I do have a problem with a multithreaded TCPClient application, every Client object has a Thread that recievies and sends messages and a thread that handle the Tasks that should be handled (depending on the messages)... (for example creates and answer that the msg threads sends). But something is going wrong... the application almost allways uses 100% cpu (if any thread have a task, and thats most of the time). I also have a feeling that some threads get prioritised less then others (can see in some loggs that an operation takes longer in thread 1 then in thread 2 for exampel... Is there any nice way to handel this problem?
I would love some help or some hints!
Anything unclear just ask :)
Thanks! /Nick
//Waiting for TCP-connections and creating them as they arrive. Starts a Thread that handles the messages recieved and sent with this thread.
private void ListenForClients()
{
try
{
this.tcpListener.Start();
while (true)
{
TcpClient client = this.tcpListener.AcceptTcpClient();
Connection c = new Connection(this.parent);
connectionCollection.Add(c);
Thread clientThread = new Thread(new ParameterizedThreadStart(c.HandleClientComm));
threadCollection.Add(clientThread);
clientThread.Start(client);
}
}
catch (Exception e)
{
}
}
//Connection constructor, creates a ToDo-thread, this handles the messages (DB, Filewriting etc.) recieived and creats new ones to be sent.
public Connection()
{
this.todo = new ArrayList();
todoT = new Thread(handleToDo);
todoT.Start();
}
//Messagehandeling-thread
public void HandleClientComm(object client)
{
try
{
TcpClient server = (TcpClient)client;
NetworkStream ns = server.GetStream();
byte[] data = new byte[1024];
string input, stringData;
online = true;
DateTime lastTime = DateTime.Now;
while (true && this.online)
{
try
{
if (lastTime.AddMinutes(2) < DateTime.Now)
break;
data = new byte[1024];
if (ns.DataAvailable && ns.CanRead)
{
int recv = ns.Read(data, 0, data.Length);
if (recv > 0)
{
lastTime = DateTime.Now;
if ((byte)data[recv - 1] == (byte)255)
{
int cnt = -1;
for (int i = 0; i < recv; i++)
{
if (data[i] == (byte)254)
{
cnt = i;
break;
}
}
int nr = recv - cnt - 2;
byte[] tmp = new byte[nr];
for (int i = 0; i < nr; i++)
{
tmp[i] = data[cnt + i + 1];
}
string crc = Encoding.UTF8.GetString(tmp);
stringData = Encoding.UTF8.GetString(data, 0, cnt);
MsgStruct msgs = new MsgStruct(stringData);
msgs.setCrc(crc);
addTodo(msgs);
if (msgs.getMsg()[0] == 'T' && this.type == 1)
this.parent.cStructHandler.sendAck(msgs, this.ID);
Console.WriteLine(todo.Count);
}
}
}
if (parent.cStructHandler.gotMsg(this.ID))
{
MsgStruct tmpCs = parent.cStructHandler.getNextMsg(this.ID);
if (tmpCs.getMsg().Length != 0 && ns.CanWrite)
{
byte[] ba = Encoding.UTF8.GetBytes(tmpCs.getMsg());
if (tmpCs.getCrc() == "")
{
ulong tmp = CRC.calc_crc(ba, ba.Length);
tmpCs.setCrc(tmp.ToString("X"));
}
if (tmpCs.canSendByTimeout())
{
string crcStr = "?" + tmpCs.getCrc() + "?";
byte[] bb = Encoding.UTF8.GetBytes(crcStr);
crcStr = Encoding.UTF8.GetString(bb);
byte[] fullMsg = new byte[ba.Length + bb.Length];
bb[0] = 254;
bb[bb.Length - 1] = 255;
ba.CopyTo(fullMsg, 0);
bb.CopyTo(fullMsg, ba.Length);
string s = System.Text.UTF8Encoding.ASCII.GetString(fullMsg);
ns.Write(fullMsg, 0, fullMsg.Length);
if (!tmpCs.isAckNeeded())
parent.cStructHandler.removeNextMsg(this.ID);
}
}
}
}
catch (Exception e)
{
break;
}
}
ns.Close();
server.Close();
dead = true;
}
catch (Exception e)
{
dead = true;
}
}
//Todo-thread
public void handleToDo()
{
try
{
int cnt = 0;
while (true)
{
if (todo.Count > 0)
{
//SWITCH CASE FOR DIFFERENT MESSAGE TYPES, DOING TASKS DEPENDING ON WHAT ONES...
}
else
{
if (dead)
{
todoT.Abort();
todoT = null;
break;
}
}
}
}
}
Stop checking if data is available etc. and just let the read() block. That's how it's supposed to work!
If you want to write stuff to the socket, do it from another thread, (direct from parent thingy?), or change your design to use async reads/writes.
Looping around, polling stuff, sleep() etc. is just a waste of CPU and/or adding avoidable latency to your app.
Related
I have the following problem and hope someone can help me.
My basic flow: I want to program any number of devices in parallel using the FTDI D2XX driver and then communicate with them for testing purposes. For this I use two arrays from BackgroundWorker - the first array for programming and the second for testing.
Programming works without any problems. But if I start the BackgroundWorker from the second array to start the test, the connection fails. If I run the complete sequence with only one BackgroundWorker for programming and one BackgroundWorker for testing, the sequence works without problems.
Initialization of BackgroundWorker
private void InitializeBackgoundWorkers()
{
for (var f = 0; f < ftdiDeviceCount; f++)
{
threadArrayProgram[f] = new BackgroundWorker();
threadArrayProgram[f].DoWork += new DoWorkEventHandler(bgr_WorkerStirrerProg_DoWork);
threadArrayProgram[f].RunWorkerCompleted += new RunWorkerCompletedEventHandler(BackgroundWorkerProgRunWorkerCompleted);
threadArrayProgram[f].WorkerReportsProgress = true;
threadArrayProgram[f].WorkerSupportsCancellation = true;
}
for (var f = 0; f < ftdiDeviceCount; f++)
{
threadArrayTest[f] = new BackgroundWorker();
threadArrayTest[f].DoWork += new DoWorkEventHandler(bgr_WorkerStirrerTest_DoWork);
threadArrayTest[f].RunWorkerCompleted += new RunWorkerCompletedEventHandler(BackgroundWorkerTestRunWorkerCompleted);
threadArrayTest[f].WorkerReportsProgress = true;
threadArrayTest[f].WorkerSupportsCancellation = true;
}
}
Aufruf der BackgroundWorker
private void button2_Click_1(object sender, EventArgs e)
{
if (!bStirrerSerached)
{
vSetProgressBarValueRuehrer(1, imaxprogressbar);
vSearchStirrer();
}
if (FtStatus == FTDI.FT_STATUS.FT_OK)
{
//bgr_Worker_Stirrer.RunWorkerAsync();
InitializeBackgoundWorkers();
//---programmieren---//
for (var f = 0; f < /*FilesToProcess*/ftdiDeviceCount; f++)
{
var fileProcessed = false;
while (!fileProcessed)
{
for (var threadNum = 0; threadNum < MaxThreads; threadNum++)
{
if (!threadArrayProgram[threadNum].IsBusy)
{
Console.WriteLine("Starting Thread: {0}", threadNum);
stemp = "Starting Thread: " + threadNum;
File.AppendAllText(slogfile, stemp);
threadArrayProgram[threadNum].RunWorkerAsync(f);
fileProcessed = true;
Thread.Sleep(1000);
break;
}
}
if (!fileProcessed)
{
Thread.Sleep(50);
}
}
}
//---testen---//
for (var f = 0; f < /*FilesToProcess*/ftdiDeviceCount; f++)
{
var fileProcessed = false;
while (!fileProcessed)
{
for (var threadNum = 0; threadNum < MaxThreads; threadNum++)
{
if (!threadArrayTest[threadNum].IsBusy)
{
Console.WriteLine("Starting Thread: {0}", threadNum);
stemp = "Starting Thread: " + threadNum;
File.AppendAllText(slogfile, stemp);
threadArrayTest[threadNum].RunWorkerAsync(f);
fileProcessed = true;
Thread.Sleep(1000);
break;
}
}
if (!fileProcessed)
{
Thread.Sleep(50);
}
}
}
}
button2.Enabled = false;
}
BackgroundWorker
private void bgr_WorkerStirrerProg_DoWork(object sender, DoWorkEventArgs e)
{
try
{
if (FtStatus == FTDI.FT_STATUS.FT_OK)
{
if (ftdiDeviceList != null)
{
//---db werte sammeln---//
cRuehrerProp = new CRuehrerProperties();
cRuehrerProp.SBenutzer = System.Security.Principal.WindowsIdentity.GetCurrent().Name;
cRuehrerProp.SComputername = System.Windows.Forms.SystemInformation.ComputerName.ToString();
//---Rührer programmieren---//
vStirrerProgram((int)e.Argument);
}
}
}
catch (NotSupportedException /*exc*/)
{
}
finally
{
this.Invoke((MethodInvoker)delegate
{
});
}
}
private void bgr_WorkerStirrerTest_DoWork(object sender, DoWorkEventArgs e)
{
try
{
if (!bfinish)
{
while (!bfinish)
{
if (bfinish)
break;
}
}
//---Test starten---//
vStirrerTest((int)e.Argument);
}
catch (NotSupportedException /*exc*/)
{
}
finally
{
this.Invoke((MethodInvoker)delegate
{
button2.Enabled = true;
myFtdiDevice.Close();
});
}
}
Testing method
private void vStirrerTest(int pos)
{
//threadnr
iPosRuehrerGrid = pos;
Console.WriteLine("Thread {0} StirrerTest", pos);
ftStatus = myFtdiDevice.CyclePort();
UInt32 newFtdiDeviceCount = 0;
do
{
// Wait for device to be re-enumerated
// The device will have the same location since it has not been
// physically unplugged, so we will keep trying to open it until it succeeds
ftStatus = myFtdiDevice.OpenByLocation(ftdiDeviceList[iPosRuehrerGrid].LocId);
Console.WriteLine("try to open locid" + ftdiDeviceList[iPosRuehrerGrid].LocId + " on device " + iPosRuehrerGrid);
//ftStatus = myFtdiDevice.OpenByLocation(ftdiDeviceListOrig[iStirrerPosold[iPosRuehrerGrid]].LocId);
Thread.Sleep(1000);
} while (ftStatus != FTDI.FT_STATUS.FT_OK);
// Close the device
myFtdiDevice.Close();
// Re-create our device list
ftStatus = myFtdiDevice.GetNumberOfDevices(ref newFtdiDeviceCount);
if (ftStatus != FTDI.FT_STATUS.FT_OK)
{
// Wait for a key press
Console.WriteLine("Failed to get number of devices (error " + ftStatus.ToString() + ")");
stemp = "Failed to get number of devices (error " + ftStatus.ToString() + ")";
File.AppendAllText(slogfile, stemp);
return;
}
// Re-populate our device list
ftStatus = myFtdiDevice.GetDeviceList(ftdiDeviceList);
bRepopulateList = true;
vSearchStirrer();
The error occurs in the do loop. If I use only one device - and thus only one thread at a time, it takes an average of 5 runs until the device is opened again. However, if I attach another device and thus have 2 programming and 2 test threads, it does not manage to open the desired device.
I have looked at the DeviceList to make sure it is looking for the right device with the right ID - which it is.
Since I don't have any experience with the Backgrounworker yet, I'm not sure if I haven't forgotten something, which is why this error occurs.
I have an online chat code, there is a list of logged in users on the system. There is a problem adding the users name in the listBox; The error is as follows: Invalid thread operation: control 'lbClients' accessed from a thread that is not the one in which it was created.
I tried the Invoke method, but it also did not work. With the Invoke method, the server adds the user to the list, but when the user disconnects, the list of users logged on to the server does not refresh. What can be done?
public void ServiceClient()
{
Socket client = clientsocket;
bool keepalive = true;
while (keepalive)
{
Byte[] buffer = new Byte[1024];
client.Receive(buffer);
string clientcommand = System.Text.Encoding.ASCII.GetString(buffer);
string[] tokens = clientcommand.Split(new Char[]{'|'});
Console.WriteLine(clientcommand);
if (tokens[0] == "CONN")
{
for(int n=0; n<clients.Count; n++) {
Client cl = (Client)clients[n];
SendToClient(cl, "JOIN|" + tokens[1]);
}
EndPoint ep = client.RemoteEndPoint;
//string add = ep.ToString();
Client c = new Client(tokens[1], ep, clientservice, client);
this.Invoke(new Action(() => clients.Add(c)));
string message = "LIST|" + GetChatterList() +"\r\n";
SendToClient(c, message);
try
{
lbClients.Items.Add(c);
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
else if (tokens[0] == "CHAT")
{
for(int n=0; n<clients.Count; n++)
{
Client cl = (Client)clients[n];
SendToClient(cl, clientcommand);
}
}
else if (tokens[0] == "PRIV")
{
string destclient = tokens[3];
for(int n=0; n<clients.Count; n++) {
Client cl = (Client)clients[n];
if(cl.Name.CompareTo(tokens[3]) == 0)
SendToClient(cl, clientcommand);
if(cl.Name.CompareTo(tokens[1]) == 0)
SendToClient(cl, clientcommand);
}
}
else if (tokens[0] == "GONE")
{
int remove = 0;
bool found = false;
int c = clients.Count;
for(int n=0; n<c; n++)
{
Client cl = (Client)clients[n];
SendToClient(cl, clientcommand);
if(cl.Name.CompareTo(tokens[1]) == 0)
{
remove = n;
found = true;
lbClients.Items.Remove(cl);
//lbClients.Items.Remove(cl.Name + " : " + cl.Host.ToString());
}
}
if(found)
this.Invoke(new Action(() => clients.RemoveAt(remove)));
client.Close();
keepalive = false;
}
else
{
int remove = 0;
bool found = false;
int c = clients.Count;
for (int n = 0; n < c; n++)
{
Client cl = (Client)clients[n];
//SendToClient(cl, clientcommand);
if (cl.Name.CompareTo(tokens[1]) == 0)
{
remove = n;
found = true;
lbClients.Items.Remove(cl);
//lbClients.Items.Remove(cl.Name + " : " + cl.Host.ToString());
}
}
if (found)
clients.RemoveAt(remove);
client.Close();
keepalive = false;
}
}
}
I'm reading continuously from a TcpClient streamreader.
The data coming from the stream is raw XML. There is no message framing. So there is now reliable method to know when the message is finished. Though I only have 3 XML messages coming from the server. But when they are coming is unknown. And I can't configure/program the server.
This is my code so far.
public void Start()
{
StreamReader reader = new StreamReader(_tcpClient.GetStream());
char[] chars = new char[Int16.MaxValue];
while (!_requestStop)
{
try
{
while ((reader.Read(chars, 0, chars.Length)) != 0)
{
string s = new string(chars);
s = removeEmptyChars(s);
if (s.IndexOf("<foo", StringComparison.OrdinalIgnoreCase) > 0 &&
s.IndexOf("</foo>", StringComparison.OrdinalIgnoreCase) > 0)
{
Console.WriteLine(s);
OnAlarmResponseComplete(new CustomEventArgs(s));
}
if (s.IndexOf("<bar", StringComparison.OrdinalIgnoreCase) > 0 &&
s.IndexOf("</bar>", StringComparison.OrdinalIgnoreCase) > 0)
{
Console.WriteLine(s);
OnAckComplete(new CustomEventArgs(s));
}
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
//break;
}
}
reader.Close();
Console.WriteLine("Stopping TcpReader thread!");
}
Then in my main thread I'm processing the events. I'm adding them to a list.
Where I process the list.
When I'm debugging my application, I will be receiving 10 foo and 10 bar messages. And in my lists I have only 1 foo and 1 bar message stored.
Are the eventhandlers to slow to process this? Or am I missing something?
Here is the code you should use to cover all kinds of input issues (foo or bar received partially, foo and bar received together, etc..)
I can't say I approve using string parsing to handle XML content, but anyways.
private static string ProcessAndTrimFooBar(string s, out bool foundAny)
{
foundAny = false;
int fooStart = s.IndexOf("<foo", StringComparison.OrdinalIgnoreCase);
int fooEnd = s.IndexOf("</foo>", StringComparison.OrdinalIgnoreCase);
int barStart = s.IndexOf("<bar", StringComparison.OrdinalIgnoreCase);
int barEnd = s.IndexOf("</bar>", StringComparison.OrdinalIgnoreCase);
bool fooExists = fooStart >= 0 && fooEnd >= 0;
bool barExists = barStart >= 0 && barEnd >= 0;
if ((fooExists && !barExists) || (fooExists && barExists && fooStart < barStart))
{
string fooNodeContent = s.Substring(fooStart, fooEnd - fooStart + 6);
s = s.Substring(fooEnd + 6);
Console.WriteLine("Received <foo>: {0}", fooNodeContent);
OnAlarmResponseComplete(new CustomEventArgs(fooNodeContent));
foundAny = true;
}
if ((barExists && !fooExists) || (barExists && fooExists && barStart < fooStart))
{
string barNodeContent = s.Substring(barStart, barEnd - barStart + 6);
s = s.Substring(barEnd + 6);
Console.WriteLine("Received <bar>: {0}", barNodeContent);
OnAckComplete(new CustomEventArgs(barNodeContent));
foundAny = true;
}
return s;
}
public static void Start()
{
StreamReader reader = new StreamReader(_tcpClient.GetStream());
char[] chars = new char[Int16.MaxValue];
while (!_requestStop)
{
try
{
int currentOffset = 0;
while ((reader.Read(chars, currentOffset, chars.Length - currentOffset)) != 0)
{
string s = new string(chars).TrimEnd('\0');
bool foundAny;
do
{
s = ProcessAndTrimFooBar(s, out foundAny);
} while (foundAny);
chars = s.PadRight(Int16.MaxValue, '\0').ToCharArray();
currentOffset = s.Length;
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
//break;
}
}
reader.Close();
Console.WriteLine("Stopping TcpReader thread!");
}
From code below, Sometimes, it will not reply all ping request, and will wait for infinite period of time.Is there any deadlock issue? if yes How to handle it? How can I get correct result for every ip without any deadlock?
class Program
{
static Semaphore PingSender { get; set; }
static object lockObj = new object();
static void Main(string[] args)
{
long pingSent = 0;
long pingReceived = 0;
PingSender = new Semaphore(10000, 10000);
for (int dotNoDot = 1; dotNoDot <= 255; dotNoDot++)
{
for (int dotNo = 1; dotNo <= 255; dotNo++)
{
try
{
string ipAddress = string.Format("111.222.{0}.{1}", dotNoDot, dotNo); //Please change necessary ip base
PingSender.WaitOne();
Ping ping = new Ping();
ping.PingCompleted += (sender, eventArgs) =>
{
//lock (lockObj)
//{
PingSender.Release(1);
Console.WriteLine(string.Format("{0}) Address: {1} and Status: {2}", pingReceived, eventArgs.UserState, eventArgs.Reply.Status));
if (eventArgs.Reply.Status == IPStatus.Success)
{
//collect online machines
}
Interlocked.Increment(ref pingReceived);
if (pingReceived == pingSent)
{
//done
}
//}
};
//lock (lockObj)
//{
pingSent++;
// }
ping.SendAsync(ipAddress, 10000, ipAddress);
}
catch (Exception ex)
{
}
}
}
}
}
I am trying to code a multithreaded WebBrowser application.
The WebBrowser elements will just navigate to a given URL,
wait until it loads and then
click a button or
submit the form.
This should happen in a loop forever.
I'm using Microsoft Visual Studio 2010 and Windows Forms
Here's my code:
//added windows form 30 webbrowser object
//and now assigning them to an webbrowser array
wbList[0] = webBrowser1; wbList[1] = webBrowser2; wbList[2] = webBrowser3;
wbList[3] = webBrowser4; wbList[4] = webBrowser5; wbList[5] = webBrowser6;
wbList[6] = webBrowser7; wbList[7] = webBrowser8; wbList[8] = webBrowser9;
//etc. until:
wbList[29] = webBrowser30;
for (int i = 0; i < 30; i++)
{
wbList[i].ScriptErrorsSuppressed = true;
wbList[i].NewWindow += new CancelEventHandler(wb_NewWindow);
}
//********************************** creating threads here
Thread[] AllThread = new Thread[100];
int irWhichWbb = 0;
for (int nn = irDirectPostCount; nn < irNumber+1; nn++)
{
AllThread[nn] = new Thread(new
ParameterizedThreadStart(this.MultiThreadWebBrowser));
AllThread[nn].Start(nn.ToString() + ";" + irWhichWbb.ToString());
irWhichWbb++;
}
Application.DoEvents();
for (int nn = 0; nn < irNumber+1; nn++)
{ AllThread[nn].Join(); }
//Multi thread function
void MultiThreadWebBrowser(object parameter)
{
string srParam = parameter.ToString();
int i = Convert.ToInt32 (srParam.Substring(0,(srParam.IndexOf(";"))));
int irWhichWb = Convert.ToInt32(srParam.Substring(srParam.IndexOf(";")+1));
string hdrs = "Referer: http://www.xxxxxxxxx.com/xxxxxxxxxx.aspx";
try
{
wbList[irWhichWb].Navigate(srVotingList[i, 0], "_self", null, hdrs);
}
catch { }
try { waitTillLoad(irWhichWb); }
catch { }
waitTillLoad3();
}
// wait until webbrowser navigate url loaded
private void waitTillLoad(int irWhichLoad)
{
WebBrowserReadyState loadStatus;
//wait till beginning of loading next page
int waittime = 100000;
int counter = 0;
while (true)
{
try
{
loadStatus = wbList[irWhichLoad].ReadyState;
Application.DoEvents();
if ((counter > waittime) ||
(loadStatus == WebBrowserReadyState.Uninitialized) ||
(loadStatus == WebBrowserReadyState.Loading) ||
(loadStatus == WebBrowserReadyState.Interactive))
{
break;
}
counter++;
}
catch { }
}
//wait till the page get loaded.
counter = 0;
while (true)
{
try
{
loadStatus = wbList[irWhichLoad].ReadyState;
Application.DoEvents();
if (loadStatus == WebBrowserReadyState.Complete)
{
break;
}
if (counter > 10000000)
break;
counter++;
}
catch { }
}
}
private void waitTillLoad3()
{
DateTime dtStart = DateTime.Now;
while (true)
{
if ((DateTime.Now - dtStart).TotalMilliseconds > 4000)
break;
Application.DoEvents();
}
}
You don't say what kind of failure you get: "doesn't work" is not a good description.
I would first try with just a single thread. Does that work?
You have empty catch blocks, so you are silently ignoring some error conditions. This may well by hiding a problem.