api, hls, metrics, pprof: always close HTTP listeners

due to a race condition, HTTP listeners could remain open even after
the closure of a component.

internal/core/api.go

@@ -189,6 +189,7 @@ type api struct {
 	hlsServer   apiHLSServer
 	parent      apiParent
 
+	ln    net.Listener
 	mutex sync.Mutex
 	s     *http.Server
 }
@@ -218,6 +219,7 @@ func newAPI(
 		rtmpsServer: rtmpsServer,
 		hlsServer:   hlsServer,
 		parent:      parent,
+		ln:          ln,
 	}
 
 	router := gin.New()
@@ -268,6 +270,7 @@ func newAPI(
 
 func (a *api) close() {
 	a.log(logger.Info, "listener is closing")
+	a.ln.Close() // in case Shutdown() is called before Serve()
 	a.s.Shutdown(context.Background())
 }
 

internal/core/hls_server.go

@@ -248,6 +248,7 @@ outer:
 
 	s.ctxCancel()
 
+	s.ln.Close() // in case Shutdown() is called before Serve()
 	hs.Shutdown(context.Background())
 
 	s.pathManager.hlsServerSet(nil)

internal/core/metrics.go

@@ -79,6 +79,7 @@ func newMetrics(
 
 func (m *metrics) close() {
 	m.log(logger.Info, "listener is closing")
+	m.ln.Close() // in case Shutdown() is called before Serve()
 	m.server.Shutdown(context.Background())
 }
 
@@ -87,10 +88,7 @@ func (m *metrics) log(level logger.Level, format string, args ...interface{}) {
 }
 
 func (m *metrics) run() {
-	err := m.server.Serve(m.ln)
-	if err != http.ErrServerClosed {
-		panic(err)
-	}
+	m.server.Serve(m.ln)
 }
 
 func (m *metrics) onMetrics(ctx *gin.Context) {

internal/core/pprof.go

@@ -49,6 +49,7 @@ func newPPROF(
 
 func (pp *pprof) close() {
 	pp.log(logger.Info, "listener is closing")
+	pp.ln.Close() // in case Shutdown() is called before Serve()
 	pp.server.Shutdown(context.Background())
 }
 
@@ -57,8 +58,5 @@ func (pp *pprof) log(level logger.Level, format string, args ...interface{}) {
 }
 
 func (pp *pprof) run() {
-	err := pp.server.Serve(pp.ln)
-	if err != http.ErrServerClosed {
-		panic(err)
-	}
+	pp.server.Serve(pp.ln)
 }