Add detach_process option to spawn

crates/top/re_sdk/src/spawn.rs

@@ -50,6 +50,9 @@ pub struct SpawnOptions {
 
     /// Hide the welcome screen.
     pub hide_welcome_screen: bool,
+
+    /// Detach Rerun Viewer process from the application process.
+    pub detach_process: bool,
 }
 
 // NOTE: No need for .exe extension on windows.
@@ -66,6 +69,7 @@ impl Default for SpawnOptions {
             extra_args: Vec::new(),
             extra_env: Vec::new(),
             hide_welcome_screen: false,
+            detach_process: true,
         }
     }
 }
@@ -283,19 +287,22 @@ pub fn spawn(opts: &SpawnOptions) -> Result<(), SpawnError> {
     rerun_bin.args(opts.extra_args.clone());
     rerun_bin.envs(opts.extra_env.clone());
 
-    // SAFETY: This code is only run in the child fork, we are not modifying any memory
-    // that is shared with the parent process.
-    #[cfg(target_family = "unix")]
-    unsafe {
-        rerun_bin.pre_exec(|| {
-            // On unix systems, we want to make sure that the child process becomes its
-            // own session leader, so that it doesn't die if the parent process crashes
-            // or is killed.
-            libc::setsid();
-
-            Ok(())
-        })
-    };
+    if opts.detach_process {
+        // SAFETY: This code is only run in the child fork, we are not modifying any memory
+        // that is shared with the parent process.
+        #[cfg(target_family = "unix")]
+        unsafe {
+            rerun_bin.pre_exec(|| {
+                // On unix systems, we want to make sure that the child process becomes its
+                // own session leader, so that it doesn't die if the parent process crashes
+                // or is killed.
+                libc::setsid();
+
+                Ok(())
+            })
+        };
+    }
+
     rerun_bin.spawn().map_err(map_err)?;
 
     if opts.wait_for_bind {

crates/top/rerun/src/commands/entrypoint.rs

@@ -220,6 +220,10 @@ If no arguments are given, a server will be hosted which a Rerun SDK can connect
     #[clap(long)]
     hide_welcome_screen: bool,
 
+    /// Detach Rerun Viewer process from the application process.
+    #[clap(long)]
+    detach_process: bool,
+
     /// Set the screen resolution (in logical points), e.g. "1920x1080".
     /// Useful together with `--screenshot-to`.
     #[clap(long)]
@@ -655,6 +659,7 @@ fn run_impl(
 
         re_viewer::StartupOptions {
             hide_welcome_screen: args.hide_welcome_screen,
+            detach_process: args.detach_process,
             memory_limit: re_memory::MemoryLimit::parse(&args.memory_limit)
                 .map_err(|err| anyhow::format_err!("Bad --memory-limit: {err}"))?,
             persist_state: args.persist_state,

crates/top/rerun_c/src/lib.rs

@@ -96,6 +96,7 @@ pub struct CSpawnOptions {
     pub port: u16,
     pub memory_limit: CStringView,
     pub hide_welcome_screen: bool,
+    pub detach_process: bool,
     pub executable_name: CStringView,
     pub executable_path: CStringView,
 }
@@ -116,6 +117,7 @@ impl CSpawnOptions {
         }
 
         spawn_opts.hide_welcome_screen = self.hide_welcome_screen;
+        spawn_opts.detach_process = self.detach_process;
 
         if !self.executable_name.is_empty() {
             spawn_opts.executable_name = self.executable_name.as_str("executable_name")?.to_owned();

crates/viewer/re_viewer/src/app.rs

@@ -62,6 +62,9 @@ pub struct StartupOptions {
     /// A user has specifically requested the welcome screen be hidden.
     pub hide_welcome_screen: bool,
 
+    /// Detach Rerun Viewer process from the application process.
+    pub detach_process: bool,
+
     /// Set the screen resolution in logical points.
     #[cfg(not(target_arch = "wasm32"))]
     pub resolution_in_points: Option<[f32; 2]>,
@@ -128,6 +131,7 @@ impl Default for StartupOptions {
             screenshot_to_path_then_quit: None,
 
             hide_welcome_screen: false,
+            detach_process: true,
 
             #[cfg(not(target_arch = "wasm32"))]
             resolution_in_points: None,

docs/content/reference/cli.md

@@ -141,6 +141,11 @@ The Rerun command-line interface:
 >
 > [Default: `false`]
 
+* `--detach-process <DETACH_PROCESS>`
+> Detach Rerun Viewer process from the application process.
+>
+> [Default: `true`]
+
 * `--window-size <WINDOW_SIZE>`
 > Set the screen resolution (in logical points), e.g. "1920x1080". Useful together with `--screenshot-to`.
 

rerun_cpp/src/rerun/spawn_options.cpp

@@ -7,6 +7,7 @@ namespace rerun {
         spawn_opts.port = port;
         spawn_opts.memory_limit = detail::to_rr_string(memory_limit);
         spawn_opts.hide_welcome_screen = hide_welcome_screen;
+        spawn_opts.detach_process = detach_process;
         spawn_opts.executable_name = detail::to_rr_string(executable_name);
         spawn_opts.executable_path = detail::to_rr_string(executable_path);
     }

rerun_cpp/src/rerun/spawn_options.hpp

@@ -31,6 +31,11 @@ namespace rerun {
         /// Defaults to `false` if unset.
         bool hide_welcome_screen = false;
 
+        /// Detach Rerun Viewer process from the application process.
+        ///
+        /// Defaults to `true` if unset.
+        bool detach_process = true;
+
         /// Specifies the name of the Rerun executable.
         ///
         /// You can omit the `.exe` suffix on Windows.

rerun_py/rerun_bindings/rerun_bindings.pyi

@@ -879,6 +879,7 @@ def spawn(
     port: int = 9876,
     memory_limit: str = ...,
     hide_welcome_screen: bool = False,
+    detach_process: bool = True,
     executable_name: str = ...,
     executable_path: Optional[str] = None,
     extra_args: list[str] = ...,

rerun_py/rerun_sdk/rerun/_spawn.py

@@ -8,6 +8,7 @@ def _spawn_viewer(
     port: int = 9876,
     memory_limit: str = "75%",
     hide_welcome_screen: bool = False,
+    detach_process: bool = True,
 ) -> None:
     """
     Internal helper to spawn a Rerun Viewer, listening on the given port.
@@ -26,6 +27,8 @@ def _spawn_viewer(
         Example: `16GB` or `50%` (of system total).
     hide_welcome_screen:
         Hide the normal Rerun welcome screen.
+    detach_process:
+        Detach Rerun Viewer process from the application process.
 
     """
 
@@ -39,4 +42,6 @@ def _spawn_viewer(
         return
     new_env["RERUN_APP_ONLY"] = "true"
 
-    rerun_bindings.spawn(port=port, memory_limit=memory_limit, hide_welcome_screen=hide_welcome_screen)
+    rerun_bindings.spawn(
+        port=port, memory_limit=memory_limit, hide_welcome_screen=hide_welcome_screen, detach_process=detach_process
+    )

rerun_py/rerun_sdk/rerun/blueprint/api.py

@@ -662,6 +662,7 @@ def spawn(
         port: int = 9876,
         memory_limit: str = "75%",
         hide_welcome_screen: bool = False,
+        detach_process: bool = True,
     ) -> None:
         """
         Spawn a Rerun viewer with this blueprint.
@@ -679,9 +680,13 @@ def spawn(
             Example: `16GB` or `50%` (of system total).
         hide_welcome_screen:
             Hide the normal Rerun welcome screen.
+        detach_process:
+            Detach Rerun Viewer process from the application process.
 
         """
-        _spawn_viewer(port=port, memory_limit=memory_limit, hide_welcome_screen=hide_welcome_screen)
+        _spawn_viewer(
+            port=port, memory_limit=memory_limit, hide_welcome_screen=hide_welcome_screen, detach_process=detach_process
+        )
         self.connect_grpc(application_id=application_id, url=f"rerun+http://127.0.0.1:{port}/proxy")
 
 

rerun_py/rerun_sdk/rerun/recording_stream.py

@@ -687,6 +687,7 @@ def spawn(
         connect: bool = True,
         memory_limit: str = "75%",
         hide_welcome_screen: bool = False,
+        detach_process: bool = True,
         default_blueprint: BlueprintLike | None = None,
     ) -> None:
         """
@@ -709,6 +710,8 @@ def spawn(
             Example: `16GB` or `50%` (of system total).
         hide_welcome_screen:
             Hide the normal Rerun welcome screen.
+        detach_process:
+            Detach Rerun Viewer process from the application process.
         default_blueprint
             Optionally set a default blueprint to use for this application. If the application
             already has an active blueprint, the new blueprint won't become active until the user
@@ -724,6 +727,7 @@ def spawn(
             connect=connect,
             memory_limit=memory_limit,
             hide_welcome_screen=hide_welcome_screen,
+            detach_process=detach_process,
             default_blueprint=default_blueprint,
             recording=self,
         )

rerun_py/rerun_sdk/rerun/sinks.py

@@ -340,6 +340,7 @@ def spawn(
     connect: bool = True,
     memory_limit: str = "75%",
     hide_welcome_screen: bool = False,
+    detach_process: bool = True,
     default_blueprint: BlueprintLike | None = None,
     recording: RecordingStream | None = None,
 ) -> None:
@@ -363,6 +364,8 @@ def spawn(
         Example: `16GB` or `50%` (of system total).
     hide_welcome_screen:
         Hide the normal Rerun welcome screen.
+    detach_process:
+        Detach Rerun Viewer process from the application process.
     recording:
         Specifies the [`rerun.RecordingStream`][] to use if `connect = True`.
         If left unspecified, defaults to the current active data recording, if there is one.
@@ -379,7 +382,9 @@ def spawn(
         logging.warning("Rerun is disabled - spawn() call ignored.")
         return
 
-    _spawn_viewer(port=port, memory_limit=memory_limit, hide_welcome_screen=hide_welcome_screen)
+    _spawn_viewer(
+        port=port, memory_limit=memory_limit, hide_welcome_screen=hide_welcome_screen, detach_process=detach_process
+    )
 
     if connect:
         connect_grpc(

rerun_py/src/python_bridge.rs

@@ -569,11 +569,12 @@ fn send_mem_sink_as_default_blueprint(
 
 /// Spawn a new viewer.
 #[pyfunction]
-#[pyo3(signature = (port = 9876, memory_limit = "75%".to_owned(), hide_welcome_screen = false, executable_name = "rerun".to_owned(), executable_path = None, extra_args = vec![], extra_env = vec![]))]
+#[pyo3(signature = (port = 9876, memory_limit = "75%".to_owned(), hide_welcome_screen = false, detach_process = true, executable_name = "rerun".to_owned(), executable_path = None, extra_args = vec![], extra_env = vec![]))]
 fn spawn(
     port: u16,
     memory_limit: String,
     hide_welcome_screen: bool,
+    detach_process: bool,
     executable_name: String,
     executable_path: Option<String>,
     extra_args: Vec<String>,
@@ -584,6 +585,7 @@ fn spawn(
         wait_for_bind: true,
         memory_limit,
         hide_welcome_screen,
+        detach_process,
         executable_name,
         executable_path,
         extra_args,