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Event after BackgroundWorker thread is aborted

Perhaps I am over thinking this but I have a number of threads doing a rather lengthy process and I want to be able to cleanly abort them if necessary. This is primarily because I don't want to start new threads until the old ones are finished. Is there a way to tell via Event or other method that a thread is fully aborted? Or should I not worry about this? Currently I have code in my abort method as follows:
private void AbortProcessing()
{
if (!Processing) return;
StopFlag = true;
for (int x = 0; x < MaxThreads; x++)
{
try
{
BW[x].CancelAsync();
}
catch { }
//Processing = false;
}
bool aborted = false;
while (!aborted)
{
aborted = true;
for (int x = 0; x < MaxThreads; x++)
{
if (BW[x].IsBusy) aborted = false;
}
Thread.Sleep(100);
}
}
The IsBusy is always true, forever, after signalling abort so this doesn't work. Any suggestions?

try this:Simple Sample for this
Thread o;
private void button1_Click(object sender, EventArgs e)
{
ThreadStart starter = ThreaadFunction;
starter += () => {
//this is this event you want to do any thing after a threaad finished the job
};
o = new Thread(starter) {IsBackground =true };
o.Start();
}
public void ThreaadFunction()
{
Thread.Sleep(1000);
// what you do in thread
}
}

Unsubscribe event in reactive extension, Execute a continuasoly

public IDisposable subscription;
public ProcessData(DeviceModel model, string name = "") : base(model, name)
{
BaseAddress = _model.Process.oxyVal.regAddr;
CurrentSampleRate=1000;
subscription = Observable.Interval(TimeSpan.FromMilliseconds(CurrentSampleRate)).Subscribe(async t => await Refresh());
}
public async Task Refresh()
{
Status = "Fetching from device...";
if ((_model == null) || !_model.IsSerialPortOpen || busy)
{
StatusTrans = "Device not connected.";
return;
}
busy = true;
try
{
await ReadFromDevice().ConfigureAwait(false);
StatusTrans = "Completed.";
}
catch (Exception ex)
{
StatusTrans = ex.Message;
Trace.WriteLine(ex.Message);
}
busy = false;
}
protected override async Task ReadFromDevice()
{
var SampleRate_var = await _model.Measurement.sampleRate.sampleRate.GetValue();
CurrentSampleRate = SampleRate_var * 1000;
/*****other code********/
}
public void ChangeSampleRate()
{
subscription?.Dispose();
Observable.Interval(TimeSpan.FromMilliseconds(CurrentSampleRate)).Subscribe(async t => await Refresh());
}
I have been trying to fetching details from device.On the start,i'll subscribe a event 1 sec,in the it try to read from device(ReadFromDevice) and i'll change get the CurrentSampleRate,Onproperty change,that time I'll dispose 1sec subscribe event and i will subscribe new event with current sample rate.But problem is ReadFromDevice happens at every 1 sec.

Try this:
var CurrentSampleRate = 30;
Observable
.Generate(0, x => true, x => x + 1, x => x, x => TimeSpan.FromMilliseconds(CurrentSampleRate))
.Subscribe(x =>
{
if (x == 50)
{
CurrentSampleRate = 1000;
}
Console.Write(".");
});
It's a little nasty in that you're changing some external state to make the observable's interval change - so you may need to use Interlocked.Exchange to make the update safe.

C#: Task Factory starts task repeatedly?

I have a probably simple question about the task factory. I have to following code:
In this task is a loop that is polling data from the RS232 and a counter that stops polling after 10 times. After this "doCollect" will be set to false.
And now comes the strange thing: The task runs repeatedly. The caller code is:
// class Main()
RS232DataAquisition _RS232DataAquisition = new RS232DataAquisition();
public override void Run()
{
System.Diagnostics.Stopwatch timeout = new System.Diagnostics.Stopwatch();
timeout.Start();
_RS232DataAquisition.Start();
while ((timeout.ElapsedMilliseconds <= (dataGatherTime_inSeconds * 1000)) && _RS232DataAquisition.DoCollect)
{
System.Threading.Thread.Sleep(100);
}
timeout.Stop();
_RS232DataAquisition.Stop();
}
Per my understanding the Run() function should start the thread and return into the while-loop waiting for the thread to finish. But it never does?!
Here's the code for ReadDataFromRS232:
// sealed class RS232DataAquisition
private bool doCollect = false;
public bool DoCollect
{
get { return doCollect; }
}
public void Start()
{
doCollect = true;
currentTask = System.Threading.Tasks.Task.Factory.StartNew(() =>
{
this.ReadDataFromRS232();
});
}
private void ReadDataFromRS232(int NumtoRead = 10)
{
var port = new System.IO.Ports.SerialPort(PortName);
int waitCount = 5;
var portExists = System.IO.Ports.SerialPort.GetPortNames().Any(x => x == PortName);
if (!portExists)
{
throw new ArgumentException("Port does not exist!");
}
while (port.IsOpen && waitCount-- > 0)
{
doCollect = false;
Wait();
}
doCollect = true;
if (!port.IsOpen)
{
port.Open();
port.NewLine = _NewLine;
port.ReadTimeout = 2000;
int number;
try { }
finally { }
port.Write("flashon\r");
while (doCollect && (_readCounter <= NumtoRead))
{
string s;
try
{
s = port.ReadLine();
}
catch
{
s = "-1";
}
int i;
if (int.TryParse(s, out i))
{
number = Convert.ToInt32(s, 10);
}
else
{
number = 0;
}
lock (thisLock) _data.Add(number);
_readCounter++;
}
port.Write("flashoff\r");
port.Close();
port.Dispose();
Wait(); Wait();
}
}
private void Wait()
{
System.Threading.Thread.Sleep(10);
System.Threading.Thread.SpinWait(1);
}
I don't get, why "ReadDataFromRS232" is beeing repeated until the timeout stops this task.
Thank you for any help :)
EDIT: Added some missing code.

As Dennis said the problem seemed to come from the missing volatile. It works now even though I have no idea why it didn't before.

Ping Completed Event Handler not working [closed]

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Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
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When I execute this code in command line, it's working fine:
class Program
{
private static List<Ping> pingers = new List<Ping>();
private static List<string> value = new List<string>();
private static int instances = 0;
private static object #lock = new object();
private static int result = 0;
private static int timeOut = 2500;
private static int ttl = 7;
public static void Main()
{
string baseIP = "192.168.1.";
Console.WriteLine("Pinging destinations of D-class in {0}*", baseIP);
CreatePingers(254);
PingOptions po = new PingOptions(ttl, true);
System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
byte[] data = enc.GetBytes("");
SpinWait wait = new SpinWait();
int cnt =1;
Stopwatch watch = Stopwatch.StartNew();
foreach (Ping p in pingers)
{
lock (#lock)
{
instances += 1;
}
p.SendAsync(string.Concat(baseIP, cnt.ToString()), timeOut, data, po);
cnt += 1;
}
//while (instances > 0)
//{
// wait.SpinOnce();
//}
watch.Stop();
for (int i = 0; i < value.Count; i++)
{
Console.WriteLine(value[i]);
}
DestroyPingers();
Console.WriteLine("Finished in {0}. Found {1} active IP-addresses.", watch.Elapsed.ToString(), result);
Console.ReadKey();
}
public static void Ping_completed(object s, PingCompletedEventArgs e)
{
lock (#lock)
{
instances -= 1;
}
if (e.Reply.Status == IPStatus.Success)
{
string sa = string.Concat("Active IP: ", e.Reply.Address.ToString());
value.Add(sa);
//Console.WriteLine(sa);
String diachiip = e.Reply.Address.ToString();
result += 1;
}
else
{
//Console.WriteLine(String.Concat("Non-active IP: ", e.Reply.Address.ToString()))
}
}
private static void CreatePingers(int cnt)
{
for (int i = 1; i <= cnt; i++)
{
Ping p = new Ping();
p.PingCompleted += Ping_completed;
pingers.Add(p);
}
}
private static void DestroyPingers()
{
foreach (Ping p in pingers)
{
p.PingCompleted -= Ping_completed;
p.Dispose();
}
pingers.Clear();
}
}
But when I convert from it to window form, it doesn't work. I don't kwow why, I have tried many different ways...
Code is here:
public partial class Form1 : Form
{
public static List<Ping> pingers = new List<Ping>();
public static List<string> value = new List<string>();
public static int instances = 0;
public static object #lock = new object();
public static int result = 0;
public int timeout = 2500;
public static int ttl = 7;
public Form1()
{
InitializeComponent();
}
public void btnscan_Click(object sender, EventArgs e)
{
string baseIP = "192.168.1.";
//int kt = Int32.Parse(txtkt.Text);
//int start = Int32.Parse(txtstart.Text);
CreatePingers(254);
PingOptions po = new PingOptions(ttl, true);
System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
byte[] data = enc.GetBytes("");
int cnt = 1;
Stopwatch watch = Stopwatch.StartNew();
foreach (Ping p in pingers)
{
lock (#lock)
{
instances += 1;
}
p.SendAsync(string.Concat(baseIP, cnt.ToString()), timeout, data, po);
cnt += 1;
}
watch.Stop();
//Result alway return 0
lst1.Items.Add(result.ToString());
lst1.Items.Add(value.Count.ToString());
for (int i = 0; i < value.Count; i++)
{
lst1.Items.Add(value[i]);
lst1.Items.Add("\n");
}
DestroyPingers();
string a = "Finished in " + watch.Elapsed.ToString() + ". Found " + result + " active IP-addresses.";
lst1.Items.Add(a);
}
public static void CreatePingers(int kt)
{
for (int start = 1; start <= kt; start++)
{
// class System.Net.NetworkInformation.Ping
Ping p = new Ping();
p.PingCompleted += Ping_completed();
pingers.Add(p);
}
}
public static PingCompletedEventHandler Ping_completed()
{
PingCompletedEventHandler a = new PingCompletedEventHandler(abc);
return a;
}
static void abc(object s, PingCompletedEventArgs e)
{
value.Add("abc");
lock (#lock)
{
instances -= 1;
}
if (e.Reply.Status == IPStatus.Success)
{
string abcd = string.Concat("Active IP: ", e.Reply.Address.ToString());
value.Add(abcd);
result += 1;
}
}
public static void DestroyPingers()
{
foreach (Ping p in pingers)
{
p.PingCompleted -= Ping_completed();
p.Dispose();
}
pingers.Clear();
}
}
What is wrong in this code?

Method SendAsync returns 0 because you are not waiting for it to complete. You are missing await and async (see msdn):
async void btnscan_Click(object sender, EventArgs e)
{
...
await p.SendAsync(string.Concat(baseIP, cnt.ToString()), timeout, data,
...
}
SpinWait was making code to work in console application. In winforms you should not use SpinWait (nor Sleep) in UI thread. You can create another thread (e.g. by using Task) and then you can copy/paste code from console application 1-to-1. But then you will need to use Invoke each time when you want to access UI controls.
async/await is really better.. if it will work (I concluded that from method name, I've no idea what method does, nor how to use it).
Perhaps I miss one thing, if SendAsync returns value, then you can get it by (the requirement to mark method where you use await with async still):
var result = await p.SendAsync(...);

How can we run two threads paralleling?

public class Program
{
static void Main(string[] args)
{
var myThread = new TestThread();
Thread t = new Thread(new ThreadStart(myThread.PrintName));
Thread t1 = new Thread(new ThreadStart(myThread.PrintType));
t.Start();
t1.Start();
Console.Read();
}
}
public class TestThread
{
public void PrintName()
{
for (int i = 1; i <= 50; i++)
{
Console.WriteLine("Name {0}", i);
}
}
public void PrintType()
{
for (int i = 100; i <= 180; i++)
{
Console.WriteLine("Type {0}", i);
}
}
}
Here How can i fixed it show that i can generate output in sequential i.e
first output of Name then only output of Type... Also I want to know about using Lock() in threads? where can i get good example. I am beginners in threading and need v.simple example.

Try this:
var myThread = new TestThread();
var x=Task.Factory.StartNew(() => myThread.PrintName());
x.ContinueWith(p => PrintType());
x.Wait();

You can look at this
There are multiple other articles, just google for 'introduction threading c#'.

The purpose of threads is to allow things to happen at the same time. If you want things to happen one after another (i.e. sequentially), then do not use threads:
var obj = new TestThread();
obj.PrintName();
obj.PrintType();
Console.Read();
Or put PrintName and PrintType into the same thread, in order to keep the UI responsive:
var myThread = new TestThread();
Thread t = new Thread(new ThreadStart(
() => {
myThread.PrintName(); myThread.PrintType();
}
));
t.Start();
// Do things in the UI meanwhile
for (i = 0; i < 100; i++) {
Console.WriteLine("UI thread {0}", i);
}
Console.Read();

//This will run two operation in sequence.
public class TestThread
{
public object obj = new object();
public void PrintName()
{
Monitor.Enter(obj);
for (int i = 1; i <= 50; i++)
{
Console.WriteLine("Name {0}", i);
}
Monitor.Exit(obj);
}
public void PrintType()
{
Monitor.Enter(obj);
for (int i = 100; i <= 180; i++)
{
Console.WriteLine("Type {0}", i);
}
Monitor.Exit(obj);
}
}

That will do the trick, you should read carefully and try to do it with 3 loops by yourself:
private static void SimpleLockTest()
{
Task[] myTasks = new Task[2];
myTasks[0] = Task.Factory.StartNew(() =>
{
LockTestThreadOne();
});
myTasks[1] = Task.Factory.StartNew(() =>
{
LockTestThreadTwo();
});
Task.WaitAll(myTasks);
Console.WriteLine("Done, press ENTER to quit");
Console.ReadLine();
}
private static object locker = new object();
private static void LockTestThreadOne()
{
Monitor.Enter(locker);
for (int i = 1; i <= 50; i++)
{
Console.WriteLine("Name {0}", i);
Monitor.Pulse(locker);
Monitor.Wait(locker);
}
Monitor.Exit(locker);
}
private static void LockTestThreadTwo()
{
Monitor.Enter(locker);
for (int i = 100; i <= 180; i++)
{
Console.WriteLine("Type {0}", i);
Monitor.Pulse(locker);
Monitor.Wait(locker, 10);
}
Monitor.Exit(locker);
}