From e9520215a09de9b2b8bf0e3fdb6d9f4cbd2c1d6b Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Wed, 23 Dec 2015 20:10:52 +0000
Subject: [PATCH] refactor: introduce a helper

which has a very narrow purpose, and can use 'defer' to release the
lock, which is nice.
---
 mesh/gossip_channel.go | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/mesh/gossip_channel.go b/mesh/gossip_channel.go
index 478f6880..17e570c7 100644
--- a/mesh/gossip_channel.go
+++ b/mesh/gossip_channel.go
@@ -184,11 +184,18 @@ func (c *GossipChannel) relay(srcName PeerName, data GossipData) {
 }
 
 func (c *GossipChannel) sendDown(conns []Connection, data GossipData) {
+	for _, sender := range c.sendersFor(conns) {
+		sender.Send(data)
+	}
+}
+
+func (c *GossipChannel) sendersFor(conns []Connection) []*GossipSender {
 	if len(conns) == 0 {
-		return
+		return nil
 	}
 	ourConnections := c.ourself.Connections()
 	c.Lock()
+	defer c.Unlock()
 	// GC - randomly (courtesy of go's map iterator) pick some
 	// existing senders and stop&remove them if the associated
 	// connection is no longer active.  We stop as soon as we
@@ -218,11 +225,7 @@ func (c *GossipChannel) sendDown(conns []Connection, data GossipData) {
 		}
 		senders[i] = sender
 	}
-	c.Unlock()
-	// send
-	for _, sender := range senders {
-		sender.Send(data)
-	}
+	return senders
 }
 
 func (c *GossipChannel) makeSender(conn Connection) *GossipSender {