Update to calloop 0.12.1 and wayland-rs 0.31.0

The update resolves the long present issue of event
source not waking up during the concurrent reads due to
not following the wayland's prepare_read protocol correctly.

In particular, this let's downstream clients, like winit, to remove
workarounds related to mesa doing blocking dispatch and winit
missing wake ups due to that.

Cargo.toml

@@ -11,8 +11,12 @@ keywords = ["wayland", "windowing"]
 rust-version = "1.65.0"
 
 [dependencies]
-wayland-client = "0.30.2"
-wayland-backend = "0.1.0"
-calloop = "0.10.0"
+wayland-client = "0.31.1"
+wayland-backend = "0.3.0"
+calloop = "0.12.1"
 log = { version = "0.4.19", optional = true }
 rustix = { version = "0.38.4", default-features = false, features = ["std"] }
+
+[dev-dependencies]
+tempfile = "3.8.0"
+wayland-protocols = { version = "0.31.0", features = ["client"] }

examples/simplest-window.rs

@@ -0,0 +1,240 @@
+use std::fs::File;
+use std::os::unix::prelude::AsFd;
+
+use calloop::EventLoop;
+use calloop_wayland_source::WaylandSource;
+use wayland_client::protocol::{
+    wl_buffer, wl_compositor, wl_keyboard, wl_registry, wl_seat, wl_shm, wl_shm_pool, wl_surface,
+};
+use wayland_client::{delegate_noop, Connection, Dispatch, QueueHandle, WEnum};
+
+use wayland_protocols::xdg::shell::client::{xdg_surface, xdg_toplevel, xdg_wm_base};
+
+fn main() {
+    let conn = Connection::connect_to_env().unwrap();
+
+    let event_queue = conn.new_event_queue();
+    let qhandle = event_queue.handle();
+
+    let display = conn.display();
+    display.get_registry(&qhandle, ());
+
+    let mut event_loop: EventLoop<State> =
+        EventLoop::try_new().expect("Failed to initialize the event loop!");
+    let loop_handle = event_loop.handle();
+    WaylandSource::new(conn, event_queue).insert(loop_handle).unwrap();
+    let stop_handle = event_loop.get_signal();
+
+    let mut state = State {
+        running: true,
+        base_surface: None,
+        buffer: None,
+        wm_base: None,
+        xdg_surface: None,
+        configured: false,
+        stop_handle,
+    };
+
+    println!("Starting the example window app, press <ESC> to quit.");
+
+    event_loop.run(None, &mut state, |_| {}).unwrap();
+}
+
+struct State {
+    running: bool,
+    base_surface: Option<wl_surface::WlSurface>,
+    buffer: Option<wl_buffer::WlBuffer>,
+    wm_base: Option<xdg_wm_base::XdgWmBase>,
+    xdg_surface: Option<(xdg_surface::XdgSurface, xdg_toplevel::XdgToplevel)>,
+    configured: bool,
+    stop_handle: calloop::LoopSignal,
+}
+
+impl Dispatch<wl_registry::WlRegistry, ()> for State {
+    fn event(
+        state: &mut Self,
+        registry: &wl_registry::WlRegistry,
+        event: wl_registry::Event,
+        _: &(),
+        _: &Connection,
+        qh: &QueueHandle<Self>,
+    ) {
+        if let wl_registry::Event::Global { name, interface, .. } = event {
+            match &interface[..] {
+                "wl_compositor" => {
+                    let compositor =
+                        registry.bind::<wl_compositor::WlCompositor, _, _>(name, 1, qh, ());
+                    let surface = compositor.create_surface(qh, ());
+                    state.base_surface = Some(surface);
+
+                    if state.wm_base.is_some() && state.xdg_surface.is_none() {
+                        state.init_xdg_surface(qh);
+                    }
+                },
+                "wl_shm" => {
+                    let shm = registry.bind::<wl_shm::WlShm, _, _>(name, 1, qh, ());
+
+                    let (init_w, init_h) = (320, 240);
+
+                    let mut file = tempfile::tempfile().unwrap();
+                    draw(&mut file, (init_w, init_h));
+                    let pool = shm.create_pool(file.as_fd(), (init_w * init_h * 4) as i32, qh, ());
+                    let buffer = pool.create_buffer(
+                        0,
+                        init_w as i32,
+                        init_h as i32,
+                        (init_w * 4) as i32,
+                        wl_shm::Format::Argb8888,
+                        qh,
+                        (),
+                    );
+                    state.buffer = Some(buffer.clone());
+
+                    if state.configured {
+                        let surface = state.base_surface.as_ref().unwrap();
+                        surface.attach(Some(&buffer), 0, 0);
+                        surface.commit();
+                    }
+                },
+                "wl_seat" => {
+                    registry.bind::<wl_seat::WlSeat, _, _>(name, 1, qh, ());
+                },
+                "xdg_wm_base" => {
+                    let wm_base = registry.bind::<xdg_wm_base::XdgWmBase, _, _>(name, 1, qh, ());
+                    state.wm_base = Some(wm_base);
+
+                    if state.base_surface.is_some() && state.xdg_surface.is_none() {
+                        state.init_xdg_surface(qh);
+                    }
+                },
+                _ => {},
+            }
+        }
+    }
+}
+
+// Ignore events from these object types in this example.
+delegate_noop!(State: ignore wl_compositor::WlCompositor);
+delegate_noop!(State: ignore wl_surface::WlSurface);
+delegate_noop!(State: ignore wl_shm::WlShm);
+delegate_noop!(State: ignore wl_shm_pool::WlShmPool);
+delegate_noop!(State: ignore wl_buffer::WlBuffer);
+
+fn draw(tmp: &mut File, (buf_x, buf_y): (u32, u32)) {
+    use std::cmp::min;
+    use std::io::Write;
+    let mut buf = std::io::BufWriter::new(tmp);
+    for y in 0..buf_y {
+        for x in 0..buf_x {
+            let a = 0xFF;
+            let r = min(((buf_x - x) * 0xFF) / buf_x, ((buf_y - y) * 0xFF) / buf_y);
+            let g = min((x * 0xFF) / buf_x, ((buf_y - y) * 0xFF) / buf_y);
+            let b = min(((buf_x - x) * 0xFF) / buf_x, (y * 0xFF) / buf_y);
+
+            let color = (a << 24) + (r << 16) + (g << 8) + b;
+            buf.write_all(&color.to_ne_bytes()).unwrap();
+        }
+    }
+    buf.flush().unwrap();
+}
+
+impl State {
+    fn init_xdg_surface(&mut self, qh: &QueueHandle<State>) {
+        let wm_base = self.wm_base.as_ref().unwrap();
+        let base_surface = self.base_surface.as_ref().unwrap();
+
+        let xdg_surface = wm_base.get_xdg_surface(base_surface, qh, ());
+        let toplevel = xdg_surface.get_toplevel(qh, ());
+        toplevel.set_title("A fantastic window!".into());
+
+        base_surface.commit();
+
+        self.xdg_surface = Some((xdg_surface, toplevel));
+    }
+}
+
+impl Dispatch<xdg_wm_base::XdgWmBase, ()> for State {
+    fn event(
+        _: &mut Self,
+        wm_base: &xdg_wm_base::XdgWmBase,
+        event: xdg_wm_base::Event,
+        _: &(),
+        _: &Connection,
+        _: &QueueHandle<Self>,
+    ) {
+        if let xdg_wm_base::Event::Ping { serial } = event {
+            wm_base.pong(serial);
+        }
+    }
+}
+
+impl Dispatch<xdg_surface::XdgSurface, ()> for State {
+    fn event(
+        state: &mut Self,
+        xdg_surface: &xdg_surface::XdgSurface,
+        event: xdg_surface::Event,
+        _: &(),
+        _: &Connection,
+        _: &QueueHandle<Self>,
+    ) {
+        if let xdg_surface::Event::Configure { serial, .. } = event {
+            xdg_surface.ack_configure(serial);
+            state.configured = true;
+            let surface = state.base_surface.as_ref().unwrap();
+            if let Some(ref buffer) = state.buffer {
+                surface.attach(Some(buffer), 0, 0);
+                surface.commit();
+            }
+        }
+    }
+}
+
+impl Dispatch<xdg_toplevel::XdgToplevel, ()> for State {
+    fn event(
+        state: &mut Self,
+        _: &xdg_toplevel::XdgToplevel,
+        event: xdg_toplevel::Event,
+        _: &(),
+        _: &Connection,
+        _: &QueueHandle<Self>,
+    ) {
+        if let xdg_toplevel::Event::Close {} = event {
+            state.running = false;
+        }
+    }
+}
+
+impl Dispatch<wl_seat::WlSeat, ()> for State {
+    fn event(
+        _: &mut Self,
+        seat: &wl_seat::WlSeat,
+        event: wl_seat::Event,
+        _: &(),
+        _: &Connection,
+        qh: &QueueHandle<Self>,
+    ) {
+        if let wl_seat::Event::Capabilities { capabilities: WEnum::Value(capabilities) } = event {
+            if capabilities.contains(wl_seat::Capability::Keyboard) {
+                seat.get_keyboard(qh, ());
+            }
+        }
+    }
+}
+
+impl Dispatch<wl_keyboard::WlKeyboard, ()> for State {
+    fn event(
+        state: &mut Self,
+        _: &wl_keyboard::WlKeyboard,
+        event: wl_keyboard::Event,
+        _: &(),
+        _: &Connection,
+        _: &QueueHandle<Self>,
+    ) {
+        if let wl_keyboard::Event::Key { key, .. } = event {
+            if key == 1 {
+                // ESC key
+                state.stop_handle.stop();
+            }
+        }
+    }
+}