autorelay: refactor relay finder and start autorelay after identify (#2120)

* Refactor relay_finder and start autorelay after identify

* Clock fork

* Remove multiple timers and use a single rate limiting chan for findNodes

* Remove clock fork

* Rename

* Use scheduledWork.nextAllowedCallToPeerSource.Add(rf.conf.minInterval)

* Fix flaky test that relied on time

config/config.go

@@ -433,7 +433,9 @@ func (cfg *Config) NewNode() (host.Host, error) {
 		ho = routed.Wrap(h, router)
 	}
 	if ar != nil {
-		return autorelay.NewAutoRelayHost(ho, ar), nil
+		arh := autorelay.NewAutoRelayHost(ho, ar)
+		arh.Start()
+		ho = arh
 	}
 	return ho, nil
 }

p2p/host/autorelay/autorelay.go

@@ -49,12 +49,15 @@ func NewAutoRelay(bhost *basic.BasicHost, opts ...Option) (*AutoRelay, error) {
 	r.relayFinder = newRelayFinder(bhost, conf.peerSource, &conf)
 	bhost.AddrsFactory = r.hostAddrs
 
+	return r, nil
+}
+
+func (r *AutoRelay) Start() {
 	r.refCount.Add(1)
 	go func() {
 		defer r.refCount.Done()
 		r.background()
 	}()
-	return r, nil
 }
 
 func (r *AutoRelay) background() {

p2p/host/autorelay/autorelay_test.go

@@ -2,14 +2,12 @@ package autorelay_test
 
 import (
 	"context"
-	"os"
 	"strings"
 	"sync/atomic"
 	"testing"
 	"time"
 
 	"github.com/libp2p/go-libp2p"
-	"github.com/libp2p/go-libp2p/core/event"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/libp2p/go-libp2p/core/peer"
@@ -97,7 +95,7 @@ func newRelay(t *testing.T) host.Host {
 			}
 		}
 		return false
-	}, 500*time.Millisecond, 10*time.Millisecond)
+	}, time.Second, 10*time.Millisecond)
 	return h
 }
 
@@ -121,7 +119,7 @@ func TestSingleCandidate(t *testing.T) {
 	)
 	defer h.Close()
 
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 3*time.Second, 100*time.Millisecond)
+	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 10*time.Second, 100*time.Millisecond)
 	// test that we don't add any more relays
 	require.Never(t, func() bool { return numRelays(h) > 1 }, 200*time.Millisecond, 50*time.Millisecond)
 	require.Equal(t, 1, counter, "expected the peer source callback to only have been called once")
@@ -179,7 +177,7 @@ func TestWaitForCandidates(t *testing.T) {
 	r2 := newRelay(t)
 	t.Cleanup(func() { r2.Close() })
 	peerChan <- peer.AddrInfo{ID: r2.ID(), Addrs: r2.Addrs()}
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 3*time.Second, 100*time.Millisecond)
+	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 10*time.Second, 100*time.Millisecond)
 }
 
 func TestBackoff(t *testing.T) {
@@ -225,15 +223,19 @@ func TestBackoff(t *testing.T) {
 	)
 	defer h.Close()
 
-	require.Eventually(t, func() bool { return reservations.Load() == 1 }, 3*time.Second, 20*time.Millisecond)
+	require.Eventually(t, func() bool {
+		return reservations.Load() == 1
+	}, 10*time.Second, 20*time.Millisecond, "reservations load should be 1 was %d", reservations.Load())
 	// make sure we don't add any relays yet
 	for i := 0; i < 2; i++ {
 		cl.Add(backoff / 3)
 		require.Equal(t, 1, int(reservations.Load()))
 	}
-	cl.Add(backoff / 2)
-	require.Eventually(t, func() bool { return reservations.Load() == 2 }, 3*time.Second, 20*time.Millisecond)
-	require.Less(t, int(counter.Load()), 100) // just make sure we're not busy-looping
+	cl.Add(backoff)
+	require.Eventually(t, func() bool {
+		return reservations.Load() == 2
+	}, 10*time.Second, 100*time.Millisecond, "reservations load should be 2 was %d", reservations.Load())
+	require.Less(t, int(counter.Load()), 300) // just make sure we're not busy-looping
 	require.Equal(t, 2, int(reservations.Load()))
 }
 
@@ -252,7 +254,7 @@ func TestStaticRelays(t *testing.T) {
 	)
 	defer h.Close()
 
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 2*time.Second, 50*time.Millisecond)
+	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 10*time.Second, 50*time.Millisecond)
 }
 
 func TestConnectOnDisconnect(t *testing.T) {
@@ -275,7 +277,7 @@ func TestConnectOnDisconnect(t *testing.T) {
 	)
 	defer h.Close()
 
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 3*time.Second, 100*time.Millisecond)
+	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 10*time.Second, 100*time.Millisecond)
 	relaysInUse := usedRelays(h)
 	require.Len(t, relaysInUse, 1)
 	oldRelay := relaysInUse[0]
@@ -286,7 +288,7 @@ func TestConnectOnDisconnect(t *testing.T) {
 		}
 	}
 
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 3*time.Second, 100*time.Millisecond)
+	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 10*time.Second, 100*time.Millisecond)
 	relaysInUse = usedRelays(h)
 	require.Len(t, relaysInUse, 1)
 	require.NotEqualf(t, oldRelay, relaysInUse[0], "old relay should not be used again")
@@ -332,28 +334,31 @@ func TestMaxAge(t *testing.T) {
 	)
 	defer h.Close()
 
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 3*time.Second, 100*time.Millisecond)
+	require.Eventually(t, func() bool {
+		return numRelays(h) > 0
+	}, 10*time.Second, 100*time.Millisecond)
 	relays := usedRelays(h)
 	require.Len(t, relays, 1)
 
-	waitFor := 500 * time.Millisecond
-	tick := 100 * time.Millisecond
-	if os.Getenv("CI") != "" {
-		// Only increase the waitFor since we are increasing the mock clock every tick.
-		waitFor *= 10
-	}
 	require.Eventually(t, func() bool {
 		// we don't know exactly when the timer is reset, just advance our timer multiple times if necessary
-		cl.Add(time.Second)
+		cl.Add(30 * time.Second)
 		return len(peerChans) == 0
-	}, waitFor, tick)
+	}, 10*time.Second, 100*time.Millisecond)
 
 	cl.Add(10 * time.Minute)
 	for _, r := range relays2 {
 		peerChan2 <- peer.AddrInfo{ID: r.ID(), Addrs: r.Addrs()}
 	}
 	cl.Add(11 * time.Minute)
+
+	require.Eventually(t, func() bool {
+		relays = usedRelays(h)
+		return len(relays) == 1
+	}, 10*time.Second, 100*time.Millisecond)
+
 	// by now the 3 relays should have been garbage collected
+	// And we should only be using a single relay. Lets close it.
 	var oldRelay peer.ID
 	for _, r := range relays1 {
 		if r.ID() == relays[0] {
@@ -369,7 +374,7 @@ func TestMaxAge(t *testing.T) {
 			return false
 		}
 		return relays[0] != oldRelay
-	}, 3*time.Second, 100*time.Millisecond)
+	}, 10*time.Second, 100*time.Millisecond)
 
 	require.Len(t, relays, 1)
 	ids := make([]peer.ID, 0, len(relays2))
@@ -379,40 +384,6 @@ func TestMaxAge(t *testing.T) {
 	require.Contains(t, ids, relays[0])
 }
 
-func expectDeltaInAddrUpdated(t *testing.T, addrUpdated event.Subscription, expectedDelta int) {
-	t.Helper()
-	delta := 0
-	for {
-		select {
-		case evAny := <-addrUpdated.Out():
-			ev := evAny.(event.EvtLocalAddressesUpdated)
-			for _, updatedAddr := range ev.Removed {
-				if updatedAddr.Action == event.Removed {
-					if _, err := updatedAddr.Address.ValueForProtocol(ma.P_CIRCUIT); err == nil {
-						delta--
-						if delta == expectedDelta {
-							return
-						}
-					}
-				}
-			}
-			for _, updatedAddr := range ev.Current {
-				if updatedAddr.Action == event.Added {
-					if _, err := updatedAddr.Address.ValueForProtocol(ma.P_CIRCUIT); err == nil {
-						delta++
-						if delta == expectedDelta {
-							return
-						}
-					}
-				}
-			}
-		case <-time.After(10 * time.Second):
-			t.Fatal("timeout waiting for address updated event")
-		}
-	}
-
-}
-
 func TestReconnectToStaticRelays(t *testing.T) {
 	cl := clock.NewMock()
 	var staticRelays []peer.AddrInfo
@@ -428,16 +399,14 @@ func TestReconnectToStaticRelays(t *testing.T) {
 	h := newPrivateNodeWithStaticRelays(t,
 		staticRelays,
 		autorelay.WithClock(cl),
+		autorelay.WithBackoff(30*time.Minute),
 	)
-
 	defer h.Close()
 
-	addrUpdated, err := h.EventBus().Subscribe(new(event.EvtLocalAddressesUpdated))
-	require.NoError(t, err)
-
-	expectDeltaInAddrUpdated(t, addrUpdated, 1)
-
 	cl.Add(time.Minute)
+	require.Eventually(t, func() bool {
+		return numRelays(h) == 1
+	}, 10*time.Second, 100*time.Millisecond)
 
 	relaysInUse := usedRelays(h)
 	oldRelay := relaysInUse[0]
@@ -446,12 +415,18 @@ func TestReconnectToStaticRelays(t *testing.T) {
 			r.Network().ClosePeer(h.ID())
 		}
 	}
+	require.Eventually(t, func() bool {
+		return numRelays(h) == 0
+	}, 10*time.Second, 100*time.Millisecond)
 
 	cl.Add(time.Hour)
-	expectDeltaInAddrUpdated(t, addrUpdated, -1)
+	require.Eventually(t, func() bool {
+		return numRelays(h) == 1
+	}, 10*time.Second, 100*time.Millisecond)
 }
 
 func TestMinInterval(t *testing.T) {
+	cl := clock.NewMock()
 	h := newPrivateNode(t,
 		func(context.Context, int) <-chan peer.AddrInfo {
 			peerChan := make(chan peer.AddrInfo, 1)
@@ -461,6 +436,7 @@ func TestMinInterval(t *testing.T) {
 			peerChan <- peer.AddrInfo{ID: r1.ID(), Addrs: r1.Addrs()}
 			return peerChan
 		},
+		autorelay.WithClock(cl),
 		autorelay.WithMinCandidates(2),
 		autorelay.WithNumRelays(1),
 		autorelay.WithBootDelay(time.Hour),
@@ -468,7 +444,9 @@ func TestMinInterval(t *testing.T) {
 	)
 	defer h.Close()
 
+	cl.Add(500 * time.Millisecond)
 	// The second call to peerSource should happen after 1 second
 	require.Never(t, func() bool { return numRelays(h) > 0 }, 500*time.Millisecond, 100*time.Millisecond)
-	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 1*time.Second, 100*time.Millisecond)
+	cl.Add(500 * time.Millisecond)
+	require.Eventually(t, func() bool { return numRelays(h) > 0 }, 10*time.Second, 100*time.Millisecond)
 }

p2p/host/autorelay/host.go

@@ -14,6 +14,10 @@ func (h *AutoRelayHost) Close() error {
 	return h.Host.Close()
 }
 
+func (h *AutoRelayHost) Start() {
+	h.ar.Start()
+}
+
 func NewAutoRelayHost(h host.Host, ar *AutoRelay) *AutoRelayHost {
 	return &AutoRelayHost{Host: h, ar: ar}
 }

p2p/host/autorelay/relay_finder.go

@@ -99,11 +99,20 @@ func newRelayFinder(host *basic.BasicHost, peerSource PeerSource, conf *config)
 	}
 }
 
+type scheduledWorkTimes struct {
+	leastFrequentInterval       time.Duration
+	nextRefresh                 time.Time
+	nextBackoff                 time.Time
+	nextOldCandidateCheck       time.Time
+	nextAllowedCallToPeerSource time.Time
+}
+
 func (rf *relayFinder) background(ctx context.Context) {
+	peerSourceRateLimiter := make(chan struct{}, 1)
 	rf.refCount.Add(1)
 	go func() {
 		defer rf.refCount.Done()
-		rf.findNodes(ctx)
+		rf.findNodes(ctx, peerSourceRateLimiter)
 	}()
 
 	rf.refCount.Add(1)
@@ -121,17 +130,33 @@ func (rf *relayFinder) background(ctx context.Context) {
 
 	bootDelayTimer := rf.conf.clock.Timer(rf.conf.bootDelay)
 	defer bootDelayTimer.Stop()
-	refreshTicker := rf.conf.clock.Ticker(rsvpRefreshInterval)
-	defer refreshTicker.Stop()
-	backoffTicker := rf.conf.clock.Ticker(rf.conf.backoff / 5)
-	defer backoffTicker.Stop()
-	oldCandidateTicker := rf.conf.clock.Ticker(rf.conf.maxCandidateAge / 5)
-	defer oldCandidateTicker.Stop()
 
-	for {
-		// when true, we need to identify push
-		var push bool
+	// This is the least frequent event. It's our fallback timer if we don't have any other work to do.
+	leastFrequentInterval := rf.conf.minInterval
+	if rf.conf.backoff > leastFrequentInterval {
+		leastFrequentInterval = rf.conf.backoff
+	}
+	if rf.conf.maxCandidateAge > leastFrequentInterval {
+		leastFrequentInterval = rf.conf.maxCandidateAge
+	}
+	if rsvpRefreshInterval > leastFrequentInterval {
+		leastFrequentInterval = rf.conf.maxCandidateAge
+	}
+
+	now := rf.conf.clock.Now()
+
+	scheduledWork := &scheduledWorkTimes{
+		leastFrequentInterval:       leastFrequentInterval,
+		nextRefresh:                 now.Add(rsvpRefreshInterval),
+		nextBackoff:                 now.Add(rf.conf.backoff / 5),
+		nextOldCandidateCheck:       now.Add(rf.conf.maxCandidateAge / 5),
+		nextAllowedCallToPeerSource: now.Add(-time.Second), // allow immediately
+	}
+
+	workTimer := rf.conf.clock.Timer(rf.runScheduledWork(ctx, now, scheduledWork, peerSourceRateLimiter).Sub(now))
+	defer workTimer.Stop()
 
+	for {
 		select {
 		case ev, ok := <-subConnectedness.Out():
 			if !ok {
@@ -141,6 +166,8 @@ func (rf *relayFinder) background(ctx context.Context) {
 			if evt.Connectedness != network.NotConnected {
 				continue
 			}
+			push := false
+
 			rf.relayMx.Lock()
 			if rf.usingRelay(evt.Peer) { // we were disconnected from a relay
 				log.Debugw("disconnected from relay", "id", evt.Peer)
@@ -150,85 +177,156 @@ func (rf *relayFinder) background(ctx context.Context) {
 				push = true
 			}
 			rf.relayMx.Unlock()
+
+			if push {
+				rf.clearCachedAddrsAndSignalAddressChange()
+			}
 		case <-rf.candidateFound:
 			rf.notifyMaybeConnectToRelay()
 		case <-bootDelayTimer.C:
 			rf.notifyMaybeConnectToRelay()
 		case <-rf.relayUpdated:
-			push = true
-		case now := <-refreshTicker.C:
-			push = rf.refreshReservations(ctx, now)
-		case now := <-backoffTicker.C:
-			rf.candidateMx.Lock()
-			for id, t := range rf.backoff {
-				if !t.Add(rf.conf.backoff).After(now) {
-					log.Debugw("removing backoff for node", "id", id)
-					delete(rf.backoff, id)
-				}
-			}
-			rf.candidateMx.Unlock()
-		case now := <-oldCandidateTicker.C:
-			var deleted bool
-			rf.candidateMx.Lock()
-			for id, cand := range rf.candidates {
-				if !cand.added.Add(rf.conf.maxCandidateAge).After(now) {
-					deleted = true
-					log.Debugw("deleting candidate due to age", "id", id)
-					delete(rf.candidates, id)
-				}
-			}
-			rf.candidateMx.Unlock()
-			if deleted {
-				rf.notifyMaybeNeedNewCandidates()
-			}
+			rf.clearCachedAddrsAndSignalAddressChange()
+		case <-workTimer.C:
+			now := rf.conf.clock.Now()
+			nextTime := rf.runScheduledWork(ctx, now, scheduledWork, peerSourceRateLimiter)
+			workTimer.Reset(nextTime.Sub(now))
 		case <-ctx.Done():
 			return
 		}
+	}
+}
 
-		if push {
-			rf.relayMx.Lock()
-			rf.cachedAddrs = nil
-			rf.relayMx.Unlock()
-			rf.host.SignalAddressChange()
+func (rf *relayFinder) clearCachedAddrsAndSignalAddressChange() {
+	rf.relayMx.Lock()
+	rf.cachedAddrs = nil
+	rf.relayMx.Unlock()
+	rf.host.SignalAddressChange()
+}
+
+func (rf *relayFinder) runScheduledWork(ctx context.Context, now time.Time, scheduledWork *scheduledWorkTimes, peerSourceRateLimiter chan<- struct{}) time.Time {
+	nextTime := now.Add(scheduledWork.leastFrequentInterval)
+
+	if now.After(scheduledWork.nextRefresh) {
+		scheduledWork.nextRefresh = now.Add(rsvpRefreshInterval)
+		if rf.refreshReservations(ctx, now) {
+			rf.clearCachedAddrsAndSignalAddressChange()
+		}
+	}
+
+	if now.After(scheduledWork.nextBackoff) {
+		scheduledWork.nextBackoff = rf.clearBackoff(now)
+	}
+
+	if now.After(scheduledWork.nextOldCandidateCheck) {
+		scheduledWork.nextOldCandidateCheck = rf.clearOldCandidates(now)
+	}
+
+	if now.After(scheduledWork.nextAllowedCallToPeerSource) {
+		scheduledWork.nextAllowedCallToPeerSource = scheduledWork.nextAllowedCallToPeerSource.Add(rf.conf.minInterval)
+		select {
+		case peerSourceRateLimiter <- struct{}{}:
+		default:
 		}
 	}
+
+	// Find the next time we need to run scheduled work.
+	if scheduledWork.nextRefresh.Before(nextTime) {
+		nextTime = scheduledWork.nextRefresh
+	}
+	if scheduledWork.nextBackoff.Before(nextTime) {
+		nextTime = scheduledWork.nextBackoff
+	}
+	if scheduledWork.nextOldCandidateCheck.Before(nextTime) {
+		nextTime = scheduledWork.nextOldCandidateCheck
+	}
+	if scheduledWork.nextAllowedCallToPeerSource.Before(nextTime) {
+		nextTime = scheduledWork.nextAllowedCallToPeerSource
+	}
+	if nextTime == now {
+		// Only happens in CI with a mock clock
+		nextTime = nextTime.Add(1) // avoids an infinite loop
+	}
+
+	return nextTime
+}
+
+// clearOldCandidates clears old candidates from the map. Returns the next time
+// to run this function.
+func (rf *relayFinder) clearOldCandidates(now time.Time) time.Time {
+	// If we don't have any candidates, we should run this again in rf.conf.maxCandidateAge.
+	nextTime := now.Add(rf.conf.maxCandidateAge)
+
+	var deleted bool
+	rf.candidateMx.Lock()
+	defer rf.candidateMx.Unlock()
+	for id, cand := range rf.candidates {
+		expiry := cand.added.Add(rf.conf.maxCandidateAge)
+		if expiry.After(now) {
+			if expiry.Before(nextTime) {
+				nextTime = expiry
+			}
+		} else {
+			deleted = true
+			log.Debugw("deleting candidate due to age", "id", id)
+			delete(rf.candidates, id)
+
+		}
+	}
+	if deleted {
+		rf.notifyMaybeNeedNewCandidates()
+	}
+
+	return nextTime
+}
+
+// clearBackoff clears old backoff entries from the map. Returns the next time
+// to run this function.
+func (rf *relayFinder) clearBackoff(now time.Time) time.Time {
+	nextTime := now.Add(rf.conf.backoff)
+
+	rf.candidateMx.Lock()
+	defer rf.candidateMx.Unlock()
+	for id, t := range rf.backoff {
+		expiry := t.Add(rf.conf.backoff)
+		if expiry.After(now) {
+			if expiry.Before(nextTime) {
+				nextTime = expiry
+			}
+		} else {
+			log.Debugw("removing backoff for node", "id", id)
+			delete(rf.backoff, id)
+		}
+	}
+
+	return nextTime
 }
 
 // findNodes accepts nodes from the channel and tests if they support relaying.
 // It is run on both public and private nodes.
 // It garbage collects old entries, so that nodes doesn't overflow.
 // This makes sure that as soon as we need to find relay candidates, we have them available.
-func (rf *relayFinder) findNodes(ctx context.Context) {
-	peerChan := rf.peerSource(ctx, rf.conf.maxCandidates)
+// peerSourceRateLimiter is used to limit how often we call the peer source.
+func (rf *relayFinder) findNodes(ctx context.Context, peerSourceRateLimiter <-chan struct{}) {
+	var peerChan <-chan peer.AddrInfo
 	var wg sync.WaitGroup
-	lastCallToPeerSource := rf.conf.clock.Now()
-
-	timer := newTimer(rf.conf.clock)
 	for {
 		rf.candidateMx.Lock()
 		numCandidates := len(rf.candidates)
 		rf.candidateMx.Unlock()
 
-		if peerChan == nil {
-			now := rf.conf.clock.Now()
-			nextAllowedCallToPeerSource := lastCallToPeerSource.Add(rf.conf.minInterval).Sub(now)
-			if numCandidates < rf.conf.minCandidates {
-				log.Debugw("not enough candidates. Resetting timer", "num", numCandidates, "desired", rf.conf.minCandidates)
-				timer.Reset(nextAllowedCallToPeerSource)
+		if peerChan == nil && numCandidates < rf.conf.minCandidates {
+			select {
+			case <-peerSourceRateLimiter:
+				peerChan = rf.peerSource(ctx, rf.conf.maxCandidates)
+			case <-ctx.Done():
+				return
 			}
 		}
 
 		select {
 		case <-rf.maybeRequestNewCandidates:
 			continue
-		case now := <-timer.Chan():
-			timer.SetRead()
-			if peerChan != nil {
-				// We're still reading peers from the peerChan. No need to query for more peers now.
-				continue
-			}
-			lastCallToPeerSource = now
-			peerChan = rf.peerSource(ctx, rf.conf.maxCandidates)
 		case pi, ok := <-peerChan:
 			if !ok {
 				wg.Wait()
@@ -530,9 +628,12 @@ func (rf *relayFinder) usingRelay(p peer.ID) bool {
 // selectCandidates returns an ordered slice of relay candidates.
 // Callers should attempt to obtain reservations with the candidates in this order.
 func (rf *relayFinder) selectCandidates() []*candidate {
+	now := rf.conf.clock.Now()
 	candidates := make([]*candidate, 0, len(rf.candidates))
 	for _, cand := range rf.candidates {
-		candidates = append(candidates, cand)
+		if cand.added.Add(rf.conf.maxCandidateAge).After(now) {
+			candidates = append(candidates, cand)
+		}
 	}
 
 	// TODO: better relay selection strategy; this just selects random relays,

p2p/host/autorelay/timer.go

@@ -1,42 +0,0 @@
-package autorelay
-
-import (
-	"time"
-
-	"github.com/benbjohnson/clock"
-)
-
-type timer struct {
-	timer   *clock.Timer
-	running bool
-	read    bool
-}
-
-func newTimer(cl clock.Clock) *timer {
-	t := cl.Timer(100 * time.Hour) // There's no way to initialize a stopped timer
-	t.Stop()
-	return &timer{timer: t}
-}
-
-func (t *timer) Chan() <-chan time.Time {
-	return t.timer.C
-}
-
-func (t *timer) Stop() {
-	if !t.running {
-		return
-	}
-	if !t.timer.Stop() && !t.read {
-		<-t.timer.C
-	}
-	t.read = false
-}
-
-func (t *timer) SetRead() {
-	t.read = true
-}
-
-func (t *timer) Reset(d time.Duration) {
-	t.Stop()
-	t.timer.Reset(d)
-}