move starting/stopping GLib event loop into libwebrtc crate

examples/screensharing/Cargo.toml

@@ -11,6 +11,3 @@ livekit = { workspace = true, features = ["rustls-tls-native-roots"] }
 livekit-api = { workspace = true }
 log = "0.4"
 clap = { version = "4.0", features = ["derive"] }
-
-[target.'cfg(target_os = "linux")'.dependencies]
-glib = "0.21.1"

examples/screensharing/src/lib.rs

@@ -68,16 +68,6 @@ mod test {
         env_logger::init();
         let args = Args::parse();
 
-        #[cfg(target_os = "linux")]
-        {
-            /* This is needed for getting the system picker for screen sharing. */
-            use glib::MainLoop;
-            let main_loop = MainLoop::new(None, false);
-            let _handle = std::thread::spawn(move || {
-                main_loop.run();
-            });
-        }
-
         let url = env::var("LIVEKIT_URL").expect("LIVEKIT_URL is not set");
         let api_key = env::var("LIVEKIT_API_KEY").expect("LIVEKIT_API_KEY is not set");
         let api_secret = env::var("LIVEKIT_API_SECRET").expect("LIVEKIT_API_SECRET is not set");

libwebrtc/Cargo.toml

@@ -7,13 +7,24 @@ license = "Apache-2.0"
 description = "Livekit safe bindings to libwebrtc"
 repository = "https://github.com/livekit/rust-sdks"
 
+[features]
+default = [ "glib-main-loop" ]
+# On Wayland, libwebrtc uses GDBus to communicate with the XDG Desktop Portal.
+# GDBus requires a GLib event loop to be running. If you already have a GLib
+# event loop running in your application, for example if you are using the
+# GTK or GStreamer Rust bindings, disable this feature.
+glib-main-loop = [ "dep:glib" ]
+
 [dependencies]
 livekit-protocol = { workspace = true }
 log = "0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 thiserror = "1.0"
 
+[target.'cfg(any(target_os = "linux", target_os = "freebsd"))'.dependencies]
+glib = { version = "0.21.3", optional = true }
+
 [target.'cfg(target_os = "android")'.dependencies]
 jni = "0.21"
 

libwebrtc/src/native/desktop_capturer.rs

@@ -78,6 +78,8 @@ impl DesktopCapturerOptions {
 
 pub(crate) struct DesktopCapturer {
     sys_handle: UniquePtr<sys_dc::ffi::DesktopCapturer>,
+    #[cfg(all(any(target_os = "linux", target_os = "freebsd"), feature = "glib-main-loop"))]
+    glib_loop: Option<glib::MainLoop>,
 }
 
 impl DesktopCapturer {
@@ -86,7 +88,14 @@ impl DesktopCapturer {
         if sys_handle.is_null() {
             None
         } else {
-            Some(Self { sys_handle })
+            Some(Self {
+                sys_handle,
+                #[cfg(all(
+                    any(target_os = "linux", target_os = "freebsd"),
+                    feature = "glib-main-loop"
+                ))]
+                glib_loop: None,
+            })
         }
     }
 
@@ -98,6 +107,14 @@ impl DesktopCapturer {
     where
         T: FnMut(Result<DesktopFrame, CaptureError>) + Send + 'static,
     {
+        #[cfg(all(any(target_os = "linux", target_os = "freebsd"), feature = "glib-main-loop"))]
+        if std::env::var("WAYLAND_DISPLAY").is_ok() {
+            let main_loop = glib::MainLoop::new(None, false);
+            self.glib_loop = Some(main_loop.clone());
+            let _handle = std::thread::spawn(move || {
+                main_loop.run();
+            });
+        }
         let pin_handle = self.sys_handle.pin_mut();
         let callback = DesktopCallback::new(callback);
         let callback_wrapper = sys_dc::DesktopCapturerCallbackWrapper::new(Box::new(callback));
@@ -118,6 +135,15 @@ impl DesktopCapturer {
     }
 }
 
+#[cfg(all(any(target_os = "linux", target_os = "freebsd"), feature = "glib-main-loop"))]
+impl Drop for DesktopCapturer {
+    fn drop(&mut self) {
+        if let Some(glib_loop) = &self.glib_loop {
+            glib_loop.quit();
+        }
+    }
+}
+
 pub(crate) struct DesktopFrame {
     sys_handle: UniquePtr<sys_dc::ffi::DesktopFrame>,
 }