Merge pull request #58 from libp2p/feat/trim-block

feat: block on trim

connmgr.go

@@ -36,9 +36,11 @@ type BasicConnMgr struct {
 	plk       sync.RWMutex
 	protected map[peer.ID]map[string]struct{}
 
-	// channel-based semaphore that enforces only a single trim is in progress
-	trimRunningCh chan struct{}
-	lastTrim      time.Time
+	trimTrigger chan chan<- struct{}
+
+	lastTrimMu sync.RWMutex
+	lastTrim   time.Time
+
 	silencePeriod time.Duration
 
 	ctx    context.Context
@@ -96,7 +98,7 @@ func NewConnManager(low, hi int, grace time.Duration) *BasicConnMgr {
 		highWater:     hi,
 		lowWater:      low,
 		gracePeriod:   grace,
-		trimRunningCh: make(chan struct{}, 1),
+		trimTrigger:   make(chan chan<- struct{}),
 		protected:     make(map[peer.ID]map[string]struct{}, 16),
 		silencePeriod: SilencePeriod,
 		ctx:           ctx,
@@ -164,50 +166,96 @@ type peerInfo struct {
 // pruning those peers with the lowest scores first, as long as they are not within their
 // grace period.
 //
-// TODO: error return value so we can cleanly signal we are aborting because:
-// (a) there's another trim in progress, or (b) the silence period is in effect.
+// This function blocks until a trim is completed. If a trim is underway, a new
+// one won't be started, and instead it'll wait until that one is completed before
+// returning.
 func (cm *BasicConnMgr) TrimOpenConns(ctx context.Context) {
+	// TODO: error return value so we can cleanly signal we are aborting because:
+	// (a) there's another trim in progress, or (b) the silence period is in effect.
+
+	// Trigger a trim.
+	ch := make(chan struct{})
 	select {
-	case cm.trimRunningCh <- struct{}{}:
-	default:
-		return
-	}
-	defer func() { <-cm.trimRunningCh }()
-	if time.Since(cm.lastTrim) < cm.silencePeriod {
-		// skip this attempt to trim as the last one just took place.
-		return
+	case cm.trimTrigger <- ch:
+	case <-cm.ctx.Done():
+	case <-ctx.Done():
+		// TODO: return an error?
 	}
 
-	defer log.EventBegin(ctx, "connCleanup").Done()
-	for _, c := range cm.getConnsToClose(ctx) {
-		log.Info("closing conn: ", c.RemotePeer())
-		log.Event(ctx, "closeConn", c.RemotePeer())
-		c.Close()
+	// Wait for the trim.
+	select {
+	case <-ch:
+	case <-cm.ctx.Done():
+	case <-ctx.Done():
+		// TODO: return an error?
 	}
-
-	cm.lastTrim = time.Now()
 }
 
 func (cm *BasicConnMgr) background() {
 	ticker := time.NewTicker(time.Minute)
 	defer ticker.Stop()
 
 	for {
+		var waiting chan<- struct{}
 		select {
 		case <-ticker.C:
-			if atomic.LoadInt32(&cm.connCount) > int32(cm.highWater) {
-				cm.TrimOpenConns(cm.ctx)
+			if atomic.LoadInt32(&cm.connCount) < int32(cm.highWater) {
+				// Below high water, skip.
+				continue
 			}
-
+		case waiting = <-cm.trimTrigger:
 		case <-cm.ctx.Done():
 			return
 		}
+		cm.trim()
+
+		// Notify anyone waiting on this trim.
+		if waiting != nil {
+			close(waiting)
+		}
+
+		for {
+			select {
+			case waiting = <-cm.trimTrigger:
+				if waiting != nil {
+					close(waiting)
+				}
+				continue
+			default:
+			}
+			break
+		}
+	}
+}
+
+func (cm *BasicConnMgr) trim() {
+	cm.lastTrimMu.RLock()
+	// read the last trim time under the lock
+	lastTrim := cm.lastTrim
+	cm.lastTrimMu.RUnlock()
+
+	// skip this attempt to trim if the last one just took place.
+	if time.Since(lastTrim) < cm.silencePeriod {
+		return
+	}
+
+	// do the actual trim.
+	defer log.EventBegin(cm.ctx, "connCleanup").Done()
+	for _, c := range cm.getConnsToClose() {
+		log.Info("closing conn: ", c.RemotePeer())
+		log.Event(cm.ctx, "closeConn", c.RemotePeer())
+		c.Close()
 	}
+
+	// finally, update the last trim time.
+	cm.lastTrimMu.Lock()
+	cm.lastTrim = time.Now()
+	cm.lastTrimMu.Unlock()
 }
 
 // getConnsToClose runs the heuristics described in TrimOpenConns and returns the
 // connections to close.
-func (cm *BasicConnMgr) getConnsToClose(ctx context.Context) []network.Conn {
+func (cm *BasicConnMgr) getConnsToClose() []network.Conn {
 	if cm.lowWater == 0 || cm.highWater == 0 {
 		// disabled
 		return nil
@@ -386,10 +434,14 @@ type CMInfo struct {
 
 // GetInfo returns the configuration and status data for this connection manager.
 func (cm *BasicConnMgr) GetInfo() CMInfo {
+	cm.lastTrimMu.RLock()
+	lastTrim := cm.lastTrim
+	cm.lastTrimMu.RUnlock()
+
 	return CMInfo{
 		HighWater:   cm.highWater,
 		LowWater:    cm.lowWater,
-		LastTrim:    cm.lastTrim,
+		LastTrim:    lastTrim,
 		GracePeriod: cm.gracePeriod,
 		ConnCount:   int(atomic.LoadInt32(&cm.connCount)),
 	}

connmgr_test.go

@@ -2,6 +2,7 @@ package connmgr
 
 import (
 	"context"
+	"sync"
 	"testing"
 	"time"
 
@@ -47,6 +48,82 @@ func randConn(t testing.TB, discNotify func(network.Network, network.Conn)) netw
 	return &tconn{peer: pid, disconnectNotify: discNotify}
 }
 
+// Make sure multiple trim calls block.
+func TestTrimBlocks(t *testing.T) {
+	cm := NewConnManager(200, 300, 0)
+
+	cm.lastTrimMu.RLock()
+
+	doneCh := make(chan struct{}, 2)
+	go func() {
+		cm.TrimOpenConns(context.Background())
+		doneCh <- struct{}{}
+	}()
+	go func() {
+		cm.TrimOpenConns(context.Background())
+		doneCh <- struct{}{}
+	}()
+	time.Sleep(time.Millisecond)
+	select {
+	case <-doneCh:
+		cm.lastTrimMu.RUnlock()
+		t.Fatal("expected trim to block")
+	default:
+		cm.lastTrimMu.RUnlock()
+	}
+	<-doneCh
+	<-doneCh
+}
+
+// Make sure we return from trim when the context is canceled.
+func TestTrimCancels(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cm := NewConnManager(200, 300, 0)
+
+	cm.lastTrimMu.RLock()
+	defer cm.lastTrimMu.RUnlock()
+
+	doneCh := make(chan struct{})
+	go func() {
+		defer close(doneCh)
+		cm.TrimOpenConns(ctx)
+	}()
+	time.Sleep(time.Millisecond)
+	cancel()
+	<-doneCh
+}
+
+// Make sure trim returns when closed.
+func TestTrimClosed(t *testing.T) {
+	cm := NewConnManager(200, 300, 0)
+	cm.Close()
+	cm.TrimOpenConns(context.Background())
+}
+
+// Make sure joining an existing trim works.
+func TestTrimJoin(t *testing.T) {
+	cm := NewConnManager(200, 300, 0)
+	cm.lastTrimMu.RLock()
+	var wg sync.WaitGroup
+	wg.Add(3)
+	go func() {
+		defer wg.Done()
+		cm.TrimOpenConns(context.Background())
+	}()
+	time.Sleep(time.Millisecond)
+	go func() {
+		defer wg.Done()
+		cm.TrimOpenConns(context.Background())
+	}()
+	go func() {
+		defer wg.Done()
+		cm.TrimOpenConns(context.Background())
+	}()
+	time.Sleep(time.Millisecond)
+	cm.lastTrimMu.RUnlock()
+	wg.Wait()
+}
+
 func TestConnTrimming(t *testing.T) {
 	cm := NewConnManager(200, 300, 0)
 	not := cm.Notifee()
@@ -86,19 +163,19 @@ func TestConnTrimming(t *testing.T) {
 
 func TestConnsToClose(t *testing.T) {
 	cm := NewConnManager(0, 10, 0)
-	conns := cm.getConnsToClose(context.Background())
+	conns := cm.getConnsToClose()
 	if conns != nil {
 		t.Fatal("expected no connections")
 	}
 
 	cm = NewConnManager(10, 0, 0)
-	conns = cm.getConnsToClose(context.Background())
+	conns = cm.getConnsToClose()
 	if conns != nil {
 		t.Fatal("expected no connections")
 	}
 
 	cm = NewConnManager(1, 1, 0)
-	conns = cm.getConnsToClose(context.Background())
+	conns = cm.getConnsToClose()
 	if conns != nil {
 		t.Fatal("expected no connections")
 	}
@@ -109,7 +186,7 @@ func TestConnsToClose(t *testing.T) {
 		conn := randConn(t, nil)
 		not.Connected(nil, conn)
 	}
-	conns = cm.getConnsToClose(context.Background())
+	conns = cm.getConnsToClose()
 	if len(conns) != 0 {
 		t.Fatal("expected no connections")
 	}

go.mod

@@ -6,3 +6,5 @@ require (
 	github.com/libp2p/go-libp2p-core v0.2.5
 	github.com/multiformats/go-multiaddr v0.2.0
 )
+
+go 1.12

go.sum

@@ -1,12 +1,9 @@
 cloud.google.com/go v0.26.0/go.mod h1:aQUYkXzVsufM+DwF1aE+0xfcU+56JwCaLick0ClmMTw=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
-github.com/btcsuite/btcd v0.0.0-20190213025234-306aecffea32 h1:qkOC5Gd33k54tobS36cXdAzJbeHaduLtnLQQwNoIi78=
-github.com/btcsuite/btcd v0.0.0-20190213025234-306aecffea32/go.mod h1:DrZx5ec/dmnfpw9KyYoQyYo7d0KEvTkk/5M/vbZjAr8=
 github.com/btcsuite/btcd v0.0.0-20190824003749-130ea5bddde3 h1:A/EVblehb75cUgXA5njHPn0kLAsykn6mJGz7rnmW5W0=
 github.com/btcsuite/btcd v0.0.0-20190824003749-130ea5bddde3/go.mod h1:3J08xEfcugPacsc34/LKRU2yO7YmuT8yt28J8k2+rrI=
 github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f/go.mod h1:TdznJufoqS23FtqVCzL0ZqgP5MqXbb4fg/WgDys70nA=
-github.com/btcsuite/btcutil v0.0.0-20190207003914-4c204d697803/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
 github.com/btcsuite/btcutil v0.0.0-20190425235716-9e5f4b9a998d/go.mod h1:+5NJ2+qvTyV9exUAL/rxXi3DcLg2Ts+ymUAY5y4NvMg=
 github.com/btcsuite/go-socks v0.0.0-20170105172521-4720035b7bfd/go.mod h1:HHNXQzUsZCxOoE+CPiyCTO6x34Zs86zZUiwtpXoGdtg=
 github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVaaLLH7j4eDXPRvw78tMflu7Ie2bzYOH4Y8rRKBY=
@@ -18,6 +15,7 @@ github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3Ee
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/gogo/protobuf v1.2.1 h1:/s5zKNz0uPFCZ5hddgPdo2TK2TVrUNMn0OOX8/aZMTE=
@@ -35,15 +33,12 @@ github.com/gxed/hashland/keccakpg v0.0.1/go.mod h1:kRzw3HkwxFU1mpmPP8v1WyQzwdGfm
 github.com/gxed/hashland/murmur3 v0.0.1 h1:SheiaIt0sda5K+8FLz952/1iWS9zrnKsEJaOJu4ZbSc=
 github.com/gxed/hashland/murmur3 v0.0.1/go.mod h1:KjXop02n4/ckmZSnY2+HKcLud/tcmvhST0bie/0lS48=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
-github.com/ipfs/go-cid v0.0.1/go.mod h1:GHWU/WuQdMPmIosc4Yn1bcCT7dSeX4lBafM7iqUPQvM=
 github.com/ipfs/go-cid v0.0.3/go.mod h1:GHWU/WuQdMPmIosc4Yn1bcCT7dSeX4lBafM7iqUPQvM=
 github.com/ipfs/go-detect-race v0.0.1 h1:qX/xay2W3E4Q1U7d9lNs1sU9nvguX0a7319XbyQ6cOk=
 github.com/ipfs/go-detect-race v0.0.1/go.mod h1:8BNT7shDZPo99Q74BpGMK+4D8Mn4j46UU0LZ723meps=
 github.com/ipfs/go-log v0.0.1 h1:9XTUN/rW64BCG1YhPK9Hoy3q8nr4gOmHHBpgFdfw6Lc=
 github.com/ipfs/go-log v0.0.1/go.mod h1:kL1d2/hzSpI0thNYjiKfjanbVNU+IIGA/WnNESY9leM=
 github.com/jbenet/go-cienv v0.1.0/go.mod h1:TqNnHUmJgXau0nCzC7kXWeotg3J9W34CUv5Djy1+FlA=
-github.com/jbenet/goprocess v0.0.0-20160826012719-b497e2f366b8 h1:bspPhN+oKYFk5fcGNuQzp6IGzYQSenLEgH3s6jkXrWw=
-github.com/jbenet/goprocess v0.0.0-20160826012719-b497e2f366b8/go.mod h1:Ly/wlsjFq/qrU3Rar62tu1gASgGw6chQbSh/XgIIXCY=
 github.com/jbenet/goprocess v0.1.3 h1:YKyIEECS/XvcfHtBzxtjBBbWK+MbvA6dG8ASiqwvr10=
 github.com/jbenet/goprocess v0.1.3/go.mod h1:5yspPrukOVuOLORacaBi858NqyClJPQxYZlqdZVfqY4=
 github.com/jessevdk/go-flags v0.0.0-20141203071132-1679536dcc89/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
@@ -58,10 +53,7 @@ github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxv
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/libp2p/go-flow-metrics v0.0.1/go.mod h1:Iv1GH0sG8DtYN3SVJ2eG221wMiNpZxBdp967ls1g+k8=
 github.com/libp2p/go-flow-metrics v0.0.2/go.mod h1:HeoSNUrOJVK1jEpDqVEiUOIXqhbnS27omG0uWU5slZs=
-github.com/libp2p/go-libp2p-core v0.0.1 h1:HSTZtFIq/W5Ue43Zw+uWZyy2Vl5WtF0zDjKN8/DT/1I=
-github.com/libp2p/go-libp2p-core v0.0.1/go.mod h1:g/VxnTZ/1ygHxH3dKok7Vno1VfpvGcGip57wjTU4fco=
 github.com/libp2p/go-libp2p-core v0.2.5 h1:iP1PIiIrlRrGbE1fYq2918yBc5NlCH3pFuIPSWU9hds=
 github.com/libp2p/go-libp2p-core v0.2.5/go.mod h1:6+5zJmKhsf7yHn1RbmYDu08qDUpIUxGdqHuEZckmZOA=
 github.com/libp2p/go-openssl v0.0.3 h1:wjlG7HvQkt4Fq4cfH33Ivpwp0omaElYEi9z26qaIkIk=
@@ -84,13 +76,9 @@ github.com/minio/sha256-simd v0.1.1 h1:5QHSlgo3nt5yKOJrC7W8w7X+NFl8cMPZm96iu8kKU
 github.com/minio/sha256-simd v0.1.1/go.mod h1:B5e1o+1/KgNmWrSQK08Y6Z1Vb5pwIktudl0J58iy0KM=
 github.com/mr-tron/base58 v1.1.0 h1:Y51FGVJ91WBqCEabAi5OPUz38eAx8DakuAm5svLcsfQ=
 github.com/mr-tron/base58 v1.1.0/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=
-github.com/mr-tron/base58 v1.1.1 h1:OJIdWOWYe2l5PQNgimGtuwHY8nDskvJ5vvs//YnzRLs=
-github.com/mr-tron/base58 v1.1.1/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=
 github.com/mr-tron/base58 v1.1.2 h1:ZEw4I2EgPKDJ2iEw0cNmLB3ROrEmkOtXIkaG7wZg+78=
 github.com/mr-tron/base58 v1.1.2/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
 github.com/multiformats/go-base32 v0.0.3/go.mod h1:pLiuGC8y0QR3Ue4Zug5UzK9LjgbkL8NSQj0zQ5Nz/AA=
-github.com/multiformats/go-multiaddr v0.0.2 h1:RBysRCv5rv3FWlhKWKoXv8tnsCUpEpIZpCmqAGZos2s=
-github.com/multiformats/go-multiaddr v0.0.2/go.mod h1:xKVEak1K9cS1VdmPZW3LSIb6lgmoS58qz/pzqmAxV44=
 github.com/multiformats/go-multiaddr v0.1.1 h1:rVAztJYMhCQ7vEFr8FvxW3mS+HF2eY/oPbOMeS0ZDnE=
 github.com/multiformats/go-multiaddr v0.1.1/go.mod h1:aMKBKNEYmzmDmxfX88/vz+J5IU55txyt0p4aiWVohjo=
 github.com/multiformats/go-multiaddr v0.1.2 h1:HWYHNSyyllbQopmVIF5K7JKJugiah+L9/kuZKHbmNdQ=
@@ -114,8 +102,6 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/smola/gocompat v0.2.0 h1:6b1oIMlUXIpz//VKEDzPVBK8KG7beVwmHIUEBIs/Pns=
 github.com/smola/gocompat v0.2.0/go.mod h1:1B0MlxbmoZNo3h8guHp8HztB3BSYR5itql9qtVc0ypY=
-github.com/spacemonkeygo/openssl v0.0.0-20181017203307-c2dcc5cca94a h1:/eS3yfGjQKG+9kayBkj0ip1BGhq6zJ3eaVksphxAaek=
-github.com/spacemonkeygo/openssl v0.0.0-20181017203307-c2dcc5cca94a/go.mod h1:7AyxJNCJ7SBZ1MfVQCWD6Uqo2oubI2Eq2y2eqf+A5r0=
 github.com/spacemonkeygo/spacelog v0.0.0-20180420211403-2296661a0572 h1:RC6RW7j+1+HkWaX/Yh71Ee5ZHaHYt7ZP4sQgUrm6cDU=
 github.com/spacemonkeygo/spacelog v0.0.0-20180420211403-2296661a0572/go.mod h1:w0SWMsp6j9O/dk4/ZpIhL+3CkG8ofA2vuv7k+ltqUMc=
 github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
@@ -133,8 +119,6 @@ go.opencensus.io v0.22.1/go.mod h1:Ap50jQcDJrx6rB6VgeeFPtuPIf3wMRvRfrfYDO6+BmA=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/crypto v0.0.0-20190225124518-7f87c0fbb88b h1:+/WWzjwW6gidDJnMKWLKLX1gxn7irUTF1fLpQovfQ5M=
-golang.org/x/crypto v0.0.0-20190225124518-7f87c0fbb88b/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
@@ -151,6 +135,7 @@ golang.org/x/net v0.0.0-20190227160552-c95aed5357e7 h1:C2F/nMkR/9sfUTpvR3QrjBuTd
 golang.org/x/net v0.0.0-20190227160552-c95aed5357e7/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859 h1:R/3boaszxrf1GEUWTVDzSKVwLmSJpwZ1yqXm8j0v2QI=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=