address PR comments

crates/re_sdk/src/recording_stream.rs

@@ -1300,6 +1300,7 @@ fn spawn(opts: &crate::SpawnOptions) -> RecordingStreamResult<()> {
 
     let connect_addr = opts.connect_addr();
 
+    // TODO(#4019): application-level handshake
     if TcpStream::connect_timeout(&connect_addr, Duration::from_secs(1)).is_ok() {
         re_log::info!(
             addr = %opts.listen_addr(),

crates/re_sdk/src/spawn.rs

@@ -37,6 +37,9 @@ pub struct SpawnOptions {
     ///
     /// Unspecified by default.
     pub executable_path: Option<String>,
+
+    /// Extra arguments that will be passed as-is to the Rerun Viewer process.
+    pub extra_args: Vec<String>,
 }
 
 // NOTE: No need for .exe extension on windows.
@@ -49,6 +52,7 @@ impl Default for SpawnOptions {
             memory_limit: "75%".into(),
             executable_name: RERUN_BINARY.into(),
             executable_path: None,
+            extra_args: Vec::new(),
         }
     }
 }
@@ -116,6 +120,9 @@ impl std::fmt::Debug for SpawnError {
 
 /// Spawns a new Rerun Viewer process ready to listen for TCP connections.
 ///
+/// If there is already a process listening on this port (Rerun or not), this function returns `Ok`
+/// WITHOUT spawning a `rerun` process (!).
+///
 /// Refer to [`SpawnOptions`]'s documentation for configuration options.
 ///
 /// This only starts a Viewer process: if you'd like to connect to it and start sending data, refer
@@ -140,7 +147,8 @@ pub fn spawn(opts: &SpawnOptions) -> Result<(), SpawnError> {
     let memory_limit = &opts.memory_limit;
     let executable_path = opts.executable_path();
 
-    if TcpStream::connect_timeout(&connect_addr, Duration::from_millis(1)).is_ok() {
+    // TODO(#4019): application-level handshake
+    if TcpStream::connect_timeout(&connect_addr, Duration::from_secs(1)).is_ok() {
         re_log::info!(
             addr = %opts.listen_addr(),
             "A process is already listening at this address. Assuming it's a Rerun Viewer."
@@ -152,6 +160,7 @@ pub fn spawn(opts: &SpawnOptions) -> Result<(), SpawnError> {
         .arg(format!("--port={port}"))
         .arg(format!("--memory-limit={memory_limit}"))
         .arg("--skip-welcome-screen")
+        .args(opts.extra_args.clone())
         .spawn();
 
     let rerun_bin = match res {

docs/code-examples/annotation_context_connections.rs

@@ -2,7 +2,7 @@
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let rec = rerun::RecordingStreamBuilder::new("rerun_example_annotation_context_connections")
-        .spawn(None)?;
+        .spawn(rerun::default_flush_timeout())?;
 
     // Log an annotation context to assign a label and color to each class
     // Create a class description with labels and color for each keypoint ID as well as some

docs/code-examples/annotation_context_rects.rs

@@ -2,7 +2,7 @@
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let rec =
-        rerun::RecordingStreamBuilder::new("rerun_example_annotation_context_rects").spawn(None)?;
+        rerun::RecordingStreamBuilder::new("rerun_example_annotation_context_rects").spawn(rerun::default_flush_timeout())?;
 
     // Log an annotation context to assign a label and color to each class
     rec.log_timeless(

docs/code-examples/annotation_context_segmentation.rs

@@ -4,7 +4,7 @@ use ndarray::{s, Array, ShapeBuilder};
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     let rec = rerun::RecordingStreamBuilder::new("rerun_example_annotation_context_segmentation")
-        .spawn(None)?;
+        .spawn(rerun::default_flush_timeout())?;
 
     // create an annotation context to describe the classes
     rec.log_timeless(

docs/code-examples/arrow3d_simple.rs

@@ -3,7 +3,7 @@
 use std::f32::consts::TAU;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_arrow3d").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_arrow3d").spawn(rerun::default_flush_timeout())?;
 
     let origins = vec![rerun::Position3D::ZERO; 100];
     let (vectors, colors): (Vec<_>, Vec<_>) = (0..100)

docs/code-examples/asset3d_out_of_tree.rs

@@ -12,7 +12,7 @@ fn main() -> anyhow::Result<()> {
     };
 
     let rec =
-        rerun::RecordingStreamBuilder::new("rerun_example_asset3d_out_of_tree").spawn(None)?;
+        rerun::RecordingStreamBuilder::new("rerun_example_asset3d_out_of_tree").spawn(rerun::default_flush_timeout())?;
 
     rec.log_timeless("world", &rerun::ViewCoordinates::RIGHT_HAND_Z_UP)?; // Set an up-axis
 

docs/code-examples/asset3d_simple.rs

@@ -8,7 +8,7 @@ fn main() -> anyhow::Result<()> {
         anyhow::bail!("Usage: {} <path_to_asset.[gltf|glb|obj]>", args[0]);
     };
 
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_asset3d_simple").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_asset3d_simple").spawn(rerun::default_flush_timeout())?;
 
     rec.log_timeless("world", &rerun::ViewCoordinates::RIGHT_HAND_Z_UP)?; // Set an up-axis
     rec.log("world/asset", &rerun::Asset3D::from_file(path)?)?;

docs/code-examples/bar_chart.rs

@@ -1,7 +1,7 @@
 //! Create and log a bar chart
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_bar_chart").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_bar_chart").spawn(rerun::default_flush_timeout())?;
 
     rec.log(
         "bar_chart",

docs/code-examples/box2d_simple.rs

@@ -1,7 +1,7 @@
 //! Log some very simple 2D boxes.
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_box2d").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_box2d").spawn(rerun::default_flush_timeout())?;
 
     rec.log(
         "simple",

docs/code-examples/box3d_batch.rs

@@ -1,7 +1,7 @@
 //! Log a batch of oriented bounding boxes.
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_box3d_batch").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_box3d_batch").spawn(rerun::default_flush_timeout())?;
 
     rec.log(
         "batch",

docs/code-examples/box3d_simple.rs

@@ -1,7 +1,7 @@
 //! Log a single 3D box.
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_box3d").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_box3d").spawn(rerun::default_flush_timeout())?;
 
     rec.log(
         "simple",

docs/code-examples/clear_recursive.rs

@@ -3,7 +3,7 @@
 use rerun::external::glam;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_clear_recursive").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_clear_recursive").spawn(rerun::default_flush_timeout())?;
 
     #[rustfmt::skip]
     let (vectors, origins, colors) = (

docs/code-examples/clear_simple.rs

@@ -3,7 +3,7 @@
 use rerun::external::glam;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_clear_simple").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_clear_simple").spawn(rerun::default_flush_timeout())?;
 
     #[rustfmt::skip]
     let (vectors, origins, colors) = (

docs/code-examples/custom_data.rs

@@ -72,7 +72,7 @@ impl rerun::Loggable for Confidence {
 // ---
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_custom_data").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_custom_data").spawn(rerun::default_flush_timeout())?;
 
     rec.log(
         "left/my_confident_point_cloud",

docs/code-examples/depth_image_3d.rs

@@ -2,7 +2,7 @@
 use ndarray::{s, Array, ShapeBuilder};
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_depth_image").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_depth_image").spawn(rerun::default_flush_timeout())?;
 
     let mut image = Array::<u16, _>::from_elem((200, 300).f(), 65535);
     image.slice_mut(s![50..150, 50..150]).fill(20000);

docs/code-examples/depth_image_simple.rs

@@ -3,7 +3,7 @@
 use ndarray::{s, Array, ShapeBuilder};
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_depth_image").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_depth_image").spawn(rerun::default_flush_timeout())?;
 
     let mut image = Array::<u16, _>::from_elem((200, 300).f(), 65535);
     image.slice_mut(s![50..150, 50..150]).fill(20000);

docs/code-examples/disconnected_space.rs

@@ -1,7 +1,7 @@
 //! Disconnect two spaces.
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let rec = rerun::RecordingStreamBuilder::new("rerun_example_disconnected_space").spawn(None)?;
+    let rec = rerun::RecordingStreamBuilder::new("rerun_example_disconnected_space").spawn(rerun::default_flush_timeout())?;
 
     // These two points can be projected into the same space..
     rec.log(