reap child processes to prevent leaving them defunct

Author: tvidal-net

deck.go

@@ -203,17 +203,17 @@ func (deck *Deck) backgroundForKey(dev *streamdeck.Device, key uint8) image.Imag
 
 func (deck *Deck) WindowChanged(window ActiveWindow) {
 	verboseLog("windowChanged %s:%s %s", window.resource, window.title, window.id)
-	var match *WindowWidgets
+	var match = false
 	for _, w := range deck.windows {
 		if w.Matches(window) {
-			match = &w
+			verboseLog("windowMatch: %s:%s", w.resource, w.title)
+			for i, widget := range w.widgets {
+				deck.overrideWidget(i, widget)
+			}
+			match = true
 		}
 	}
-	if match != nil {
-		for i, widget := range match.widgets {
-			deck.overrideWidget(i, widget)
-		}
-	} else {
+	if !match {
 		for key := range deck.overrides {
 			deck.restoreWidget(key)
 		}
@@ -299,17 +299,12 @@ func executeCommand(cmd string) error {
 	args := SPACES.Split(cmd, -1)
 	exe := expandExecutable(args[0])
 
-	c := exec.Command(exe, args[1:]...) //nolint:gosec
-	if *verboseConfig {
-		c.Stdout = os.Stdout
-		c.Stderr = os.Stderr
-	}
-
-	if e := c.Start(); e != nil {
+	command := exec.Command(exe, args[1:]...)
+	if err := command.Start(); err != nil {
 		errorLogF("failed to execute '%s %s'", exe, args[1:])
-		return e
+		return err
 	}
-	return c.Process.Release()
+	return command.Process.Release()
 }
 
 func (deck *Deck) Widgets(yield func(Widget) bool) {

main.go

@@ -86,6 +86,22 @@ func expandPath(base, path string) (string, error) {
 	return filepath.Abs(path)
 }
 
+func reapChildProcesses() {
+	sigs := make(chan os.Signal)
+	signal.Notify(sigs, syscall.SIGCHLD)
+
+	for range sigs {
+		for {
+			var status syscall.WaitStatus
+			pid, err := syscall.Wait4(-1, &status, syscall.WNOHANG, nil)
+			if pid <= 0 || err != nil {
+				break
+			}
+			verboseLog("reaped pid=%d status=%d", pid, status.ExitStatus())
+		}
+	}
+}
+
 func eventLoop(dev *streamdeck.Device, tch chan interface{}) error {
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
@@ -97,6 +113,7 @@ func eventLoop(dev *streamdeck.Device, tch chan interface{}) error {
 	keyTimestamps := make(map[uint8]time.Time)
 
 	go pa.Start()
+	go reapChildProcesses()
 
 	wch := MonitorActiveWindowChanged()