.sync_wake_condvar.clone());
+                        data.sync_wake_condvar.wait(&mut remote);
+                    }
                 }
             }
             PendingJobState::Abandoned => {}
@@ -204,7 +215,7 @@ impl CpuWorkerData {
 
     fn dispatch_completions(&self) {
         let completions = &mut *self.completed_jobs_local.borrow_mut();
-        mem::swap(completions, &mut *self.completed_jobs_remote.lock());
+        mem::swap(completions, &mut self.completed_jobs_remote.lock().queue);
         while let Some(id) = completions.pop_front() {
             let job_data = self.pending_jobs.remove(&id).unwrap();
             let job = job_data.job.take().unwrap();
@@ -242,7 +253,7 @@ impl CpuWorkerData {
 impl CpuWorker {
     pub fn new(ring: &Rc<IoUring>, eng: &Rc<AsyncEngine>) -> Result<Self, CpuWorkerError> {
         let new_jobs: Arc<Mutex<VecDeque<Job>>> = Default::default();
-        let completed_jobs: Arc<Mutex<VecDeque<CpuJobId>>> = Default::default();
+        let completed_jobs: Arc<Mutex<CompletedJobsExchange>> = Default::default();
         let (stop_read, stop_write) =
             uapi::pipe2(c::O_CLOEXEC).map_err(|e| CpuWorkerError::Pipe(e.into()))?;
         let have_new_jobs =
@@ -281,6 +292,7 @@ impl CpuWorker {
             ring: ring.clone(),
             _stop: stop_read,
             pending_job_data_cache: Default::default(),
+            sync_wake_condvar: Arc::new(Condvar::new()),
         });
         Ok(Self {
             _completions_listener: eng.spawn(
@@ -309,11 +321,28 @@ impl CpuWorker {
             job_data,
         }
     }
+
+    #[cfg(feature = "it")]
+    pub fn wait_idle(&self) -> bool {
+        let was_idle = self.data.pending_jobs.is_empty();
+        loop {
+            self.data.dispatch_completions();
+            if self.data.pending_jobs.is_empty() {
+                break;
+            }
+            let mut remote = self.data.completed_jobs_remote.lock();
+            while remote.queue.is_empty() {
+                remote.condvar = Some(self.data.sync_wake_condvar.clone());
+                self.data.sync_wake_condvar.wait(&mut remote);
+            }
+        }
+        was_idle
+    }
 }
 
 fn work(
     new_jobs: Arc<Mutex<VecDeque<Job>>>,
-    completed_jobs: Arc<Mutex<VecDeque<CpuJobId>>>,
+    completed_jobs: Arc<Mutex<CompletedJobsExchange>>,
     stop: OwnedFd,
     have_new_jobs: OwnedFd,
     have_completed_jobs: OwnedFd,
@@ -343,7 +372,7 @@ fn work(
 struct Worker {
     eng: Rc<AsyncEngine>,
     ring: Rc<IoUring>,
-    completed_jobs: Arc<Mutex<VecDeque<CpuJobId>>>,
+    completed_jobs: Arc<Mutex<CompletedJobsExchange>>,
     have_completed_jobs: OwnedFd,
     async_jobs: CopyHashMap<CpuJobId, AsyncJob>,
     stopped: Cell<bool>,
@@ -428,7 +457,14 @@ impl Worker {
     }
 
     fn send_completion(&self, id: CpuJobId) {
-        self.completed_jobs.lock().push_back(id);
+        let cv = {
+            let mut exchange = self.completed_jobs.lock();
+            exchange.queue.push_back(id);
+            exchange.condvar.take()
+        };
+        if let Some(cv) = cv {
+            cv.notify_all();
+        }
         if let Err(e) = uapi::eventfd_write(self.have_completed_jobs.raw(), 1) {
             panic!("Could not signal job completion: {}", ErrorFmt(e));
         }

src/gfx_api.rs

@@ -1,7 +1,6 @@
 use {
     crate::{
         allocator::Allocator,
-        clientmem::ClientMemOffset,
         cpu_worker::CpuWorker,
         cursor::Cursor,
         damage::DamageVisualizer,
@@ -513,11 +512,37 @@ pub struct PendingShmUpload {
     id: u64,
 }
 
+pub trait ShmMemory {
+    fn len(&self) -> usize;
+    fn safe_access(&self) -> ShmMemoryBacking;
+    fn access(&self, f: &mut dyn FnMut(&[Cell<u8>])) -> Result<(), Box<dyn Error + Sync + Send>>;
+}
+
+pub enum ShmMemoryBacking {
+    Ptr(*const [Cell<u8>]),
+    Fd(Rc<OwnedFd>, usize),
+}
+
+impl ShmMemory for Vec<Cell<u8>> {
+    fn len(&self) -> usize {
+        self.len()
+    }
+
+    fn safe_access(&self) -> ShmMemoryBacking {
+        ShmMemoryBacking::Ptr(&**self)
+    }
+
+    fn access(&self, f: &mut dyn FnMut(&[Cell<u8>])) -> Result<(), Box<dyn Error + Sync + Send>> {
+        f(self);
+        Ok(())
+    }
+}
+
 pub trait AsyncShmGfxTexture: GfxTexture {
     fn async_upload(
         self: Rc<Self>,
         callback: Rc<dyn AsyncShmGfxTextureCallback>,
-        mem: &Rc<ClientMemOffset>,
+        mem: Rc<dyn ShmMemory>,
         damage: Region,
     ) -> Result<Option<PendingShmUpload>, GfxError>;
 

src/gfx_apis/gl.rs

@@ -67,7 +67,6 @@ macro_rules! dynload {
 
 use {
     crate::{
-        clientmem::ClientMemError,
         gfx_api::{
             AcquireSync, CopyTexture, FillRect, GfxApiOpt, GfxContext, GfxError, GfxTexture,
             ReleaseSync, SyncFile,
@@ -95,7 +94,7 @@ use {
     },
     isnt::std_1::vec::IsntVecExt,
     once_cell::sync::Lazy,
-    std::{cell::RefCell, rc::Rc, sync::Arc},
+    std::{cell::RefCell, error::Error, rc::Rc, sync::Arc},
     thiserror::Error,
 };
 
@@ -199,7 +198,7 @@ enum RenderError {
     #[error("Buffer format {0} is not supported for shm buffers in OpenGL context")]
     UnsupportedShmFormat(&'static str),
     #[error("Could not access the client memory")]
-    AccessFailed(#[source] ClientMemError),
+    AccessFailed(#[source] Box<dyn Error + Sync + Send>),
 }
 
 #[derive(Default)]

src/gfx_apis/gl/renderer/texture.rs

@@ -1,10 +1,9 @@
 use {
     crate::{
-        clientmem::ClientMemOffset,
         format::Format,
         gfx_api::{
             AsyncShmGfxTexture, AsyncShmGfxTextureCallback, GfxError, GfxTexture, PendingShmUpload,
-            ShmGfxTexture,
+            ShmGfxTexture, ShmMemory,
         },
         gfx_apis::gl::{
             gl::texture::GlTexture,
@@ -102,12 +101,15 @@ impl AsyncShmGfxTexture for Texture {
     fn async_upload(
         self: Rc<Self>,
         _callback: Rc<dyn AsyncShmGfxTextureCallback>,
-        mem: &Rc<ClientMemOffset>,
-        damage: Region,
+        mem: Rc<dyn ShmMemory>,
+        _damage: Region,
     ) -> Result<Option<PendingShmUpload>, GfxError> {
-        mem.access(|data| self.clone().sync_upload(data, damage))
-            .map_err(RenderError::AccessFailed)??;
-        Ok(None)
+        let mut res = Ok(());
+        mem.access(&mut |data| {
+            res = self.clone().sync_upload(data, Region::default());
+        })
+        .map_err(RenderError::AccessFailed)?;
+        res.map(|_| None)
     }
 
     fn sync_upload(self: Rc<Self>, data: &[Cell<u8>], _damage: Region) -> Result<(), GfxError> {

src/gfx_apis/vulkan/image.rs

@@ -1,11 +1,10 @@
 use {
     crate::{
-        clientmem::ClientMemOffset,
         format::Format,
         gfx_api::{
             AcquireSync, AsyncShmGfxTexture, AsyncShmGfxTextureCallback,
             AsyncShmGfxTextureUploadCancellable, GfxApiOpt, GfxError, GfxFramebuffer, GfxImage,
-            GfxTexture, PendingShmUpload, ReleaseSync, ShmGfxTexture, SyncFile,
+            GfxTexture, PendingShmUpload, ReleaseSync, ShmGfxTexture, ShmMemory, SyncFile,
         },
         gfx_apis::vulkan::{
             allocator::VulkanAllocation, device::VulkanDevice, format::VulkanModifierLimits,
@@ -579,13 +578,13 @@ impl AsyncShmGfxTexture for VulkanImage {
     fn async_upload(
         self: Rc<Self>,
         callback: Rc<dyn AsyncShmGfxTextureCallback>,
-        mem: &Rc<ClientMemOffset>,
+        mem: Rc<dyn ShmMemory>,
         damage: Region,
     ) -> Result<Option<PendingShmUpload>, GfxError> {
         let VulkanImageMemory::Internal(shm) = &self.ty else {
             unreachable!();
         };
-        let pending = shm.async_upload(&self, mem, damage, callback)?;
+        let pending = shm.async_upload(&self, &mem, damage, callback)?;
         Ok(pending)
     }
 

src/gfx_apis/vulkan/shm_image.rs

@@ -1,6 +1,5 @@
 use {
     crate::{
-        clientmem::ClientMemOffset,
         cpu_worker::{
             jobs::{
                 img_copy::ImgCopyWork,
@@ -9,7 +8,9 @@ use {
             CpuJob, CpuWork, CpuWorker,
         },
         format::{Format, FormatShmInfo},
-        gfx_api::{AsyncShmGfxTextureCallback, PendingShmUpload, SyncFile},
+        gfx_api::{
+            AsyncShmGfxTextureCallback, PendingShmUpload, ShmMemory, ShmMemoryBacking, SyncFile,
+        },
         gfx_apis::vulkan::{
             allocator::VulkanAllocation,
             command::VulkanCommandBuffer,
@@ -329,7 +330,7 @@ impl VulkanShmImage {
     pub fn async_upload(
         &self,
         img: &Rc<VulkanImage>,
-        client_mem: &Rc<ClientMemOffset>,
+        client_mem: &Rc<dyn ShmMemory>,
         damage: Region,
         callback: Rc<dyn AsyncShmGfxTextureCallback>,
     ) -> Result<Option<PendingShmUpload>, VulkanError> {
@@ -350,13 +351,13 @@ impl VulkanShmImage {
         &self,
         img: &Rc<VulkanImage>,
         data: &VulkanShmImageAsyncData,
-        client_mem: &Rc<ClientMemOffset>,
+        client_mem: &Rc<dyn ShmMemory>,
         mut damage: Region,
     ) -> Result<(), VulkanError> {
         if data.busy.get() {
             return Err(VulkanError::AsyncCopyBusy);
         }
-        if self.size > client_mem.ptr().len() as u64 {
+        if self.size > client_mem.len() as u64 {
             return Err(VulkanError::InvalidBufferSize);
         }
         data.busy.set(true);
@@ -530,7 +531,7 @@ impl VulkanShmImage {
     fn async_upload_after_allocation(
         &self,
         img: &Rc<VulkanImage>,
-        client_mem: &Rc<ClientMemOffset>,
+        client_mem: &Rc<dyn ShmMemory>,
         res: Result<VulkanStagingBuffer, VulkanError>,
     ) -> Result<(), VulkanError> {
         let staging = Rc::new(res?);
@@ -546,73 +547,76 @@ impl VulkanShmImage {
         data: &VulkanShmImageAsyncData,
         staging: &VulkanStagingBuffer,
         copies: &[BufferImageCopy2],
-        client_mem: &Rc<ClientMemOffset>,
+        client_mem: &Rc<dyn ShmMemory>,
     ) -> Result<(), VulkanError> {
         img.renderer.check_defunct()?;
 
         let id = img.renderer.allocate_point();
         let pending;
-        if client_mem.pool().sigbus_impossible() {
-            let mut job = data.copy_job.take().unwrap_or_else(|| {
-                Box::new(CopyUploadJob {
-                    img: None,
-                    id,
-                    _mem: None,
-                    work: unsafe { ImgCopyWork::new() },
-                })
-            });
-            job.id = id;
-            job.img = Some(img.clone());
-            job._mem = Some(client_mem.clone());
-            job.work.src = client_mem.ptr() as _;
-            job.work.dst = staging.allocation.mem.unwrap();
-            job.work.width = img.width as _;
-            job.work.stride = img.stride as _;
-            job.work.bpp = self.shm_info.bpp as _;
-            job.work.rects.clear();
-            for copy in copies {
-                job.work.rects.push(
-                    Rect::new_sized(
-                        copy.image_offset.x as _,
-                        copy.image_offset.y as _,
-                        copy.image_extent.width as _,
-                        copy.image_extent.height as _,
-                    )
-                    .unwrap(),
-                );
+        match client_mem.safe_access() {
+            ShmMemoryBacking::Ptr(ptr) => {
+                let mut job = data.copy_job.take().unwrap_or_else(|| {
+                    Box::new(CopyUploadJob {
+                        img: None,
+                        id,
+                        _mem: None,
+                        work: unsafe { ImgCopyWork::new() },
+                    })
+                });
+                job.id = id;
+                job.img = Some(img.clone());
+                job._mem = Some(client_mem.clone());
+                job.work.src = ptr as _;
+                job.work.dst = staging.allocation.mem.unwrap();
+                job.work.width = img.width as _;
+                job.work.stride = img.stride as _;
+                job.work.bpp = self.shm_info.bpp as _;
+                job.work.rects.clear();
+                for copy in copies {
+                    job.work.rects.push(
+                        Rect::new_sized(
+                            copy.image_offset.x as _,
+                            copy.image_offset.y as _,
+                            copy.image_extent.width as _,
+                            copy.image_extent.height as _,
+                        )
+                        .unwrap(),
+                    );
+                }
+                pending = data.cpu.submit(job);
             }
-            pending = data.cpu.submit(job);
-        } else {
-            let mut min_offset = client_mem.ptr().len() as u64;
-            let mut max_offset = 0;
-            for copy in copies {
-                min_offset = min_offset.min(copy.buffer_offset);
-                let len = img.stride * (copy.image_extent.height - 1)
-                    + copy.image_extent.width * self.shm_info.bpp;
-                max_offset = max_offset.max(copy.buffer_offset + len as u64);
+            ShmMemoryBacking::Fd(fd, offset) => {
+                let mut min_offset = client_mem.len() as u64;
+                let mut max_offset = 0;
+                for copy in copies {
+                    min_offset = min_offset.min(copy.buffer_offset);
+                    let len = img.stride * (copy.image_extent.height - 1)
+                        + copy.image_extent.width * self.shm_info.bpp;
+                    max_offset = max_offset.max(copy.buffer_offset + len as u64);
+                }
+                let mut job = data.io_job.take().unwrap_or_else(|| {
+                    Box::new(IoUploadJob {
+                        img: None,
+                        id,
+                        _mem: None,
+                        work: unsafe { ReadWriteWork::new() },
+                        fd: None,
+                    })
+                });
+                job.id = id;
+                job.img = Some(img.clone());
+                job._mem = Some(client_mem.clone());
+                job.fd = Some(fd.clone());
+                unsafe {
+                    let config = job.work.config();
+                    config.fd = fd.raw();
+                    config.offset = offset + min_offset as usize;
+                    config.ptr = staging.allocation.mem.unwrap().add(min_offset as _);
+                    config.len = max_offset.saturating_sub(min_offset) as usize;
+                    config.write = false;
+                }
+                pending = data.cpu.submit(job);
             }
-            let mut job = data.io_job.take().unwrap_or_else(|| {
-                Box::new(IoUploadJob {
-                    img: None,
-                    id,
-                    _mem: None,
-                    work: unsafe { ReadWriteWork::new() },
-                    fd: None,
-                })
-            });
-            job.id = id;
-            job.img = Some(img.clone());
-            job._mem = Some(client_mem.clone());
-            job.fd = Some(client_mem.pool().fd().clone());
-            unsafe {
-                let config = job.work.config();
-                config.fd = client_mem.pool().fd().raw();
-                config.offset = client_mem.offset() + min_offset as usize;
-                config.ptr = staging.allocation.mem.unwrap().add(min_offset as _);
-                config.len = max_offset.saturating_sub(min_offset) as usize;
-                config.write = false;
-            }
-            pending = data.cpu.submit(job);
         }
 
         img.renderer.pending_cpu_jobs.set(id, pending);
@@ -653,7 +657,7 @@ impl VulkanShmImage {
 pub(super) struct IoUploadJob {
     img: Option<Rc<VulkanImage>>,
     id: u64,
-    _mem: Option<Rc<ClientMemOffset>>,
+    _mem: Option<Rc<dyn ShmMemory>>,
     fd: Option<Rc<OwnedFd>>,
     work: ReadWriteWork,
 }
@@ -661,7 +665,7 @@ pub(super) struct IoUploadJob {
 pub(super) struct CopyUploadJob {
     img: Option<Rc<VulkanImage>>,
     id: u64,
-    _mem: Option<Rc<ClientMemOffset>>,
+    _mem: Option<Rc<dyn ShmMemory>>,
     work: ImgCopyWork,
 }
 

src/ifs/wl_surface/commit_timeline.rs

@@ -460,7 +460,7 @@ fn schedule_async_upload(
         }
     };
     back_tex
-        .async_upload(node_ref.clone(), mem, back.damage.get())
+        .async_upload(node_ref.clone(), mem.clone(), back.damage.get())
         .map_err(WlSurfaceError::PrepareAsyncUpload)
 }
 

src/it/test_client.rs

@@ -85,10 +85,9 @@ impl TestClient {
     }
 
     pub async fn sync(&self) {
-        self.run.state.eng.yield_now().await;
         self.run.sync().await;
         self.tran.sync().await;
-        self.run.state.eng.yield_now().await;
+        self.run.state.idle().await;
     }
 
     pub async fn take_screenshot(&self, include_cursor: bool) -> Result<Vec<u8>, TestError> {

src/it/test_gfx_api.rs

@@ -1,14 +1,13 @@
 use {
     crate::{
         allocator::{Allocator, AllocatorError, BufferObject, BufferUsage},
-        clientmem::{ClientMemError, ClientMemOffset},
         cpu_worker::CpuWorker,
         format::{Format, ARGB8888, XRGB8888},
         gfx_api::{
             AcquireSync, AsyncShmGfxTexture, AsyncShmGfxTextureCallback, CopyTexture, FillRect,
             FramebufferRect, GfxApiOpt, GfxContext, GfxError, GfxFormat, GfxFramebuffer, GfxImage,
             GfxTexture, GfxWriteModifier, PendingShmUpload, ReleaseSync, ResetStatus,
-            ShmGfxTexture, SyncFile,
+            ShmGfxTexture, ShmMemory, SyncFile,
         },
         rect::{Rect, Region},
         theme::Color,
@@ -20,6 +19,7 @@ use {
     std::{
         any::Any,
         cell::{Cell, RefCell},
+        error::Error,
         ffi::CString,
         fmt::{Debug, Formatter},
         ops::Deref,
@@ -36,7 +36,7 @@ enum TestGfxError {
     #[error("Could not import dmabuf")]
     ImportDmaBuf(#[source] AllocatorError),
     #[error("Could not access the client memory")]
-    AccessFailed(#[source] ClientMemError),
+    AccessFailed(#[source] Box<dyn Error + Sync + Send>),
 }
 
 impl From<TestGfxError> for GfxError {
@@ -336,12 +336,15 @@ impl AsyncShmGfxTexture for TestGfxImage {
     fn async_upload(
         self: Rc<Self>,
         _callback: Rc<dyn AsyncShmGfxTextureCallback>,
-        mem: &Rc<ClientMemOffset>,
-        damage: Region,
+        mem: Rc<dyn ShmMemory>,
+        _damage: Region,
     ) -> Result<Option<PendingShmUpload>, GfxError> {
-        mem.access(|d| self.clone().sync_upload(d, damage))
-            .map_err(TestGfxError::AccessFailed)??;
-        Ok(None)
+        let mut res = Ok(());
+        mem.access(&mut |d| {
+            res = self.clone().sync_upload(d, Region::default());
+        })
+        .map_err(TestGfxError::AccessFailed)?;
+        res.map(|_| None)
     }
 
     fn sync_upload(self: Rc<Self>, mem: &[Cell<u8>], _damage: Region) -> Result<(), GfxError> {

src/it/test_ifs/test_jay_compositor.rs

@@ -54,6 +54,8 @@ impl TestJayCompositor {
         &self,
         include_cursor: bool,
     ) -> Result<(DmaBuf, Option<Rc<OwnedFd>>), TestError> {
+        self.tran.sync().await;
+        self.tran.run.state.idle().await;
         let js = Rc::new(TestJayScreenshot {
             id: self.tran.id(),
             state: self.tran.run.state.clone(),

src/portal.rs

@@ -2,6 +2,7 @@ mod ptl_display;
 mod ptl_remote_desktop;
 mod ptl_render_ctx;
 mod ptl_screencast;
+mod ptl_text;
 mod ptr_gui;
 
 use {

src/portal/ptl_text.rs

@@ -0,0 +1,101 @@
+use {
+    crate::{
+        format::ARGB8888,
+        gfx_api::{GfxContext, GfxTexture},
+        pango::{
+            consts::{CAIRO_FORMAT_ARGB32, CAIRO_OPERATOR_SOURCE},
+            CairoContext, CairoImageSurface, PangoCairoContext, PangoFontDescription, PangoLayout,
+        },
+        rect::Rect,
+        theme::Color,
+    },
+    std::{ops::Neg, rc::Rc, sync::Arc},
+};
+
+struct Data {
+    image: Rc<CairoImageSurface>,
+    cctx: Rc<CairoContext>,
+    _pctx: Rc<PangoCairoContext>,
+    _fd: PangoFontDescription,
+    layout: PangoLayout,
+}
+
+fn create_data(font: &str, width: i32, height: i32, scale: Option<f64>) -> Option<Data> {
+    let image = CairoImageSurface::new_image_surface(CAIRO_FORMAT_ARGB32, width, height).ok()?;
+    let cctx = image.create_context().ok()?;
+    let pctx = cctx.create_pango_context().ok()?;
+    let mut fd = PangoFontDescription::from_string(font);
+    if let Some(scale) = scale {
+        fd.set_size((fd.size() as f64 * scale).round() as _);
+    }
+    let layout = pctx.create_layout().ok()?;
+    layout.set_font_description(&fd);
+    Some(Data {
+        image,
+        cctx,
+        _pctx: pctx,
+        _fd: fd,
+        layout,
+    })
+}
+
+fn measure(font: &str, text: &str, scale: Option<f64>, full: bool) -> Option<TextMeasurement> {
+    let data = create_data(font, 1, 1, scale)?;
+    data.layout.set_text(text);
+    let mut res = TextMeasurement::default();
+    res.ink_rect = data.layout.inc_pixel_rect();
+    if full {
+        res.logical_rect = data.layout.logical_pixel_rect();
+        res.baseline = data.layout.pixel_baseline();
+    }
+    Some(res)
+}
+
+#[derive(Debug, Copy, Clone, Default)]
+pub struct TextMeasurement {
+    pub ink_rect: Rect,
+    pub logical_rect: Rect,
+    pub baseline: i32,
+}
+
+pub fn render(
+    ctx: &Rc<dyn GfxContext>,
+    height: Option<i32>,
+    font: &Arc<String>,
+    text: &str,
+    color: Color,
+    scale: Option<f64>,
+    include_measurements: bool,
+) -> Option<(Rc<dyn GfxTexture>, TextMeasurement)> {
+    let measurement = measure(font, text, scale, include_measurements)?;
+    let y = match height {
+        Some(_) => None,
+        _ => Some(measurement.ink_rect.y1().neg()),
+    };
+    let x = measurement.ink_rect.x1().neg();
+    let width = measurement.ink_rect.width();
+    let height = height.unwrap_or(measurement.ink_rect.height());
+    let data = create_data(font, width, height, scale)?;
+    data.layout.set_text(text);
+    let font_height = data.layout.pixel_size().1;
+    data.cctx.set_operator(CAIRO_OPERATOR_SOURCE);
+    data.cctx
+        .set_source_rgba(color.r as _, color.g as _, color.b as _, color.a as _);
+    let y = y.unwrap_or((height - font_height) / 2);
+    data.cctx.move_to(x as f64, y as f64);
+    data.layout.show_layout();
+    data.image.flush();
+    let bytes = data.image.data().ok()?;
+    ctx.clone()
+        .shmem_texture(
+            None,
+            bytes,
+            ARGB8888,
+            width,
+            height,
+            data.image.stride(),
+            None,
+        )
+        .ok()
+        .map(|t| (t.into_texture(), measurement))
+}

src/portal/ptr_gui.rs

@@ -5,12 +5,16 @@ use {
         cursor::KnownCursor,
         fixed::Fixed,
         format::ARGB8888,
-        gfx_api::{needs_render_usage, AcquireSync, GfxContext, GfxFramebuffer, ReleaseSync},
+        gfx_api::{
+            needs_render_usage, AcquireSync, GfxContext, GfxFramebuffer, GfxTexture, ReleaseSync,
+        },
         ifs::zwlr_layer_shell_v1::OVERLAY,
-        portal::ptl_display::{PortalDisplay, PortalOutput, PortalSeat},
+        portal::{
+            ptl_display::{PortalDisplay, PortalOutput, PortalSeat},
+            ptl_text::{self, TextMeasurement},
+        },
         renderer::renderer_base::RendererBase,
         scale::Scale,
-        text::{self, TextMeasurement, TextTexture},
         theme::Color,
         utils::{
             asyncevent::AsyncEvent, clonecell::CloneCell, copyhashmap::CopyHashMap,
@@ -31,10 +35,10 @@ use {
     },
     ahash::AHashSet,
     std::{
-        borrow::Cow,
         cell::{Cell, RefCell},
         ops::Deref,
         rc::Rc,
+        sync::Arc,
     },
 };
 
@@ -117,8 +121,8 @@ pub struct Button {
     pub bg_color: Cell<Color>,
     pub bg_hover_color: Cell<Color>,
     pub text: RefCell<String>,
-    pub font: RefCell<Cow<'static, str>>,
-    pub tex: CloneCell<Option<TextTexture>>,
+    pub font: Arc<String>,
+    pub tex: CloneCell<Option<Rc<dyn GfxTexture>>>,
     pub owner: CloneCell<Option<Rc<dyn ButtonOwner>>>,
 }
 
@@ -139,7 +143,7 @@ impl Default for Button {
             bg_color: Cell::new(Color::from_gray(255)),
             bg_hover_color: Cell::new(Color::from_gray(255)),
             text: Default::default(),
-            font: RefCell::new(DEFAULT_FONT.into()),
+            font: Arc::new(DEFAULT_FONT.to_string()),
             tex: Default::default(),
             owner: Default::default(),
         }
@@ -162,21 +166,16 @@ impl GuiElement for Button {
         _max_width: f32,
         _max_height: f32,
     ) -> (f32, f32) {
-        let old_tex = self.tex.take();
-        let font = self.font.borrow_mut();
         let text = self.text.borrow_mut();
-        let tex = text::render_fitting2(
+        let tex = ptl_text::render(
             ctx,
-            old_tex,
             None,
-            &font,
+            &self.font,
             &text,
             Color::from_gray(0),
-            false,
             Some(scale as _),
             true,
-        )
-        .ok();
+        );
         let (tex, msmt) = match tex {
             Some((a, b)) => (Some(a), Some(b)),
             _ => (None, None),
@@ -215,7 +214,7 @@ impl GuiElement for Button {
         if let Some(tex) = self.tex.get() {
             let (tx, ty) = r.scale_point_f(x1 + self.tex_off_x.get(), y1 + self.tex_off_y.get());
             r.render_texture(
-                &tex.texture,
+                &tex,
                 None,
                 tx.round() as _,
                 ty.round() as _,
@@ -262,16 +261,16 @@ const DEFAULT_FONT: &str = "sans-serif 16";
 
 pub struct Label {
     pub data: GuiElementData,
-    pub font: RefCell<Cow<'static, str>>,
+    pub font: Arc<String>,
     pub text: RefCell<String>,
-    pub tex: CloneCell<Option<TextTexture>>,
+    pub tex: CloneCell<Option<Rc<dyn GfxTexture>>>,
 }
 
 impl Default for Label {
     fn default() -> Self {
         Self {
             data: Default::default(),
-            font: RefCell::new(DEFAULT_FONT.into()),
+            font: Arc::new(DEFAULT_FONT.into()),
             text: RefCell::new("".to_string()),
             tex: Default::default(),
         }
@@ -290,24 +289,19 @@ impl GuiElement for Label {
         _max_width: f32,
         _max_height: f32,
     ) -> (f32, f32) {
-        let old_tex = self.tex.take();
         let text = self.text.borrow_mut();
-        let font = self.font.borrow_mut();
-        let tex = text::render_fitting2(
+        let tex = ptl_text::render(
             ctx,
-            old_tex,
             None,
-            &font,
+            &self.font,
             &text,
             Color::from_gray(255),
-            false,
             Some(scale as _),
             false,
-        )
-        .ok();
+        );
         let (tex, width, height) = match tex {
             Some((t, _)) => {
-                let (width, height) = t.texture.size();
+                let (width, height) = t.size();
                 (Some(t.clone()), width, height)
             }
             _ => (None, 0, 0),
@@ -320,7 +314,7 @@ impl GuiElement for Label {
         if let Some(tex) = self.tex.get() {
             let (tx, ty) = r.scale_point_f(x, y);
             r.render_texture(
-                &tex.texture,
+                &tex,
                 None,
                 tx.round() as _,
                 ty.round() as _,

src/renderer.rs

@@ -131,20 +131,22 @@ impl Renderer<'_> {
                     );
                 }
                 if let Some(status) = &rd.status {
-                    let (x, y) = self.base.scale_point(x + status.tex_x, y + status.tex_y);
-                    self.base.render_texture(
-                        &status.tex.texture,
-                        None,
-                        x,
-                        y,
-                        None,
-                        None,
-                        scale,
-                        None,
-                        None,
-                        AcquireSync::None,
-                        ReleaseSync::None,
-                    );
+                    if let Some(texture) = status.tex.texture() {
+                        let (x, y) = self.base.scale_point(x + status.tex_x, y);
+                        self.base.render_texture(
+                            &texture,
+                            None,
+                            x,
+                            y,
+                            None,
+                            None,
+                            scale,
+                            None,
+                            None,
+                            AcquireSync::None,
+                            ReleaseSync::None,
+                        );
+                    }
                 }
             }
             if let Some(ws) = output.workspace.get() {
@@ -196,23 +198,25 @@ impl Renderer<'_> {
             std::slice::from_ref(&pos.at_point(x, y)),
             &Color::from_rgba_straight(20, 20, 20, 255),
         );
-        if let Some(tex) = placeholder.textures.get(&self.base.scale) {
-            let (tex_width, tex_height) = tex.texture.size();
-            let x = x + (pos.width() - tex_width) / 2;
-            let y = y + (pos.height() - tex_height) / 2;
-            self.base.render_texture(
-                &tex.texture,
-                None,
-                x,
-                y,
-                None,
-                None,
-                self.base.scale,
-                None,
-                None,
-                AcquireSync::None,
-                ReleaseSync::None,
-            );
+        if let Some(tex) = placeholder.textures.borrow().get(&self.base.scale) {
+            if let Some(texture) = tex.texture() {
+                let (tex_width, tex_height) = texture.size();
+                let x = x + (pos.width() - tex_width) / 2;
+                let y = y + (pos.height() - tex_height) / 2;
+                self.base.render_texture(
+                    &texture,
+                    None,
+                    x,
+                    y,
+                    None,
+                    None,
+                    self.base.scale,
+                    None,
+                    None,
+                    AcquireSync::None,
+                    ReleaseSync::None,
+                );
+            }
         }
         self.render_tl_aux(placeholder.tl_data(), bounds, true);
     }
@@ -243,7 +247,7 @@ impl Renderer<'_> {
                 for title in titles {
                     let (x, y) = self.base.scale_point(x + title.x, y + title.y);
                     self.base.render_texture(
-                        &title.tex.texture,
+                        &title.tex,
                         None,
                         x,
                         y,
@@ -466,21 +470,23 @@ impl Renderer<'_> {
         let title_underline =
             [Rect::new_sized(x + bw, y + bw + th, pos.width() - 2 * bw, 1).unwrap()];
         self.base.fill_boxes(&title_underline, &uc);
-        if let Some(title) = floating.title_textures.get(&self.base.scale) {
-            let (x, y) = self.base.scale_point(x + bw, y + bw);
-            self.base.render_texture(
-                &title.texture,
-                None,
-                x,
-                y,
-                None,
-                None,
-                self.base.scale,
-                None,
-                None,
-                AcquireSync::None,
-                ReleaseSync::None,
-            );
+        if let Some(title) = floating.title_textures.borrow().get(&self.base.scale) {
+            if let Some(texture) = title.texture() {
+                let (x, y) = self.base.scale_point(x + bw, y + bw);
+                self.base.render_texture(
+                    &texture,
+                    None,
+                    x,
+                    y,
+                    None,
+                    None,
+                    self.base.scale,
+                    None,
+                    None,
+                    AcquireSync::None,
+                    ReleaseSync::None,
+                );
+            }
         }
         let body = Rect::new_sized(
             x + bw,

src/state.rs

@@ -148,13 +148,15 @@ pub struct State {
     pub config: CloneCell<Option<Rc<ConfigProxy>>>,
     pub theme: Theme,
     pub pending_container_layout: AsyncQueue<Rc<ContainerNode>>,
-    pub pending_container_render_data: AsyncQueue<Rc<ContainerNode>>,
+    pub pending_container_render_positions: AsyncQueue<Rc<ContainerNode>>,
+    pub pending_container_render_title: AsyncQueue<Rc<ContainerNode>>,
     pub pending_output_render_data: AsyncQueue<Rc<OutputNode>>,
     pub pending_float_layout: AsyncQueue<Rc<FloatNode>>,
     pub pending_float_titles: AsyncQueue<Rc<FloatNode>>,
     pub pending_input_popup_positioning: AsyncQueue<Rc<ZwpInputPopupSurfaceV2>>,
     pub pending_toplevel_screencasts: AsyncQueue<Rc<JayScreencast>>,
     pub pending_screencast_reallocs_or_reconfigures: AsyncQueue<Rc<JayScreencast>>,
+    pub pending_placeholder_render_textures: AsyncQueue<Rc<PlaceholderNode>>,
     pub dbus: Dbus,
     pub fdcloser: Arc<FdCloser>,
     pub logger: Option<Arc<Logger>>,
@@ -343,8 +345,10 @@ impl DrmDevData {
 struct UpdateTextTexturesVisitor;
 impl NodeVisitorBase for UpdateTextTexturesVisitor {
     fn visit_container(&mut self, node: &Rc<ContainerNode>) {
-        node.children.iter().for_each(|c| c.title_tex.clear());
-        node.schedule_compute_render_data();
+        node.children
+            .iter()
+            .for_each(|c| c.title_tex.borrow_mut().clear());
+        node.schedule_render_titles();
         node.node_visit_children(self);
     }
     fn visit_output(&mut self, node: &Rc<OutputNode>) {
@@ -352,13 +356,17 @@ impl NodeVisitorBase for UpdateTextTexturesVisitor {
         node.node_visit_children(self);
     }
     fn visit_float(&mut self, node: &Rc<FloatNode>) {
-        node.title_textures.clear();
+        node.title_textures.borrow_mut().clear();
         node.schedule_render_titles();
         node.node_visit_children(self);
     }
+    fn visit_workspace(&mut self, node: &Rc<WorkspaceNode>) {
+        node.title_texture.take();
+        node.node_visit_children(self);
+    }
     fn visit_placeholder(&mut self, node: &Rc<PlaceholderNode>) {
-        node.textures.clear();
-        node.update_texture();
+        node.textures.borrow_mut().clear();
+        node.schedule_update_texture();
         node.node_visit_children(self);
     }
 }
@@ -463,11 +471,13 @@ impl State {
             impl NodeVisitorBase for Walker {
                 fn visit_container(&mut self, node: &Rc<ContainerNode>) {
                     node.render_data.borrow_mut().titles.clear();
-                    node.children.iter().for_each(|c| c.title_tex.clear());
+                    node.children
+                        .iter()
+                        .for_each(|c| c.title_tex.borrow_mut().clear());
                     node.node_visit_children(self);
                 }
                 fn visit_workspace(&mut self, node: &Rc<WorkspaceNode>) {
-                    node.title_texture.set(None);
+                    node.title_texture.take();
                     node.node_visit_children(self);
                 }
                 fn visit_output(&mut self, node: &Rc<OutputNode>) {
@@ -477,11 +487,11 @@ impl State {
                     node.node_visit_children(self);
                 }
                 fn visit_float(&mut self, node: &Rc<FloatNode>) {
-                    node.title_textures.clear();
+                    node.title_textures.borrow_mut().clear();
                     node.node_visit_children(self);
                 }
                 fn visit_placeholder(&mut self, node: &Rc<PlaceholderNode>) {
-                    node.textures.clear();
+                    node.textures.borrow_mut().clear();
                     node.node_visit_children(self);
                 }
             }
@@ -819,13 +829,15 @@ impl State {
         }
         self.dbus.clear();
         self.pending_container_layout.clear();
-        self.pending_container_render_data.clear();
+        self.pending_container_render_positions.clear();
+        self.pending_container_render_title.clear();
         self.pending_output_render_data.clear();
         self.pending_float_layout.clear();
         self.pending_float_titles.clear();
         self.pending_input_popup_positioning.clear();
         self.pending_toplevel_screencasts.clear();
         self.pending_screencast_reallocs_or_reconfigures.clear();
+        self.pending_placeholder_render_textures.clear();
         self.render_ctx_watchers.clear();
         self.workspace_watchers.clear();
         self.toplevel_lists.clear();
@@ -1218,6 +1230,16 @@ impl State {
             output.vblank();
         }
     }
+
+    #[cfg(feature = "it")]
+    pub async fn idle(&self) {
+        loop {
+            self.eng.idle().await;
+            if self.cpu_worker.wait_idle() {
+                break;
+            }
+        }
+    }
 }
 
 #[derive(Debug, Error)]

src/text.rs

@@ -1,7 +1,11 @@
 use {
     crate::{
+        cpu_worker::{AsyncCpuWork, CpuJob, CpuWork, CpuWorker, PendingJob},
         format::ARGB8888,
-        gfx_api::{GfxContext, GfxError, GfxTexture, ShmGfxTexture},
+        gfx_api::{
+            AsyncShmGfxTexture, AsyncShmGfxTextureCallback, GfxContext, GfxError, GfxTexture,
+            PendingShmUpload,
+        },
         pango::{
             consts::{
                 CAIRO_FORMAT_ARGB32, CAIRO_OPERATOR_SOURCE, PANGO_ELLIPSIZE_END, PANGO_SCALE,
@@ -9,14 +13,19 @@ use {
             CairoContext, CairoImageSurface, PangoCairoContext, PangoError, PangoFontDescription,
             PangoLayout,
         },
-        rect::Rect,
+        rect::{Rect, Region},
         theme::Color,
-        utils::clonecell::UnsafeCellCloneSafe,
+        utils::{
+            clonecell::CloneCell, double_buffered::DoubleBuffered, on_drop_event::OnDropEvent,
+        },
     },
     std::{
         borrow::Cow,
-        ops::{Deref, Neg},
-        rc::Rc,
+        cell::{Cell, RefCell},
+        mem,
+        ops::Neg,
+        rc::{Rc, Weak},
+        sync::Arc,
     },
     thiserror::Error,
 };
@@ -31,54 +40,64 @@ pub enum TextError {
     PangoContext(#[source] PangoError),
     #[error("Could not create a pango layout")]
     CreateLayout(#[source] PangoError),
-    #[error("Could not import the rendered text")]
-    RenderError(#[source] GfxError),
     #[error("Could not access the cairo image data")]
     ImageData(#[source] PangoError),
-}
-
-#[derive(PartialEq)]
-struct Config<'a> {
-    x: i32,
-    y: Option<i32>,
-    width: i32,
-    height: i32,
-    padding: i32,
-    font: Cow<'a, str>,
-    text: Cow<'a, str>,
-    color: Color,
-    ellipsize: bool,
-    markup: bool,
-    scale: Option<f64>,
+    #[error("Texture upload failed")]
+    Upload(#[source] GfxError),
+    #[error("Could not create a texture")]
+    CreateTexture(#[source] GfxError),
+    #[error("Rendering is not scheduled or not yet completed")]
+    NotScheduled,
 }
 
 impl<'a> Config<'a> {
     fn to_static(self) -> Config<'static> {
-        Config {
-            x: self.x,
-            y: self.y,
-            width: self.width,
-            height: self.height,
-            padding: self.padding,
-            font: Cow::Owned(self.font.into_owned()),
-            text: Cow::Owned(self.text.into_owned()),
-            color: self.color,
-            ellipsize: self.ellipsize,
-            markup: self.markup,
-            scale: self.scale,
+        match self {
+            Config::None => Config::None,
+            Config::RenderFitting {
+                height,
+                font,
+                text,
+                color,
+                markup,
+                scale,
+            } => Config::RenderFitting {
+                height,
+                font,
+                text: text.into_owned().into(),
+                color,
+                markup,
+                scale,
+            },
+            Config::Render {
+                x,
+                y,
+                width,
+                height,
+                padding,
+                font,
+                text,
+                color,
+                ellipsize,
+                markup,
+                scale,
+            } => Config::Render {
+                x,
+                y,
+                width,
+                height,
+                padding,
+                font,
+                text: text.into_owned().into(),
+                color,
+                ellipsize,
+                markup,
+                scale,
+            },
         }
     }
 }
 
-#[derive(Clone)]
-pub struct TextTexture {
-    config: Rc<Config<'static>>,
-    shm_texture: Rc<dyn ShmGfxTexture>,
-    pub texture: Rc<dyn GfxTexture>,
-}
-
-unsafe impl UnsafeCellCloneSafe for TextTexture {}
-
 struct Data {
     image: Rc<CairoImageSurface>,
     cctx: Rc<CairoContext>,
@@ -118,12 +137,11 @@ fn create_data(font: &str, width: i32, height: i32, scale: Option<f64>) -> Resul
     })
 }
 
-pub fn measure(
+fn measure(
     font: &str,
     text: &str,
     markup: bool,
     scale: Option<f64>,
-    full: bool,
 ) -> Result<TextMeasurement, TextError> {
     let data = create_data(font, 1, 1, scale)?;
     if markup {
@@ -133,31 +151,10 @@ pub fn measure(
     }
     let mut res = TextMeasurement::default();
     res.ink_rect = data.layout.inc_pixel_rect();
-    if full {
-        res.logical_rect = data.layout.logical_pixel_rect();
-        res.baseline = data.layout.pixel_baseline();
-    }
     Ok(res)
 }
 
-pub fn render(
-    ctx: &Rc<dyn GfxContext>,
-    old: Option<TextTexture>,
-    width: i32,
-    height: i32,
-    font: &str,
-    text: &str,
-    color: Color,
-    scale: Option<f64>,
-) -> Result<TextTexture, TextError> {
-    render2(
-        ctx, old, 1, None, width, height, 1, font, text, color, true, false, scale,
-    )
-}
-
-fn render2(
-    ctx: &Rc<dyn GfxContext>,
-    old: Option<TextTexture>,
+fn render(
     x: i32,
     y: Option<i32>,
     width: i32,
@@ -169,25 +166,14 @@ fn render2(
     ellipsize: bool,
     markup: bool,
     scale: Option<f64>,
-) -> Result<TextTexture, TextError> {
-    let width = width.min(3840);
-    let config = Config {
-        x,
-        y,
-        width,
-        height,
-        padding,
-        font: Cow::Borrowed(font),
-        text: Cow::Borrowed(text),
-        color,
-        ellipsize,
-        markup,
-        scale,
-    };
-    if let Some(old2) = &old {
-        if old2.config.deref() == &config {
-            return Ok(old.unwrap());
-        }
+) -> Result<RenderedText, TextError> {
+    if width == 0 || height == 0 {
+        return Ok(RenderedText {
+            width,
+            height,
+            stride: width * 4,
+            data: vec![],
+        });
     }
     let data = create_data(font, width, height, scale)?;
     if ellipsize {
@@ -208,79 +194,368 @@ fn render2(
     data.cctx.move_to(x as f64, y as f64);
     data.layout.show_layout();
     data.image.flush();
-    let bytes = match data.image.data() {
-        Ok(d) => d,
-        Err(e) => return Err(TextError::ImageData(e)),
-    };
-    let old = old.map(|o| o.shm_texture);
-    match ctx.clone().shmem_texture(
-        old,
-        bytes,
-        ARGB8888,
+    Ok(RenderedText {
         width,
         height,
-        data.image.stride(),
-        None,
-    ) {
-        Ok(t) => Ok(TextTexture {
-            config: Rc::new(config.to_static()),
-            texture: t.clone().into_texture(),
-            shm_texture: t,
-        }),
-        Err(e) => Err(TextError::RenderError(e)),
-    }
+        stride: data.image.stride(),
+        data: data.image.data().map_err(TextError::ImageData)?.to_vec(),
+    })
 }
 
-pub fn render_fitting(
-    ctx: &Rc<dyn GfxContext>,
-    old: Option<TextTexture>,
+fn render_fitting(
     height: Option<i32>,
     font: &str,
     text: &str,
     color: Color,
     markup: bool,
     scale: Option<f64>,
-) -> Result<TextTexture, TextError> {
-    render_fitting2(ctx, old, height, font, text, color, markup, scale, false).map(|(a, _)| a)
+) -> Result<RenderedText, TextError> {
+    let measurement = measure(font, text, markup, scale)?;
+    let x = measurement.ink_rect.x1().neg();
+    let y = match height {
+        Some(_) => None,
+        _ => Some(measurement.ink_rect.y1().neg()),
+    };
+    let width = measurement.ink_rect.width();
+    let height = height.unwrap_or(measurement.ink_rect.height());
+    render(
+        x, y, width, height, 0, font, text, color, false, markup, scale,
+    )
 }
 
 #[derive(Debug, Copy, Clone, Default)]
 pub struct TextMeasurement {
     pub ink_rect: Rect,
-    pub logical_rect: Rect,
-    pub baseline: i32,
 }
 
-pub fn render_fitting2(
-    ctx: &Rc<dyn GfxContext>,
-    old: Option<TextTexture>,
-    height: Option<i32>,
-    font: &str,
-    text: &str,
-    color: Color,
-    markup: bool,
-    scale: Option<f64>,
-    include_measurements: bool,
-) -> Result<(TextTexture, TextMeasurement), TextError> {
-    let measurement = measure(font, text, markup, scale, include_measurements)?;
-    let y = match height {
-        Some(_) => None,
-        _ => Some(measurement.ink_rect.y1().neg()),
-    };
-    let res = render2(
-        ctx,
-        old,
-        measurement.ink_rect.x1().neg(),
-        y,
-        measurement.ink_rect.width(),
-        height.unwrap_or(measurement.ink_rect.height()),
-        0,
-        font,
-        text,
-        color,
-        false,
-        markup,
-        scale,
-    );
-    res.map(|r| (r, measurement))
+struct RenderedText {
+    width: i32,
+    height: i32,
+    stride: i32,
+    data: Vec<Cell<u8>>,
+}
+
+#[derive(Default)]
+struct RenderWork {
+    config: Config<'static>,
+    result: Option<Result<RenderedText, TextError>>,
+}
+
+struct RenderJob {
+    work: RenderWork,
+    data: Weak<Shared>,
+}
+
+impl CpuWork for RenderWork {
+    fn run(&mut self) -> Option<Box<dyn AsyncCpuWork>> {
+        self.result = Some(self.render());
+        None
+    }
+}
+
+impl RenderWork {
+    fn render(&mut self) -> Result<RenderedText, TextError> {
+        match self.config {
+            Config::None => unreachable!(),
+            Config::RenderFitting {
+                height,
+                ref font,
+                ref text,
+                color,
+                markup,
+                scale,
+            } => render_fitting(height, font, text, color, markup, scale),
+            Config::Render {
+                x,
+                y,
+                width,
+                height,
+                padding,
+                ref font,
+                ref text,
+                color,
+                ellipsize,
+                markup,
+                scale,
+            } => render(
+                x, y, width, height, padding, font, text, color, ellipsize, markup, scale,
+            ),
+        }
+    }
+}
+
+pub struct TextTexture {
+    data: Rc<Shared>,
+}
+
+impl Drop for TextTexture {
+    fn drop(&mut self) {
+        if let Some(pending) = self.data.pending_render.take() {
+            pending.detach();
+        }
+        self.data.pending_upload.take();
+        self.data.render_job.take();
+        self.data.waiter.take();
+    }
+}
+
+struct Shared {
+    cpu_worker: Rc<CpuWorker>,
+    ctx: Rc<dyn GfxContext>,
+    textures: DoubleBuffered<TextBuffer>,
+    pending_render: Cell<Option<PendingJob>>,
+    pending_upload: Cell<Option<PendingShmUpload>>,
+    render_job: Cell<Option<Box<RenderJob>>>,
+    result: Cell<Option<Result<(), TextError>>>,
+    waiter: Cell<Option<Rc<dyn OnCompleted>>>,
+    busy: Cell<bool>,
+    flip_is_noop: Cell<bool>,
+}
+
+impl Shared {
+    fn complete(&self, res: Result<(), TextError>) {
+        if res.is_err() {
+            self.textures.back().config.take();
+        }
+        self.busy.set(false);
+        self.result.set(Some(res));
+        if let Some(waiter) = self.waiter.take() {
+            waiter.completed();
+        }
+    }
+}
+
+#[derive(PartialEq, Default)]
+enum Config<'a> {
+    #[default]
+    None,
+    RenderFitting {
+        height: Option<i32>,
+        font: Arc<String>,
+        text: Cow<'a, str>,
+        color: Color,
+        markup: bool,
+        scale: Option<f64>,
+    },
+    Render {
+        x: i32,
+        y: Option<i32>,
+        width: i32,
+        height: i32,
+        padding: i32,
+        font: Arc<String>,
+        text: Cow<'a, str>,
+        color: Color,
+        ellipsize: bool,
+        markup: bool,
+        scale: Option<f64>,
+    },
+}
+
+#[derive(Default)]
+struct TextBuffer {
+    config: RefCell<Config<'static>>,
+    tex: CloneCell<Option<Rc<dyn AsyncShmGfxTexture>>>,
+}
+
+pub trait OnCompleted {
+    fn completed(self: Rc<Self>);
+}
+
+impl TextTexture {
+    pub fn new(cpu_worker: &Rc<CpuWorker>, ctx: &Rc<dyn GfxContext>) -> Self {
+        let data = Rc::new(Shared {
+            cpu_worker: cpu_worker.clone(),
+            ctx: ctx.clone(),
+            textures: Default::default(),
+            pending_render: Default::default(),
+            pending_upload: Default::default(),
+            render_job: Default::default(),
+            result: Default::default(),
+            waiter: Default::default(),
+            busy: Default::default(),
+            flip_is_noop: Default::default(),
+        });
+        Self { data }
+    }
+
+    pub fn texture(&self) -> Option<Rc<dyn GfxTexture>> {
+        self.data
+            .textures
+            .front()
+            .tex
+            .get()
+            .map(|t| t.into_texture())
+    }
+
+    fn apply_config(&self, on_completed: Rc<dyn OnCompleted>, config: Config<'_>) {
+        if self.data.busy.replace(true) {
+            unreachable!();
+        }
+        self.data.waiter.set(Some(on_completed));
+        self.data.flip_is_noop.set(false);
+        if *self.data.textures.front().config.borrow() == config {
+            self.data.flip_is_noop.set(true);
+            self.data.complete(Ok(()));
+            return;
+        }
+        if *self.data.textures.back().config.borrow() == config {
+            self.data.complete(Ok(()));
+            return;
+        }
+        let mut job = self.data.render_job.take().unwrap_or_else(|| {
+            Box::new(RenderJob {
+                work: Default::default(),
+                data: Rc::downgrade(&self.data),
+            })
+        });
+        job.work = RenderWork {
+            config: config.to_static(),
+            result: None,
+        };
+        let pending = self.data.cpu_worker.submit(job);
+        self.data.pending_render.set(Some(pending));
+    }
+
+    pub fn schedule_render(
+        &self,
+        on_completed: Rc<dyn OnCompleted>,
+        x: i32,
+        y: Option<i32>,
+        width: i32,
+        height: i32,
+        padding: i32,
+        font: &Arc<String>,
+        text: &str,
+        color: Color,
+        ellipsize: bool,
+        markup: bool,
+        scale: Option<f64>,
+    ) {
+        let config = Config::Render {
+            x,
+            y,
+            width,
+            height,
+            padding,
+            font: font.clone(),
+            text: Cow::Borrowed(text),
+            color,
+            ellipsize,
+            markup,
+            scale,
+        };
+        self.apply_config(on_completed, config)
+    }
+
+    pub fn schedule_render_fitting(
+        &self,
+        on_completed: Rc<dyn OnCompleted>,
+        height: Option<i32>,
+        font: &Arc<String>,
+        text: &str,
+        color: Color,
+        markup: bool,
+        scale: Option<f64>,
+    ) {
+        let config = Config::RenderFitting {
+            height,
+            font: font.clone(),
+            text: text.into(),
+            color,
+            markup,
+            scale,
+        };
+        self.apply_config(on_completed, config)
+    }
+
+    pub fn flip(&self) -> Result<(), TextError> {
+        let res = self
+            .data
+            .result
+            .take()
+            .unwrap_or(Err(TextError::NotScheduled));
+        if res.is_ok() && !self.data.flip_is_noop.get() {
+            self.data.textures.flip();
+        }
+        res
+    }
+}
+
+impl CpuJob for RenderJob {
+    fn work(&mut self) -> &mut dyn CpuWork {
+        &mut self.work
+    }
+
+    fn completed(mut self: Box<Self>) {
+        let Some(data) = self.data.upgrade() else {
+            return;
+        };
+        let result = self.work.result.take().unwrap();
+        *data.textures.back().config.borrow_mut() = mem::take(&mut self.work.config);
+        data.render_job.set(Some(self));
+        let rt = match result {
+            Ok(d) => d,
+            Err(e) => {
+                data.complete(Err(e));
+                return;
+            }
+        };
+        let mut tex = data.textures.back().tex.take();
+        if rt.width == 0 || rt.height == 0 {
+            data.complete(Ok(()));
+            return;
+        }
+        if let Some(t) = &tex {
+            if !t.compatible_with(ARGB8888, rt.width, rt.height, rt.stride) {
+                tex = None;
+            }
+        }
+        let tex = match tex {
+            Some(t) => t,
+            _ => {
+                let tex = data
+                    .ctx
+                    .clone()
+                    .async_shmem_texture(ARGB8888, rt.width, rt.height, rt.stride, &data.cpu_worker)
+                    .map_err(TextError::CreateTexture);
+                match tex {
+                    Ok(t) => t,
+                    Err(e) => {
+                        data.complete(Err(e));
+                        return;
+                    }
+                }
+            }
+        };
+        let pending = tex
+            .clone()
+            .async_upload(
+                data.clone(),
+                Rc::new(rt.data),
+                Region::new2(Rect::new_sized_unchecked(0, 0, rt.width, rt.height)),
+            )
+            .map_err(TextError::Upload);
+        if pending.is_ok() {
+            data.textures.back().tex.set(Some(tex));
+        }
+        match pending {
+            Ok(Some(p)) => data.pending_upload.set(Some(p)),
+            Ok(None) => data.complete(Ok(())),
+            Err(e) => data.complete(Err(e)),
+        }
+    }
+}
+
+impl AsyncShmGfxTextureCallback for Shared {
+    fn completed(self: Rc<Self>, res: Result<(), GfxError>) {
+        self.pending_upload.take();
+        self.complete(res.map_err(TextError::Upload));
+    }
+}
+
+impl OnCompleted for OnDropEvent {
+    fn completed(self: Rc<Self>) {
+        // nothing
+    }
 }

src/theme.rs

@@ -1,7 +1,6 @@
-use std::{
-    cell::{Cell, RefCell},
-    cmp::Ordering,
-    ops::Mul,
+use {
+    crate::utils::clonecell::CloneCell,
+    std::{cell::Cell, cmp::Ordering, ops::Mul, sync::Arc},
 };
 
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -290,15 +289,18 @@ pub const DEFAULT_FONT: &str = "monospace 8";
 pub struct Theme {
     pub colors: ThemeColors,
     pub sizes: ThemeSizes,
-    pub font: RefCell<String>,
+    pub font: CloneCell<Arc<String>>,
+    pub default_font: Arc<String>,
 }
 
 impl Default for Theme {
     fn default() -> Self {
+        let default_font = Arc::new(DEFAULT_FONT.to_string());
         Self {
             colors: Default::default(),
             sizes: Default::default(),
-            font: RefCell::new(DEFAULT_FONT.to_string()),
+            font: CloneCell::new(default_font.clone()),
+            default_font,
         }
     }
 }

src/tree/container.rs

@@ -4,6 +4,7 @@ use {
         cursor::KnownCursor,
         cursor_user::CursorUser,
         fixed::Fixed,
+        gfx_api::GfxTexture,
         ifs::wl_seat::{
             collect_kb_foci, collect_kb_foci2,
             tablet::{TabletTool, TabletToolChanges, TabletToolId},
@@ -14,21 +15,23 @@ use {
         renderer::Renderer,
         scale::Scale,
         state::State,
-        text::{self, TextTexture},
+        text::TextTexture,
         tree::{
             walker::NodeVisitor, ContainingNode, Direction, FindTreeResult, FindTreeUsecase,
             FoundNode, Node, NodeId, ToplevelData, ToplevelNode, ToplevelNodeBase, WorkspaceNode,
         },
         utils::{
+            asyncevent::AsyncEvent,
             clonecell::CloneCell,
             double_click_state::DoubleClickState,
             errorfmt::ErrorFmt,
             hash_map_ext::HashMapExt,
             linkedlist::{LinkedList, LinkedNode, NodeRef},
             numcell::NumCell,
+            on_drop_event::OnDropEvent,
             rc_eq::rc_eq,
             scroller::Scroller,
-            smallmap::{SmallMap, SmallMapMut},
+            smallmap::SmallMapMut,
             threshold_counter::ThresholdCounter,
         },
     },
@@ -81,7 +84,7 @@ tree_id!(ContainerNodeId);
 pub struct ContainerTitle {
     pub x: i32,
     pub y: i32,
-    pub tex: TextTexture,
+    pub tex: Rc<dyn GfxTexture>,
 }
 
 #[derive(Default)]
@@ -109,7 +112,8 @@ pub struct ContainerNode {
     pub content_height: Cell<i32>,
     pub sum_factors: Cell<f64>,
     layout_scheduled: Cell<bool>,
-    compute_render_data_scheduled: Cell<bool>,
+    compute_render_positions_scheduled: Cell<bool>,
+    render_titles_scheduled: Cell<bool>,
     num_children: NumCell<usize>,
     pub children: LinkedList<ContainerChild>,
     focus_history: LinkedList<NodeRef<ContainerChild>>,
@@ -134,7 +138,7 @@ pub struct ContainerChild {
     pub active: Cell<bool>,
     pub attention_requested: Cell<bool>,
     title: RefCell<String>,
-    pub title_tex: SmallMap<Scale, TextTexture, 2>,
+    pub title_tex: RefCell<SmallMapMut<Scale, TextTexture, 2>>,
     pub title_rect: Cell<Rect>,
     focus_history: Cell<Option<LinkedNode<NodeRef<ContainerChild>>>>,
 
@@ -213,7 +217,8 @@ impl ContainerNode {
             content_height: Cell::new(0),
             sum_factors: Cell::new(1.0),
             layout_scheduled: Cell::new(false),
-            compute_render_data_scheduled: Cell::new(false),
+            compute_render_positions_scheduled: Cell::new(false),
+            render_titles_scheduled: Cell::new(false),
             num_children: NumCell::new(1),
             children,
             focus_history: Default::default(),
@@ -351,7 +356,8 @@ impl ContainerNode {
 
     pub fn on_colors_changed(self: &Rc<Self>) {
         // log::info!("on_colors_changed");
-        self.schedule_compute_render_data();
+        self.schedule_render_titles();
+        self.schedule_compute_render_positions();
     }
 
     fn damage(&self) {
@@ -387,7 +393,8 @@ impl ContainerNode {
         }
         self.state.tree_changed();
         // log::info!("perform_layout");
-        self.schedule_compute_render_data();
+        self.schedule_render_titles();
+        self.schedule_compute_render_positions();
     }
 
     fn perform_mono_layout(self: &Rc<Self>, child: &ContainerChild) {
@@ -660,23 +667,115 @@ impl ContainerNode {
         self.tl_title_changed();
     }
 
-    pub fn schedule_compute_render_data(self: &Rc<Self>) {
-        if !self.compute_render_data_scheduled.replace(true) {
-            self.state.pending_container_render_data.push(self.clone());
+    pub fn schedule_render_titles(self: &Rc<Self>) {
+        if !self.render_titles_scheduled.replace(true) {
+            self.state.pending_container_render_title.push(self.clone());
         }
     }
 
-    fn compute_render_data(&self) {
-        self.compute_render_data_scheduled.set(false);
+    fn render_titles(&self) -> Rc<AsyncEvent> {
+        let on_completed = Rc::new(OnDropEvent::default());
+        let Some(ctx) = self.state.render_ctx.get() else {
+            return on_completed.event();
+        };
+        let theme = &self.state.theme;
+        let th = theme.sizes.title_height.get();
+        let font = theme.font.get();
+        let last_active = self.focus_history.last().map(|v| v.node.node_id());
+        let have_active = self.children.iter().any(|c| c.active.get());
+        let scales = self.state.scales.lock();
+        for child in self.children.iter() {
+            let rect = child.title_rect.get();
+            let color = if child.active.get() {
+                theme.colors.focused_title_text.get()
+            } else if child.attention_requested.get() {
+                theme.colors.unfocused_title_text.get()
+            } else if !have_active && last_active == Some(child.node.node_id()) {
+                theme.colors.focused_inactive_title_text.get()
+            } else {
+                theme.colors.unfocused_title_text.get()
+            };
+            let title = child.title.borrow_mut();
+            let tt = &mut *child.title_tex.borrow_mut();
+            for (scale, _) in scales.iter() {
+                let tex = tt
+                    .get_or_insert_with(*scale, || TextTexture::new(&self.state.cpu_worker, &ctx));
+                let mut th = th;
+                let mut scalef = None;
+                let mut width = rect.width();
+                if *scale != 1 {
+                    let scale = scale.to_f64();
+                    th = (th as f64 * scale).round() as _;
+                    width = (width as f64 * scale).round() as _;
+                    scalef = Some(scale);
+                }
+                tex.schedule_render(
+                    on_completed.clone(),
+                    1,
+                    None,
+                    width,
+                    th,
+                    1,
+                    &font,
+                    title.deref(),
+                    color,
+                    true,
+                    false,
+                    scalef,
+                );
+            }
+        }
+        on_completed.event()
+    }
+
+    fn compute_title_data(&self) {
+        let rd = &mut *self.render_data.borrow_mut();
+        for (_, v) in rd.titles.iter_mut() {
+            v.clear();
+        }
+        let abs_x = self.abs_x1.get();
+        let abs_y = self.abs_y1.get();
+        for child in self.children.iter() {
+            let rect = child.title_rect.get();
+            if self.toplevel_data.visible.get() {
+                self.state.damage(rect.move_(abs_x, abs_y));
+            }
+            let title = child.title.borrow_mut();
+            let tt = &*child.title_tex.borrow();
+            for (scale, tex) in tt {
+                if let Err(e) = tex.flip() {
+                    log::error!("Could not render title {}: {}", title, ErrorFmt(e));
+                }
+                if let Some(tex) = tex.texture() {
+                    let titles = rd.titles.get_or_default_mut(*scale);
+                    titles.push(ContainerTitle {
+                        x: rect.x1(),
+                        y: rect.y1(),
+                        tex,
+                    })
+                }
+            }
+        }
+        rd.titles.remove_if(|_, v| v.is_empty());
+    }
+
+    fn schedule_compute_render_positions(self: &Rc<Self>) {
+        if !self.compute_render_positions_scheduled.replace(true) {
+            self.state
+                .pending_container_render_positions
+                .push(self.clone());
+        }
+    }
+
+    fn compute_render_positions(&self) {
+        self.compute_render_positions_scheduled.set(false);
         let mut rd = self.render_data.borrow_mut();
         let rd = rd.deref_mut();
         let theme = &self.state.theme;
         let th = theme.sizes.title_height.get();
         let bw = theme.sizes.border_width.get();
-        let font = theme.font.borrow_mut();
         let cwidth = self.width.get();
         let cheight = self.height.get();
-        let ctx = self.state.render_ctx.get();
         for (_, v) in rd.titles.iter_mut() {
             v.clear();
         }
@@ -690,7 +789,6 @@ impl ContainerNode {
         let mono = self.mono_child.is_some();
         let split = self.split.get();
         let have_active = self.children.iter().any(|c| c.active.get());
-        let scales = self.state.scales.lock();
         let abs_x = self.abs_x1.get();
         let abs_y = self.abs_y1.get();
         for (i, child) in self.children.iter().enumerate() {
@@ -708,64 +806,28 @@ impl ContainerNode {
                 };
                 rd.border_rects.push(rect.unwrap());
             }
-            let color = if child.active.get() {
+            if child.active.get() {
                 rd.active_title_rects.push(rect);
-                theme.colors.focused_title_text.get()
             } else if child.attention_requested.get() {
                 rd.attention_title_rects.push(rect);
-                theme.colors.unfocused_title_text.get()
             } else if !have_active && last_active == Some(child.node.node_id()) {
                 rd.last_active_rect = Some(rect);
-                theme.colors.focused_inactive_title_text.get()
             } else {
                 rd.title_rects.push(rect);
-                theme.colors.unfocused_title_text.get()
-            };
+            }
             if !mono {
                 let rect = Rect::new_sized(rect.x1(), rect.y2(), rect.width(), 1).unwrap();
                 rd.underline_rects.push(rect);
             }
-            let title = child.title.borrow_mut();
-            for (scale, _) in scales.iter() {
-                let old_tex = child.title_tex.remove(scale);
-                let titles = rd.titles.get_or_default_mut(*scale);
-                'render_title: {
-                    let mut th = th;
-                    let mut scalef = None;
-                    let mut width = rect.width();
-                    if *scale != 1 {
-                        let scale = scale.to_f64();
-                        th = (th as f64 * scale).round() as _;
-                        width = (width as f64 * scale).round() as _;
-                        scalef = Some(scale);
-                    }
-                    if th == 0 || width == 0 || title.is_empty() {
-                        break 'render_title;
-                    }
-                    if let Some(ctx) = &ctx {
-                        match text::render(
-                            ctx,
-                            old_tex,
-                            width,
-                            th,
-                            &font,
-                            title.deref(),
-                            color,
-                            scalef,
-                        ) {
-                            Ok(t) => {
-                                child.title_tex.insert(*scale, t.clone());
-                                titles.push(ContainerTitle {
-                                    x: rect.x1(),
-                                    y: rect.y1(),
-                                    tex: t,
-                                })
-                            }
-                            Err(e) => {
-                                log::error!("Could not render title {}: {}", title, ErrorFmt(e));
-                            }
-                        }
-                    }
+            let tt = &*child.title_tex.borrow();
+            for (scale, tex) in tt {
+                if let Some(tex) = tex.texture() {
+                    let titles = rd.titles.get_or_default_mut(*scale);
+                    titles.push(ContainerTitle {
+                        x: rect.x1(),
+                        y: rect.y1(),
+                        tex,
+                    })
                 }
             }
         }
@@ -1010,7 +1072,7 @@ impl ContainerNode {
         }
         self.update_title();
         // log::info!("node_child_title_changed");
-        self.schedule_compute_render_data();
+        self.schedule_render_titles();
     }
 
     fn update_child_active(
@@ -1027,7 +1089,8 @@ impl ContainerNode {
                 .set(Some(self.focus_history.add_last(node.clone())));
         }
         // log::info!("node_child_active_changed");
-        self.schedule_compute_render_data();
+        self.schedule_render_titles();
+        self.schedule_compute_render_positions();
         if let Some(parent) = self.toplevel_data.parent.get() {
             parent.node_child_active_changed(self.deref(), active, depth + 1);
         }
@@ -1175,11 +1238,22 @@ pub async fn container_layout(state: Rc<State>) {
     }
 }
 
-pub async fn container_render_data(state: Rc<State>) {
+pub async fn container_render_positions(state: Rc<State>) {
     loop {
-        let container = state.pending_container_render_data.pop().await;
-        if container.compute_render_data_scheduled.get() {
-            container.compute_render_data();
+        let container = state.pending_container_render_positions.pop().await;
+        if container.compute_render_positions_scheduled.get() {
+            container.compute_render_positions();
+        }
+    }
+}
+
+pub async fn container_render_titles(state: Rc<State>) {
+    loop {
+        let container = state.pending_container_render_title.pop().await;
+        if container.render_titles_scheduled.get() {
+            container.render_titles_scheduled.set(false);
+            container.render_titles().triggered().await;
+            container.compute_title_data();
         }
     }
 }
@@ -1562,7 +1636,7 @@ impl ContainingNode for ContainerNode {
             return;
         }
         self.mod_attention_requests(set);
-        self.schedule_compute_render_data();
+        self.schedule_compute_render_positions();
     }
 
     fn cnode_workspace(self: Rc<Self>) -> Rc<WorkspaceNode> {

src/tree/float.rs

@@ -12,14 +12,15 @@ use {
         renderer::Renderer,
         scale::Scale,
         state::State,
-        text::{self, TextTexture},
+        text::TextTexture,
         tree::{
             walker::NodeVisitor, ContainingNode, Direction, FindTreeResult, FindTreeUsecase,
             FoundNode, Node, NodeId, StackedNode, ToplevelNode, WorkspaceNode,
         },
         utils::{
-            clonecell::CloneCell, copyhashmap::CopyHashMap, double_click_state::DoubleClickState,
-            errorfmt::ErrorFmt, linkedlist::LinkedNode,
+            asyncevent::AsyncEvent, clonecell::CloneCell, double_click_state::DoubleClickState,
+            errorfmt::ErrorFmt, linkedlist::LinkedNode, on_drop_event::OnDropEvent,
+            smallmap::SmallMapMut,
         },
     },
     ahash::AHashMap,
@@ -47,7 +48,7 @@ pub struct FloatNode {
     pub layout_scheduled: Cell<bool>,
     pub render_titles_scheduled: Cell<bool>,
     pub title: RefCell<String>,
-    pub title_textures: CopyHashMap<Scale, TextTexture>,
+    pub title_textures: RefCell<SmallMapMut<Scale, TextTexture, 2>>,
     cursors: RefCell<AHashMap<CursorType, CursorState>>,
     pub attention_requested: Cell<bool>,
 }
@@ -96,7 +97,9 @@ pub async fn float_titles(state: Rc<State>) {
     loop {
         let node = state.pending_float_titles.pop().await;
         if node.render_titles_scheduled.get() {
-            node.render_title();
+            node.render_titles_scheduled.set(false);
+            node.render_title_phase1().triggered().await;
+            node.render_title_phase2();
         }
     }
 }
@@ -182,8 +185,8 @@ impl FloatNode {
         }
     }
 
-    fn render_title(&self) {
-        self.render_titles_scheduled.set(false);
+    fn render_title_phase1(&self) -> Rc<AsyncEvent> {
+        let on_completed = Rc::new(OnDropEvent::default());
         let theme = &self.state.theme;
         let th = theme.sizes.title_height.get();
         let tc = match self.active.get() {
@@ -191,20 +194,22 @@ impl FloatNode {
             false => theme.colors.unfocused_title_text.get(),
         };
         let bw = theme.sizes.border_width.get();
-        let font = theme.font.borrow_mut();
+        let font = theme.font.get();
         let title = self.title.borrow_mut();
         let pos = self.position.get();
-        if pos.width() <= 2 * bw || title.is_empty() {
-            return;
+        if pos.width() <= 2 * bw {
+            return on_completed.event();
         }
         let ctx = match self.state.render_ctx.get() {
             Some(c) => c,
-            _ => return,
+            _ => return on_completed.event(),
         };
         let scales = self.state.scales.lock();
         let tr = Rect::new_sized(pos.x1() + bw, pos.y1() + bw, pos.width() - 2 * bw, th).unwrap();
+        let tt = &mut *self.title_textures.borrow_mut();
         for (scale, _) in scales.iter() {
-            let old_tex = self.title_textures.remove(scale);
+            let tex =
+                tt.get_or_insert_with(*scale, || TextTexture::new(&self.state.cpu_worker, &ctx));
             let mut th = tr.height();
             let mut scalef = None;
             let mut width = tr.width();
@@ -217,16 +222,39 @@ impl FloatNode {
             if th == 0 || width == 0 {
                 continue;
             }
-            let texture = match text::render(&ctx, old_tex, width, th, &font, &title, tc, scalef) {
-                Ok(t) => t,
-                Err(e) => {
-                    log::error!("Could not render title {}: {}", title, ErrorFmt(e));
-                    return;
-                }
-            };
-            self.title_textures.set(*scale, texture);
+            tex.schedule_render(
+                on_completed.clone(),
+                1,
+                None,
+                width,
+                th,
+                1,
+                &font,
+                &title,
+                tc,
+                true,
+                false,
+                scalef,
+            );
         }
-        if self.visible.get() {
+        on_completed.event()
+    }
+
+    fn render_title_phase2(&self) {
+        let theme = &self.state.theme;
+        let th = theme.sizes.title_height.get();
+        let bw = theme.sizes.border_width.get();
+        let title = self.title.borrow();
+        let tt = &*self.title_textures.borrow();
+        for (_, tt) in tt {
+            if let Err(e) = tt.flip() {
+                log::error!("Could not render title {}: {}", title, ErrorFmt(e));
+            }
+        }
+        let pos = self.position.get();
+        if self.visible.get() && pos.width() >= 2 * bw {
+            let tr =
+                Rect::new_sized(pos.x1() + bw, pos.y1() + bw, pos.width() - 2 * bw, th).unwrap();
             self.state.damage(tr);
         }
     }

src/tree/output.rs

@@ -30,15 +30,16 @@ use {
         renderer::Renderer,
         scale::Scale,
         state::State,
-        text::{self, TextTexture},
+        text::TextTexture,
         tree::{
             walker::NodeVisitor, Direction, FindTreeResult, FindTreeUsecase, FoundNode, Node,
             NodeId, StackedNode, WorkspaceNode,
         },
         utils::{
-            clonecell::CloneCell, copyhashmap::CopyHashMap, errorfmt::ErrorFmt,
-            event_listener::EventSource, hash_map_ext::HashMapExt, linkedlist::LinkedList,
-            scroller::Scroller, transform_ext::TransformExt,
+            asyncevent::AsyncEvent, clonecell::CloneCell, copyhashmap::CopyHashMap,
+            errorfmt::ErrorFmt, event_listener::EventSource, hash_map_ext::HashMapExt,
+            linkedlist::LinkedList, on_drop_event::OnDropEvent, scroller::Scroller,
+            transform_ext::TransformExt,
         },
         wire::{JayOutputId, JayScreencastId, ZwlrScreencopyFrameV1Id},
     },
@@ -114,12 +115,14 @@ pub enum PointerType {
 
 pub async fn output_render_data(state: Rc<State>) {
     loop {
-        let container = state.pending_output_render_data.pop().await;
-        if container.global.destroyed.get() {
+        let output = state.pending_output_render_data.pop().await;
+        if output.global.destroyed.get() {
             continue;
         }
-        if container.update_render_data_scheduled.get() {
-            container.update_render_data();
+        if output.update_render_data_scheduled.get() {
+            output.update_render_data_scheduled.set(false);
+            output.update_render_data_phase1().triggered().await;
+            output.update_render_data_phase2();
         }
     }
 }
@@ -367,17 +370,12 @@ impl OutputNode {
         }
     }
 
-    fn update_render_data(&self) {
-        self.update_render_data_scheduled.set(false);
-        let mut rd = self.render_data.borrow_mut();
-        rd.titles.clear();
-        rd.inactive_workspaces.clear();
-        rd.attention_requested_workspaces.clear();
-        rd.captured_inactive_workspaces.clear();
-        rd.active_workspace = None;
-        rd.status = None;
-        let mut pos = 0;
-        let font = self.state.theme.font.borrow_mut();
+    fn update_render_data_phase1(self: &Rc<Self>) -> Rc<AsyncEvent> {
+        let on_completed = Rc::new(OnDropEvent::default());
+        let Some(ctx) = self.state.render_ctx.get() else {
+            return on_completed.event();
+        };
+        let font = self.state.theme.font.get();
         let theme = &self.state.theme;
         let th = theme.sizes.title_height.get();
         let scale = self.global.persistent.scale.get();
@@ -391,40 +389,72 @@ impl OutputNode {
             texture_height = (th as f64 * scale).round() as _;
         }
         let active_id = self.workspace.get().map(|w| w.id);
+        for ws in self.workspaces.iter() {
+            let tex = &mut *ws.title_texture.borrow_mut();
+            let tex = tex.get_or_insert_with(|| TextTexture::new(&self.state.cpu_worker, &ctx));
+            let tc = match active_id == Some(ws.id) {
+                true => theme.colors.focused_title_text.get(),
+                false => theme.colors.unfocused_title_text.get(),
+            };
+            tex.schedule_render_fitting(
+                on_completed.clone(),
+                Some(texture_height),
+                &font,
+                &ws.name,
+                tc,
+                false,
+                scale,
+            );
+        }
+        let mut rd = self.render_data.borrow_mut();
+        let tex = rd.status.get_or_insert_with(|| OutputStatus {
+            tex_x: 0,
+            tex: TextTexture::new(&self.state.cpu_worker, &ctx),
+        });
+        let status = self.status.get();
+        let tc = self.state.theme.colors.bar_text.get();
+        tex.tex.schedule_render_fitting(
+            on_completed.clone(),
+            Some(texture_height),
+            &font,
+            &status,
+            tc,
+            true,
+            scale,
+        );
+        on_completed.event()
+    }
+
+    fn update_render_data_phase2(&self) {
+        let mut rd = self.render_data.borrow_mut();
+        rd.titles.clear();
+        rd.inactive_workspaces.clear();
+        rd.attention_requested_workspaces.clear();
+        rd.captured_inactive_workspaces.clear();
+        rd.active_workspace = None;
+        let mut pos = 0;
+        let theme = &self.state.theme;
+        let th = theme.sizes.title_height.get();
+        let scale = self.global.persistent.scale.get();
+        let scale = if scale != 1 {
+            Some(scale.to_f64())
+        } else {
+            None
+        };
+        let active_id = self.workspace.get().map(|w| w.id);
         let non_exclusive_rect = self.non_exclusive_rect.get();
         let output_width = non_exclusive_rect.width();
         rd.underline = Rect::new_sized(0, th, output_width, 1).unwrap();
         for ws in self.workspaces.iter() {
-            let old_tex = ws.title_texture.take();
             let mut title_width = th;
-            'create_texture: {
-                if let Some(ctx) = self.state.render_ctx.get() {
-                    if th == 0 || ws.name.is_empty() {
-                        break 'create_texture;
-                    }
-                    let tc = match active_id == Some(ws.id) {
-                        true => theme.colors.focused_title_text.get(),
-                        false => theme.colors.unfocused_title_text.get(),
-                    };
-                    let title = match text::render_fitting(
-                        &ctx,
-                        old_tex,
-                        Some(texture_height),
-                        &font,
-                        &ws.name,
-                        tc,
-                        false,
-                        scale,
-                    ) {
-                        Ok(t) => t,
-                        Err(e) => {
-                            log::error!("Could not render title {}: {}", ws.name, ErrorFmt(e));
-                            break 'create_texture;
-                        }
-                    };
-                    ws.title_texture.set(Some(title.clone()));
+            let title = &*ws.title_texture.borrow();
+            if let Some(title) = title {
+                if let Err(e) = title.flip() {
+                    log::error!("Could not render title: {}", ErrorFmt(e));
+                }
+                if let Some(texture) = title.texture() {
                     let mut x = pos + 1;
-                    let (mut width, _) = title.texture.size();
+                    let (mut width, _) = texture.size();
                     if let Some(scale) = scale {
                         width = (width as f64 / scale).round() as _;
                     }
@@ -438,7 +468,7 @@ impl OutputNode {
                         x2: pos + title_width,
                         tex_x: x,
                         tex_y: 0,
-                        tex: title.texture,
+                        tex: texture,
                         ws: ws.deref().clone(),
                     });
                 }
@@ -461,43 +491,18 @@ impl OutputNode {
             }
             pos += title_width;
         }
-        'set_status: {
-            let old_tex = rd.status.take().map(|s| s.tex);
-            let ctx = match self.state.render_ctx.get() {
-                Some(ctx) => ctx,
-                _ => break 'set_status,
-            };
-            let status = self.status.get();
-            if status.is_empty() {
-                break 'set_status;
+        if let Some(status) = &mut rd.status {
+            if let Err(e) = status.tex.flip() {
+                log::error!("Could not render status: {}", ErrorFmt(e));
             }
-            let tc = self.state.theme.colors.bar_text.get();
-            let title = match text::render_fitting(
-                &ctx,
-                old_tex,
-                Some(texture_height),
-                &font,
-                &status,
-                tc,
-                true,
-                scale,
-            ) {
-                Ok(t) => t,
-                Err(e) => {
-                    log::error!("Could not render status {}: {}", status, ErrorFmt(e));
-                    break 'set_status;
+            if let Some(texture) = status.tex.texture() {
+                let (mut width, _) = texture.size();
+                if let Some(scale) = scale {
+                    width = (width as f64 / scale).round() as _;
                 }
-            };
-            let (mut width, _) = title.texture.size();
-            if let Some(scale) = scale {
-                width = (width as f64 / scale).round() as _;
+                let pos = output_width - width - 1;
+                status.tex_x = pos;
             }
-            let pos = output_width - width - 1;
-            rd.status = Some(OutputStatus {
-                tex_x: pos,
-                tex_y: 0,
-                tex: title,
-            });
         }
         if self.title_visible.get() {
             let title_rect = Rect::new_sized(
@@ -945,7 +950,6 @@ pub struct OutputTitle {
 
 pub struct OutputStatus {
     pub tex_x: i32,
-    pub tex_y: i32,
     pub tex: TextTexture,
 }
 

src/tree/placeholder.rs

@@ -8,14 +8,22 @@ use {
         renderer::Renderer,
         scale::Scale,
         state::State,
-        text::{self, TextTexture},
+        text::TextTexture,
         tree::{
             Direction, FindTreeResult, FindTreeUsecase, FoundNode, Node, NodeId, NodeVisitor,
             ToplevelData, ToplevelNode, ToplevelNodeBase,
         },
-        utils::{errorfmt::ErrorFmt, smallmap::SmallMap},
+        utils::{
+            asyncevent::AsyncEvent, errorfmt::ErrorFmt, on_drop_event::OnDropEvent,
+            smallmap::SmallMapMut,
+        },
+    },
+    std::{
+        cell::{Cell, RefCell},
+        ops::Deref,
+        rc::Rc,
+        sync::Arc,
     },
-    std::{cell::Cell, ops::Deref, rc::Rc},
 };
 
 tree_id!(PlaceholderNodeId);
@@ -24,7 +32,18 @@ pub struct PlaceholderNode {
     id: PlaceholderNodeId,
     toplevel: ToplevelData,
     destroyed: Cell<bool>,
-    pub textures: SmallMap<Scale, TextTexture, 2>,
+    update_textures_scheduled: Cell<bool>,
+    state: Rc<State>,
+    pub textures: RefCell<SmallMapMut<Scale, TextTexture, 2>>,
+}
+
+pub async fn placeholder_render_textures(state: Rc<State>) {
+    loop {
+        let container = state.pending_placeholder_render_textures.pop().await;
+        container.update_textures_scheduled.set(false);
+        container.update_texture_phase1().triggered().await;
+        container.update_texture_phase2();
+    }
 }
 
 impl PlaceholderNode {
@@ -37,6 +56,8 @@ impl PlaceholderNode {
                 node.node_client(),
             ),
             destroyed: Default::default(),
+            update_textures_scheduled: Cell::new(false),
+            state: state.clone(),
             textures: Default::default(),
         }
     }
@@ -45,39 +66,53 @@ impl PlaceholderNode {
         self.destroyed.get()
     }
 
-    pub fn update_texture(&self) {
-        if let Some(ctx) = self.toplevel.state.render_ctx.get() {
-            let scales = self.toplevel.state.scales.lock();
-            let rect = self.toplevel.pos.get();
-            for (scale, _) in scales.iter() {
-                let old_tex = self.textures.remove(scale);
-                let mut width = rect.width();
-                let mut height = rect.height();
-                if *scale != 1 {
-                    let scale = scale.to_f64();
-                    width = (width as f64 * scale).round() as _;
-                    height = (height as f64 * scale).round() as _;
-                }
-                if width != 0 && height != 0 {
-                    let font = format!("monospace {}", width / 10);
-                    match text::render_fitting(
-                        &ctx,
-                        old_tex,
-                        Some(height),
-                        &font,
-                        "Fullscreen",
-                        self.toplevel.state.theme.colors.unfocused_title_text.get(),
-                        false,
-                        None,
-                    ) {
-                        Ok(t) => {
-                            self.textures.insert(*scale, t);
-                        }
-                        Err(e) => {
-                            log::warn!("Could not render fullscreen texture: {}", ErrorFmt(e));
-                        }
-                    }
-                }
+    pub fn schedule_update_texture(self: &Rc<Self>) {
+        if !self.update_textures_scheduled.replace(true) {
+            self.state
+                .pending_placeholder_render_textures
+                .push(self.clone());
+        }
+    }
+
+    fn update_texture_phase1(&self) -> Rc<AsyncEvent> {
+        let on_completed = Rc::new(OnDropEvent::default());
+        let Some(ctx) = self.toplevel.state.render_ctx.get() else {
+            return on_completed.event();
+        };
+        let scales = self.toplevel.state.scales.lock();
+        let rect = self.toplevel.pos.get();
+        let mut textures = self.textures.borrow_mut();
+        for (scale, _) in scales.iter() {
+            let tex = textures
+                .get_or_insert_with(*scale, || TextTexture::new(&self.state.cpu_worker, &ctx));
+            let mut width = rect.width();
+            let mut height = rect.height();
+            if *scale != 1 {
+                let scale = scale.to_f64();
+                width = (width as f64 * scale).round() as _;
+                height = (height as f64 * scale).round() as _;
+            }
+            if width != 0 && height != 0 {
+                let font = Arc::new(format!("monospace {}", width / 10));
+                tex.schedule_render_fitting(
+                    on_completed.clone(),
+                    Some(height),
+                    &font,
+                    "Fullscreen",
+                    self.toplevel.state.theme.colors.unfocused_title_text.get(),
+                    false,
+                    None,
+                );
+            }
+        }
+        on_completed.event()
+    }
+
+    fn update_texture_phase2(&self) {
+        let textures = &*self.textures.borrow();
+        for (_, texture) in textures {
+            if let Err(e) = texture.flip() {
+                log::warn!("Could not render fullscreen texture: {}", ErrorFmt(e));
             }
         }
     }
@@ -162,7 +197,7 @@ impl ToplevelNodeBase for PlaceholderNode {
         if let Some(p) = self.toplevel.parent.get() {
             p.node_child_size_changed(self.deref(), rect.width(), rect.height());
         }
-        self.update_texture();
+        self.schedule_update_texture();
     }
 
     fn tl_close(self: Rc<Self>) {

src/tree/workspace.rs

@@ -57,7 +57,7 @@ pub struct WorkspaceNode {
     pub jay_workspaces: CopyHashMap<(ClientId, JayWorkspaceId), Rc<JayWorkspace>>,
     pub may_capture: Cell<bool>,
     pub has_capture: Cell<bool>,
-    pub title_texture: Cell<Option<TextTexture>>,
+    pub title_texture: RefCell<Option<TextTexture>>,
     pub attention_requests: ThresholdCounter,
     pub render_highlight: NumCell<u32>,
 }

src/utils.rs

@@ -30,6 +30,7 @@ pub mod num_cpus;
 pub mod numcell;
 pub mod on_change;
 pub mod on_drop;
+pub mod on_drop_event;
 pub mod once;
 pub mod opaque;
 pub mod opaque_cell;

src/utils/clonecell.rs

@@ -9,6 +9,7 @@ use {
         fmt::{Debug, Formatter},
         mem,
         rc::{Rc, Weak},
+        sync::Arc,
     },
 };
 
@@ -83,6 +84,7 @@ unsafe impl<T: UnsafeCellCloneSafe> UnsafeCellCloneSafe for Option<T> {}
 
 unsafe impl<T: ?Sized> UnsafeCellCloneSafe for Rc<T> {}
 unsafe impl<T: ?Sized> UnsafeCellCloneSafe for Weak<T> {}
+unsafe impl<T: ?Sized> UnsafeCellCloneSafe for Arc<T> {}
 
 unsafe impl<T> UnsafeCellCloneSafe for NodeRef<T> {}
 

src/utils/on_drop_event.rs

@@ -0,0 +1,18 @@
+use {crate::utils::asyncevent::AsyncEvent, std::rc::Rc};
+
+#[derive(Default)]
+pub struct OnDropEvent {
+    ae: Rc<AsyncEvent>,
+}
+
+impl OnDropEvent {
+    pub fn event(&self) -> Rc<AsyncEvent> {
+        self.ae.clone()
+    }
+}
+
+impl Drop for OnDropEvent {
+    fn drop(&mut self) {
+        self.ae.trigger()
+    }
+}

src/utils/smallmap.rs

@@ -201,13 +201,20 @@ impl<K: Eq, V, const N: usize> SmallMapMut<K, V, N> {
     pub fn get_or_default_mut(&mut self, k: K) -> &mut V
     where
         V: Default,
+    {
+        self.get_or_insert_with(k, || V::default())
+    }
+
+    pub fn get_or_insert_with<F>(&mut self, k: K, f: F) -> &mut V
+    where
+        F: FnOnce() -> V,
     {
         for (ek, ev) in &mut self.m {
             if ek == &k {
                 return unsafe { (ev as *mut V).deref_mut() };
             }
         }
-        self.m.push((k, V::default()));
+        self.m.push((k, f()));
         &mut self.m.last_mut().unwrap().1
     }