I write an Windows C# application which can create up to 16 threads. Each thread creates a socket for a remote device. Each thread send commands to read the device status. (every 300 ms) It is OK when I create one or two threads to read the status. But when I create 10 threads to read device status, I will get wrong data in the socket receive buffer.
Please refer to the following for my socket driver code:
class SocketClient {
private IPAddress ipAddress;
private IPEndPoint remoteEP;
private Socket mSocket;
private SocketAsyncEventArgs e = new SocketAsyncEventArgs();
private System.Timers.Timer timer_connection;
private static byte[] response = new byte[1024];
private Boolean waittingConnectDone;
private Boolean boolConnected;
public SocketClient() {
}
private byte[] acknowledge = null;
public Boolean Connect(String IP, int Port) {
Boolean bRet = true;
ipAddress = IPAddress.Parse(IP);
remoteEP = new IPEndPoint(ipAddress, Port);
mSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
mSocket.ReceiveTimeout = 500;
try {
waittingConnectDone = false;
e.RemoteEndPoint = remoteEP;
e.UserToken = mSocket;
e.Completed += new EventHandler<socketasynceventargs>(e_Completed);
mSocket.ConnectAsync(e);
if (timer_connection != null) {
timer_connection.Dispose();
} else {
timer_connection = new System.Timers.Timer();
}
timer_connection.Interval = 2000;
timer_connection.Elapsed += new ElapsedEventHandler(timer_connection_Tick);
timer_connection.Start();
while (true) {
if (waittingConnectDone)
break;
Application.DoEvents();
}
bRet = boolConnected;
} catch {
Debug.WriteLine("### Ethernet ### Connection Error!");
bRet = false;
}
return bRet;
}
private void e_Completed(object sender, SocketAsyncEventArgs e) {
boolConnected = true;
waittingConnectDone = true;
}
private void timer_connection_Tick(object sender, EventArgs e) {
if (!mSocket.Connected) {
timer_connection.Stop();
boolConnected = false;
waittingConnectDone = true;
}
}
public void Disconnect() {
try {
mSocket.Shutdown(SocketShutdown.Both);
mSocket.Close();
} catch {
}
}
Each Thread use following code to read the device status:
private byte[] acknowledge = null;
private static byte[] response = new byte[1024];
public byte[] sendCommand(byte[] Cmp_TxData) {
try {
bytesSent = mSocket.Send(Cmp_TxData);
bytesRec = mSocket.Receive(response);
acknowledge = new byte[bytesRec];
Array.Copy(response, 0, acknowledge, 0, bytesRec);
}
catch
{
acknowledge = null;
}
return acknowledge;
}
And the buffer data error is something like following:
TX --> 00-03-01-F4-00-03-44-14
RX <-- 00-00-00-00-00-00-00-00-00-00-00
Sometimes I read correct data, but sometimes the data are all 0!
Is there anything wrong with my socket driver?
Really appreciate your help.