Expose a multi process mutex lock file config

configs/config.yaml

@@ -114,6 +114,8 @@ emulator:
       repo:
         # enable auto-download for the list of cores (list->lib)
         sync: true
+        # external cross-process mutex lock
+        extLock: "{user}/.cr/cloud-game.lock"
         main:
           type: buildbot
           url: https://buildbot.libretro.com/nightly

pkg/config/emulator/config.go

@@ -24,6 +24,7 @@ type LibretroConfig struct {
 		}
 		Repo struct {
 			Sync      bool
+			ExtLock   string
 			Main      LibretroRepoConfig
 			Secondary LibretroRepoConfig
 		}

pkg/config/worker/config.go

@@ -61,17 +61,16 @@ func (c *Config) ParseFlags() {
 
 // expandSpecialTags replaces all the special tags in the config.
 func (c *Config) expandSpecialTags() {
-	// home dir
-	dir := c.Emulator.Storage
-	if dir != "" {
-		tag := "{user}"
-		if strings.Contains(dir, tag) {
-			userHomeDir, err := environment.GetUserHome()
-			if err != nil {
-				log.Fatalln("couldn't read user home directory", err)
-			}
-			c.Emulator.Storage = strings.Replace(dir, tag, userHomeDir, -1)
+	tag := "{user}"
+	for _, dir := range []*string{&c.Emulator.Storage, &c.Emulator.Libretro.Cores.Repo.ExtLock} {
+		if *dir == "" || !strings.Contains(*dir, tag) {
+			continue
 		}
+		userHomeDir, err := environment.GetUserHome()
+		if err != nil {
+			log.Fatalln("couldn't read user home directory", err)
+		}
+		*dir = strings.Replace(*dir, tag, userHomeDir, -1)
 	}
 }
 

pkg/emulator/libretro/manager/remotehttp/manager.go

@@ -26,7 +26,10 @@ type Manager struct {
 func NewRemoteHttpManager(conf emulator.LibretroConfig) Manager {
 	repoConf := conf.Cores.Repo.Main
 	// used for synchronization of multiple process
-	fileLock := os.TempDir() + string(os.PathSeparator) + "cloud_game.lock"
+	fileLock := conf.Cores.Repo.ExtLock
+	if fileLock == "" {
+		fileLock = os.TempDir() + string(os.PathSeparator) + "cloud_game.lock"
+	}
 
 	arch, err := core.GetCoreExt()
 	if err != nil {