The Issue
I am trying to handle disconnection for my app and whatever approach I have tried so far has failed, I tried to disconnect from server side, I tried to disconnect from client side but receiving issues on both ends, What I am trying to achieve here is to disconnect the app through a QUIT command without having to close it from the close icon as it throws an exception
client.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace MessengerConsole
{
class Client
{
static string username;
static int port = 8888;
static IPAddress clientIP;
static Socket serverSocket;
static Thread processThread;
static bool connected = false;
static string GetIp()
{
Console.WriteLine("Type the server ip:");
String clientIP = Console.ReadLine();
Console.WriteLine("Client IP: " + clientIP);
//return clientIP;
//temp solution
return "192.168.0.106";
}
static void printSession()
{
Console.Clear();
Console.WriteLine("//=====================================================");
Console.WriteLine("// Session Details ");
Console.WriteLine("// =====================");
Console.WriteLine("// IP: " + clientIP + "\n// Time: " + DateTime.Now);
Console.WriteLine("//=====================================================");
}
static void clientReceiver()
{
while (true)
{
Thread.Sleep(500);
byte[] buffer = new byte[300];
int rece = serverSocket.Receive(buffer, 0, buffer.Length, 0);
Array.Resize(ref buffer, rece);
if (connected == false)
{
Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer) + " Connected!");
connected = true;
}
else
{
if (Encoding.Default.GetString(buffer) == "QUIT")
{
//Quit
Console.WriteLine("Server Shutdown");
serverSocket.Shutdown(SocketShutdown.Both);
serverSocket.Close();
}
else
{
Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer));
}
}
}
}
public static void StartClient()
{
processThread = new Thread(clientReceiver);
Console.WriteLine("Please enter your name");
username = Console.ReadLine();
clientIP = IPAddress.Parse(GetIp()); //Returns IP from GetIP()
Console.WriteLine("Please enter HostPort");
//string portString = Console.ReadLine();
//temp port
string portString = "80";
try
{
port = Convert.ToInt32(portString);
}
catch
{
port = 8888;
}
try
{
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
serverSocket.Connect(new IPEndPoint(clientIP, port));
processThread.Start();
byte[] name = Encoding.Default.GetBytes(username);
//Send Name
serverSocket.Send(name);
// byte[] data = Encoding.Default.GetBytes("<" + username + "> Connected");
//serverSocket.Send(data, 0, data.Length, 0);
printSession();
while (serverSocket.Connected)
{
//byte[] sdata = Encoding.Default.GetBytes("<" + username + ">" + Console.ReadLine());
byte[] sdata = Encoding.Default.GetBytes(Console.ReadLine());
if(Encoding.Default.GetString(sdata) == "QUIT")
{
serverSocket.Send(sdata, sdata.Length, 0);
serverSocket.Shutdown(SocketShutdown.Both);
serverSocket.Disconnect(true);
serverSocket.Close();
}
else
{
serverSocket.Send(sdata, 0, sdata.Length, 0);
}
}
}
catch (Exception e)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine(e.Message);
Console.ForegroundColor = ConsoleColor.White;
}
}
}
}
server.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Net.Sockets;
using System.Net;
using System.Threading;
namespace MessengerConsole
{
class Server
{
//Server Socket
static Socket serverSocket;
//Client Socket
static Socket clientSocket;
//Other Variables
static int port = 8888;
static IPAddress serverIP;
static Thread processThread;
static string username;
static bool connected = false;
//Function returns IP Address
static string GetIp()
{
//Computer Name
string hostname = Dns.GetHostName();
/*The IPHostEntry class associates a Domain Name System (DNS) host name with an array of aliases and
* an array of matching IP addresses.
*/
IPHostEntry ipentry = Dns.GetHostEntry(hostname);
//The Address
IPAddress[] ipAddress = ipentry.AddressList;
return ipAddress[ipAddress.Length - 1].ToString();
}
static void printSession()
{
Console.Clear();
Console.WriteLine("//=====================================================");
Console.WriteLine("// Session Details ");
Console.WriteLine("// =====================");
Console.WriteLine("// You are hosting the server");
Console.WriteLine("// Time: " + DateTime.Now);
Console.WriteLine("//=====================================================");
}
//Receive
static void serverReciever()
{
while (true)
{
Thread.Sleep(500);
byte[] buffer = new byte[300];
int rece = clientSocket.Receive(buffer, 0, buffer.Length, 0);
Array.Resize(ref buffer, rece);
if (connected == false)
{
Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer) + " Connected!");
connected = true;
}
else
{
if(Encoding.Default.GetString(buffer) == "QUIT")
{
//Quit
Console.WriteLine("Client disconnected from the chat");
clientSocket.Shutdown(SocketShutdown.Both);
clientSocket.Close();
}
else
{
Console.WriteLine("[" + DateTime.Now.ToString() + "] " + Encoding.Default.GetString(buffer));
}
}
}
}
public static void StartServer()
{
//Thread
processThread = new Thread(serverReciever);
//Display
Console.WriteLine("Your Local Ip is " + GetIp());
Console.WriteLine("Please enter your name");
username = Console.ReadLine();
Console.WriteLine("Please enter HostPort");
// string portString = Console.ReadLine();
//temp solution
string portString = "80";
try
{
port = Convert.ToInt32(portString);
}
catch
{
port = 8888;
}
try
{
//GetIp returns string
serverIP = IPAddress.Parse(GetIp());
//TCP Socket
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
serverSocket.Bind(new IPEndPoint(serverIP, port));
serverSocket.Listen(0);
//Server Socket listening for client requests
clientSocket = serverSocket.Accept();
printSession();
processThread.Start();
byte[] name = Encoding.Default.GetBytes(username);
clientSocket.Send(name);
while (true)
{
byte[] sdata = Encoding.Default.GetBytes(Console.ReadLine());
clientSocket.Send(sdata, 0, sdata.Length, 0);
}
}
catch
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Server already open!");
Console.ForegroundColor = ConsoleColor.White;
}
}
}
}
This is the error I have received
Unhandled exception. System.ObjectDisposedException: Cannot access a disposed object. Object name: 'System.Net.Sockets.Socket'. at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, SocketError& errorCode) at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags) at MessengerConsole.Client.clientReceiver() in C:\Users\MessengerConsoleAppV2\MessengerConsole\Client.cs:line 42 at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) --- End of stack trace from previous location where exception was thrown --- at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()
I tried using Socket.Disconnect(), Socket.Close(), Socket.Dispose() and all of them yield same result
EDIT:
adding return
in the
if(Encoding.Default.GetString(sdata) == "QUIT")
{
serverSocket.Send(sdata, sdata.Length, 0);
serverSocket.Shutdown(SocketShutdown.Both);
serverSocket.Close();
return;
}
Results in no errors on the server side but the client still throws the exception of the disposed object being accessed
Unhandled exception. System.ObjectDisposedException: Cannot access a disposed object. Object name: 'System.Net.Sockets.Socket'. at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, SocketError& errorCode) at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags) at MessengerConsole.Client.clientReceiver() in C:\Users\MessengerConsoleAppV2\MessengerConsole\Client.cs:line 44 at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) --- End of stack trace from previous location where exception was thrown --- at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()
In all places of code related to QUIT
you only closing and disposing socket, but not returning from infinite loop serving this socket. I think this stack is thrown on next iteration when Connected
property is evaluated on disposed socket, try adding return
statement after you close socket.
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