From 5b0ec14ea7c81158fcc1e9c52aa58296f7c783ca Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Fri, 6 Dec 2019 17:22:49 +0200
Subject: [PATCH] don't spawn a goroutine for scheduling connections

---
 gossipsub.go | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/gossipsub.go b/gossipsub.go
index 33f02dc..5550f4d 100644
--- a/gossipsub.go
+++ b/gossipsub.go
@@ -47,6 +47,9 @@ var (
 	// number of active connection attempts for peers obtained through px
 	GossipSubConnectors = 16
 
+	// maximum number of pending connections for peers attempted through px
+	GossipSubMaxPendingConnections = 1024
+
 	// timeout for connection attempts
 	GossipSubConnectionTimeout = 30 * time.Second
 )
@@ -61,7 +64,7 @@ func NewGossipSub(ctx context.Context, h host.Host, opts ...Option) (*PubSub, er
 		gossip:  make(map[peer.ID][]*pb.ControlIHave),
 		control: make(map[peer.ID]*pb.ControlMessage),
 		backoff: make(map[string]map[peer.ID]time.Time),
-		connect: make(chan connectInfo, GossipSubConnectors),
+		connect: make(chan connectInfo, GossipSubMaxPendingConnections),
 		mcache:  NewMessageCache(GossipSubHistoryGossip, GossipSubHistoryLength),
 	}
 	return NewPubSub(ctx, h, rt, opts...)
@@ -325,16 +328,14 @@ func (gs *GossipSubRouter) pxConnect(peers []*pb.PeerInfo) {
 		return
 	}
 
-	// initiate connections, without blocking the event loop
-	go func() {
-		for _, ci := range toconnect {
-			select {
-			case gs.connect <- ci:
-			case <-gs.p.ctx.Done():
-				return
-			}
+	for _, ci := range toconnect {
+		select {
+		case gs.connect <- ci:
+		default:
+			log.Debugf("ignoring peer connection attempt; too many pending connections")
+			break
 		}
-	}()
+	}
 }
 
 func (gs *GossipSubRouter) connector() {