Merge pull request #15 from m1k1o/hls-exit-on-error

HLS: add error to OnStop.

Author: m1k1o

hls/manager.go

@@ -20,7 +20,7 @@ import (
 // how often should be cleanup called
 const cleanupPeriod = 4 * time.Second
 
-// timeot for first playlist, when it waits for new data
+// timeout for first playlist, when it waits for new data
 const playlistTimeout = 60 * time.Second
 
 // minimum segments available to consider stream as active
@@ -40,7 +40,7 @@ type ManagerCtx struct {
 	events     struct {
 		onStart  func()
 		onCmdLog func(message string)
-		onStop   func()
+		onStop   func(err error)
 	}
 
 	cmd         *exec.Cmd
@@ -92,7 +92,7 @@ func (m *ManagerCtx) Start() error {
 	read, write := io.Pipe()
 	m.cmd.Stdout = write
 
-	//create a new process group
+	// create a new process group
 	m.cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
 
 	m.active = false
@@ -104,6 +104,7 @@ func (m *ManagerCtx) Start() error {
 	m.playlistLoad = make(chan string)
 	m.shutdown = make(chan interface{})
 
+	// read playlist on stdout
 	go func() {
 		buf := make([]byte, 1024)
 
@@ -125,14 +126,15 @@ func (m *ManagerCtx) Start() error {
 				}
 			}
 
+			// if stdout pipe has been closed
 			if err != nil {
-				// When command fails to start, we reach this branch after a while
 				m.logger.Err(err).Msg("cmd read failed")
 				return
 			}
 		}
 	}()
 
+	// periodic cleanup
 	go func() {
 		ticker := time.NewTicker(cleanupPeriod)
 		defer ticker.Stop()
@@ -152,21 +154,54 @@ func (m *ManagerCtx) Start() error {
 		m.events.onStart()
 	}
 
-	return m.cmd.Start()
+	// start program
+	err = m.cmd.Start()
+
+	// wait for program to exit
+	go func() {
+		err = m.cmd.Wait()
+		if err != nil {
+			if exiterr, ok := err.(*exec.ExitError); ok {
+				// The program has exited with an exit code != 0
+
+				// This works on both Unix and Windows. Although package
+				// syscall is generally platform dependent, WaitStatus is
+				// defined for both Unix and Windows and in both cases has
+				// an ExitStatus() method with the same signature.
+				if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
+					m.logger.Warn().Int("exit-status", status.ExitStatus()).Msg("the program has exited with an exit code != 0")
+				}
+			} else {
+				m.logger.Err(err).Msg("the program has exited with an error")
+			}
+		} else {
+			m.logger.Info().Msg("the program has successfully exited")
+		}
+
+		close(m.shutdown)
+
+		if m.events.onStop != nil {
+			m.events.onStop(err)
+		}
+
+		err := os.RemoveAll(m.tempdir)
+		m.logger.Err(err).Msg("removing tempdir")
+
+		m.mu.Lock()
+		m.cmd = nil
+		m.mu.Unlock()
+	}()
+
+	return err
 }
 
 func (m *ManagerCtx) Stop() {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	if m.cmd == nil {
-		return
-	}
-
-	m.logger.Debug().Msg("performing stop")
-	close(m.shutdown)
+	if m.cmd != nil && m.cmd.Process != nil {
+		m.logger.Debug().Msg("performing stop")
 
-	if m.cmd.Process != nil {
 		pgid, err := syscall.Getpgid(m.cmd.Process.Pid)
 		if err == nil {
 			err := syscall.Kill(-pgid, syscall.SIGKILL)
@@ -176,15 +211,6 @@ func (m *ManagerCtx) Stop() {
 			err := m.cmd.Process.Kill()
 			m.logger.Err(err).Msg("killing proccess")
 		}
-		_ = m.cmd.Wait()
-		m.cmd = nil
-	}
-
-	err := os.RemoveAll(m.tempdir)
-	m.logger.Err(err).Msg("removing tempdir")
-
-	if m.events.onStop != nil {
-		m.events.onStop()
 	}
 }
 
@@ -225,14 +251,14 @@ func (m *ManagerCtx) ServePlaylist(w http.ResponseWriter, r *http.Request) {
 	if !m.active {
 		select {
 		case playlist = <-m.playlistLoad:
+		// when command exits before providing any playlist
 		case <-m.shutdown:
 			m.logger.Warn().Msg("playlist load failed because of shutdown")
-			// When command failed to start and timeout has been increased we reach this branch after a while
-			http.Error(w, "404 playlist not found", http.StatusNotFound)
+			http.Error(w, "500 playlist not available", http.StatusInternalServerError)
 			return
 		case <-time.After(playlistTimeout):
 			m.logger.Warn().Msg("playlist load channel timeouted")
-			http.Error(w, "500 not available", http.StatusInternalServerError)
+			http.Error(w, "504 playlist timeout", http.StatusGatewayTimeout)
 			return
 		}
 	}
@@ -269,6 +295,6 @@ func (m *ManagerCtx) OnCmdLog(event func(message string)) {
 	m.events.onCmdLog = event
 }
 
-func (m *ManagerCtx) OnStop(event func()) {
+func (m *ManagerCtx) OnStop(event func(err error)) {
 	m.events.onStop = event
 }

hls/types.go

@@ -12,5 +12,5 @@ type Manager interface {
 
 	OnStart(event func())
 	OnCmdLog(event func(message string))
-	OnStop(event func())
+	OnStop(event func(err error))
 }