Run plot comms on the R thread

crates/ark/src/comm_handler.rs

@@ -18,9 +18,12 @@ use serde::de::DeserializeOwned;
 use serde::Serialize;
 use stdext::result::ResultExt;
 
+use crate::console::Console;
+
 /// Context provided to `CommHandler` methods, giving access to the outgoing
-/// channel and close-request mechanism. In the future, we'll provide access to
-/// more of the Console state, such as the currently active environment.
+/// channel, close-request mechanism, and the Console singleton (via
+/// `console()`). Through the Console, handlers can reach runtime state such
+/// as the graphics device context.
 #[derive(Debug)]
 pub struct CommHandlerContext {
     pub outgoing_tx: CommOutgoingTx,
@@ -56,6 +59,11 @@ impl CommHandlerContext {
         };
         self.outgoing_tx.send(CommMsg::Data(json)).log_err();
     }
+
+    /// Access the Console singleton (the R runtime).
+    pub(crate) fn console(&self) -> &Console {
+        Console::get()
+    }
 }
 
 /// Trait for comm handlers that run synchronously on the R thread.

crates/ark/src/console.rs

@@ -147,7 +147,7 @@ use crate::lsp::state_handlers::ConsoleInputs;
 use crate::modules;
 use crate::modules::ARK_ENVS;
 use crate::plots::graphics_device;
-use crate::plots::graphics_device::GraphicsDeviceNotification;
+use crate::plots::graphics_device::DeviceContext;
 use crate::r_task;
 use crate::r_task::BoxFuture;
 use crate::r_task::RTask;
@@ -334,4 +334,7 @@ pub(crate) struct Console {
 
     /// Comm handlers registered on the R thread (keyed by comm ID).
     comms: HashMap<String, ConsoleComm>,
+
+    /// Graphics device state (plot recording, rendering, comm management).
+    device_context: DeviceContext,
 }

crates/ark/src/console/console_repl.rs

@@ -326,7 +326,6 @@ impl Console {
         dap: Arc<Mutex<Dap>>,
         session_mode: SessionMode,
         default_repos: DefaultRepos,
-        graphics_device_rx: AsyncUnboundedReceiver<GraphicsDeviceNotification>,
         console_notification_rx: AsyncUnboundedReceiver<ConsoleNotification>,
     ) {
         // Set the main thread ID.
@@ -481,17 +480,16 @@ impl Console {
             }
         });
 
-        // Initialize the GD context on this thread.
+        // Perform R-side graphics device initialization (register as
+        // interactive, spawn notification listener). The `DeviceContext`
+        // itself is already created as part of `Console::new()`.
+        //
         // Note that we do it after init is complete to avoid deadlocking
         // integration tests by spawning an async task. The deadlock is caused
         // by https://github.com/posit-dev/ark/blob/bd827e735970ca17102aeddfbe2c3ccf26950a36/crates/ark/src/r_task.rs#L261.
         // We should be able to remove this escape hatch in `r_task()` by
         // instantiating an `Console` in unit tests as well.
-        graphics_device::init_graphics_device(
-            console.comm_event_tx.clone(),
-            console.iopub_tx().clone(),
-            graphics_device_rx,
-        );
+        graphics_device::init_graphics_device();
 
         // Now that R has started and libr and ark have fully initialized, run site and user
         // level R profiles, in that order
@@ -589,6 +587,8 @@ impl Console {
         dap: Arc<Mutex<Dap>>,
         session_mode: SessionMode,
     ) -> Self {
+        let device_context = DeviceContext::new(iopub_tx.clone());
+
         Self {
             r_request_rx,
             comm_event_tx,
@@ -634,6 +634,7 @@ impl Console {
             read_console_shutdown: Cell::new(false),
             debug_filter: ConsoleFilter::new(),
             comms: HashMap::new(),
+            device_context,
         }
     }
 
@@ -685,6 +686,10 @@ impl Console {
         &self.comm_event_tx
     }
 
+    pub(crate) fn device_context(&self) -> &DeviceContext {
+        &self.device_context
+    }
+
     /// Run a closure while capturing console output.
     /// Returns the closure's result paired with any captured output.
     pub(crate) fn with_capture<T>(f: impl FnOnce() -> T) -> (T, String) {
@@ -2235,13 +2240,6 @@ impl Console {
         // might end up being executed on the LSP thread.
         // https://github.com/rstudio/positron/issues/431
         unsafe { R_RunPendingFinalizers() };
-
-        // Check for Positron render requests.
-        //
-        // TODO: This should move to a spawned task that'd be woken up by
-        // incoming messages on plot comms. This way we'll prevent the delays
-        // introduced by timeout-based event polling.
-        graphics_device::on_process_idle_events();
     }
 
     pub(super) fn eval_env(&self) -> RObject {