From d4db3cf00b5de8f4c495b3505d1e454f1103671e Mon Sep 17 00:00:00 2001
From: "Matt T. Proud" <matt@soundcloud.com>
Date: Wed, 5 Jun 2013 16:29:05 +0200
Subject: [PATCH] Code Review: Last replacement wins.

---
 retrieval/targetpool.go | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/retrieval/targetpool.go b/retrieval/targetpool.go
index aa884a4820..6a3b39d4d5 100644
--- a/retrieval/targetpool.go
+++ b/retrieval/targetpool.go
@@ -26,7 +26,7 @@ const (
 	intervalKey = "interval"
 
 	targetAddQueueSize     = 100
-	targetReplaceQueueSize = 100
+	targetReplaceQueueSize = 1
 )
 
 type TargetPool struct {
@@ -82,7 +82,16 @@ func (p *TargetPool) addTarget(target Target) {
 }
 
 func (p *TargetPool) ReplaceTargets(newTargets []Target) {
-	p.replaceTargetsQueue <- newTargets
+	p.Lock()
+	defer p.Unlock()
+
+	// If there is anything remaining in the queue for effectuation, clear it out,
+	// because the last mutation should win.
+	select {
+	case <-p.replaceTargetsQueue:
+	default:
+		p.replaceTargetsQueue <- newTargets
+	}
 }
 
 func (p *TargetPool) replaceTargets(newTargets []Target) {