Move X11Source to smithay under`x11rb_event_source` feature

CHANGELOG.md

@@ -27,6 +27,7 @@
 
 #### Backends
 
+- `x11rb` event source integration used in anvil's XWayland implementation is now part of smithay at `utils::x11rb`. Enabled through the `x11rb_event_source` feature. 
 - New `DrmNode` type in drm backend. This is primarily for use a backend which needs to run as client inside another session.
 
 ### Bugfixes

Cargo.toml

@@ -46,6 +46,7 @@ wayland-protocols = { version = "0.29.0", features = ["unstable_protocols", "sta
 wayland-server = { version = "0.29.0", optional = true }
 wayland-sys = { version = "0.29.0", optional = true }
 winit = { version = "0.25.0", optional = true }
+x11rb = { version = "0.9.0", optional = true }
 xkbcommon = "0.4.0"
 scan_fmt = { version = "0.2.3", default-features = false }
 
@@ -71,6 +72,7 @@ backend_session_libseat = ["backend_session", "libseat"]
 renderer_gl = ["gl_generator", "backend_egl"]
 use_system_lib = ["wayland_frontend", "wayland-sys", "wayland-server/use_system_lib"]
 wayland_frontend = ["wayland-server", "wayland-commons", "wayland-protocols", "tempfile"]
+x11rb_event_source = ["x11rb"]
 xwayland = ["wayland_frontend"]
 test_all_features = ["default", "use_system_lib", "wayland-server/dlopen"]
 

anvil/Cargo.toml

@@ -28,7 +28,7 @@ features = [ "wayland_frontend", "slog-stdlog" ]
 
 [dependencies.x11rb]
 optional = true
-version = "0.8"
+version = "0.9.0"
 default-features = false
 features = [ "composite" ]
 
@@ -43,6 +43,6 @@ udev = [ "smithay/backend_libinput", "smithay/backend_udev", "smithay/backend_dr
 logind = [ "smithay/backend_session_logind" ]
 elogind = ["logind", "smithay/backend_session_elogind" ]
 libseat = ["smithay/backend_session_libseat" ]
-xwayland = [ "smithay/xwayland", "x11rb" ]
+xwayland = [ "smithay/xwayland", "x11rb", "smithay/x11rb_event_source" ]
 debug = [ "fps_ticker", "image/png" ]
 test_all_features = ["default", "debug"]

anvil/src/xwayland/mod.rs

@@ -4,7 +4,7 @@ use std::{
 
 use smithay::{
     reexports::wayland_server::{protocol::wl_surface::WlSurface, Client},
-    utils::{Logical, Point},
+    utils::{x11rb::X11Source, Logical, Point},
     wayland::compositor::give_role,
 };
 
@@ -27,10 +27,6 @@ use crate::{
     AnvilState,
 };
 
-use x11rb_event_source::X11Source;
-
-mod x11rb_event_source;
-
 impl<BackendData: 'static> AnvilState<BackendData> {
     pub fn start_xwayland(&mut self) {
         if let Err(e) = self.xwayland.start() {
@@ -237,7 +233,7 @@ pub fn commit_hook(surface: &WlSurface) {
     }
 }
 
-#[derive(Clone)]
+#[derive(Debug, Clone)]
 pub struct X11Surface {
     surface: WlSurface,
 }

src/reexports.rs

@@ -21,3 +21,5 @@ pub use wayland_protocols;
 pub use wayland_server;
 #[cfg(feature = "backend_winit")]
 pub use winit;
+#[cfg(feature = "x11rb_event_source")]
+pub use x11rb;

src/utils/mod.rs

@@ -3,6 +3,9 @@
 mod geometry;
 pub mod signaling;
 
+#[cfg(feature = "x11rb_event_source")]
+pub mod x11rb;
+
 pub use self::geometry::{Buffer, Logical, Physical, Point, Raw, Rectangle, Size};
 
 /// This resource is not managed by Smithay

src/utils/x11rb.rs

@@ -1,3 +1,8 @@
+//! Helper utilities for using x11rb as an event source in calloop.
+//!
+//! The primary use for this module is XWayland integration but is also widely useful for an X11
+//! backend in a compositor.
+
 use std::{
     io::Result as IOResult,
     sync::Arc,
@@ -13,7 +18,7 @@ use x11rb::{
     rust_connection::RustConnection,
 };
 
-use smithay::reexports::calloop::{
+use calloop::{
     channel::{sync_channel, Channel, Event as ChannelEvent, SyncSender},
     EventSource, Poll, PostAction, Readiness, Token, TokenFactory,
 };
@@ -28,9 +33,10 @@ use smithay::reexports::calloop::{
 /// iteration. Calloop only allows "when an FD becomes readable".
 ///
 /// [1]: https://docs.rs/x11rb/0.8.1/x11rb/event_loop_integration/index.html#threads-and-races
+#[derive(Debug)]
 pub struct X11Source {
     connection: Arc<RustConnection>,
-    channel: Channel<Event>,
+    channel: Option<Channel<Event>>,
     event_thread: Option<JoinHandle<()>>,
     close_window: Window,
     close_type: Atom,
@@ -56,9 +62,10 @@ impl X11Source {
         let event_thread = Some(spawn(move || {
             run_event_thread(conn, sender, log2);
         }));
+
         Self {
             connection,
-            channel,
+            channel: Some(channel),
             event_thread,
             close_window,
             close_type,
@@ -70,9 +77,7 @@ impl X11Source {
 impl Drop for X11Source {
     fn drop(&mut self) {
         // Signal the worker thread to exit by dropping the read end of the channel.
-        // There is no easy and nice way to do this, so do it the ugly way: Replace it.
-        let (_, channel) = sync_channel(1);
-        self.channel = channel;
+        self.channel.take();
 
         // Send an event to wake up the worker so that it actually exits
         let event = ClientMessageEvent {
@@ -83,6 +88,7 @@ impl Drop for X11Source {
             type_: self.close_type,
             data: [0; 20].into(),
         };
+
         let _ = self
             .connection
             .send_event(false, self.close_window, EventMask::NO_EVENT, event);
@@ -108,23 +114,39 @@ impl EventSource for X11Source {
         C: FnMut(Self::Event, &mut Self::Metadata) -> Self::Ret,
     {
         let log = self.log.clone();
-        self.channel
-            .process_events(readiness, token, move |event, meta| match event {
+
+        if let Some(channel) = &mut self.channel {
+            channel.process_events(readiness, token, move |event, meta| match event {
                 ChannelEvent::Closed => slog::warn!(log, "Event thread exited"),
                 ChannelEvent::Msg(event) => callback(event, meta),
             })
+        } else {
+            Ok(PostAction::Remove)
+        }
     }
 
     fn register(&mut self, poll: &mut Poll, factory: &mut TokenFactory) -> IOResult<()> {
-        self.channel.register(poll, factory)
+        if let Some(channel) = &mut self.channel {
+            channel.register(poll, factory)?;
+        }
+
+        Ok(())
     }
 
     fn reregister(&mut self, poll: &mut Poll, factory: &mut TokenFactory) -> IOResult<()> {
-        self.channel.reregister(poll, factory)
+        if let Some(channel) = &mut self.channel {
+            channel.reregister(poll, factory)?;
+        }
+
+        Ok(())
     }
 
     fn unregister(&mut self, poll: &mut Poll) -> IOResult<()> {
-        self.channel.unregister(poll)
+        if let Some(channel) = &mut self.channel {
+            channel.unregister(poll)?;
+        }
+
+        Ok(())
     }
 }