From 8cb0da0597022a670219b351fa3a5f320083a0a5 Mon Sep 17 00:00:00 2001
From: exrok <exrok@i64.dev>
Date: Sat, 20 Dec 2025 19:46:40 +0000
Subject: [PATCH] fix(alsa): Don't leak alsactl process

This bug was found when alsactl was repeatedly failing due to a missing
device causing a number of alsactl processes to be running.

This PR uses tokio's kill_on_drop and an added the process handle to a field
in the device. I have not checked the rest of the code base for similar
issues but at least after this PR alsa is fixed. :)
---
 src/blocks/sound/alsa.rs | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/blocks/sound/alsa.rs b/src/blocks/sound/alsa.rs
index fd3467615f..efd2f18dc5 100644
--- a/src/blocks/sound/alsa.rs
+++ b/src/blocks/sound/alsa.rs
@@ -12,23 +12,32 @@ pub(super) struct Device {
     volume: u32,
     muted: bool,
     monitor: ChildStdout,
+    #[expect(
+        dead_code,
+        reason = "Only used in drop to trigger kill and reap of child process"
+    )]
+    process: tokio::process::Child,
 }
 
 impl Device {
     pub(super) fn new(name: String, device: String, natural_mapping: bool) -> Result<Self> {
+        let mut process = Command::new("alsactl")
+            .arg("monitor")
+            .kill_on_drop(true)
+            .stdout(Stdio::piped())
+            .spawn()
+            .error("Failed to start alsactl monitor")?;
         Ok(Device {
             name,
             device,
             natural_mapping,
             volume: 0,
             muted: false,
-            monitor: Command::new("alsactl")
-                .arg("monitor")
-                .stdout(Stdio::piped())
-                .spawn()
-                .error("Failed to start alsactl monitor")?
+            monitor: process
                 .stdout
+                .take()
                 .error("Failed to pipe alsactl monitor output")?,
+            process,
         })
     }
 }