fix(toolchain): force kill existing pid for process manager not stopp…

…ed cleanly (#506)

Fixes GDT-156

packages/toolchain/src/config/meta.rs

@@ -22,6 +22,10 @@ pub struct Meta {
 	/// See `backend_port`.
 	#[serde(default)]
 	pub editor_port: Option<u16>,
+
+	/// See `backend_port`.
+	#[serde(default)]
+	pub process_manager_state: HashMap<String, ProcessManagerState>,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -58,6 +62,15 @@ pub struct Backend {
 	pub db_url: Option<String>,
 }
 
+#[derive(Default, Clone, Serialize, Deserialize)]
+pub struct ProcessManagerState {
+	/// Stores the PID of the current child process.
+	///
+	/// We use this to kill the existing PID in case the parent process dies without gracefully
+	/// killing the children.
+	pub pid: Option<u32>,
+}
+
 lazy_static! {
 	/// List of all meta paths cached in memory.
 	///

packages/toolchain/src/util/process_manager/mod.rs

@@ -6,7 +6,7 @@ use tokio::{
 	sync::{broadcast, mpsc, watch, Mutex},
 };
 
-use crate::util::task::TaskCtx;
+use crate::{config::meta, paths, util::task::TaskCtx};
 
 #[cfg(unix)]
 mod unix;
@@ -119,6 +119,17 @@ impl ProcessManager {
 	where
 		CommandFut: Future<Output = Result<CommandOpts>>,
 	{
+		// Terminate the previous process if needed
+		if let Some(old_pid) = meta::mutate_project(&paths::data_dir()?, |x| {
+			x.process_manager_state
+				.get_mut(self.key)
+				.and_then(|x| x.pid.take())
+		})
+		.await?
+		{
+			os::kill_process_tree(old_pid).await?;
+		}
+
 		// Start new process if needed. Otherwise, will hook to the existing process.
 		//
 		// Clonign value required since this holds a read lock on the inner
@@ -175,7 +186,7 @@ impl ProcessManager {
 
 				// Re-throw error
 				if let Some(error) = error {
-					bail!("process erorr: {error}");
+					bail!("process error: {error}");
 				}
 
 				Ok(exit_code)
@@ -269,9 +280,18 @@ impl ProcessManager {
 
 		// Spawn the command
 		let mut child = cmd.spawn()?;
+		let child_pid = child.id().expect("missing child pid");
+
+		// Save the PID
+		meta::mutate_project(&paths::data_dir()?, |x| {
+			x.process_manager_state
+				.entry(self.key.to_string())
+				.or_default()
+				.pid = Some(child_pid);
+		})
+		.await?;
 
 		// Update state
-		let child_pid = child.id().expect("missing child pid");
 		self.status_tx
 			.send(ProcessStatus::Running { pid: child_pid })
 			.context("send ProcessStatus::Running")?;
@@ -341,6 +361,16 @@ impl ProcessManager {
 		stdout_handle.await??;
 		stderr_handle.await??;
 
+		// Remove PID
+		meta::mutate_project(&paths::data_dir()?, |x| {
+			x.process_manager_state.get_mut(self.key).map(|x| {
+				if x.pid == Some(child_pid) {
+					x.pid = None;
+				}
+			})
+		})
+		.await?;
+
 		// Update state
 		self.status_tx
 			.send(ProcessStatus::Exited {