diff --git a/src/backends/xorg/mod.rs b/src/backends/xorg/mod.rs
index c9beeb4b..8a760519 100644
--- a/src/backends/xorg/mod.rs
+++ b/src/backends/xorg/mod.rs
@@ -24,6 +24,7 @@ use uapi::c;
 use xcb_dl::{ffi, Xcb, XcbShm, XcbXinput, XcbXkb};
 use xcb_dl_util::error::{XcbError, XcbErrorParser};
 use xcb_dl_util::xcb_box::XcbBox;
+use crate::utils::clonecell::CloneCell;
 
 #[derive(Debug, Error)]
 pub enum XorgBackendError {
@@ -246,7 +247,7 @@ impl XorgBackend {
                 width: Cell::new(0),
                 height: Cell::new(0),
                 image: RefCell::new(None),
-                cb: RefCell::new(None),
+                cb: CloneCell::new(None),
             });
             {
                 let class = "i4\0i4\0";
@@ -378,7 +379,7 @@ impl XorgBackend {
                 _kb: info.deviceid,
                 mouse: info.attachment,
                 removed: Cell::new(false),
-                cb: RefCell::new(None),
+                cb: CloneCell::new(None),
                 events: RefCell::new(Default::default()),
                 button_map: Default::default(),
                 last_position: Cell::new((0, 0)),
@@ -685,9 +686,8 @@ impl XorgBackend {
                 }
             }
         }
-        let buffer = surface.buffer.borrow();
-        if let Some(buffer) = &*buffer {
-            self.render_buffer(image, buffer, x, y);
+        if let Some(buffer) = surface.buffer.get() {
+            self.render_buffer(image, &buffer, x, y);
             let mut fr = surface.frame_requests.borrow_mut();
             for cb in fr.drain(..) {
                 surface.client.dispatch_frame_requests.push(cb);
@@ -776,7 +776,7 @@ struct XorgOutput {
     width: Cell<u32>,
     height: Cell<u32>,
     image: RefCell<Option<Image<Rc<ServerMem>>>>,
-    cb: RefCell<Option<Rc<dyn Fn()>>>,
+    cb: CloneCell<Option<Rc<dyn Fn()>>>,
 }
 
 impl Drop for XorgOutput {
@@ -790,7 +790,7 @@ impl Drop for XorgOutput {
 
 impl XorgOutput {
     fn changed(&self) {
-        if let Some(cb) = self.cb.borrow().clone() {
+        if let Some(cb) = self.cb.get() {
             cb();
         }
     }
@@ -814,7 +814,7 @@ impl Output for XorgOutput {
     }
 
     fn on_change(&self, cb: Rc<dyn Fn()>) {
-        *self.cb.borrow_mut() = Some(cb);
+        self.cb.set(Some(cb));
     }
 }
 
@@ -824,7 +824,7 @@ struct XorgSeat {
     _kb: ffi::xcb_input_device_id_t,
     mouse: ffi::xcb_input_device_id_t,
     removed: Cell<bool>,
-    cb: RefCell<Option<Rc<dyn Fn()>>>,
+    cb: CloneCell<Option<Rc<dyn Fn()>>>,
     events: RefCell<VecDeque<SeatEvent>>,
     button_map: CopyHashMap<u32, u32>,
     last_position: Cell<(ffi::xcb_input_fp1616_t, ffi::xcb_input_fp1616_t)>,
@@ -832,7 +832,7 @@ struct XorgSeat {
 
 impl XorgSeat {
     fn changed(&self) {
-        if let Some(cb) = self.cb.borrow().clone() {
+        if let Some(cb) = self.cb.get() {
             cb();
         }
     }
@@ -889,6 +889,6 @@ impl Seat for XorgSeat {
     }
 
     fn on_change(&self, cb: Rc<dyn Fn()>) {
-        *self.cb.borrow_mut() = Some(cb);
+        self.cb.set(Some(cb));
     }
 }
diff --git a/src/client/mod.rs b/src/client/mod.rs
index 72e663f4..9171d532 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -247,7 +247,7 @@ impl Clients {
             dispatch_frame_requests: AsyncQueue::new(),
         });
         let display = Rc::new(WlDisplay::new(&data));
-        *data.objects.display.borrow_mut() = Some(display.clone());
+        data.objects.display.set(Some(display.clone()));
         data.objects.add_client_object(display).expect("");
         let client = ClientHolder {
             _handler: global.eng.spawn(tasks::client(data.clone(), recv)),
@@ -365,7 +365,7 @@ impl Client {
     }
 
     pub fn display(&self) -> Result<Rc<WlDisplay>, ClientError> {
-        match self.objects.display.borrow_mut().clone() {
+        match self.objects.display.get() {
             Some(d) => Ok(d),
             _ => Err(ClientError::NotADisplay(WL_DISPLAY_ID)),
         }
diff --git a/src/client/objects.rs b/src/client/objects.rs
index dc6c2c14..da4640dc 100644
--- a/src/client/objects.rs
+++ b/src/client/objects.rs
@@ -13,9 +13,10 @@ use ahash::AHashMap;
 use std::cell::{RefCell, RefMut};
 use std::mem;
 use std::rc::Rc;
+use crate::utils::clonecell::CloneCell;
 
 pub struct Objects {
-    pub display: RefCell<Option<Rc<WlDisplay>>>,
+    pub display: CloneCell<Option<Rc<WlDisplay>>>,
     registry: CopyHashMap<ObjectId, Rc<dyn Object>>,
     registries: CopyHashMap<WlRegistryId, Rc<WlRegistry>>,
     pub surfaces: CopyHashMap<WlSurfaceId, Rc<WlSurface>>,
@@ -33,7 +34,7 @@ const SEG_SIZE: usize = 8 * mem::size_of::<usize>();
 impl Objects {
     pub fn new() -> Self {
         Self {
-            display: RefCell::new(None),
+            display: CloneCell::new(None),
             registry: Default::default(),
             registries: Default::default(),
             surfaces: Default::default(),
@@ -54,7 +55,7 @@ impl Objects {
             }
             registry.clear();
         }
-        *self.display.borrow_mut() = None;
+        self.display.set(None);
         self.regions.clear();
         self.registries.clear();
         self.surfaces.clear();
diff --git a/src/ifs/wl_buffer/mod.rs b/src/ifs/wl_buffer/mod.rs
index fd3a0d48..9f991f78 100644
--- a/src/ifs/wl_buffer/mod.rs
+++ b/src/ifs/wl_buffer/mod.rs
@@ -70,7 +70,7 @@ impl WlBuffer {
         {
             let surfaces = self.surfaces.lock();
             for surface in surfaces.values() {
-                *surface.buffer.borrow_mut() = None;
+                surface.buffer.set(None);
             }
         }
         self.client.remove_obj(self).await?;
diff --git a/src/ifs/wl_seat/mod.rs b/src/ifs/wl_seat/mod.rs
index 5a807640..0e07c653 100644
--- a/src/ifs/wl_seat/mod.rs
+++ b/src/ifs/wl_seat/mod.rs
@@ -16,13 +16,14 @@ use crate::utils::buffd::MsgParser;
 use crate::utils::copyhashmap::CopyHashMap;
 use crate::xkbcommon::XkbContext;
 use crate::State;
-use ahash::AHashMap;
+use ahash::{AHashMap, AHashSet};
 use bstr::ByteSlice;
 use std::cell::{Cell, RefCell};
 use std::io::Write;
 use std::rc::Rc;
 pub use types::*;
 use uapi::{c, OwnedFd};
+use crate::utils::clonecell::CloneCell;
 
 id!(WlSeatId);
 
@@ -42,6 +43,8 @@ const TOUCH: u32 = 4;
 #[allow(dead_code)]
 const MISSING_CAPABILITY: u32 = 0;
 
+const BTN_LEFT: u32 = 0x110;
+
 pub struct WlSeatGlobal {
     name: GlobalName,
     state: Rc<State>,
@@ -50,7 +53,9 @@ pub struct WlSeatGlobal {
     move_start_pos: Cell<(Fixed, Fixed)>,
     extents_start_pos: Cell<(i32, i32)>,
     pos: Cell<(Fixed, Fixed)>,
-    cursor_node: RefCell<Rc<dyn Node>>,
+    cursor_node: CloneCell<Rc<dyn Node>>,
+    keyboard_node: CloneCell<Rc<dyn Node>>,
+    pressed_keys: RefCell<AHashSet<u32>>,
     bindings: RefCell<AHashMap<ClientId, AHashMap<WlSeatId, Rc<WlSeatObj>>>>,
     layout: Rc<OwnedFd>,
     layout_size: u32,
@@ -82,7 +87,9 @@ impl WlSeatGlobal {
             move_start_pos: Cell::new((Fixed(0), Fixed(0))),
             extents_start_pos: Cell::new((0, 0)),
             pos: Cell::new((Fixed(0), Fixed(0))),
-            cursor_node: RefCell::new(state.root.clone()),
+            cursor_node: CloneCell::new(state.root.clone()),
+            keyboard_node: CloneCell::new(state.root.clone()),
+            pressed_keys: RefCell::new(Default::default()),
             bindings: Default::default(),
             layout,
             layout_size,
@@ -90,7 +97,7 @@ impl WlSeatGlobal {
     }
 
     pub fn move_(&self, node: &Rc<ToplevelNode>) {
-        let cursor = self.cursor_node.borrow().clone();
+        let cursor = self.cursor_node.get();
         if cursor.id() == node.id() {
             self.move_.set(true);
             self.move_start_pos.set(self.pos.get());
@@ -119,21 +126,42 @@ impl WlSeatGlobal {
         self.handle_new_position(x, y).await;
     }
 
-    fn for_each_pointer<C>(&self, client: ClientId, mut f: C)
+    fn for_each_seat<C>(&self, client: ClientId, mut f: C)
     where
-        C: FnMut(&Rc<WlPointer>),
+        C: FnMut(&Rc<WlSeatObj>),
     {
         let bindings = self.bindings.borrow();
         if let Some(hm) = bindings.get(&client) {
             for seat in hm.values() {
-                let pointers = seat.pointers.lock();
-                for pointer in pointers.values() {
-                    f(pointer);
-                }
+                f(seat);
             }
         }
     }
 
+    fn for_each_pointer<C>(&self, client: ClientId, mut f: C)
+    where
+        C: FnMut(&Rc<WlPointer>),
+    {
+        self.for_each_seat(client, |seat| {
+            let pointers = seat.pointers.lock();
+            for pointer in pointers.values() {
+                f(pointer);
+            }
+        })
+    }
+
+    fn for_each_kb<C>(&self, client: ClientId, mut f: C)
+    where
+        C: FnMut(&Rc<WlKeyboard>),
+    {
+        self.for_each_seat(client, |seat| {
+            let keyboards = seat.keyboards.lock();
+            for keyboard in keyboards.values() {
+                f(keyboard);
+            }
+        })
+    }
+
     async fn tl_pointer_event<F>(&self, tl: &ToplevelNode, mut f: F)
     where
         F: FnMut(&Rc<WlPointer>) -> DynEventFormatter,
@@ -145,9 +173,20 @@ impl WlSeatGlobal {
         let _ = client.flush().await;
     }
 
+    async fn tl_kb_event<F>(&self, tl: &ToplevelNode, mut f: F)
+    where
+        F: FnMut(&Rc<WlKeyboard>) -> DynEventFormatter,
+    {
+        let client = &tl.surface.surface.surface.client;
+        self.for_each_kb(client.id, |p| {
+            client.event_locked(f(p));
+        });
+        let _ = client.flush().await;
+    }
+
     async fn handle_new_position(&self, x: Fixed, y: Fixed) {
         self.pos.set((x, y));
-        let cur_node = self.cursor_node.borrow().clone();
+        let cur_node = self.cursor_node.get();
         if self.move_.get() {
             if let NodeKind::Toplevel(tn) = cur_node.into_kind() {
                 let (move_start_x, move_start_y) = self.move_start_pos.get();
@@ -172,7 +211,7 @@ impl WlSeatGlobal {
                     .await;
             }
             enter = true;
-            *self.cursor_node.borrow_mut() = node_dyn;
+            self.cursor_node.set(node_dyn);
         }
         if let NodeKind::Toplevel(tl) = &node {
             let ee = tl.surface.surface.surface.effective_extents.get();
@@ -196,19 +235,41 @@ impl WlSeatGlobal {
         if state == KeyState::Released {
             self.move_.set(false);
         }
-        let node = self.cursor_node.borrow().clone().into_kind();
-        if let NodeKind::Toplevel(node) = node {
+        let node = self.cursor_node.get();
+        let mut enter = false;
+        if button == BTN_LEFT {
+            let kb_node = self.keyboard_node.get();
+            if kb_node.id() != node.id() {
+                enter = true;
+                if let NodeKind::Toplevel(tl) = kb_node.clone().into_kind() {
+                    self.tl_kb_event(&tl, |k| k.leave(0, tl.surface.surface.surface.id))
+                        .await;
+                }
+                self.keyboard_node.set(node.clone());
+            }
+        }
+        if let NodeKind::Toplevel(node) = node.into_kind() {
             let state = match state {
                 KeyState::Released => wl_pointer::RELEASED,
                 KeyState::Pressed => wl_pointer::PRESSED,
             };
             self.tl_pointer_event(&node, |p| p.button(0, 0, button, state))
                 .await;
+            if enter {
+                self.tl_kb_event(&node, |k| {
+                    k.enter(
+                        0,
+                        node.surface.surface.surface.id,
+                        self.pressed_keys.borrow().iter().cloned().collect(),
+                    )
+                })
+                .await;
+            }
         }
     }
 
     async fn scroll_event(&self, delta: i32, axis: ScrollAxis) {
-        let node = self.cursor_node.borrow().clone().into_kind();
+        let node = self.cursor_node.get().into_kind();
         if let NodeKind::Toplevel(node) = node {
             let axis = match axis {
                 ScrollAxis::Horizontal => wl_pointer::HORIZONTAL_SCROLL,
@@ -219,7 +280,31 @@ impl WlSeatGlobal {
         }
     }
 
-    async fn key_event(&self, _key: u32, _state: KeyState) {}
+    async fn key_event(&self, key: u32, state: KeyState) {
+        let state = {
+            let mut pk = self.pressed_keys.borrow_mut();
+            match state {
+                KeyState::Released => {
+                    if !pk.remove(&key) {
+                        return;
+                    }
+                    log::info!("release");
+                    wl_keyboard::RELEASED
+                }
+                KeyState::Pressed => {
+                    if !pk.insert(key) {
+                        return;
+                    }
+                    log::info!("press");
+                    wl_keyboard::PRESSED
+                }
+            }
+        };
+        let node = self.keyboard_node.get().into_kind();
+        if let NodeKind::Toplevel(node) = node {
+            self.tl_kb_event(&node, |k| k.key(0, 0, key, state)).await;
+        }
+    }
 
     async fn bind_(
         self: Rc<Self>,
@@ -311,11 +396,7 @@ impl WlSeatObj {
         self.client.add_client_obj(&p)?;
         self.keyboards.set(req.id, p.clone());
         self.client
-            .event(p.keymap(
-                wl_keyboard::XKB_V1,
-                p.keymap_fd()?,
-                self.global.layout_size,
-            ))
+            .event(p.keymap(wl_keyboard::XKB_V1, p.keymap_fd()?, self.global.layout_size))
             .await?;
         Ok(())
     }
diff --git a/src/ifs/wl_seat/wl_keyboard/mod.rs b/src/ifs/wl_seat/wl_keyboard/mod.rs
index 4d40886e..ebab27b6 100644
--- a/src/ifs/wl_seat/wl_keyboard/mod.rs
+++ b/src/ifs/wl_seat/wl_keyboard/mod.rs
@@ -22,10 +22,8 @@ const REPEAT_INFO: u32 = 5;
 const NO_KEYMAP: u32 = 0;
 pub(super) const XKB_V1: u32 = 1;
 
-#[allow(dead_code)]
-const RELEASED: u32 = 0;
-#[allow(dead_code)]
-const PRESSED: u32 = 1;
+pub(super) const RELEASED: u32 = 0;
+pub(super) const PRESSED: u32 = 1;
 
 id!(WlKeyboardId);
 
@@ -65,7 +63,7 @@ impl WlKeyboard {
                 rem as usize,
             );
             match res {
-                Ok(_) | Err(Errno(c::EINTR)) => { },
+                Ok(_) | Err(Errno(c::EINTR)) => {}
                 Err(e) => return Err(WlKeyboardError::KeymapCopy(e.into())),
             }
         }
diff --git a/src/ifs/wl_shm_pool/mod.rs b/src/ifs/wl_shm_pool/mod.rs
index d6aadaa2..4153697a 100644
--- a/src/ifs/wl_shm_pool/mod.rs
+++ b/src/ifs/wl_shm_pool/mod.rs
@@ -5,10 +5,10 @@ use crate::clientmem::ClientMem;
 use crate::ifs::wl_buffer::WlBuffer;
 use crate::object::{Interface, Object, ObjectId};
 use crate::utils::buffd::MsgParser;
-use std::cell::RefCell;
 use std::rc::Rc;
 pub use types::*;
 use uapi::OwnedFd;
+use crate::utils::clonecell::CloneCell;
 
 const CREATE_BUFFER: u32 = 0;
 const DESTROY: u32 = 1;
@@ -20,7 +20,7 @@ pub struct WlShmPool {
     id: WlShmPoolId,
     client: Rc<Client>,
     fd: OwnedFd,
-    mem: RefCell<Rc<ClientMem>>,
+    mem: CloneCell<Rc<ClientMem>>,
 }
 
 impl WlShmPool {
@@ -33,7 +33,7 @@ impl WlShmPool {
         Ok(Self {
             id,
             client: client.clone(),
-            mem: RefCell::new(Rc::new(ClientMem::new(fd.raw(), len)?)),
+            mem: CloneCell::new(Rc::new(ClientMem::new(fd.raw(), len)?)),
             fd,
         })
     }
@@ -47,7 +47,6 @@ impl WlShmPool {
         if req.height < 0 || req.width < 0 || req.stride < 0 || req.offset < 0 {
             return Err(CreateBufferError::NegativeParameters);
         }
-        let mem = self.mem.borrow();
         let buffer = Rc::new(WlBuffer::new(
             req.id,
             &self.client,
@@ -56,7 +55,7 @@ impl WlShmPool {
             req.height as u32,
             req.stride as u32,
             format,
-            &mem,
+            &self.mem.get(),
         )?);
         self.client.add_client_obj(&buffer)?;
         Ok(())
@@ -70,14 +69,13 @@ impl WlShmPool {
 
     async fn resize(&self, parser: MsgParser<'_, '_>) -> Result<(), ResizeError> {
         let req: Resize = self.client.parse(self, parser)?;
-        let mut mem = self.mem.borrow_mut();
         if req.size < 0 {
             return Err(ResizeError::NegativeSize);
         }
-        if (req.size as usize) < mem.len() {
+        if (req.size as usize) < self.mem.get().len() {
             return Err(ResizeError::CannotShrink);
         }
-        *mem = Rc::new(ClientMem::new(self.fd.raw(), req.size as usize)?);
+        self.mem.set(Rc::new(ClientMem::new(self.fd.raw(), req.size as usize)?));
         Ok(())
     }
 
diff --git a/src/ifs/wl_surface/mod.rs b/src/ifs/wl_surface/mod.rs
index d97b10f2..e87f1a65 100644
--- a/src/ifs/wl_surface/mod.rs
+++ b/src/ifs/wl_surface/mod.rs
@@ -21,6 +21,7 @@ use std::mem;
 use std::ops::{Deref, DerefMut};
 use std::rc::Rc;
 pub use types::*;
+use crate::utils::clonecell::CloneCell;
 
 const DESTROY: u32 = 0;
 const ATTACH: u32 = 1;
@@ -73,7 +74,7 @@ pub struct WlSurface {
     opaque_region: Cell<Option<Region>>,
     pub extents: Cell<SurfaceExtents>,
     pub effective_extents: Cell<SurfaceExtents>,
-    pub buffer: RefCell<Option<Rc<WlBuffer>>>,
+    pub buffer: CloneCell<Option<Rc<WlBuffer>>>,
     pub children: RefCell<Option<Box<ParentData>>>,
     role_data: RefCell<RoleData>,
     pub frame_requests: RefCell<Vec<Rc<WlCallback>>>,
@@ -207,7 +208,7 @@ impl WlSurface {
             opaque_region: Cell::new(None),
             extents: Default::default(),
             effective_extents: Default::default(),
-            buffer: RefCell::new(None),
+            buffer: CloneCell::new(None),
             children: Default::default(),
             role_data: RefCell::new(RoleData::None),
             frame_requests: RefCell::new(vec![]),
@@ -225,7 +226,7 @@ impl WlSurface {
     fn calculate_extents(&self) {
         {
             let mut extents = SurfaceExtents::default();
-            if let Some(b) = self.buffer.borrow().deref() {
+            if let Some(b) = self.buffer.get() {
                 extents.x2 = b.width as i32;
                 extents.y2 = b.height as i32;
             }
@@ -278,6 +279,9 @@ impl WlSurface {
 
     async fn destroy(&self, parser: MsgParser<'_, '_>) -> Result<(), DestroyError> {
         let _req: Destroy = self.parse(parser)?;
+        if self.role_data.borrow().is_some() {
+            return Err(DestroyError::ReloObjectStillExists);
+        }
         {
             let mut children = self.children.borrow_mut();
             if let Some(children) = &mut *children {
@@ -287,49 +291,12 @@ impl WlSurface {
             }
             *children = None;
         }
-        let mut ss_parent = None;
         {
-            let mut data = self.role_data.borrow_mut();
-            match &mut *data {
-                RoleData::None => {}
-                RoleData::Subsurface(ss) => {
-                    ss_parent = Some(ss.subsurface.parent.clone());
-                    let mut children = ss.subsurface.parent.children.borrow_mut();
-                    if let Some(children) = &mut *children {
-                        children.subsurfaces.remove(&self.id);
-                    }
-                }
-                RoleData::XdgSurface(xdg) => {
-                    let children = xdg.popups.lock();
-                    for child in children.values() {
-                        let mut rd = child.surface.surface.role_data.borrow_mut();
-                        if let RoleData::XdgSurface(xdg) = &mut *rd {
-                            if let XdgSurfaceRoleData::Popup(p) = &mut xdg.role_data {
-                                p.parent = None;
-                            }
-                        }
-                    }
-                    if let XdgSurfaceRoleData::Popup(p) = &mut xdg.role_data {
-                        if let Some(p) = &p.parent {
-                            let mut rd = p.surface.role_data.borrow_mut();
-                            if let RoleData::XdgSurface(xdg) = &mut *rd {
-                                xdg.popups.remove(&self.id);
-                            }
-                        }
-                    }
-                }
-            }
-            *data = RoleData::None;
-        }
-        {
-            let buffer = self.buffer.borrow();
-            if let Some(buffer) = &*buffer {
+            let buffer = self.buffer.get();
+            if let Some(buffer) = &buffer {
                 buffer.surfaces.remove(&self.id);
             }
         }
-        if let Some(parent) = ss_parent {
-            parent.calculate_extents();
-        }
         self.client.remove_obj(self).await?;
         Ok(())
     }
@@ -337,14 +304,13 @@ impl WlSurface {
     async fn attach(&self, parser: MsgParser<'_, '_>) -> Result<(), AttachError> {
         let req: Attach = self.parse(parser)?;
         {
-            let mut buffer = self.buffer.borrow_mut();
-            if let Some(buffer) = buffer.take() {
+            if let Some(buffer) = self.buffer.take() {
                 self.client.event(buffer.release()).await?;
                 buffer.surfaces.remove(&self.id);
             }
             let mut rd = self.role_data.borrow_mut();
             if req.buffer.is_some() {
-                *buffer = Some(self.client.get_buffer(req.buffer)?);
+                self.buffer.set(Some(self.client.get_buffer(req.buffer)?));
                 if let RoleData::XdgSurface(xdg) = &mut *rd {
                     if let XdgSurfaceRoleData::Toplevel(td) = &mut xdg.role_data {
                         if td.node.is_none() {
@@ -370,7 +336,7 @@ impl WlSurface {
                     }
                 }
             } else {
-                *buffer = None;
+                self.buffer.set(None);
                 if let RoleData::XdgSurface(xdg) = &mut *rd {
                     if let XdgSurfaceRoleData::Toplevel(td) = &mut xdg.role_data {
                         td.node = None;
@@ -574,6 +540,6 @@ impl Object for WlSurface {
         *self.children.borrow_mut() = None;
         *self.role_data.borrow_mut() = RoleData::None;
         mem::take(self.frame_requests.borrow_mut().deref_mut());
-        *self.buffer.borrow_mut() = None;
+        self.buffer.set(None);
     }
 }
diff --git a/src/ifs/wl_surface/types.rs b/src/ifs/wl_surface/types.rs
index 4f95d2b6..4bcf4be9 100644
--- a/src/ifs/wl_surface/types.rs
+++ b/src/ifs/wl_surface/types.rs
@@ -49,6 +49,8 @@ pub enum DestroyError {
     ParseFailed(#[source] Box<MsgParserError>),
     #[error(transparent)]
     ClientError(Box<ClientError>),
+    #[error("Cannot destroy a `wl_surface` before its role object")]
+    ReloObjectStillExists,
 }
 efrom!(DestroyError, ParseFailed, MsgParserError);
 efrom!(DestroyError, ClientError, ClientError);
diff --git a/src/tasks.rs b/src/tasks.rs
index 08bc225c..aa8ceceb 100644
--- a/src/tasks.rs
+++ b/src/tasks.rs
@@ -6,6 +6,7 @@ use crate::utils::asyncevent::AsyncEvent;
 use crate::State;
 use std::cell::{Cell, RefCell};
 use std::rc::Rc;
+use crate::utils::clonecell::CloneCell;
 
 pub async fn handle_backend_events(state: Rc<State>) {
     let mut beh = BackendEventHandler { state };
@@ -77,7 +78,7 @@ impl OutputHandler {
                 floating_outputs: RefCell::new(Default::default()),
             },
             backend: self.output.clone(),
-            child: RefCell::new(None),
+            child: CloneCell::new(None),
             floating: Default::default(),
         });
         self.state.root.outputs.set(self.output.id(), on.clone());
diff --git a/src/tree.rs b/src/tree.rs
index a812ba99..8648292c 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -6,6 +6,7 @@ use ahash::AHashMap;
 use std::cell::{Cell, RefCell};
 use std::mem;
 use std::rc::Rc;
+use crate::utils::clonecell::CloneCell;
 
 linear_ids!(NodeIds, NodeId);
 
@@ -135,7 +136,7 @@ impl Node for DisplayNode {
 pub struct OutputNode {
     pub common: NodeCommon,
     pub backend: Rc<dyn Output>,
-    pub child: RefCell<Option<Rc<dyn Node>>>,
+    pub child: CloneCell<Option<Rc<dyn Node>>>,
     pub floating: LinkedList<Rc<dyn Node>>,
 }
 
@@ -151,7 +152,7 @@ impl Node for OutputNode {
         for floating in self.floating.iter() {
             floating.clear();
         }
-        if let Some(child) = self.child.borrow_mut().take() {
+        if let Some(child) = self.child.take() {
             child.clear();
         }
     }
diff --git a/src/utils/buffd/formatter.rs b/src/utils/buffd/formatter.rs
index 85e0cd7c..6659c0c6 100644
--- a/src/utils/buffd/formatter.rs
+++ b/src/utils/buffd/formatter.rs
@@ -70,7 +70,7 @@ impl<'a> MsgFormatter<'a> {
                 fds: self.fds,
             };
             f(&mut fmt);
-            let len = self.buf.out_pos - pos + 4;
+            let len = self.buf.out_pos - pos - 4;
             let none = [MaybeUninit::new(0); 4];
             self.buf.write(&none[..self.buf.out_pos.wrapping_neg() & 3]);
             len as u32
diff --git a/src/utils/clonecell.rs b/src/utils/clonecell.rs
new file mode 100644
index 00000000..74b2d404
--- /dev/null
+++ b/src/utils/clonecell.rs
@@ -0,0 +1,49 @@
+use std::cell::UnsafeCell;
+use std::mem;
+use std::rc::Rc;
+use crate::utils::ptr_ext::{MutPtrExt, PtrExt};
+
+pub struct CloneCell<T: UnsafeCellCloneSafe> {
+    data: UnsafeCell<T>,
+}
+
+impl<T: UnsafeCellCloneSafe> CloneCell<T> {
+    pub fn new(t: T) -> Self {
+        Self {
+            data: UnsafeCell::new(t),
+        }
+    }
+
+    #[inline(always)]
+    pub fn get(&self) -> T {
+        unsafe {
+            self.data.get().deref().clone()
+        }
+    }
+
+    #[inline(always)]
+    pub fn set(&self, t: T) {
+        unsafe {
+            let _ = mem::replace(self.data.get().deref_mut(), t);
+        }
+    }
+
+    #[inline(always)]
+    pub fn take(&self) -> T where T: Default {
+        unsafe {
+            mem::take(self.data.get().deref_mut())
+        }
+    }
+}
+
+impl<T: Default + UnsafeCellCloneSafe> Default for CloneCell<T> {
+    fn default() -> Self {
+        Self::new(Default::default())
+    }
+}
+
+pub unsafe trait UnsafeCellCloneSafe: Clone { }
+
+unsafe impl<T: UnsafeCellCloneSafe> UnsafeCellCloneSafe for Option<T> { }
+
+unsafe impl<T: ?Sized> UnsafeCellCloneSafe for Rc<T> { }
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index 63c2480f..98f15a2e 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -8,3 +8,4 @@ pub mod oneshot;
 pub mod ptr_ext;
 pub mod queue;
 pub mod vec_ext;
+pub mod clonecell;