lib/discover: Don't leak goroutines (#5950)

This commit is contained in:
Simon Frei 2019-08-22 12:30:57 +02:00 committed by GitHub
parent 24d4290d03
commit 534f07d9ca
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GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 147 additions and 220 deletions

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@ -7,9 +7,13 @@
package beacon
import (
"fmt"
"net"
"time"
"github.com/thejerf/suture"
"github.com/syncthing/syncthing/lib/util"
)
type recv struct {
@ -19,7 +23,93 @@ type recv struct {
type Interface interface {
suture.Service
fmt.Stringer
Send(data []byte)
Recv() ([]byte, net.Addr)
Error() error
}
type cast struct {
*suture.Supervisor
name string
reader util.ServiceWithError
writer util.ServiceWithError
outbox chan recv
inbox chan []byte
stopped chan struct{}
}
// newCast creates a base object for multi- or broadcasting. Afterwards the
// caller needs to set reader and writer with the addReader and addWriter
// methods to get a functional implementation of Interface.
func newCast(name string) *cast {
return &cast{
Supervisor: suture.New(name, suture.Spec{
// Don't retry too frenetically: an error to open a socket or
// whatever is usually something that is either permanent or takes
// a while to get solved...
FailureThreshold: 2,
FailureBackoff: 60 * time.Second,
// Only log restarts in debug mode.
Log: func(line string) {
l.Debugln(line)
},
PassThroughPanics: true,
}),
name: name,
inbox: make(chan []byte),
outbox: make(chan recv, 16),
stopped: make(chan struct{}),
}
}
func (c *cast) addReader(svc func(chan struct{}) error) {
c.reader = c.createService(svc, "reader")
c.Add(c.reader)
}
func (c *cast) addWriter(svc func(stop chan struct{}) error) {
c.writer = c.createService(svc, "writer")
c.Add(c.writer)
}
func (c *cast) createService(svc func(chan struct{}) error, suffix string) util.ServiceWithError {
return util.AsServiceWithError(func(stop chan struct{}) error {
l.Debugln("Starting", c.name, suffix)
err := svc(stop)
l.Debugf("Stopped %v %v: %v", c.name, suffix, err)
return err
})
}
func (c *cast) Stop() {
c.Supervisor.Stop()
close(c.stopped)
}
func (c *cast) String() string {
return fmt.Sprintf("%s@%p", c.name, c)
}
func (c *cast) Send(data []byte) {
select {
case c.inbox <- data:
case <-c.stopped:
}
}
func (c *cast) Recv() ([]byte, net.Addr) {
select {
case recv := <-c.outbox:
return recv.data, recv.src
case <-c.stopped:
}
return nil, nil
}
func (c *cast) Error() error {
if err := c.reader.Error(); err != nil {
return err
}
return c.writer.Error()
}

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@ -7,85 +7,22 @@
package beacon
import (
"fmt"
"net"
"time"
"github.com/thejerf/suture"
"github.com/syncthing/syncthing/lib/util"
)
type Broadcast struct {
*suture.Supervisor
port int
inbox chan []byte
outbox chan recv
br *broadcastReader
bw *broadcastWriter
func NewBroadcast(port int) Interface {
c := newCast("broadcastBeacon")
c.addReader(func(stop chan struct{}) error {
return readBroadcasts(c.outbox, port, stop)
})
c.addWriter(func(stop chan struct{}) error {
return writeBroadcasts(c.inbox, port, stop)
})
return c
}
func NewBroadcast(port int) *Broadcast {
b := &Broadcast{
Supervisor: suture.New("broadcastBeacon", suture.Spec{
// Don't retry too frenetically: an error to open a socket or
// whatever is usually something that is either permanent or takes
// a while to get solved...
FailureThreshold: 2,
FailureBackoff: 60 * time.Second,
// Only log restarts in debug mode.
Log: func(line string) {
l.Debugln(line)
},
PassThroughPanics: true,
}),
port: port,
inbox: make(chan []byte),
outbox: make(chan recv, 16),
}
b.br = &broadcastReader{
port: port,
outbox: b.outbox,
}
b.br.ServiceWithError = util.AsServiceWithError(b.br.serve)
b.Add(b.br)
b.bw = &broadcastWriter{
port: port,
inbox: b.inbox,
}
b.bw.ServiceWithError = util.AsServiceWithError(b.bw.serve)
b.Add(b.bw)
return b
}
func (b *Broadcast) Send(data []byte) {
b.inbox <- data
}
func (b *Broadcast) Recv() ([]byte, net.Addr) {
recv := <-b.outbox
return recv.data, recv.src
}
func (b *Broadcast) Error() error {
if err := b.br.Error(); err != nil {
return err
}
return b.bw.Error()
}
type broadcastWriter struct {
util.ServiceWithError
port int
inbox chan []byte
}
func (w *broadcastWriter) serve(stop chan struct{}) error {
l.Debugln(w, "starting")
defer l.Debugln(w, "stopping")
func writeBroadcasts(inbox <-chan []byte, port int, stop chan struct{}) error {
conn, err := net.ListenUDP("udp4", nil)
if err != nil {
l.Debugln(err)
@ -104,7 +41,7 @@ func (w *broadcastWriter) serve(stop chan struct{}) error {
for {
var bs []byte
select {
case bs = <-w.inbox:
case bs = <-inbox:
case <-stop:
return nil
}
@ -112,8 +49,7 @@ func (w *broadcastWriter) serve(stop chan struct{}) error {
addrs, err := net.InterfaceAddrs()
if err != nil {
l.Debugln(err)
w.SetError(err)
continue
return err
}
var dsts []net.IP
@ -133,13 +69,13 @@ func (w *broadcastWriter) serve(stop chan struct{}) error {
success := 0
for _, ip := range dsts {
dst := &net.UDPAddr{IP: ip, Port: w.port}
dst := &net.UDPAddr{IP: ip, Port: port}
conn.SetWriteDeadline(time.Now().Add(time.Second))
_, err := conn.WriteTo(bs, dst)
_, err = conn.WriteTo(bs, dst)
conn.SetWriteDeadline(time.Time{})
if err, ok := err.(net.Error); ok && err.Timeout() {
if nerr, ok := err.(net.Error); ok && nerr.Timeout() {
// Write timeouts should not happen. We treat it as a fatal
// error on the socket.
l.Debugln(err)
@ -149,7 +85,6 @@ func (w *broadcastWriter) serve(stop chan struct{}) error {
if err != nil {
// Some other error that we don't expect. Debug and continue.
l.Debugln(err)
w.SetError(err)
continue
}
@ -157,27 +92,15 @@ func (w *broadcastWriter) serve(stop chan struct{}) error {
success++
}
if success > 0 {
w.SetError(nil)
if success == 0 {
l.Debugln("couldn't send any braodcasts")
return err
}
}
}
func (w *broadcastWriter) String() string {
return fmt.Sprintf("broadcastWriter@%p", w)
}
type broadcastReader struct {
util.ServiceWithError
port int
outbox chan recv
}
func (r *broadcastReader) serve(stop chan struct{}) error {
l.Debugln(r, "starting")
defer l.Debugln(r, "stopping")
conn, err := net.ListenUDP("udp4", &net.UDPAddr{Port: r.port})
func readBroadcasts(outbox chan<- recv, port int, stop chan struct{}) error {
conn, err := net.ListenUDP("udp4", &net.UDPAddr{Port: port})
if err != nil {
l.Debugln(err)
return err
@ -200,14 +123,12 @@ func (r *broadcastReader) serve(stop chan struct{}) error {
return err
}
r.SetError(nil)
l.Debugf("recv %d bytes from %s", n, addr)
c := make([]byte, n)
copy(c, bs)
select {
case r.outbox <- recv{c, addr}:
case outbox <- recv{c, addr}:
case <-stop:
return nil
default:
@ -216,10 +137,6 @@ func (r *broadcastReader) serve(stop chan struct{}) error {
}
}
func (r *broadcastReader) String() string {
return fmt.Sprintf("broadcastReader@%p", r)
}
func bcast(ip *net.IPNet) *net.IPNet {
var bc = &net.IPNet{}
bc.IP = make([]byte, len(ip.IP))

View File

@ -8,86 +8,25 @@ package beacon
import (
"errors"
"fmt"
"net"
"time"
"github.com/thejerf/suture"
"golang.org/x/net/ipv6"
"github.com/syncthing/syncthing/lib/util"
)
type Multicast struct {
*suture.Supervisor
inbox chan []byte
outbox chan recv
mr *multicastReader
mw *multicastWriter
func NewMulticast(addr string) Interface {
c := newCast("multicastBeacon")
c.addReader(func(stop chan struct{}) error {
return readMulticasts(c.outbox, addr, stop)
})
c.addWriter(func(stop chan struct{}) error {
return writeMulticasts(c.inbox, addr, stop)
})
return c
}
func NewMulticast(addr string) *Multicast {
m := &Multicast{
Supervisor: suture.New("multicastBeacon", suture.Spec{
// Don't retry too frenetically: an error to open a socket or
// whatever is usually something that is either permanent or takes
// a while to get solved...
FailureThreshold: 2,
FailureBackoff: 60 * time.Second,
// Only log restarts in debug mode.
Log: func(line string) {
l.Debugln(line)
},
PassThroughPanics: true,
}),
inbox: make(chan []byte),
outbox: make(chan recv, 16),
}
m.mr = &multicastReader{
addr: addr,
outbox: m.outbox,
}
m.mr.ServiceWithError = util.AsServiceWithError(m.mr.serve)
m.Add(m.mr)
m.mw = &multicastWriter{
addr: addr,
inbox: m.inbox,
}
m.mw.ServiceWithError = util.AsServiceWithError(m.mw.serve)
m.Add(m.mw)
return m
}
func (m *Multicast) Send(data []byte) {
m.inbox <- data
}
func (m *Multicast) Recv() ([]byte, net.Addr) {
recv := <-m.outbox
return recv.data, recv.src
}
func (m *Multicast) Error() error {
if err := m.mr.Error(); err != nil {
return err
}
return m.mw.Error()
}
type multicastWriter struct {
util.ServiceWithError
addr string
inbox <-chan []byte
}
func (w *multicastWriter) serve(stop chan struct{}) error {
l.Debugln(w, "starting")
defer l.Debugln(w, "stopping")
gaddr, err := net.ResolveUDPAddr("udp6", w.addr)
func writeMulticasts(inbox <-chan []byte, addr string, stop chan struct{}) error {
gaddr, err := net.ResolveUDPAddr("udp6", addr)
if err != nil {
l.Debugln(err)
return err
@ -117,7 +56,7 @@ func (w *multicastWriter) serve(stop chan struct{}) error {
for {
var bs []byte
select {
case bs = <-w.inbox:
case bs = <-inbox:
case <-stop:
return nil
}
@ -137,7 +76,6 @@ func (w *multicastWriter) serve(stop chan struct{}) error {
if err != nil {
l.Debugln(err, "on write to", gaddr, intf.Name)
w.SetError(err)
continue
}
@ -152,33 +90,20 @@ func (w *multicastWriter) serve(stop chan struct{}) error {
}
}
if success > 0 {
w.SetError(nil)
if success == 0 {
return err
}
}
}
func (w *multicastWriter) String() string {
return fmt.Sprintf("multicastWriter@%p", w)
}
type multicastReader struct {
util.ServiceWithError
addr string
outbox chan<- recv
}
func (r *multicastReader) serve(stop chan struct{}) error {
l.Debugln(r, "starting")
defer l.Debugln(r, "stopping")
gaddr, err := net.ResolveUDPAddr("udp6", r.addr)
func readMulticasts(outbox chan<- recv, addr string, stop chan struct{}) error {
gaddr, err := net.ResolveUDPAddr("udp6", addr)
if err != nil {
l.Debugln(err)
return err
}
conn, err := net.ListenPacket("udp6", r.addr)
conn, err := net.ListenPacket("udp6", addr)
if err != nil {
l.Debugln(err)
return err
@ -226,21 +151,16 @@ func (r *multicastReader) serve(stop chan struct{}) error {
n, _, addr, err := pconn.ReadFrom(bs)
if err != nil {
l.Debugln(err)
r.SetError(err)
continue
return err
}
l.Debugf("recv %d bytes from %s", n, addr)
c := make([]byte, n)
copy(c, bs)
select {
case r.outbox <- recv{c, addr}:
case outbox <- recv{c, addr}:
default:
l.Debugln("dropping message")
}
}
}
func (r *multicastReader) String() string {
return fmt.Sprintf("multicastReader@%p", r)
}

View File

@ -22,6 +22,7 @@ import (
"github.com/syncthing/syncthing/lib/events"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syncthing/syncthing/lib/rand"
"github.com/syncthing/syncthing/lib/util"
"github.com/thejerf/suture"
)
@ -73,30 +74,20 @@ func NewLocal(id protocol.DeviceID, addr string, addrList AddressLister, evLogge
if err != nil {
return nil, err
}
c.startLocalIPv4Broadcasts(bcPort)
c.beacon = beacon.NewBroadcast(bcPort)
} else {
// A multicast client
c.name = "IPv6 local"
c.startLocalIPv6Multicasts(addr)
c.beacon = beacon.NewMulticast(addr)
}
c.Add(c.beacon)
c.Add(util.AsService(c.recvAnnouncements))
go c.sendLocalAnnouncements()
c.Add(util.AsService(c.sendLocalAnnouncements))
return c, nil
}
func (c *localClient) startLocalIPv4Broadcasts(localPort int) {
c.beacon = beacon.NewBroadcast(localPort)
c.Add(c.beacon)
go c.recvAnnouncements(c.beacon)
}
func (c *localClient) startLocalIPv6Multicasts(localMCAddr string) {
c.beacon = beacon.NewMulticast(localMCAddr)
c.Add(c.beacon)
go c.recvAnnouncements(c.beacon)
}
// Lookup returns a list of addresses the device is available at.
func (c *localClient) Lookup(device protocol.DeviceID) (addresses []string, err error) {
if cache, ok := c.Get(device); ok {
@ -144,7 +135,7 @@ func (c *localClient) announcementPkt(instanceID int64, msg []byte) ([]byte, boo
return msg, true
}
func (c *localClient) sendLocalAnnouncements() {
func (c *localClient) sendLocalAnnouncements(stop chan struct{}) {
var msg []byte
var ok bool
instanceID := rand.Int63()
@ -156,13 +147,22 @@ func (c *localClient) sendLocalAnnouncements() {
select {
case <-c.localBcastTick:
case <-c.forcedBcastTick:
case <-stop:
return
}
}
}
func (c *localClient) recvAnnouncements(b beacon.Interface) {
func (c *localClient) recvAnnouncements(stop chan struct{}) {
b := c.beacon
warnedAbout := make(map[string]bool)
for {
select {
case <-stop:
return
default:
}
buf, addr := b.Recv()
if len(buf) < 4 {
l.Debugf("discover: short packet from %s")