From 1362aae61a29991a5108c6ddfb4ba5a28eb867c6 Mon Sep 17 00:00:00 2001
From: simon <me@simon987.net>
Date: Wed, 17 Jul 2019 21:49:51 -0400
Subject: [PATCH] Gracefully handle SIGINT

---
 beemer.go | 18 +++++++++++++-----
 cli.go    | 16 +++++++++++-----
 util.go   | 11 +++++++++++
 3 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/beemer.go b/beemer.go
index b31c9c4..1106e4e 100644
--- a/beemer.go
+++ b/beemer.go
@@ -6,6 +6,8 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"sync"
+	"syscall"
 	"time"
 )
 
@@ -16,6 +18,7 @@ type Beemer struct {
 	beemChan      chan string
 	watcher       *fsnotify.Watcher
 	inactiveDelay time.Duration
+	globalWg      *sync.WaitGroup
 }
 
 type File struct {
@@ -132,12 +135,11 @@ func (b Beemer) handleWatcherEvents() {
 }
 
 func (b Beemer) work() {
-	for {
-		select {
-		case name := <-b.beemChan:
-			b.beemFile(name)
-		}
+	b.globalWg.Add(1)
+	for name := range b.beemChan {
+		b.beemFile(name)
 	}
+	b.globalWg.Done()
 }
 
 func (b Beemer) handleFileInactive(t *time.Timer, name string) {
@@ -159,6 +161,12 @@ func (b Beemer) beemFile(filename string) {
 	name, args := b.beemCommand(newName, filepath.Dir(filename))
 
 	cmd := exec.Command(name, args...)
+
+	// Don't send SIGINT to child processes
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		Setpgid: true,
+	}
+
 	out, err := cmd.CombinedOutput()
 	if err != nil {
 		logrus.WithField("name", filename).WithError(err).Error(string(out))
diff --git a/cli.go b/cli.go
index a0d057e..8ff69cc 100644
--- a/cli.go
+++ b/cli.go
@@ -6,10 +6,14 @@ import (
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 	"os"
+	"os/signal"
+	"sync"
+	"syscall"
 	"time"
 )
 
 func globalInit() {
+	//TODO cmdline flag
 	logrus.SetLevel(logrus.TraceLevel)
 }
 
@@ -66,14 +70,13 @@ func main() {
 			beemChan:      make(chan string, transfers),
 			beemCommand:   parseCommand(cmdString),
 			inactiveDelay: inactiveDelay,
+			globalWg:      &sync.WaitGroup{},
 		}
 
 		beemer.initTempDir()
 
 		beemer.watcher, _ = fsnotify.NewWatcher()
 
-		defer beemer.dispose()
-
 		go beemer.handleWatcherEvents()
 
 		beemer.initWatchDir(watchDir)
@@ -82,10 +85,13 @@ func main() {
 			go beemer.work()
 		}
 
-		//TODO gracefully handle SIGINT
-		done := make(chan bool)
-		<-done
+		sigChan := make(chan os.Signal, 1)
+		signal.Notify(sigChan, syscall.SIGINT)
 
+		defer beemer.dispose()
+
+		<-sigChan
+		logrus.Info("Received SIGINT")
 		return nil
 	}
 
diff --git a/util.go b/util.go
index d91d141..865c6e8 100644
--- a/util.go
+++ b/util.go
@@ -108,8 +108,19 @@ func isDir(name string) bool {
 
 func (b Beemer) dispose() {
 	b.watcher.Close()
+	close(b.beemChan)
+
+	logrus.WithField("chanLen", len(b.beemChan)).Info("Waiting for beem queue to drain...")
+	<-b.beemChan
+
+	logrus.Info("Waiting for current commands to finish...")
+	b.globalWg.Wait()
+
+	logrus.Info("Cleaning up temp dir...")
 	err := os.RemoveAll(b.tempDir)
 	if err != nil {
 		logrus.Fatal(err)
 	}
+
+	logrus.Info("Goodbye.")
 }