clarify synhronization constructs

exchange/bitswap/wantmanager.go

@@ -14,23 +14,17 @@ import (
 )
 
 type WantManager struct {
-	receiver bsnet.Receiver
-
-	incoming chan []*bsmsg.Entry
-
-	// notification channel for new peers connecting
-	connect chan peer.ID
-
-	// notification channel for peers disconnecting
-	disconnect chan peer.ID
+	// sync channels for Run loop
+	incoming   chan []*bsmsg.Entry
+	connect    chan peer.ID // notification channel for new peers connecting
+	disconnect chan peer.ID // notification channel for peers disconnecting
 
+	// synchronized by Run loop, only touch inside there
 	peers map[peer.ID]*msgQueue
-
-	wl *wantlist.Wantlist
+	wl    *wantlist.Wantlist
 
 	network bsnet.BitSwapNetwork
-
-	ctx context.Context
+	ctx     context.Context
 }
 
 func NewWantManager(ctx context.Context, network bsnet.BitSwapNetwork) *WantManager {
@@ -58,8 +52,9 @@ type cancellation struct {
 type msgQueue struct {
 	p peer.ID
 
-	outlk sync.Mutex
-	out   bsmsg.BitSwapMessage
+	outlk   sync.Mutex
+	out     bsmsg.BitSwapMessage
+	network bsnet.BitSwapNetwork
 
 	work chan struct{}
 	done chan struct{}
@@ -112,7 +107,7 @@ func (pm *WantManager) startPeerHandler(p peer.ID) *msgQueue {
 		return nil
 	}
 
-	mq := newMsgQueue(p)
+	mq := pm.newMsgQueue(p)
 
 	// new peer, we will want to give them our full wantlist
 	fullwantlist := bsmsg.New(true)
@@ -123,7 +118,7 @@ func (pm *WantManager) startPeerHandler(p peer.ID) *msgQueue {
 	mq.work <- struct{}{}
 
 	pm.peers[p] = mq
-	go pm.runQueue(mq)
+	go mq.runQueue(pm.ctx)
 	return mq
 }
 
@@ -138,12 +133,12 @@ func (pm *WantManager) stopPeerHandler(p peer.ID) {
 	delete(pm.peers, p)
 }
 
-func (pm *WantManager) runQueue(mq *msgQueue) {
+func (mq *msgQueue) runQueue(ctx context.Context) {
 	for {
 		select {
 		case <-mq.work: // there is work to be done
 
-			err := pm.network.ConnectTo(pm.ctx, mq.p)
+			err := mq.network.ConnectTo(ctx, mq.p)
 			if err != nil {
 				log.Errorf("cant connect to peer %s: %s", mq.p, err)
 				// TODO: cant connect, what now?
@@ -161,7 +156,7 @@ func (pm *WantManager) runQueue(mq *msgQueue) {
 			mq.outlk.Unlock()
 
 			// send wantlist updates
-			err = pm.network.SendMessage(pm.ctx, mq.p, wlm)
+			err = mq.network.SendMessage(ctx, mq.p, wlm)
 			if err != nil {
 				log.Error("bitswap send error: ", err)
 				// TODO: what do we do if this fails?
@@ -224,10 +219,11 @@ func (pm *WantManager) Run() {
 	}
 }
 
-func newMsgQueue(p peer.ID) *msgQueue {
+func (wm *WantManager) newMsgQueue(p peer.ID) *msgQueue {
 	mq := new(msgQueue)
 	mq.done = make(chan struct{})
 	mq.work = make(chan struct{}, 1)
+	mq.network = wm.network
 	mq.p = p
 
 	return mq