I have been working on an ActiveX control in C#. It is packaged in a Windows Control library and the code is in a user control. The control is used as an automation receiver that is used to update a page dynamically through the use of event listeners in javascript
That works, the problem is that when I run the test webpage that runs the ActiveX control, the socket does not start listening for about a minute and a half, after which it runs fine. My initial thoughts are that this is an iis problem. When I run the test webpage, I check netstat to see if my socket is listening, and it is, but I get all these time_wait connections, these eventually die out and are completely closed, and I am finally able to use my control properly
netstat -
Active Connection
Proto Local Address Foreign Address Stat
â€
TCP *:http localhost:4444 ESTABLISHE
TCP *:http localhost:4446 TIME_WAI
TCP *:http localhost:4448 TIME_WAI
TCP *:http localhost:4450 TIME_WAI
TCP *:http localhost:4452 TIME_WAI
TCP *:http localhost:4454 TIME_WAI
TCP *:http localhost:4456 TIME_WAI
TCP *:http localhost:4458 TIME_WAI
TCP *:http localhost:4460 TIME_WAI
TCP *:http localhost:4462 TIME_WAI
TCP *:http localhost:4465 TIME_WAI
TCP *:http localhost:4466 ESTABLISHE
TCP *:4421 localhost:http TIME_WAI
TCP *:4444 localhost:http ESTABLISHE
TCP *:4466 localhost:http ESTABLISHE
â€
UDP *:55557 *:
…
Does anyone have an idea why this is happening, I need this control to listen instantly. I am not completely sure that the time_waits have anything to do with this problem but I am at a loss to explain it, and I need to get this completed
The code for the ActiveX Control is
using System
using System.Componen tModel
using System.Drawing
using System.Windows. Forms
using System.Runtime. InteropServices
using System.Net
using System.Net.Sock ets
using System.Threadin g
namespace LiveContro
public delegate void EventHandler(st ring Message)
[GuidAttribute(" 47209E59-A736-4c14-AD57-201E5162C297")
[InterfaceTypeAt tribute(ComInte rfaceType.Inter faceIsIDispatch )
public interface ILiveContro
[DispIdAttribute (0x60020000)
void MessageNotify(s tring Message);
public interface ILiveControlPub li
string MultiCastIP {get; set;
int MultiCastPort { get; set;
int MultiCastTTL { get; set;
int CharLimit { get; set;
void CloseSocket();
[ClassInterface( ClassInterfaceT ype.AutoDispatc h),ComSourceInt erfaces(typeof( ILiveControl))
public class MultiCast : System.Windows. Forms.UserContr ol, ILiveControlPub li
private string _multiCastIP
private int _multiCastPort
private int _multiCastTTL;
private Socket _receiveSocket
private string _multiCastMessa ge
private int _charLimit = 25000
private Thread trd = null
public string MultiCastI
get { return _multiCastIP;
set {_multiCastIP = value;
public int MultiCastPor
get { return _multiCastPort;
set {_multiCastPort = value;
public int MultiCastTT
get { return _multiCastTTL;
set {_multiCastTTL = value;
public string MultiCastMessag
get { return _multiCastMessa ge;
set {_multiCastMess age = value;
public int CharLimi
get { return _charLimit;
set {_charLimit = value;
event EventHandler MessageNotify
public MultiCast(
trd = new Thread(new ThreadStart(thi s.StartListenin g))
trd.IsBackgroun d = true
trd.Start()
#region Socket Method
public void CloseSocket(
trd.Suspend()
trd.Abort()
_receiveSocket. Shutdown(Socket Shutdown.Both)
_receiveSocket. Close()
private void StartListening(
tr
{
// initialize socke
_receiveSocket = new Socket(AddressF amily.InterNetw ork,SocketType. Dgram,ProtocolT ype.Udp)
IPEndPoint ipept = new IPEndPoint(IPAd dress.Any, _multiCastPort)
//bind socket to IPEndPoint
_receiveSocket. Bind(ipept);
IPAddress ip = IPAddress.Parse (_multiCastIP);
_receiveSocket. SetSocketOption (SocketOptionLe vel.IP,SocketOp tionName.AddMem bership,
new MulticastOption (ip));
byte[] MessageBuffer = new byte[_charLimit];
//listening loop
while(true)
{
_receiveSocket. Receive(Message Buffer);
//transform received byte[] to string
_multiCastMessa ge = System.Text.Enc oding.ASCII.Get String(MessageB uffer);
if(_multiCastMe ssage.Length > 0)
{
// Broadcast Message to event listeners if they exist
if (MessageNotify != null)
{
//fire event MessageNotify(_ multiCastMessag e);
}
}
}
}
catch (Exception ex)
{
// Broadcast Message to event listeners if they exist
if (MessageNotify != null)
{
//fire event
MessageNotify(e x.Message);
}
}
finally
{
//Should never get here but just in case close the socket
_receiveSocket. Close();
}
}
#endregion
}
}
This is called in the webpage;
<body onunload="Unloa d();"><form id="Form1" method="post" runat="server"> <object id=LiveControl classid=LiveCon trol.dll#LiveCo ntrol.MultiCast VIEWASTEXT><par am name="MultiCast IP" value="*.*.*.*" ><param name="MultiCast Port" value=55557><pa ram name="MultiCast TTL" value=16><param name="CharLimit " value=50000></object><script language="javas cript">
function Unload()
{
document.Form1. LiveControl.Clo seSocket();
}
</script><script language=javasc ript for=LiveControl event="MessageN otify(a)">
alert(a);
</script>
