From 802166ba23b447aef296b7f2b9ae7dd36a0cfc9e Mon Sep 17 00:00:00 2001
From: Alex P <dtk077@gmail.com>
Date: Wed, 29 Oct 2025 00:26:48 +0200
Subject: [PATCH] fix: use atomic.Bool for audio source to prevent mutex
 contention during switching

---
 audio.go   | 16 ++++++++--------
 jsonrpc.go |  9 +++------
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/audio.go b/audio.go
index 87c3ada3..2945bab3 100644
--- a/audio.go
+++ b/audio.go
@@ -22,7 +22,7 @@ var (
 	audioLogger          zerolog.Logger
 	currentAudioTrack    *webrtc.TrackLocalStaticSample
 	inputTrackHandling   atomic.Bool
-	useUSBForAudioOutput bool
+	useUSBForAudioOutput atomic.Bool
 	audioOutputEnabled   atomic.Bool
 	audioInputEnabled    atomic.Bool
 )
@@ -32,7 +32,7 @@ func initAudio() {
 
 	// Load audio output source from config
 	ensureConfigLoaded()
-	useUSBForAudioOutput = config.AudioOutputSource == "usb"
+	useUSBForAudioOutput.Store(config.AudioOutputSource == "usb")
 
 	// Enable both by default
 	audioOutputEnabled.Store(true)
@@ -57,7 +57,7 @@ func startAudio() error {
 	// Start output audio if not running and enabled
 	if outputSource == nil && audioOutputEnabled.Load() {
 		alsaDevice := "hw:0,0" // HDMI
-		if useUSBForAudioOutput {
+		if useUSBForAudioOutput.Load() {
 			alsaDevice = "hw:1,0" // USB
 		}
 
@@ -167,17 +167,17 @@ func SetAudioOutputSource(useUSB bool) error {
 	audioMutex.Lock()
 	defer audioMutex.Unlock()
 
-	if useUSBForAudioOutput == useUSB {
+	if useUSBForAudioOutput.Load() == useUSB {
 		return nil
 	}
 
 	audioLogger.Info().
-		Bool("old_usb", useUSBForAudioOutput).
+		Bool("old_usb", useUSBForAudioOutput.Load()).
 		Bool("new_usb", useUSB).
 		Msg("Switching audio output source")
 
-	oldValue := useUSBForAudioOutput
-	useUSBForAudioOutput = useUSB
+	oldValue := useUSBForAudioOutput.Load()
+	useUSBForAudioOutput.Store(useUSB)
 
 	ensureConfigLoaded()
 	if useUSB {
@@ -187,7 +187,7 @@ func SetAudioOutputSource(useUSB bool) error {
 	}
 	if err := SaveConfig(); err != nil {
 		audioLogger.Error().Err(err).Msg("Failed to save config")
-		useUSBForAudioOutput = oldValue
+		useUSBForAudioOutput.Store(oldValue)
 		return err
 	}
 
diff --git a/jsonrpc.go b/jsonrpc.go
index 2dc2f095..93b0654c 100644
--- a/jsonrpc.go
+++ b/jsonrpc.go
@@ -899,7 +899,7 @@ func updateUsbRelatedConfig(wasAudioEnabled bool) error {
 	if config.UsbDevices != nil && !config.UsbDevices.Audio && config.AudioOutputSource == "usb" {
 		audioMutex.Lock()
 		config.AudioOutputSource = "hdmi"
-		useUSBForAudioOutput = false
+		useUSBForAudioOutput.Store(false)
 		audioSourceChanged = true
 		audioMutex.Unlock()
 	}
@@ -908,7 +908,7 @@ func updateUsbRelatedConfig(wasAudioEnabled bool) error {
 	if config.UsbDevices != nil && config.UsbDevices.Audio && !wasAudioEnabled {
 		audioMutex.Lock()
 		config.AudioOutputSource = "usb"
-		useUSBForAudioOutput = true
+		useUSBForAudioOutput.Store(true)
 		audioSourceChanged = true
 		audioMutex.Unlock()
 	}
@@ -970,10 +970,7 @@ func rpcSetUsbDeviceState(device string, enabled bool) error {
 }
 
 func rpcGetAudioOutputSource() (string, error) {
-	audioMutex.Lock()
-	defer audioMutex.Unlock()
-
-	if useUSBForAudioOutput {
+	if useUSBForAudioOutput.Load() {
 		return "usb", nil
 	}
 	return "hdmi", nil