do not get stuck on NeedMorePeers

internal/announcer/periodic.go

@@ -3,6 +3,7 @@ package announcer
 import (
  "math"
  "net"
+ "sync"
  "time"
 
  "github.com/cenkalti/backoff"
@@ -20,25 +21,28 @@ const (
 )
 
 type PeriodicalAnnouncer struct {
- Tracker tracker.Tracker
- status Status
- statsCommandC chan statsRequest
- numWant int
- interval time.Duration
- minInterval time.Duration
- seeders int
- leechers int
- lastError error
- log logger.Logger
- completedC chan struct{}
- newPeers chan []*net.TCPAddr
- backoff backoff.BackOff
- requests chan *Request
- lastAnnounce time.Time
- HasAnnounced bool
- needMorePeersC chan bool
- closeC chan struct{}
- doneC chan struct{}
+ Tracker tracker.Tracker
+ status Status
+ statsCommandC chan statsRequest
+ numWant int
+ interval time.Duration
+ minInterval time.Duration
+ seeders int
+ leechers int
+ lastError error
+ log logger.Logger
+ completedC chan struct{}
+ newPeers chan []*net.TCPAddr
+ backoff backoff.BackOff
+ requests chan *Request
+ lastAnnounce time.Time
+ HasAnnounced bool
+ closeC chan struct{}
+ doneC chan struct{}
+
+ needMorePeers bool
+ mNeedMorePeers sync.RWMutex
+ needMorePeersC chan struct{}
 }
 
 type Request struct {
@@ -61,7 +65,7 @@ func NewPeriodicalAnnouncer(trk tracker.Tracker, numWant int, minInterval time.D
  completedC: completedC,
  newPeers: newPeers,
  requests: requests,
- needMorePeersC: make(chan bool),
+ needMorePeersC: make(chan struct{}, 1),
  closeC: make(chan struct{}),
  doneC: make(chan struct{}),
  backoff: &backoff.ExponentialBackOff{
@@ -99,9 +103,13 @@ func (a *PeriodicalAnnouncer) Stats() Stats {
 }
 
 func (a *PeriodicalAnnouncer) NeedMorePeers(val bool) {
+ a.mNeedMorePeers.Lock()
+ a.needMorePeers = val
+ a.mNeedMorePeers.Unlock()
  select {
- case a.needMorePeersC <- val:
+ case a.needMorePeersC <- struct{}{}:
  case <-a.doneC:
+ default:
  }
 }
 
@@ -112,8 +120,6 @@ func (a *PeriodicalAnnouncer) Run() {
  timer := time.NewTimer(math.MaxInt64)
  defer timer.Stop()
 
- var needMorePeers bool
-
  ca := newCancelableAnnouncer(a.Tracker, a.requests, a.newPeers)
  defer ca.Cancel()
 
@@ -136,20 +142,27 @@ func (a *PeriodicalAnnouncer) Run() {
  a.lastError = nil
  a.status = Working
  a.backoff.Reset()
+ a.mNeedMorePeers.RLock()
+ needMorePeers := a.needMorePeers
+ a.mNeedMorePeers.RUnlock()
  if needMorePeers {
  timer.Reset(a.minInterval)
  } else {
  timer.Reset(a.interval)
  }
  case a.lastError = <-ca.ErrorC:
  ca.announcing = false
+ a.lastAnnounce = time.Now()
  a.status = NotWorking
  a.log.Debugln("announce error:", a.lastError)
  timer.Reset(a.backoff.NextBackOff())
- case needMorePeers = <-a.needMorePeersC:
+ case <-a.needMorePeersC:
  if ca.announcing {
  break
  }
+ a.mNeedMorePeers.RLock()
+ needMorePeers := a.needMorePeers
+ a.mNeedMorePeers.RUnlock()
  if needMorePeers {
  timer.Reset(time.Until(a.lastAnnounce.Add(a.minInterval)))
  } else {