Terminate file playback process groups

fileplayback/player.go

@@ -21,6 +21,7 @@ type Player struct {
 	stopChan  chan struct{}
 	ctx       context.Context
 	cancel    context.CancelFunc
+	cmd       *exec.Cmd
 	mutex     sync.Mutex
 	wg        sync.WaitGroup
 	playing   bool
@@ -99,6 +100,7 @@ func (p *Player) Stop() error {
 		if p.cancel != nil {
 			p.cancel()
 		}
+		terminateProcessGroup(p.cmd)
 	}
 	p.mutex.Unlock()
 
@@ -106,7 +108,7 @@ func (p *Player) Stop() error {
 	// worker have exited, otherwise old audio can enter the new playback.
 	p.wg.Wait()
 	p.mutex.Lock()
-	p.playing, p.stopping, p.cancel = false, false, nil
+	p.playing, p.stopping, p.cancel, p.cmd = false, false, nil, nil
 	localPlayback := p.localPlayback
 	p.mutex.Unlock()
 	if localPlayback != nil {
@@ -159,6 +161,7 @@ func (p *Player) readFileAudio() {
 	ctx := p.ctx
 	p.mutex.Unlock()
 	cmd := exec.CommandContext(ctx, "ffmpeg", args...)
+	configureProcessGroup(cmd)
 	pipe, err := cmd.StdoutPipe()
 	if err != nil {
 		p.mutex.Lock()
@@ -175,6 +178,9 @@ func (p *Player) readFileAudio() {
 		p.reportError(errors.New("failed to start ffmpeg: " + err.Error()))
 		return
 	}
+	p.mutex.Lock()
+	p.cmd = cmd
+	p.mutex.Unlock()
 
 	// Stereo has 2 channels, so we need twice the buffer size
 	byteBuffer := make([]byte, frameSize*2*2) // frameSize * 2 channels * 2 bytes per sample
@@ -185,7 +191,7 @@ func (p *Player) readFileAudio() {
 	for {
 		select {
 		case <-p.stopChan:
-			cmd.Process.Kill()
+			terminateProcessGroup(cmd)
 			cmd.Wait()
 			return
 		case <-ticker.C:

fileplayback/process_other.go

@@ -0,0 +1,13 @@
+//go:build !(aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris)
+
+package fileplayback
+
+import "os/exec"
+
+func configureProcessGroup(cmd *exec.Cmd) {}
+
+func terminateProcessGroup(cmd *exec.Cmd) {
+	if cmd != nil && cmd.Process != nil {
+		_ = cmd.Process.Kill()
+	}
+}

fileplayback/process_unix.go

@@ -0,0 +1,19 @@
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+
+package fileplayback
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func configureProcessGroup(cmd *exec.Cmd) {
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+}
+
+func terminateProcessGroup(cmd *exec.Cmd) {
+	if cmd == nil || cmd.Process == nil {
+		return
+	}
+	_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
+}

fileplayback/process_unix_test.go

@@ -0,0 +1,16 @@
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+
+package fileplayback
+
+import (
+	"os/exec"
+	"testing"
+)
+
+func TestConfigureProcessGroupCreatesSeparateGroup(t *testing.T) {
+	cmd := exec.Command("true")
+	configureProcessGroup(cmd)
+	if cmd.SysProcAttr == nil || !cmd.SysProcAttr.Setpgid {
+		t.Fatal("ffmpeg process was not configured to lead its own process group")
+	}
+}