From 3953bf0031b6b2a4302b333aa65fc8ccaa7d788c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Thu, 30 Apr 2015 15:06:05 +0300
Subject: [PATCH] p2p: limit the outbound dialing too
---
p2p/server.go | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/p2p/server.go b/p2p/server.go
index 5e0c917fc..5424b5463 100644
--- a/p2p/server.go
+++ b/p2p/server.go
@@ -27,6 +27,9 @@ const (
// 'added as peer'.
maxAcceptConns = 50
+ // Maximum number of concurrently dialing outbound connections.
+ maxDialingConns = 50
+
// total timeout for encryption handshake and protocol
// handshake in both directions.
handshakeTimeout = 5 * time.Second
@@ -401,7 +404,11 @@ func (srv *Server) dialLoop() {
defer srv.loopWG.Done()
defer refresh.Stop()
- // TODO: maybe limit number of active dials
+ // Limit the number of concurrent dials
+ slots := make(chan struct{}, maxDialingConns)
+ for i := 0; i < maxDialingConns; i++ {
+ slots <- struct{}{}
+ }
dial := func(dest *discover.Node) {
// Don't dial nodes that would fail the checks in addPeer.
// This is important because the connection handshake is a lot
@@ -413,6 +420,9 @@ func (srv *Server) dialLoop() {
if !ok || dialing[dest.ID] {
return
}
+ // Request a dial slot to prevent CPU exhaustion
+ <-slots
+ defer func() { slots <- struct{}{} }()
dialing[dest.ID] = true
srv.peerWG.Add(1)
--
GitLab