From 21995ea4cdd352e599bbcf0f9bd276b683cb11cd Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.top>
Date: Fri, 1 Apr 2022 20:44:32 +0400
Subject: [PATCH] Added mutex for lastPlayedCache.

---
 internal/radio/icecast.go | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/internal/radio/icecast.go b/internal/radio/icecast.go
index db3bd42..7fe8c2c 100644
--- a/internal/radio/icecast.go
+++ b/internal/radio/icecast.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"os/exec"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/pkg/errors"
@@ -65,19 +66,27 @@ func IcecastGetStatus(icecastURL string) (*IcecastStatus, error) {
 }
 
 func IcecastLastPlayedSongs(lastNSongs int, playlistPath string) ([]Song, error) {
-	if lpcLen := len(lastPlayedCache); lpcLen > 0 {
-		if lastNSongs > lpcLen {
-			lastNSongs = lpcLen
+	{
+		lastPlayedCacheMutex.Lock()
+		defer lastPlayedCacheMutex.Unlock()
+		if lpcLen := len(lastPlayedCache); lpcLen > 0 {
+			if lastNSongs > lpcLen {
+				lastNSongs = lpcLen
+			}
+			return lastPlayedCache[lpcLen-lastNSongs:], nil
 		}
-		return lastPlayedCache[lpcLen-lastNSongs:], nil
 	}
 
 	return lastPlayedSongs(lastNSongs, playlistPath)
 }
 
 func IcecastLastSong(playlistPath string) (Song, error) {
-	if lpcLen := len(lastPlayedCache); lpcLen > 0 {
-		return lastPlayedCache[lpcLen-1], nil
+	{
+		lastPlayedCacheMutex.Lock()
+		defer lastPlayedCacheMutex.Unlock()
+		if lpcLen := len(lastPlayedCache); lpcLen > 0 {
+			return lastPlayedCache[lpcLen-1], nil
+		}
 	}
 
 	songs, err := lastPlayedSongs(1, playlistPath)
@@ -121,6 +130,7 @@ func lastPlayedSongs(lastNSongs int, playlistPath string) ([]Song, error) {
 var playlistWatcher watcher.InotifyWatcher
 var playlistFired chan uint32
 var lastPlayedCache []Song
+var lastPlayedCacheMutex sync.Mutex
 
 func IcecastWatchPlaylist(playlistPath string, lastNSongs int) error {
 	playlistWatcher, err := watcher.NewInotifyWatcher()
@@ -141,6 +151,8 @@ func IcecastWatchPlaylist(playlistPath string, lastNSongs int) error {
 		for {
 			select {
 			case <-playlistFired:
+				lastPlayedCacheMutex.Lock()
+				defer lastPlayedCacheMutex.Unlock()
 				songs, err := lastPlayedSongs(lastNSongs, playlistPath)
 				if err == nil && len(songs) > 0 {
 					lastPlayedCache = songs