Thread.MemoryBarrier() questions

Question

Hi!
I'm trying to avoid my code being rearranged by the CLR using Thread.MemoryBarrier(), as such:
/// <summary>
/// Client created a character!
/// </summary>
public static void HandleCharacterCreate(NetworkClient Client, ProcessedPacket P)
Logger.LogInfo("Received CharacterCreate!");
string AccountName = SanitizeAccount(P.ReadPascalString());
//Need to be variable length, because the success packet contains a token.
PacketStream CCStatusPacket = new PacketStream((byte)PacketType.CHARACTER_CREATION_STATUS, 0);
using (var db = DataAccess.Get())
Account Acc = db.Accounts.GetByUsername(AccountName);
if (Acc.NumCharacters >= 3)
CCStatusPacket.WriteByte((int)LoginDataModel.Entities.CharacterCreationStatus.ExceededCharacterLimit);
Client.SendEncrypted(CCStatusPacket.PacketID, CCStatusPacket.ToArray());
return;
//TODO: Send GUID to client...
Sim Char = new Sim(Guid.NewGuid());
Char.Timestamp = P.ReadPascalString();
Char.Name = P.ReadPascalString();
Char.Sex = P.ReadPascalString();
Char.Description = P.ReadPascalString();
Char.HeadOutfitID = P.ReadUInt64();
Char.BodyOutfitID = P.ReadUInt64();
Char.Appearance = (AppearanceType)P.ReadByte();
Char.ResidingCity = new CityInfo(false);
Char.ResidingCity.Name = P.ReadPascalString();
Char.ResidingCity.Thumbnail = P.ReadUInt64();
Char.ResidingCity.UUID = P.ReadPascalString();
Char.ResidingCity.Map = P.ReadUInt64();
Char.ResidingCity.IP = P.ReadPascalString();
Char.ResidingCity.Port = P.ReadInt32();
Char.CreatedThisSession = true;
var characterModel = new Character();
characterModel.Name = Char.Name;
characterModel.Sex = Char.Sex;
characterModel.Description = Char.Description;
characterModel.LastCached = ProtoHelpers.ParseDateTime(Char.Timestamp);
characterModel.GUID = Char.GUID;
characterModel.HeadOutfitID = (long)Char.HeadOutfitID;
characterModel.BodyOutfitID = (long)Char.BodyOutfitID;
characterModel.AccountID = Acc.AccountID;
characterModel.AppearanceType = (int)Char.Appearance;
characterModel.City = Char.ResidingCity.UUID;
characterModel.CityName = Char.ResidingCity.Name;
characterModel.CityThumb = (long)Char.ResidingCity.Thumbnail;
characterModel.CityMap = (long)Char.ResidingCity.Map;
characterModel.CityIp = Char.ResidingCity.IP;
characterModel.CityPort = Char.ResidingCity.Port;
var status = db.Characters.CreateCharacter(characterModel);
switch (status)
case LoginDataModel.Entities.CharacterCreationStatus.NameAlreadyExisted:
CCStatusPacket.WriteByte((int)LoginDataModel.Entities.CharacterCreationStatus.NameAlreadyExisted);
Client.SendEncrypted(CCStatusPacket.PacketID, CCStatusPacket.ToArray());
break;
case LoginDataModel.Entities.CharacterCreationStatus.NameTooLong:
CCStatusPacket.WriteByte((int)LoginDataModel.Entities.CharacterCreationStatus.NameTooLong);
Client.SendEncrypted(CCStatusPacket.PacketID, CCStatusPacket.ToArray());
break;
case LoginDataModel.Entities.CharacterCreationStatus.Success:
Guid Token = Guid.NewGuid();
//This actually updates the record, not sure how.
Acc.NumCharacters++;
Thread.MemoryBarrier();
//THIS NEEDS TO HAPPEN FIRST FOR CITY SERVER AUTHENTICATION TO WORK!
foreach (CityInfo CServer in NetworkFacade.CServerListener.CityServers)
if (CServer.UUID.Equals(Char.ResidingCity.UUID, StringComparison.CurrentCultureIgnoreCase))
PacketStream CServerPacket = new PacketStream(0x01, 0);
CServerPacket.WriteHeader();
ushort PacketLength = (ushort)(PacketHeaders.UNENCRYPTED + 4 + (Client.RemoteIP.Length + 1)
+ (Char.GUID.ToString().Length + 1) + (Token.ToString().Length + 1));
CServerPacket.WriteUInt16(PacketLength);
CServerPacket.WriteInt32(Acc.AccountID);
CServerPacket.WritePascalString(Client.RemoteIP);
CServerPacket.WritePascalString(Char.GUID.ToString());
CServerPacket.WritePascalString(Token.ToString());
CServer.Client.Send(CServerPacket.ToArray());
break;
Thread.MemoryBarrier();
CCStatusPacket.WriteByte((int)LoginDataModel.Entities.CharacterCreationStatus.Success);
CCStatusPacket.WritePascalString(Char.GUID.ToString());
CCStatusPacket.WritePascalString(Token.ToString());
Client.SendEncrypted(CCStatusPacket.PacketID, CCStatusPacket.ToArray());
break;
Will it work on sections of code, or simply on the next statement following it? Is there any other ways to make sure my code is run in the order I specified? 

Answer 1

>>Will it work on sections of code.
Yes, Thread.MemoryBarrier() works like a fence that makes sure that the processor that executes the current thread cannot reorder instructions in such a way that any
memory access before the call to the Thread.MemoryBarrier() method is being done after the call to the method.
The lock statement implicitly generates a full memory barrier, i.e. lock (_lock) { ... } is equivalent to Thread.MemoryBarrier(); { ... } Thread.MemoryBarrier(); as far as memory barriers are concerned.
You only need memory barriers when working with shared writable fields though. Please refer to the following page for more information:
http://www.albahari.com/threading/part4.aspx.
Please also remember to mark helpful posts as answer and/or helpful and please start a new thread if you have a new question.