op-node: p2p alt-sync review fixes

op-node/p2p/host_test.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 
 	"github.com/ethereum-optimism/optimism/op-node/eth"
+	"github.com/ethereum-optimism/optimism/op-node/metrics"
 	"github.com/ethereum-optimism/optimism/op-node/rollup"
 	"github.com/ethereum-optimism/optimism/op-node/testlog"
 	"github.com/ethereum-optimism/optimism/op-node/testutils"
@@ -125,7 +126,7 @@ func TestP2PFull(t *testing.T) {
 	runCfgB := &testutils.MockRuntimeConfig{P2PSeqAddress: common.Address{0x42}}
 
 	logA := testlog.Logger(t, log.LvlError).New("host", "A")
-	nodeA, err := NewNodeP2P(context.Background(), &rollup.Config{}, logA, &confA, &mockGossipIn{}, nil, runCfgA, nil)
+	nodeA, err := NewNodeP2P(context.Background(), &rollup.Config{}, logA, &confA, &mockGossipIn{}, nil, runCfgA, metrics.NoopMetrics)
 	require.NoError(t, err)
 	defer nodeA.Close()
 
@@ -148,7 +149,7 @@ func TestP2PFull(t *testing.T) {
 
 	logB := testlog.Logger(t, log.LvlError).New("host", "B")
 
-	nodeB, err := NewNodeP2P(context.Background(), &rollup.Config{}, logB, &confB, &mockGossipIn{}, nil, runCfgB, nil)
+	nodeB, err := NewNodeP2P(context.Background(), &rollup.Config{}, logB, &confB, &mockGossipIn{}, nil, runCfgB, metrics.NoopMetrics)
 	require.NoError(t, err)
 	defer nodeB.Close()
 	hostB := nodeB.Host()
@@ -277,7 +278,7 @@ func TestDiscovery(t *testing.T) {
 	resourcesCtx, resourcesCancel := context.WithCancel(context.Background())
 	defer resourcesCancel()
 
-	nodeA, err := NewNodeP2P(context.Background(), rollupCfg, logA, &confA, &mockGossipIn{}, nil, runCfgA, nil)
+	nodeA, err := NewNodeP2P(context.Background(), rollupCfg, logA, &confA, &mockGossipIn{}, nil, runCfgA, metrics.NoopMetrics)
 	require.NoError(t, err)
 	defer nodeA.Close()
 	hostA := nodeA.Host()
@@ -292,7 +293,7 @@ func TestDiscovery(t *testing.T) {
 	confB.DiscoveryDB = discDBC
 
 	// Start B
-	nodeB, err := NewNodeP2P(context.Background(), rollupCfg, logB, &confB, &mockGossipIn{}, nil, runCfgB, nil)
+	nodeB, err := NewNodeP2P(context.Background(), rollupCfg, logB, &confB, &mockGossipIn{}, nil, runCfgB, metrics.NoopMetrics)
 	require.NoError(t, err)
 	defer nodeB.Close()
 	hostB := nodeB.Host()
@@ -307,7 +308,7 @@ func TestDiscovery(t *testing.T) {
 		}})
 
 	// Start C
-	nodeC, err := NewNodeP2P(context.Background(), rollupCfg, logC, &confC, &mockGossipIn{}, nil, runCfgC, nil)
+	nodeC, err := NewNodeP2P(context.Background(), rollupCfg, logC, &confC, &mockGossipIn{}, nil, runCfgC, metrics.NoopMetrics)
 	require.NoError(t, err)
 	defer nodeC.Close()
 	hostC := nodeC.Host()

op-node/p2p/sync.go

@@ -178,7 +178,7 @@ type SyncClient struct {
 	newStreamFn     newStreamFn
 	payloadByNumber protocol.ID
 
-	sync.Mutex
+	peersLock sync.Mutex
 	// syncing worker per peer
 	peers map[peer.ID]context.CancelFunc
 
@@ -244,8 +244,8 @@ func (s *SyncClient) Start() {
 }
 
 func (s *SyncClient) AddPeer(id peer.ID) {
-	s.Lock()
-	defer s.Unlock()
+	s.peersLock.Lock()
+	defer s.peersLock.Unlock()
 	if _, ok := s.peers[id]; ok {
 		s.log.Warn("cannot register peer for sync duties, peer was already registered", "peer", id)
 		return
@@ -258,8 +258,8 @@ func (s *SyncClient) AddPeer(id peer.ID) {
 }
 
 func (s *SyncClient) RemovePeer(id peer.ID) {
-	s.Lock()
-	defer s.Unlock()
+	s.peersLock.Lock()
+	defer s.peersLock.Unlock()
 	cancel, ok := s.peers[id]
 	if !ok {
 		s.log.Warn("cannot remove peer from sync duties, peer was not registered", "peer", id)
@@ -357,6 +357,7 @@ func (s *SyncClient) onRangeRequest(ctx context.Context, req rangeRequest) {
 			s.inFlight[num] = pr.complete
 		case <-ctx.Done():
 			log.Info("did not schedule full P2P sync range", "current", num, "err", ctx.Err())
+			return
 		default: // peers may all be busy processing requests already
 			log.Info("no peers ready to handle block requests for more P2P requests for L2 block history", "current", num)
 			return
@@ -366,9 +367,7 @@ func (s *SyncClient) onRangeRequest(ctx context.Context, req rangeRequest) {
 
 func (s *SyncClient) onQuarantineEvict(key common.Hash, value syncResult) {
 	delete(s.quarantineByNum, uint64(value.payload.BlockNumber))
-	if s.metrics != nil {
 	s.metrics.PayloadsQuarantineSize(s.quarantine.Len())
-	}
 	if !s.trusted.Contains(key) {
 		s.log.Debug("evicting untrusted payload from quarantine", "id", value.payload.ID(), "peer", value.peer)
 		// TODO(CLI-3732): downscore peer for having provided us a bad block that never turned out to be canonical
@@ -380,7 +379,8 @@ func (s *SyncClient) onQuarantineEvict(key common.Hash, value syncResult) {
 func (s *SyncClient) tryPromote(h common.Hash) {
 	parentRes, ok := s.quarantine.Get(h)
 	if ok {
-		// Simply reschedule the result, to get it (and possibly its parents) out of quarantine without recursion
+		// Simply reschedule the result, to get it (and possibly its parents) out of quarantine without recursion.
+		// s.results is buffered, but skip the promotion if the channel is full as it would cause a deadlock.
 		select {
 		case s.results <- parentRes:
 		default:
@@ -426,9 +426,7 @@ func (s *SyncClient) onResult(ctx context.Context, res syncResult) {
 	// Always put it in quarantine first. If promotion fails because the receiver is too busy, this functions as cache.
 	s.quarantine.Add(res.payload.BlockHash, res)
 	s.quarantineByNum[uint64(res.payload.BlockNumber)] = res.payload.BlockHash
-	if s.metrics != nil {
 	s.metrics.PayloadsQuarantineSize(s.quarantine.Len())
-	}
 	// If we know this block is canonical, then promote it
 	if s.trusted.Contains(res.payload.BlockHash) {
 		s.promote(ctx, res)
@@ -438,10 +436,10 @@ func (s *SyncClient) onResult(ctx context.Context, res syncResult) {
 // peerLoop for syncing from a single peer
 func (s *SyncClient) peerLoop(ctx context.Context, id peer.ID) {
 	defer func() {
-		s.Lock()
+		s.peersLock.Lock()
 		delete(s.peers, id) // clean up
 		s.wg.Done()
-		s.Unlock()
+		s.peersLock.Unlock()
 		s.log.Debug("stopped syncing loop of peer", "id", id)
 	}()
 
@@ -485,7 +483,6 @@ func (s *SyncClient) peerLoop(ctx context.Context, id peer.ID) {
 			//  increase the p2p-sync part of the peer score
 			//  (don't allow the score to grow indefinitely only based on this factor though)
 
-			if s.metrics != nil {
 			resultCode := byte(0)
 			if err != nil {
 				if re, ok := err.(requestResultErr); ok {
@@ -495,7 +492,6 @@ func (s *SyncClient) peerLoop(ctx context.Context, id peer.ID) {
 				}
 			}
 			s.metrics.ClientPayloadByNumberEvent(pr.num, resultCode, took)
-			}
 		case <-ctx.Done():
 			return
 		}
@@ -666,9 +662,7 @@ func (srv *ReqRespServer) HandleSyncRequest(ctx context.Context, log log.Logger,
 	} else {
 		log.Debug("successfully served sync response", "req", req)
 	}
-	if srv.metrics != nil {
 	srv.metrics.ServerPayloadByNumberEvent(req, 0, time.Since(start))
-	}
 }
 
 var invalidRequestErr = errors.New("invalid request")