Merge pull request #2741 from nspcc-dev/separate-broadcast-queue-handling

Rework broadcast logic

pkg/network/helper_test.go

@@ -1,6 +1,7 @@
 package network
 
 import (
+	"context"
 	"fmt"
 	"net"
 	"sync"
@@ -109,18 +110,21 @@ func (p *localPeer) EnqueueMessage(msg *Message) error {
 	if err != nil {
 		return err
 	}
-	return p.EnqueuePacket(true, b)
+	return p.EnqueueHPPacket(b)
 }
-func (p *localPeer) EnqueuePacket(block bool, m []byte) error {
+func (p *localPeer) BroadcastPacket(_ context.Context, m []byte) error {
-	return p.EnqueueHPPacket(block, m)
+	return p.EnqueueHPPacket(m)
 }
 func (p *localPeer) EnqueueP2PMessage(msg *Message) error {
 	return p.EnqueueMessage(msg)
 }
 func (p *localPeer) EnqueueP2PPacket(m []byte) error {
-	return p.EnqueueHPPacket(true, m)
+	return p.EnqueueHPPacket(m)
 }
-func (p *localPeer) EnqueueHPPacket(_ bool, m []byte) error {
+func (p *localPeer) BroadcastHPPacket(_ context.Context, m []byte) error {
+	return p.EnqueueHPPacket(m)
+}
+func (p *localPeer) EnqueueHPPacket(m []byte) error {
 	msg := &Message{}
 	r := io.NewBinReaderFromBuf(m)
 	err := msg.Decode(r)

pkg/network/peer.go

@@ -1,6 +1,7 @@
 package network
 
 import (
+	"context"
 	"net"
 
 	"github.com/nspcc-dev/neo-go/pkg/network/payload"
@@ -19,16 +20,21 @@ type Peer interface {
 	PeerAddr() net.Addr
 	Disconnect(error)
 
-	// EnqueueMessage is a temporary wrapper that sends a message via
+	// EnqueueMessage is a blocking packet enqueuer similar to EnqueueP2PMessage,
-	// EnqueuePacket if there is no error in serializing it.
+	// but using the lowest priority queue.
 	EnqueueMessage(*Message) error
 
-	// EnqueuePacket is a blocking packet enqueuer, it doesn't return until
+	// BroadcastPacket is a context-bound packet enqueuer, it either puts the
-	// it puts the given packet into the queue. It accepts a slice of bytes that
+	// given packet into the queue or exits with errors if the context expires
+	// or peer disconnects. It accepts a slice of bytes that
 	// can be shared with other queues (so that message marshalling can be
-	// done once for all peers). It does nothing if the peer has not yet
+	// done once for all peers). It returns an error if the peer has not yet
 	// completed handshaking.
-	EnqueuePacket(bool, []byte) error
+	BroadcastPacket(context.Context, []byte) error
+
+	// BroadcastHPPacket is the same as BroadcastPacket, but uses a high-priority
+	// queue.
+	BroadcastHPPacket(context.Context, []byte) error
 
 	// EnqueueP2PMessage is a temporary wrapper that sends a message via
 	// EnqueueP2PPacket if there is no error in serializing it.
@@ -37,17 +43,17 @@ type Peer interface {
 	// EnqueueP2PPacket is a blocking packet enqueuer, it doesn't return until
 	// it puts the given packet into the queue. It accepts a slice of bytes that
 	// can be shared with other queues (so that message marshalling can be
-	// done once for all peers). It does nothing if the peer has not yet
+	// done once for all peers). It returns an error if the peer has not yet
 	// completed handshaking. This queue is intended to be used for unicast
 	// peer to peer communication that is more important than broadcasts
-	// (handled by EnqueuePacket) but less important than high-priority
+	// (handled by BroadcastPacket) but less important than high-priority
-	// messages (handled by EnqueueHPPacket).
+	// messages (handled by EnqueueHPPacket and BroadcastHPPacket).
 	EnqueueP2PPacket([]byte) error
 
 	// EnqueueHPPacket is a blocking high priority packet enqueuer, it
 	// doesn't return until it puts the given packet into the high-priority
 	// queue.
-	EnqueueHPPacket(bool, []byte) error
+	EnqueueHPPacket([]byte) error
 	Version() *payload.Version
 	LastBlockIndex() uint32
 	Handshaked() bool

pkg/network/server.go

@@ -1,6 +1,7 @@
 package network
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/binary"
 	"errors"
@@ -755,7 +756,7 @@ func (s *Server) handleInvCmd(p Peer, inv *payload.Inventory) error {
 			return err
 		}
 		if inv.Type == payload.ExtensibleType {
-			return p.EnqueueHPPacket(true, pkt)
+			return p.EnqueueHPPacket(pkt)
 		}
 		return p.EnqueueP2PPacket(pkt)
 	}
@@ -817,7 +818,7 @@ func (s *Server) handleGetDataCmd(p Peer, inv *payload.Inventory) error {
 			pkt, err := msg.Bytes()
 			if err == nil {
 				if inv.Type == payload.ExtensibleType {
-					err = p.EnqueueHPPacket(true, pkt)
+					err = p.EnqueueHPPacket(pkt)
 				} else {
 					err = p.EnqueueP2PPacket(pkt)
 				}
@@ -1348,7 +1349,7 @@ func (s *Server) RequestTx(hashes ...util.Uint256) {
 // iteratePeersWithSendMsg sends the given message to all peers using two functions
 // passed, one is to send the message and the other is to filtrate peers (the
 // peer is considered invalid if it returns false).
-func (s *Server) iteratePeersWithSendMsg(msg *Message, send func(Peer, bool, []byte) error, peerOK func(Peer) bool) {
+func (s *Server) iteratePeersWithSendMsg(msg *Message, send func(Peer, context.Context, []byte) error, peerOK func(Peer) bool) {
 	var deadN, peerN, sentN int
 
 	// Get a copy of s.peers to avoid holding a lock while sending.
@@ -1357,53 +1358,48 @@ func (s *Server) iteratePeersWithSendMsg(msg *Message, send func(Peer, bool, []b
 	if peerN == 0 {
 		return
 	}
-	mrand.Shuffle(peerN, func(i, j int) {
-		peers[i], peers[j] = peers[j], peers[i]
-	})
 	pkt, err := msg.Bytes()
 	if err != nil {
 		return
 	}
 
-	// If true, this node isn't counted any more, either it's dead or we
+	var replies = make(chan error, peerN) // Cache is there just to make goroutines exit faster.
-	// have already sent an Inv to it.
+	var ctx, cancel = context.WithTimeout(context.Background(), s.TimePerBlock/2)
-	finished := make([]bool, peerN)
+	for _, peer := range peers {
-
+		go func(p Peer, ctx context.Context, pkt []byte) {
-	// Try non-blocking sends first and only block if have to.
+			// Do this before packet is sent, reader thread can get the reply before this routine wakes up.
-	for _, blocking := range []bool{false, true} {
-		for i, peer := range peers {
-			// Send to 2/3 of good peers.
-			if 3*sentN >= 2*(peerN-deadN) {
-				return
-			}
-			if finished[i] {
-				continue
-			}
-			err := send(peer, blocking, pkt)
-			if err == nil {
 			if msg.Command == CMDGetAddr {
-					peer.AddGetAddrSent()
+				p.AddGetAddrSent()
 			}
+			replies <- send(p, ctx, pkt)
+		}(peer, ctx, pkt)
+	}
+	for r := range replies {
+		if r == nil {
 			sentN++
-			} else if !blocking && errors.Is(err, errBusy) {
-				// Can be retried.
-				continue
 		} else {
 			deadN++
 		}
-			finished[i] = true
+		if sentN+deadN == peerN {
+			break
+		}
+		// Send to 2/3 of good peers.
+		if 3*sentN >= 2*(peerN-deadN) && ctx.Err() == nil {
+			cancel()
 		}
 	}
+	cancel()
+	close(replies)
 }
 
 // broadcastMessage sends the message to all available peers.
 func (s *Server) broadcastMessage(msg *Message) {
-	s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, nil)
+	s.iteratePeersWithSendMsg(msg, Peer.BroadcastPacket, nil)
 }
 
 // broadcastHPMessage sends the high-priority message to all available peers.
 func (s *Server) broadcastHPMessage(msg *Message) {
-	s.iteratePeersWithSendMsg(msg, Peer.EnqueueHPPacket, nil)
+	s.iteratePeersWithSendMsg(msg, Peer.BroadcastHPPacket, nil)
 }
 
 // relayBlocksLoop subscribes to new blocks in the ledger and broadcasts them
@@ -1421,7 +1417,7 @@ mainloop:
 			msg := NewMessage(CMDInv, payload.NewInventory(payload.BlockType, []util.Uint256{b.Hash()}))
 			// Filter out nodes that are more current (avoid spamming the network
 			// during initial sync).
-			s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, func(p Peer) bool {
+			s.iteratePeersWithSendMsg(msg, Peer.BroadcastPacket, func(p Peer) bool {
 				return p.Handshaked() && p.LastBlockIndex() < b.Index
 			})
 			s.extensiblePool.RemoveStale(b.Index)
@@ -1467,7 +1463,7 @@ func (s *Server) broadcastTxHashes(hs []util.Uint256) {
 
 	// We need to filter out non-relaying nodes, so plain broadcast
 	// functions don't fit here.
-	s.iteratePeersWithSendMsg(msg, Peer.EnqueuePacket, Peer.IsFullNode)
+	s.iteratePeersWithSendMsg(msg, Peer.BroadcastPacket, Peer.IsFullNode)
 }
 
 // initStaleMemPools initializes mempools for stale tx/payload processing.

pkg/network/tcp_peer.go

@@ -1,6 +1,7 @@
 package network
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net"
@@ -31,7 +32,6 @@ const (
 
 var (
 	errGone           = errors.New("the peer is gone already")
-	errBusy           = errors.New("peer is busy")
 	errStateMismatch  = errors.New("tried to send protocol message before handshake completed")
 	errPingPong       = errors.New("ping/pong timeout")
 	errUnexpectedPong = errors.New("pong message wasn't expected")
@@ -81,40 +81,45 @@ func NewTCPPeer(conn net.Conn, s *Server) *TCPPeer {
 	}
 }
 
-// putPacketIntoQueue puts the given message into the given queue if the peer has
+// putBroadcastPacketIntoQueue puts the given message into the given queue if
-// done handshaking.
+// the peer has done handshaking using the given context.
-func (p *TCPPeer) putPacketIntoQueue(queue chan<- []byte, block bool, msg []byte) error {
+func (p *TCPPeer) putBroadcastPacketIntoQueue(ctx context.Context, queue chan<- []byte, msg []byte) error {
 	if !p.Handshaked() {
 		return errStateMismatch
 	}
-	var ret error
-	if block {
-		timer := time.NewTimer(p.server.TimePerBlock / 2)
-		select {
-		case queue <- msg:
-		case <-p.done:
-			ret = errGone
-		case <-timer.C:
-			ret = errBusy
-		}
-		if !errors.Is(ret, errBusy) && !timer.Stop() {
-			<-timer.C
-		}
-	} else {
 	select {
 	case queue <- msg:
 	case <-p.done:
 		return errGone
-		default:
+	case <-ctx.Done():
-			return errBusy
+		return ctx.Err()
 	}
-	}
+	return nil
-	return ret
 }
 
-// EnqueuePacket implements the Peer interface.
+// putPacketIntoQueue puts the given message into the given queue if the peer has
-func (p *TCPPeer) EnqueuePacket(block bool, msg []byte) error {
+// done handshaking.
-	return p.putPacketIntoQueue(p.sendQ, block, msg)
+func (p *TCPPeer) putPacketIntoQueue(queue chan<- []byte, msg []byte) error {
+	if !p.Handshaked() {
+		return errStateMismatch
+	}
+	select {
+	case queue <- msg:
+	case <-p.done:
+		return errGone
+	}
+	return nil
+}
+
+// BroadcastPacket implements the Peer interface.
+func (p *TCPPeer) BroadcastPacket(ctx context.Context, msg []byte) error {
+	return p.putBroadcastPacketIntoQueue(ctx, p.sendQ, msg)
+}
+
+// BroadcastHPPacket implements the Peer interface. It the peer is not yet
+// handshaked it's a noop.
+func (p *TCPPeer) BroadcastHPPacket(ctx context.Context, msg []byte) error {
+	return p.putBroadcastPacketIntoQueue(ctx, p.hpSendQ, msg)
 }
 
 // putMessageIntoQueue serializes the given Message and puts it into given queue if
@@ -124,7 +129,7 @@ func (p *TCPPeer) putMsgIntoQueue(queue chan<- []byte, msg *Message) error {
 	if err != nil {
 		return err
 	}
-	return p.putPacketIntoQueue(queue, true, b)
+	return p.putPacketIntoQueue(queue, b)
 }
 
 // EnqueueMessage is a temporary wrapper that sends a message via
@@ -135,7 +140,7 @@ func (p *TCPPeer) EnqueueMessage(msg *Message) error {
 
 // EnqueueP2PPacket implements the Peer interface.
 func (p *TCPPeer) EnqueueP2PPacket(msg []byte) error {
-	return p.putPacketIntoQueue(p.p2pSendQ, true, msg)
+	return p.putPacketIntoQueue(p.p2pSendQ, msg)
 }
 
 // EnqueueP2PMessage implements the Peer interface.
@@ -145,8 +150,8 @@ func (p *TCPPeer) EnqueueP2PMessage(msg *Message) error {
 
 // EnqueueHPPacket implements the Peer interface. It the peer is not yet
 // handshaked it's a noop.
-func (p *TCPPeer) EnqueueHPPacket(block bool, msg []byte) error {
+func (p *TCPPeer) EnqueueHPPacket(msg []byte) error {
-	return p.putPacketIntoQueue(p.hpSendQ, block, msg)
+	return p.putPacketIntoQueue(p.hpSendQ, msg)
 }
 
 func (p *TCPPeer) writeMsg(msg *Message) error {