From: Sergey Matveev <stargrave@stargrave.org>
Date: Mon, 28 Nov 2022 14:55:14 +0000 (+0300)
Subject: Simpler cancellation with global variables
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=6f4d478fee7c0bf82c004c2804a25fc35e002d44;p=btrtrc.git

Simpler cancellation with global variables
---

diff --git a/cmd/btrtrc/main.go b/cmd/btrtrc/main.go
index 70bc8c90..880348be 100644
--- a/cmd/btrtrc/main.go
+++ b/cmd/btrtrc/main.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/signal"
 	"strings"
+	"sync"
 	"syscall"
 
 	"github.com/anacrolix/dht/v2"
@@ -18,6 +19,11 @@ import (
 
 const TorrentExt = ".torrent"
 
+var (
+	Cancel = make(chan struct{})
+	Jobs   sync.WaitGroup
+)
+
 func main() {
 	log.SetFlags(log.Ldate | log.Ltime)
 	dhtBoot := flag.String("dht", "dht.cypherpunks.ru:8991", "Comma-separated list of DHT bootstrap nodes")
@@ -63,27 +69,25 @@ func main() {
 	defer client.Close()
 
 	needsShutdown := make(chan os.Signal)
-	overallStatusCancel := make(chan struct{})
-	txStatsDumperCancel := make(chan struct{})
 	signal.Notify(needsShutdown, syscall.SIGTERM, syscall.SIGINT)
 	go func() {
 		<-needsShutdown
-		overallStatusCancel <- struct{}{}
-		txStatsDumperCancel <- struct{}{}
+		close(Cancel)
 		client.Close()
 	}()
 
 	fifosPrepare()
 	log.Println("started", client.PublicIPs())
-	go overallStatus(client, overallStatusCancel)
+	Jobs.Add(1)
+	go overallStatus(client)
 	go fifoList(client)
 	go fifoDHTList(client)
 	go fifoAdd(client)
 	go fifoDel(client)
-	go txStatsDumper(client, txStatsDumperCancel)
+	Jobs.Add(1)
+	go txStatsDumper(client)
 	<-client.Closed()
-	<-overallStatusCancel
-	<-txStatsDumperCancel
+	Jobs.Wait()
 	fifosCleanup()
 	log.Println("finished")
 }
diff --git a/cmd/btrtrc/status.go b/cmd/btrtrc/status.go
index 3d937efa..8cb0cbc4 100644
--- a/cmd/btrtrc/status.go
+++ b/cmd/btrtrc/status.go
@@ -8,13 +8,13 @@ import (
 	"github.com/dustin/go-humanize"
 )
 
-func overallStatus(c *torrent.Client, cancel chan struct{}) {
+func overallStatus(c *torrent.Client) {
 	tick := time.Tick(time.Second)
 	var prev torrent.ConnStats
 	for {
 		select {
-		case <-cancel:
-			close(cancel)
+		case <-Cancel:
+			Jobs.Done()
 			return
 		case <-tick:
 		}
diff --git a/cmd/btrtrc/txstats.go b/cmd/btrtrc/txstats.go
index 6ce62bab..f05a4b8f 100644
--- a/cmd/btrtrc/txstats.go
+++ b/cmd/btrtrc/txstats.go
@@ -60,13 +60,13 @@ func txStatsDumpAll(c *torrent.Client) {
 	}
 }
 
-func txStatsDumper(c *torrent.Client, cancel chan struct{}) {
+func txStatsDumper(c *torrent.Client) {
 	tick := time.Tick(10 * time.Second)
 	for {
 		txStatsDumpAll(c)
 		select {
-		case <-cancel:
-			close(cancel)
+		case <-Cancel:
+			Jobs.Done()
 			return
 		case <-tick:
 		}