From ef7d8f8fa2a05f887be9a6a10766d4144aa7985b Mon Sep 17 00:00:00 2001
From: kenshinx <kenshin.acs@gmail.com>
Date: Thu, 12 Feb 2015 16:06:09 +0800
Subject: [PATCH] Remove mutex lock during call dns.ResponseWriter.WriteMsg

Write io buffer needn't mutex operation.
Refere to kenshinx/godns#1
---
 handler.go | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/handler.go b/handler.go
index 2e812b9..310ea16 100644
--- a/handler.go
+++ b/handler.go
@@ -27,7 +27,6 @@ type GODNSHandler struct {
 	resolver *Resolver
 	cache    Cache
 	hosts    Hosts
-	mu       *sync.Mutex
 }
 
 func NewHandler() *GODNSHandler {
@@ -73,7 +72,7 @@ func NewHandler() *GODNSHandler {
 
 	hosts := NewHosts(settings.Hosts, settings.Redis)
 
-	return &GODNSHandler{resolver, cache, hosts, new(sync.Mutex)}
+	return &GODNSHandler{resolver, cache, hosts}
 }
 
 func (h *GODNSHandler) do(Net string, w dns.ResponseWriter, req *dns.Msg) {
@@ -127,10 +126,8 @@ func (h *GODNSHandler) do(Net string, w dns.ResponseWriter, req *dns.Msg) {
 			Debug("%s didn't hit cache: %s", Q.String(), err)
 		} else {
 			Debug("%s hit cache", Q.String())
-			h.mu.Lock()
 			mesg.Id = req.Id
 			w.WriteMsg(mesg)
-			h.mu.Unlock()
 			return
 		}
 	}