Don't accumulate goroutines forever

This commit is contained in:
Jakob Borg 2013-12-24 11:10:49 -05:00
parent 746d52930d
commit f5ea00b297

View File

@ -86,6 +86,8 @@ import (
"net"
"sync"
"time"
"github.com/calmh/syncthing/buffers"
)
const (
@ -217,12 +219,18 @@ func (d *Discoverer) externalLookup(node string) (string, bool) {
return "", false
}
var res = make(chan string, 1)
conn, err := net.DialUDP("udp", nil, extIP)
if err != nil {
log.Printf("discover/external: %v; no external lookup", err)
return "", false
}
defer conn.Close()
err = conn.SetDeadline(time.Now().Add(5 * time.Second))
if err != nil {
log.Printf("discover/external: %v; no external lookup", err)
return "", false
}
_, err = conn.Write(EncodePacket(Packet{QueryMagic, 0, node, nil}))
if err != nil {
@ -230,34 +238,27 @@ func (d *Discoverer) externalLookup(node string) (string, bool) {
return "", false
}
go func() {
var buf = make([]byte, 1024)
n, err := conn.Read(buf)
if err != nil {
log.Printf("discover/external/read: %v; no external lookup", err)
return
}
var buf = buffers.Get(1024)
defer buffers.Put(buf)
pkt, err := DecodePacket(buf[:n])
if err != nil {
log.Printf("discover/external/read: %v; no external lookup", err)
return
}
if pkt.Magic != AnnouncementMagic {
log.Printf("discover/external/read: bad magic; no external lookup", err)
return
}
res <- fmt.Sprintf("%s:%d", ipStr(pkt.IP), pkt.Port)
}()
select {
case r := <-res:
return r, true
case <-time.After(5 * time.Second):
n, err := conn.Read(buf)
if err != nil {
log.Printf("discover/external/read: %v; no external lookup", err)
return "", false
}
pkt, err := DecodePacket(buf[:n])
if err != nil {
log.Printf("discover/external/read: %v; no external lookup", err)
return "", false
}
if pkt.Magic != AnnouncementMagic {
log.Printf("discover/external/read: bad magic; no external lookup", err)
return "", false
}
return fmt.Sprintf("%s:%d", ipStr(pkt.IP), pkt.Port), true
}
func (d *Discoverer) Lookup(node string) (string, bool) {