device: use channel close to shut down and drain outbound channel

This is a similar treatment to the handling of the encryption
channel found a few commits ago: Use the closing of the channel
to manage goroutine lifetime and shutdown.
It is considerably simpler because there is only a single writer.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
This commit is contained in:
Josh Bleecher Snyder 2020-12-15 15:54:48 -08:00 committed by Jason A. Donenfeld
parent 63066ce406
commit 2832e96339
2 changed files with 35 additions and 56 deletions

View file

@ -17,7 +17,7 @@ import (
)
const (
PeerRoutineNumber = 3
PeerRoutineNumber = 2
)
type Peer struct {
@ -287,7 +287,6 @@ func (peer *Peer) Stop() {
peer.queue.Lock()
close(peer.queue.nonce)
close(peer.queue.outbound)
close(peer.queue.inbound)
peer.queue.Unlock()

View file

@ -372,6 +372,7 @@ func (peer *Peer) RoutineNonce() {
logDebug.Println(peer, "- Routine: nonce worker - stopped")
peer.queue.packetInNonceQueueIsAwaitingKey.Set(false)
device.queue.encryption.wg.Done() // no more writes from us
close(peer.queue.outbound) // no more writes to this channel
peer.routines.stopping.Done()
}()
@ -545,46 +546,26 @@ func (peer *Peer) RoutineSequentialSender() {
logDebug := device.log.Debug
logError := device.log.Error
defer func() {
for {
select {
case elem, ok := <-peer.queue.outbound:
if ok {
elem.Lock()
if !elem.IsDropped() {
device.PutMessageBuffer(elem.buffer)
elem.Drop()
}
device.PutOutboundElement(elem)
}
default:
goto out
}
}
out:
logDebug.Println(peer, "- Routine: sequential sender - stopped")
peer.routines.stopping.Done()
}()
defer logDebug.Println(peer, "- Routine: sequential sender - stopped")
logDebug.Println(peer, "- Routine: sequential sender - started")
for {
select {
case <-peer.routines.stop:
return
case elem, ok := <-peer.queue.outbound:
if !ok {
return
}
for elem := range peer.queue.outbound {
elem.Lock()
if elem.IsDropped() {
device.PutOutboundElement(elem)
continue
}
if !peer.isRunning.Get() {
// peer has been stopped; return re-usable elems to the shared pool.
// This is an optimization only. It is possible for the peer to be stopped
// immediately after this check, in which case, elem will get processed.
// The timers and SendBuffer code are resilient to a few stragglers.
// TODO(josharian): rework peer shutdown order to ensure
// that we never accidentally keep timers alive longer than necessary.
device.PutMessageBuffer(elem.buffer)
device.PutOutboundElement(elem)
continue
}
peer.timersAnyAuthenticatedPacketTraversal()
peer.timersAnyAuthenticatedPacketSent()
@ -605,4 +586,3 @@ func (peer *Peer) RoutineSequentialSender() {
peer.keepKeyFreshSending()
}
}
}