对于我的基于网络的项目，我需要锁定一些代码以防止同时访问。 这是我的代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Utility;
using DataBaseConnection;
using System.Net.Sockets;
using System.Data;
using System.IO;
namespace SunHavenClasses
{
public delegate void CtatReceiveDelegate(string message);
public class ServerHandlerClass
{
public event CtatReceiveDelegate OnChatDataReceive;
private Settings settings;
private DBCon con;
private Utility.Network.Server server;
private Dictionary<string, Socket> UsersOnline;
private Dictionary<string, int> unAuthenticatedIps;
private string pass = "logisoftlogicielbarundipankar";
public ServerHandlerClass(Settings s)
{
settings = s;
con = s.GetConnection();
server = new Utility.Network.Server(7777);
server.ClientConnectEventArise += OnUserConnect;//.OnClientConnect(OnUserConnect);
server.ClientDataReceiveEventArise += OnUsersDataReceive;
server.ClientDataSendEventArise += OnDataSendToUser;
server.ClientDisconnectEventArise += OnUserDisconnect;
server.OnBlockUser += OnUserBlocked;
UsersOnline = new Dictionary<string, Socket>();
unAuthenticatedIps = new Dictionary<string, int>();
}
private void OnUserConnect(Utility.Network.ServerEventArguments e)
{
Stream data = Utility.Serializing.Serialize(settings);
data = ZipNEncrypt.Zip(new string[] { "settings" }, new Stream[] { data }, pass);
server.Send(data, e.ClientSocket);
//MessageBox.Show(e.ClientSocket.RemoteEndPoint.ToString() + " is Connected!!");
}
private void OnUsersDataReceive(Utility.Network.ServerEventArguments e)
{
Dictionary<string, System.IO.Stream> data = ZipNEncrypt.Unzip(e.Data, pass);
User user;
try
{
user = (User)Serializing.Deserialize(data["user"]);
if (!UsersOnline.ContainsKey(user.GetUserId()))
{
server.BlockIp(e.ClientSocket);
return;
}
data.Remove("user");
}
catch (Exception)
{
bool passed = true;
foreach (string key in data.Keys)
{
if (key.Equals("LoggedIn")) break;
string[] str = key.Split('_');
if (str[0].Equals("GetData"))
{
string strr = (string)Serializing.Deserialize(data[key]);
if (strr.Contains("Users"))
{
string ip = e.ClientSocket.RemoteEndPoint.ToString().Split(':')[0];
/*CHANGE 1.2.10 00:14*/
lock (unAuthenticatedIps)
{
if (!unAuthenticatedIps.ContainsKey(ip))
{
unAuthenticatedIps.Add(ip, 1);
}
else unAuthenticatedIps[ip] += 1;
if (unAuthenticatedIps[ip] >= 11) passed = false;
}
/*CHANGE 1.2.10 00:14*/
break;
}
else passed = false;//server.AddBlockedIp(ip);
}
else passed = false;
}
if (!passed)
{
server.BlockIp(e.ClientSocket);
}
}
foreach (string key in data.Keys)
{
if (key.Equals("LoggedIn"))
{
try
{
User u = (User)Serializing.Deserialize(data["LoggedIn"]);
if (!UsersOnline.ContainsKey(u.GetUserId()))
{
if (User.ValidateUser(u.GetUserId(), u.GetPassword(), con))
{
/*CHANGE 1.2.10 00:14*/
lock (UsersOnline)
{
UsersOnline.Add(u.GetUserId(), e.ClientSocket);
string ip = e.ClientSocket.RemoteEndPoint.ToString().Split(':')[0];
Utility.Log.Write("UserLog.log", u.GetUserId() +
" Logged In From Ip " + ip);
}
/*CHANGE 1.2.10 00:14*/
}
else
{
server.BlockIp(e.ClientSocket);
return;
}
}
else
{
Stream tmpStream = Serializing.Serialize("Same User");
tmpStream = ZipNEncrypt.Zip(new string[] { key + "ERROR_SameUser" },
new Stream[] { tmpStream }, pass);
server.Send(tmpStream, e.ClientSocket);
return;
}
}
catch (Exception) { }
return;
}
else if (key.Equals("chat"))
{
string ip = e.ClientSocket.RemoteEndPoint.ToString().Split(':')[0];
string message = ip + " : "+ (string)Serializing.Deserialize(data[key]);
OnChatDataReceive(message);
return;
}
string[] str = key.Split('_');
Stream dataStream = null;
object obj = null;
try
{
if (str[0].StartsWith("Get"))
{
if (str[0].Equals("GetData"))
{
string query = (string)Serializing.Deserialize(data[key]);
obj = con.GetData(query);
}
else if (str[0].Equals("GetColumn"))
{
string query = (string)Serializing.Deserialize(data[key]);
string[] tmp = query.Split('%');
obj = con.GetColumn(tmp[0], tmp[1]);
}
else if (str[0].Equals("GetColumnDistrinctValue"))
{
string query = (string)Serializing.Deserialize(data[key]);
string[] tmp = query.Split('%');
obj = con.GetColumnDistrinctValue(tmp[0], tmp[1]);
}
}
else
{
lock (this)
{
if (str[0].Equals("ExecuteUpdate"))
{
if (str[1].Equals("Query"))
{
Query query = (Query)Serializing.Deserialize(data[key]);
obj = con.ExecuteUpdate(query);
}
else if (str[1].Equals("String"))
{
string query = (string)Serializing.Deserialize(data[key]);
obj = con.ExecuteUpdate(query);
}
}
else if (str[0].Equals("ExecuteBatchUpdate"))
{
if (str[1].Equals("Query"))
{
Query[] query = (Query[])Serializing.Deserialize(data[key]);
obj = con.ExecuteBatchUpdate(query);
}
else if (str[1].Equals("String"))
{
string[] query = (string[])Serializing.Deserialize(data[key]);
obj = con.ExecuteBatchUpdate(query);
}
}
else if (str[0].Equals("ExecutrInsert"))
{
Query query = (Query)Serializing.Deserialize(data[key]);
obj = con.ExecutrInsert(query);
}
}
}
dataStream = Serializing.Serialize(obj);
dataStream = ZipNEncrypt.Zip(new string[] { key },
new Stream[] { dataStream }, pass);
}
catch (Exception ex)
{
dataStream = Serializing.Serialize(ex.Message);
dataStream = ZipNEncrypt.Zip(new string[] { key + "_ERROR" },
new Stream[] { dataStream }, pass);
}
server.Send(dataStream, e.ClientSocket);
}
}
private void OnDataSendToUser(Utility.Network.ServerEventArguments e)
{
}
private void OnUserDisconnect(Utility.Network.ServerEventArguments e)
{
//System.Windows.Forms.MessageBox.Show("Disconnected");
string ip = e.ClientSocket.RemoteEndPoint.ToString().Split(':')[0];
/*CHANGE 1.2.10 00:14*/
lock (unAuthenticatedIps)
{
if (unAuthenticatedIps.ContainsKey(ip))
unAuthenticatedIps.Remove(ip);
}
lock (UsersOnline)
{
foreach (string key in UsersOnline.Keys)
if (UsersOnline[key].Equals(e.ClientSocket))
{
Utility.Log.Write("UserLog.log", key + " Logged Out From Ip " + ip);
UsersOnline.Remove(key);
break;
}
}
/*CHANGE 1.2.10 00:14*/
}
private void OnUserBlocked(Utility.Network.ServerEventArguments e)
{
string ip = e.ClientSocket.RemoteEndPoint.ToString().Split(':')[0];
Utility.Log.Write("UserLog.log", "Blocked For Illegal Access From Ip " + ip);
}
public void Send(Stream dataStream)
{
foreach (string key in UsersOnline.Keys)
{
try
{
server.Send(dataStream, UsersOnline[key]);
}
catch (Exception) { }
}
}
public void Send(Stream dataStream, Socket client)
{
try
{
server.Send(dataStream, client);
}
catch (Exception) { }
}
/*changed*/
public bool AddUser(string userId, Socket socket)
{
if (UsersOnline.ContainsKey(userId)) return false;
UsersOnline.Add(userId, null);
return true;
}
public void RemoveUser(string userId)
{
if (!UsersOnline.ContainsKey(userId) || UsersOnline[userId] != null) return;
UsersOnline.Remove(userId);
}
}
}
现在我不确定我是否正确使用了锁。请给我一些建议。 谢谢。
最佳答案
我猜你读的比写的多？如果是这样，ReaderWriterLockSlim 可能更适合减少阻塞(当您只想检查 key 时进行读取，并在操作数据时进行写入)。
我的意思是，您可以首先对读取进行双重检查锁定，然后如果失败，则进行写入锁定，再次检查并在必要时添加。
此外 - lock(this) 通常不受欢迎；最好有一个单独的锁对象。
请注意，为了有效，所有访问都必须遵守锁定；例如，有些地方 UsersOnline 被锁定，而有些地方则无需锁定即可访问；第二种情况可能会爆炸得一团糟。
例如:
if (!UsersOnline.ContainsKey(u.GetUserId()))
{
if (User.ValidateUser(u.GetUserId(), u.GetPassword(), con))
{
/*CHANGE 1.2.10 00:14*/
lock (UsersOnline)
{
UsersOnline.Add(u.GetUserId(), e.ClientSocket);
在上面，如果两个线程可能正在查看 UsersOnline，那么您在没有锁的情况下尝试 ContainsKey 就已经失败了。如果当您执行此操作时另一个线程正在改变状态....繁荣。
关于C# - 对锁感到困惑，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/2173035/