Addressing deadlocks in WAL forge implementation

internal/wal/wal_forge.go

@@ -192,12 +192,8 @@ func (wl *walForge) rotateLogIfNeeded(entrySize uint32) error {
 
 // rotateLog rotates the log by closing the current segment file,
 // incrementing the current segment index, and opening a new segment file.
-// This method is thread safe.
 func (wl *walForge) rotateLog() error {
 	fmt.Println("rotating log")
-	wl.mu.Lock()
-	defer wl.mu.Unlock()
-
 	// TODO: Ideally this function should not return any error
 	// Check for the conditions where it can return an error
 	// and handle them gracefully.
@@ -237,11 +233,7 @@ func (wl *walForge) rotateLog() error {
 
 // Writes out any data in the WAL's in-memory buffer to the segment file.
 // and syncs the segment file to disk.
-// This method is thread safe.
 func (wl *walForge) sync() error {
-	wl.mu.Lock()
-	defer wl.mu.Unlock()
-
 	// Flush the buffer to the segment file
 	if err := wl.csWriter.Flush(); err != nil {
 		return err
@@ -265,10 +257,12 @@ func (wl *walForge) periodicSyncBuffer() {
 	for {
 		select {
 		case <-wl.bufferSyncTicker.C:
+			wl.mu.Lock()
 			err := wl.sync()
 			if err != nil {
 				slog.Error("failed to sync buffer", slog.String("error", err.Error()))
 			}
+			wl.mu.Unlock()
 		case <-wl.ctx.Done():
 			return
 		}
@@ -281,9 +275,11 @@ func (wl *walForge) periodicRotateSegment() {
 		select {
 		case <-wl.segmentRotationTicker.C:
 			// TODO: Remove this error handling once we clean up the error handling in the rotateLog function.
+			wl.mu.Lock()
 			if err := wl.rotateLog(); err != nil {
 				slog.Error("failed to rotate segment", slog.String("error", err.Error()))
 			}
+			wl.mu.Unlock()
 		case <-wl.ctx.Done():
 			return
 		}