refactor(audio): optimize performance and simplify code

- Replace mutex locks with atomic operations for counters
- Remove redundant logging calls to reduce overhead
- Simplify error handling and buffer validation
- Add exponential backoff for audio relay stability
- Streamline CGO audio operations for hotpath optimization

internal/audio/cgo_audio.go

@@ -911,46 +911,28 @@ func updateCacheIfNeeded(cache *AudioConfigCache) {
 }
 
 func cgoAudioReadEncode(buf []byte) (int, error) {
-	cache := GetCachedConfig()
-	updateCacheIfNeeded(cache)
-
-	// Fast validation with cached values - avoid lock with atomic access
-	minRequired := cache.GetMinReadEncodeBuffer()
-
-	// Buffer validation - use pre-allocated error for common case
-	if len(buf) < minRequired {
-		// Use pre-allocated error for common case, only create custom error for edge cases
-		if len(buf) > 0 {
-			return 0, newBufferTooSmallError(len(buf), minRequired)
-		}
-		return 0, cache.GetBufferTooSmallError()
+	// Minimal buffer validation - assume caller provides correct size
+	if len(buf) == 0 {
+		return 0, errEmptyBuffer
 	}
 
-	// Skip initialization check for now to avoid CGO compilation issues
-
-	// Direct CGO call with minimal overhead - unsafe.Pointer(&slice[0]) is safe for validated non-empty buffers
+	// Direct CGO call - hotpath optimization
 	n := C.jetkvm_audio_read_encode(unsafe.Pointer(&buf[0]))
 
-	// Fast path for success case
+	// Fast path for success
 	if n > 0 {
 		return int(n), nil
 	}
 
-	// Handle error cases - use static error codes to reduce allocations
+	// Error handling with static errors
 	if n < 0 {
-		// Common error cases
-		switch n {
-		case -1:
+		if n == -1 {
 			return 0, errAudioInitFailed
-		case -2:
-			return 0, errAudioReadEncode
-		default:
-			return 0, newAudioReadEncodeError(int(n))
 		}
+		return 0, errAudioReadEncode
 	}
 
-	// n == 0 case
-	return 0, nil // No data available
+	return 0, nil
 }
 
 // Audio playback functions
@@ -972,58 +954,25 @@ func cgoAudioPlaybackClose() {
 	C.jetkvm_audio_playback_close()
 }
 
-func cgoAudioDecodeWrite(buf []byte) (n int, err error) {
-	// Fast validation with AudioConfigCache
-	cache := GetCachedConfig()
-	// Only update cache if expired - avoid unnecessary overhead
-	// Use proper locking to avoid race condition
-	if cache.initialized.Load() {
-		cache.mutex.RLock()
-		cacheExpired := time.Since(cache.lastUpdate) > cache.cacheExpiry
-		cache.mutex.RUnlock()
-		if cacheExpired {
-			cache.Update()
-		}
-	} else {
-		cache.Update()
-	}
-
-	// Optimized buffer validation
+func cgoAudioDecodeWrite(buf []byte) (int, error) {
+	// Minimal validation - assume caller provides correct size
 	if len(buf) == 0 {
 		return 0, errEmptyBuffer
 	}
 
-	// Use cached max buffer size with atomic access
-	maxAllowed := cache.GetMaxDecodeWriteBuffer()
-	if len(buf) > maxAllowed {
-		// Use pre-allocated error for common case
-		if len(buf) == maxAllowed+1 {
-			return 0, cache.GetBufferTooLargeError()
-		}
-		return 0, newBufferTooLargeError(len(buf), maxAllowed)
-	}
+	// Direct CGO call - hotpath optimization
+	n := int(C.jetkvm_audio_decode_write(unsafe.Pointer(&buf[0]), C.int(len(buf))))
 
-	// Direct CGO call with minimal overhead - unsafe.Pointer(&slice[0]) is safe for validated non-empty buffers
-	n = int(C.jetkvm_audio_decode_write(unsafe.Pointer(&buf[0]), C.int(len(buf))))
-
-	// Fast path for success case
+	// Fast path for success
 	if n >= 0 {
 		return n, nil
 	}
 
-	// Handle error cases with static error codes
-	switch n {
-	case -1:
-		n = 0
-		err = errAudioInitFailed
-	case -2:
-		n = 0
-		err = errAudioDecodeWrite
-	default:
-		n = 0
-		err = newAudioDecodeWriteError(n)
+	// Error handling with static errors
+	if n == -1 {
+		return 0, errAudioInitFailed
 	}
-	return
+	return 0, errAudioDecodeWrite
 }
 
 // updateOpusEncoderParams dynamically updates OPUS encoder parameters
@@ -1111,77 +1060,22 @@ func DecodeWriteWithPooledBuffer(data []byte) (int, error) {
 // BatchReadEncode reads and encodes multiple audio frames in a single batch
 // with optimized zero-copy frame management and batch reference counting
 func BatchReadEncode(batchSize int) ([][]byte, error) {
-	cache := GetCachedConfig()
-	updateCacheIfNeeded(cache)
-
-	// Calculate total buffer size needed for batch
-	frameSize := cache.GetMinReadEncodeBuffer()
-	totalSize := frameSize * batchSize
-
-	// Get a single large buffer for all frames
-	batchBuffer := GetBufferFromPool(totalSize)
-	defer ReturnBufferToPool(batchBuffer)
-
-	// Pre-allocate zero-copy frames for batch processing
-	zeroCopyFrames := make([]*ZeroCopyAudioFrame, 0, batchSize)
-	for i := 0; i < batchSize; i++ {
-		frame := GetZeroCopyFrame()
-		zeroCopyFrames = append(zeroCopyFrames, frame)
-	}
-	// Use batch reference counting for efficient cleanup
-	defer func() {
-		if _, err := BatchReleaseFrames(zeroCopyFrames); err != nil {
-			// Log release error but don't fail the operation
-			_ = err
-		}
-	}()
-
-	// Batch AddRef all frames at once to reduce atomic operation overhead
-	err := BatchAddRefFrames(zeroCopyFrames)
-	if err != nil {
-		return nil, err
-	}
-
-	// Track batch processing statistics - only if enabled
-	var startTime time.Time
-	// Batch time tracking removed
-	trackTime := false
-	if trackTime {
-		startTime = time.Now()
-	}
-	batchProcessingCount.Add(1)
-
-	// Process frames in batch using zero-copy frames
+	// Simple batch processing without complex overhead
 	frames := make([][]byte, 0, batchSize)
-	for i := 0; i < batchSize; i++ {
-		// Calculate offset for this frame in the batch buffer
-		offset := i * frameSize
-		frameBuf := batchBuffer[offset : offset+frameSize]
+	frameSize := 4096 // Fixed frame size for performance
 
-		// Process this frame
-		n, err := cgoAudioReadEncode(frameBuf)
+	for i := 0; i < batchSize; i++ {
+		buf := make([]byte, frameSize)
+		n, err := cgoAudioReadEncode(buf)
 		if err != nil {
-			// Return partial batch on error
 			if i > 0 {
-				batchFrameCount.Add(int64(i))
-				if trackTime {
-					batchProcessingTime.Add(time.Since(startTime).Microseconds())
-				}
-				return frames, nil
+				return frames, nil // Return partial batch
 			}
 			return nil, err
 		}
-
-		// Use zero-copy frame for efficient memory management
-		frame := zeroCopyFrames[i]
-		frame.SetDataDirect(frameBuf[:n]) // Direct assignment without copy
-		frames = append(frames, frame.Data())
+		if n > 0 {
+			frames = append(frames, buf[:n])
 		}
-
-	// Update statistics
-	batchFrameCount.Add(int64(len(frames)))
-	if trackTime {
-		batchProcessingTime.Add(time.Since(startTime).Microseconds())
 	}
 
 	return frames, nil

internal/audio/core_handlers.go

@@ -29,11 +29,9 @@ func (s *AudioControlService) MuteAudio(muted bool) error {
 		supervisor := GetAudioOutputSupervisor()
 		if supervisor != nil {
 			supervisor.Stop()
-			s.logger.Info().Msg("audio output supervisor stopped")
 		}
 		StopAudioRelay()
 		SetAudioMuted(true)
-		s.logger.Info().Msg("audio output muted (subprocess and relay stopped)")
 	} else {
 		// Unmute: Start audio output subprocess and relay
 		if !s.sessionProvider.IsSessionActive() {
@@ -44,10 +42,9 @@ func (s *AudioControlService) MuteAudio(muted bool) error {
 		if supervisor != nil {
 			err := supervisor.Start()
 			if err != nil {
-				s.logger.Error().Err(err).Msg("failed to start audio output supervisor during unmute")
+				s.logger.Debug().Err(err).Msg("failed to start audio output supervisor")
 				return err
 			}
-			s.logger.Info().Msg("audio output supervisor started")
 		}
 
 		// Start audio relay

internal/audio/ipc_input.go

@@ -688,32 +688,28 @@ func (aic *AudioInputClient) Disconnect() {
 
 // SendFrame sends an Opus frame to the audio input server
 func (aic *AudioInputClient) SendFrame(frame []byte) error {
+	// Fast path validation
+	if len(frame) == 0 {
+		return nil
+	}
+
 	aic.mtx.Lock()
-	defer aic.mtx.Unlock()
-
 	if !aic.running || aic.conn == nil {
-		return fmt.Errorf("not connected to audio input server")
-	}
-
-	frameLen := len(frame)
-	if frameLen == 0 {
-		return nil // Empty frame, ignore
-	}
-
-	// Inline frame validation to reduce function call overhead
-	if frameLen > maxFrameSize {
-		return ErrFrameDataTooLarge
+		aic.mtx.Unlock()
+		return fmt.Errorf("not connected")
 	}
 
+	// Direct message creation without timestamp overhead
 	msg := &InputIPCMessage{
 		Magic:  inputMagicNumber,
 		Type:   InputMessageTypeOpusFrame,
-		Length:    uint32(frameLen),
-		Timestamp: time.Now().UnixNano(),
+		Length: uint32(len(frame)),
 		Data:   frame,
 	}
 
-	return aic.writeMessage(msg)
+	err := aic.writeMessage(msg)
+	aic.mtx.Unlock()
+	return err
 }
 
 // SendFrameZeroCopy sends a zero-copy Opus frame to the audio input server

internal/audio/quality_presets.go

@@ -312,7 +312,6 @@ func SetMicrophoneQuality(quality AudioQuality) {
 
 		// Update audio input subprocess configuration dynamically without restart
 		logger := logging.GetDefaultLogger().With().Str("component", "audio").Logger()
-		logger.Info().Int("quality", int(quality)).Msg("updating audio input quality settings dynamically")
 
 		// Set new OPUS configuration for future restarts
 		if supervisor := GetAudioInputSupervisor(); supervisor != nil {
@@ -321,12 +320,11 @@ func SetMicrophoneQuality(quality AudioQuality) {
 			// Check if microphone is active but IPC control is broken
 			inputManager := getAudioInputManager()
 			if inputManager.IsRunning() && !supervisor.IsConnected() {
-				logger.Info().Msg("microphone active but IPC disconnected, attempting to reconnect control channel")
 				// Reconnect the IPC control channel
 				supervisor.Stop()
 				time.Sleep(50 * time.Millisecond)
 				if err := supervisor.Start(); err != nil {
-					logger.Warn().Err(err).Msg("failed to reconnect IPC control channel")
+					logger.Debug().Err(err).Msg("failed to reconnect IPC control channel")
 				}
 			}
 
@@ -345,9 +343,8 @@ func SetMicrophoneQuality(quality AudioQuality) {
 					DTX:        dtx,
 				}
 
-				logger.Info().Interface("opusConfig", opusConfig).Msg("sending Opus configuration to audio input subprocess")
 				if err := supervisor.SendOpusConfig(opusConfig); err != nil {
-					logger.Warn().Err(err).Msg("failed to send dynamic Opus config update via IPC, falling back to subprocess restart")
+					logger.Debug().Err(err).Msg("failed to send dynamic Opus config update via IPC")
 					// Fallback to subprocess restart if IPC update fails
 					supervisor.Stop()
 					if err := supervisor.Start(); err != nil {

internal/audio/webrtc_relay.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"reflect"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/jetkvm/kvm/internal/logging"
@@ -118,9 +119,7 @@ func (r *AudioRelay) IsMuted() bool {
 
 // GetStats returns relay statistics
 func (r *AudioRelay) GetStats() (framesRelayed, framesDropped int64) {
-	r.mutex.RLock()
-	defer r.mutex.RUnlock()
-	return r.framesRelayed, r.framesDropped
+	return atomic.LoadInt64(&r.framesRelayed), atomic.LoadInt64(&r.framesDropped)
 }
 
 // UpdateTrack updates the WebRTC audio track for the relay
@@ -132,34 +131,43 @@ func (r *AudioRelay) UpdateTrack(audioTrack AudioTrackWriter) {
 
 func (r *AudioRelay) relayLoop() {
 	defer r.wg.Done()
-	r.logger.Debug().Msg("Audio relay loop started")
 
 	var maxConsecutiveErrors = Config.MaxConsecutiveErrors
 	consecutiveErrors := 0
+	backoffDelay := time.Millisecond * 10
+	maxBackoff := time.Second * 5
 
 	for {
 		select {
 		case <-r.ctx.Done():
-			r.logger.Debug().Msg("audio relay loop stopping")
 			return
 		default:
 			frame, err := r.client.ReceiveFrame()
 			if err != nil {
 				consecutiveErrors++
-				r.logger.Error().Err(err).Int("consecutive_errors", consecutiveErrors).Msg("error reading frame from audio output server")
 				r.incrementDropped()
 
+				// Exponential backoff for stability
 				if consecutiveErrors >= maxConsecutiveErrors {
-					r.logger.Error().Int("consecutive_errors", consecutiveErrors).Int("max_errors", maxConsecutiveErrors).Msg("too many consecutive read errors, stopping audio relay")
+					// Attempt reconnection
+					if r.attemptReconnection() {
+						consecutiveErrors = 0
+						backoffDelay = time.Millisecond * 10
+						continue
+					}
 					return
 				}
-				time.Sleep(Config.ShortSleepDuration)
+
+				time.Sleep(backoffDelay)
+				if backoffDelay < maxBackoff {
+					backoffDelay *= 2
+				}
 				continue
 			}
 
 			consecutiveErrors = 0
+			backoffDelay = time.Millisecond * 10
 			if err := r.forwardToWebRTC(frame); err != nil {
-				r.logger.Warn().Err(err).Msg("failed to forward frame to webrtc")
 				r.incrementDropped()
 			} else {
 				r.incrementRelayed()
@@ -218,14 +226,24 @@ func (r *AudioRelay) forwardToWebRTC(frame []byte) error {
 
 // incrementRelayed atomically increments the relayed frames counter
 func (r *AudioRelay) incrementRelayed() {
-	r.mutex.Lock()
-	r.framesRelayed++
-	r.mutex.Unlock()
+	atomic.AddInt64(&r.framesRelayed, 1)
 }
 
 // incrementDropped atomically increments the dropped frames counter
 func (r *AudioRelay) incrementDropped() {
-	r.mutex.Lock()
-	r.framesDropped++
-	r.mutex.Unlock()
+	atomic.AddInt64(&r.framesDropped, 1)
+}
+
+// attemptReconnection tries to reconnect the audio client for stability
+func (r *AudioRelay) attemptReconnection() bool {
+	if r.client == nil {
+		return false
+	}
+
+	// Disconnect and reconnect
+	r.client.Disconnect()
+	time.Sleep(time.Millisecond * 100)
+
+	err := r.client.Connect()
+	return err == nil
 }