From 23d4972158bd61db6b4955026a100b7a5325b38a Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Sat, 25 Aug 2012 19:57:25 +0200
Subject: [PATCH] locking

---
 zone.go | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/zone.go b/zone.go
index 8d20ba52..abc41872 100644
--- a/zone.go
+++ b/zone.go
@@ -5,6 +5,7 @@ package dns
 import (
 	"github.com/miekg/radix"
 	"strings"
+	"sync"
 )
 
 // Zone represents a DNS zone. Currently there is no locking implemented.
@@ -12,6 +13,7 @@ type Zone struct {
 	Origin       string // Origin of the zone
 	Wildcard     int    // Whenever we see a wildcard name, this is incremented
 	*radix.Radix        // Zone data
+	mutex	 *sync.RWMutex
 }
 
 // ZoneData holds all the RRs having their ownername equal to Name.
@@ -20,7 +22,7 @@ type ZoneData struct {
 	RR         map[uint16][]RR        // Map of the RR type to the RR
 	Signatures map[uint16][]*RR_RRSIG // DNSSEC signatures for the RRs, stored under type covered
 	NonAuth    bool                   // Always false, except for NSsets that differ from z.Origin
-	mutex      *sync.RWMutex          // lock for reading/writing
+	mutex      *sync.RWMutex
 }
 
 // toRadixName reverses a domainname so that when we store it in the radix tree
@@ -59,8 +61,10 @@ func (z *Zone) Insert(r RR) error {
 	}
 
 	key := toRadixName(r.Header().Name)
+	z.mutex.Lock()
 	zd := z.Radix.Find(key)
 	if zd == nil {
+		defer z.mutex.Unlock()
 		// Check if its a wildcard name
 		if len(r.Header().Name) > 1 && r.Header().Name[0] == '*' && r.Header().Name[1] == '.' {
 			z.Wildcard++
@@ -85,6 +89,9 @@ func (z *Zone) Insert(r RR) error {
 		z.Radix.Insert(key, zd)
 		return nil
 	}
+	z.mutex.Unlock()
+	zd.Value.(*ZoneData).mutex.Lock()
+	defer zd.Value.(*ZoneData).mutex.Unlock()
 	// Name already there
 	switch t := r.Header().Rrtype; t {
 	case TypeRRSIG:
@@ -105,10 +112,15 @@ func (z *Zone) Insert(r RR) error {
 // this is a no-op.
 func (z *Zone) Remove(r RR) error {
 	key := toRadixName(r.Header().Name)
+	z.mutex.Lock()
 	zd := z.Radix.Find(key)
 	if zd == nil {
+		defer z.mutex.Unlock()
 		return nil
 	}
+	z.mutex.Unlock()
+	zd.Value.(*ZoneData).mutex.Lock()
+	defer zd.Value.(*ZoneData).mutex.Unlock()
 	remove := false
 	switch t := r.Header().Rrtype; t {
 	case TypeRRSIG: