Merge pull request #148 from jesseduffield/147_child_processes

ensure the current task is stopped before exit

pkg/gui/gui.go

@@ -163,7 +163,7 @@ func NewGui(log *logrus.Entry, dockerCommand *commands.DockerCommand, oSCommand
 		Config:        config,
 		Tr:            tr,
 		statusManager: &statusManager{},
-		T:             tasks.NewTaskManager(log),
+		T:             tasks.NewTaskManager(log, tr),
 		ErrorChan:     errorChan,
 		CyclableViews: cyclableViews,
 	}
@@ -247,6 +247,9 @@ func (gui *Gui) goEvery(interval time.Duration, function func() error) {
 
 // Run setup the gui with keybindings and start the mainloop
 func (gui *Gui) Run() error {
+	// closing our task manager which in turn closes the current task if there is any, so we aren't leaving processes lying around after closing lazydocker
+	defer gui.T.Close()
+
 	g, err := gocui.NewGui(gocui.OutputNormal, OverlappingEdges)
 	if err != nil {
 		return err

pkg/i18n/english.go

@@ -24,6 +24,7 @@ type TranslationSet struct {
 	UnattachableContainerError                 string
 	CannotAttachStoppedContainerError          string
 	CannotAccessDockerSocketError              string
+	CannotKillChildError                       string
 
 	Donate                     string
 	Cancel                     string
@@ -110,6 +111,7 @@ func englishSet() TranslationSet {
 		UnattachableContainerError:        "Container does not support attaching. You must either run the service with the '-it' flag or use `stdin_open: true, tty: true` in the docker-compose.yml file",
 		CannotAttachStoppedContainerError: "You cannot attach to a stopped container, you need to start it first (which you can actually do with the 'r' key) (yes I'm too lazy to do this automatically for you) (pretty cool that I get to communicate one-on-one with you in the form of an error message though)",
 		CannotAccessDockerSocketError:     "Can't access docker socket at: unix:///var/run/docker.sock\nRun lazydocker as root or read https://docs.docker.com/install/linux/linux-postinstall/",
+		CannotKillChildError:              "Waited three seconds for child process to stop. There may be an orphan process that continues to run on your system.",
 
 		Donate:  "Donate",
 		Confirm: "Confirm",

pkg/tasks/tasks.go

@@ -1,9 +1,11 @@
 package tasks
 
 import (
+	"fmt"
 	"sync"
 	"time"
 
+	"github.com/jesseduffield/lazydocker/pkg/i18n"
 	"github.com/sirupsen/logrus"
 )
 
@@ -13,19 +15,43 @@ type TaskManager struct {
 	waitingMutex      sync.Mutex
 	taskIDMutex       sync.Mutex
 	Log               *logrus.Entry
+	Tr                *i18n.TranslationSet
 	waitingTaskAlerts chan struct{}
 	newTaskId         int
 }
 
 type Task struct {
 	stop          chan struct{}
+	stopped       bool
+	stopMutex     sync.Mutex
 	notifyStopped chan struct{}
 	Log           *logrus.Entry
 	f             func(chan struct{})
 }
 
-func NewTaskManager(log *logrus.Entry) *TaskManager {
-	return &TaskManager{Log: log}
+func NewTaskManager(log *logrus.Entry, translationSet *i18n.TranslationSet) *TaskManager {
+	return &TaskManager{Log: log, Tr: translationSet}
+}
+
+// Close closes the task manager, killing whatever task may currently be running
+func (t *TaskManager) Close() {
+	if t.currentTask == nil {
+		return
+	}
+
+	c := make(chan struct{}, 1)
+
+	go func() {
+		t.currentTask.Stop()
+		c <- struct{}{}
+	}()
+
+	select {
+	case <-c:
+		return
+	case <-time.After(3 * time.Second):
+		fmt.Println(t.Tr.CannotKillChildError)
+	}
 }
 
 func (t *TaskManager) NewTask(f func(stop chan struct{})) error {
@@ -68,10 +94,16 @@ func (t *TaskManager) NewTask(f func(stop chan struct{})) error {
 }
 
 func (t *Task) Stop() {
+	t.stopMutex.Lock()
+	defer t.stopMutex.Unlock()
+	if t.stopped {
+		return
+	}
 	close(t.stop)
 	t.Log.Info("closed stop channel, waiting for notifyStopped message")
 	<-t.notifyStopped
 	t.Log.Info("received notifystopped message")
+	t.stopped = true
 	return
 }