How to properly close console, Without causing the loss of the data received.
the Task Count is increased when the event is received, and the Task Count is decreased when the event is over. When OnStopping, while is executed until the Task count is 0, it ends.
public class TaskHandler
{
private static int TaskCount = 0;
private static object obj = new object();
public static void TaskStart()
{
lock (obj)
{
TaskCount++;
}
}
public static void TaskEnd()
{
lock (obj)
{
TaskCount--;
}
}
public static int GetTaskCount => TaskCount;
}
private void OnStopping()
{
timer.Elapsed -= timerHandler;
// Is there any way to ensure that Event execution is complete?
while (TaskHandler.GetTaskCount != 0)
{
_logger.LogInformation($"Task Count:{TaskHandler.GetTaskCount}...");
Thread.Sleep(3000);
}
_logger.LogInformation($"Task Count: 0... Can close...");
_logger.LogInformation("close...");
}
private static void timerStart()
{
timer.Interval = 1000;
timer.Elapsed += timerHandler;
timer.Start();
}
private static void timerHandler(object sender, EventArgs e)
{
try
{
TaskHandler.TaskStart();
Console.WriteLine("Delay Start");
Thread.Sleep(10000);
Console.WriteLine("Delay End");
TaskHandler.TaskEnd();
}
catch (Exception ex)
{
}
}
Related
I have a class with timer like below
public class helper
{
Timer timer = new Timer();
private int counter = 0;
private int returnCode = 0;
public int Process()
{
SetTimer();
Console.WriteLine("The application started ");
return counter;
}
public void SetTimer()
{
int optionalWay = 0;
// Create a timer with a two second interval.
timer = new System.Timers.Timer(2000);
// Hook up the Elapsed event for the timer.
timer.Elapsed += (sender, e) => OnTimedEvent(sender, e, optionalWay);
timer.AutoReset = true;
timer.Enabled = true;
}
private void OnTimedEvent(Object source, ElapsedEventArgs e, int optionalWay)
{
counter++;
Console.WriteLine("Timer is ticking");
if (counter == 10)
{
timer.Stop();
timer.Dispose();
returnCode = returnCode + 1;
}
}
}
I have main function like this below
public static void Main()
{
helper helper = new helper();
int code = helper.Process();
Console.WriteLine("Main " + code.ToString());
Console.ReadLine();
}
what I want to do is return to main when my timer is stopped, not before that
, my timer class is running fine, main is getting printed like below
So main should wait till the result from timer is 1. And then end process
The code is working as it should. There is nothing inside the helper.Process() function that can wait or block the execution, so the function is returning immediately to the main before the OnTimedEvent is even executed.
A workaround can be done by implementing an event in the helper class and raise that event after the timer completes its work. And the main can listen to that event and act accordingly.
public class helper
{
Timer timer = new Timer();
private int counter = 0;
private int returnCode = 0;
public event EventHandler<int> Done;
...
private void OnTimedEvent(Object source, ElapsedEventArgs e, int optionalWay)
{
counter++;
Console.WriteLine("Timer is ticking");
if (counter == 10)
{
timer.Stop();
timer.Dispose();
returnCode = returnCode + 1;
if (Done != null)
{
Done.Invoke(this, returnCode);
}
}
}
}
And in the Program.cs
static void Main(string[] args)
{
helper helper = new helper();
helper.Done += helper_Done;
helper.Process();
Console.ReadLine();
}
static void helper_Done(object sender, int e)
{
Console.WriteLine("Main " + e.ToString());
}
Update
The Timer class uses a new thread from ThreadPool to execute the Elapsed event handler. So it cannot return to the Main which is running on a different thread. In short: what you are trying to do cannot not be achieved with a Timer.
Here is another solution using Thread.Sleep() which will satisfy your requirement, but keep in mind using Thread.Sleep() like this is not recommended.
public class helper
{
private int counter = 0;
private int returnCode = 0;
public int Process()
{
Console.WriteLine("The application started ");
StartTimer(2000);
return returnCode;
}
private void StartTimer(int ms)
{
while (counter++ < 10)
{
System.Threading.Thread.Sleep(ms);
Console.WriteLine("Timer is ticking");
}
returnCode = returnCode + 1;
}
}
class Program
{
static void Main(string[] args)
{
helper helper = new helper();
int code = helper.Process();
Console.WriteLine("Main " + code.ToString());
Console.ReadLine();
}
}
Again, this is NOT a good practice to use Thread.Sleep for a delayed execution and Thread.Sleep is less accurate compare to Timer.Elapsed. Try to change the design of your application and use Event or Callback function.
Change the Process function of helper class to accept a callback:
public void Process(Action<int> callBack)
{
SetTimer();
Console.WriteLine("The application started ");
if (timer != null)
timer.Disposed += (o, e) => callBack(counter);
}
Change the main function to send the callback:
static void Main(string[] args)
{
Console.WriteLine("Hello World!");
helper helper = new helper();
helper.Process(c => Console.WriteLine("Main " + c.ToString()));
Console.ReadLine();
}
I have two options in mind, one of them and the ugliest, is to loop until timer is stopped, basically doing so:
public class helper
{
Timer timer = new Timer();
private int counter = 0;
private int returnCode = 0;
private bool timerWorking = false;
public int Process()
{
SetTimer();
Console.WriteLine("The application started ");
while(timerWorking){}
return counter;
}
public void SetTimer()
{
// All the staff you already have
timerWorking = true;
}
private void OnTimedEvent(Object source, ElapsedEventArgs e, int optionalWay)
{
counter++;
Console.WriteLine("Timer is ticking");
if (counter == 10)
{
//All the staff you already have
timerWorking = false;
}
}
}
Or, the more elegant, passing or registering a callback to be executed once the ending point is reached:
public class helper
{
Timer timer = new Timer();
private int counter = 0;
private int returnCode = 0;
Action<int> _doAfterTimerEnds
public void Process(Action<int> doAfterTimerEnds)
{
SetTimer();
_doAfterTimerEnds = doAfterTimerEnds;
Console.WriteLine("The application started ");
}
public void SetTimer()
{
int optionalWay = 0;
// Create a timer with a two second interval.
timer = new System.Timers.Timer(2000);
// Hook up the Elapsed event for the timer.
timer.Elapsed += (sender, e) => OnTimedEvent(sender, e, optionalWay);
timer.AutoReset = true;
timer.Enabled = true;
}
private void OnTimedEvent(Object source, ElapsedEventArgs e, int optionalWay)
{
counter++;
Console.WriteLine("Timer is ticking");
if (counter == 10)
{
timer.Stop();
timer.Dispose();
returnCode = returnCode + 1;
_doAfterTimerEnds(returnCode)
}
}
}
public static void Main()
{
var returnCode = 0;
var helper = new helper();
helper.Process(code => returnCode = code);
while (returnCode != 1) {}
Console.WriteLine("Main " + returnCode);
Console.ReadLine();
}
UPDATE: I've tested this last version and it is working as expected.
Is it possible to optimise my console application? It uses up to 60% of CPU because of while(true) loop.
The idea is to kill Microsoft managment console (services) process every time it starts up. And to start/stop services - use pswrd and console.
public static void Main(string[] args)
{
Thread consoleInput = new Thread(_consoleInput);
consoleInput.Start();
killProcess();
}
static void _consoleInput(){
getPassword();
sendServiceCommands();
}
static void killProcess(){
while(true){
try{
System.Diagnostics.Process[] myProcs = System.Diagnostics.Process.GetProcessesByName("mmc");
myProcs[0].Kill();
}
catch(Exception e){}
}
}
You need System.Threading.Timer. Something like this:
public class Killer
{
protected const int timerInterval = 1000; // define here interval between ticks
protected Timer timer = new Timer(timerInterval); // creating timer
public Killer()
{
timer.Elapsed += Timer_Elapsed;
}
public void Start()
{
timer.Start();
}
public void Stop()
{
timer.Stop();
}
public void Timer_Elapsed(object sender, ElapsedEventArgs e)
{
try
{
System.Diagnostics.Process[] myProcs = System.Diagnostics.Process.GetProcessesByName("mmc");
myProcs[0].Kill();
}
catch {}
}
}
...
public static void Main(string[] args)
{
Killer killer = new Killer();
Thread consoleInput = new Thread(_consoleInput);
_consoleInput.Start();
killer.Start();
...
// whenever you want you may stop your killer
killer.Stop();
}
I'm trying to run collection of tasks. I have a procesing object model, which properties I don't know. That's is why I've created a child of this class. I have a collection of ProcesingTask objects. This is my code:
public sealed class ProcessingTask : ProcessingObject
{
private CancellationTokenSource cancelToken;
private System.Timers.Timer _timer;
public int TimeOut {private get; set; }
public int ProcessObjectID { get; private set; }
public Task ProcessObjectTask { get; private set; }
public QueueObject queueObject { private get; set; }
public ProcessingTask(int processObjectID)
{
this.ProcessObjectID = processObjectID;
ResetTask();
}
private void InitialTimeOut()
{
_timer = new System.Timers.Timer(TimeOut);
_timer.Elapsed += new ElapsedEventHandler(TimedOut);
_timer.Enabled = true;
}
private void TimedOut(object sender, ElapsedEventArgs e)
{
cancelToken.Cancel();
Console.WriteLine("Thread {0} was timed out...", ProcessObjectID);
_timer.Stop();
}
public void ResetTask()
{
cancelToken = new CancellationTokenSource();
ProcessObjectTask = new Task(() => DoTaskWork(), cancelToken.Token);
}
public void DoTaskWork()
{
InitialTimeOut();
Random rand = new Random();
int operationTime = rand.Next(2000, 20000);
Thread.Sleep(operationTime);
_timer.Stop();
Console.WriteLine("Thread {0} was finished...", ProcessObjectID);
}
}
public class CustomThreadPool
{
private IList<ProcessingTask> _processingTasks;
public CustomThreadPool(List<ProcessingTask> processingObjects)
{
this._processingTasks = processingObjects;
}
public void RunThreadPool(Queue<QueueObject> queue, int batchSize)
{
for (int i = 1; i <= batchSize; i++)
{
QueueObject queueObject = queue.ToArray().ToList().FirstOrDefault();
ProcessingTask task = _processingTasks.FirstOrDefault(x => x.ProcessObjectID == queueObject.QueueObjectId);
task.queueObject = queue.Dequeue();
task.TimeOut = 3000;
task.ProcessObjectTask.Start();
}
}
public void WaitAll()
{
var tasks = _processingTasks.Select(x => x.ProcessObjectTask).ToArray();
Task.WaitAll(tasks);
}
}
I need to stop DoTaskWork() if running time was timed out. I'm trying to use timer and CancellationToken. But DoTaskWork() still doing his job after TimedOut(). Is any way to resolve this issue?
Though you send the cancel signal, you don't do anything with that in DoTaskWork
public void DoTaskWork()
{
InitialTimeOut();
Random rand = new Random();
int operationTime = rand.Next(2000, 20000);
// Thread.Sleep(operationTime); // this imitates a non-responsive operation
// but this imitates a responsive operation:
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
while (!cancelToken.IsCancellationRequested
&& stopwatch.ElapsedMilliseconds < operationTime)
{
Thread.Sleep(10);
}
_timer.Stop();
Console.WriteLine("Thread {0} was finished...", ProcessObjectID);
}
You have to implement your method DoTaskWork() accordingly.
Assume this as a sample. I am assuming that your thead is doing some continuos work rather just sleep. Otherwise you can use abort method which will just abort the thread even if its in sleep mode.
public void DoTaskWork()
{
InitialTimeOut();
Random rand = new Random();
int operationTime = rand.Next(2000, 20000);
while (true)
{
if (cancelToken.IsCancellationRequested)
{
throw new Exception("Cancellation requested.");
}
Thread.Sleep(operationTime);
}
_timer.Stop();
Console.WriteLine("Thread {0} was finished...", ProcessObjectID);
}
According to this Stack Overflow discussion,using Thread.Sleep() is almost always a bad idea. How would I refactor my code to use a timer instead. I tried to make a start by doing the following:
namespace Engine
{
internal class Program
{
public static DbConnect DbObject = new DbConnect();
System.Timers.Timer timer = new System.Timers.Timer();
// error here
timer.Interval = 2000;
timer.Elapsed += new System.Timers.ElapsedEventHandler(timer_Elapsed);
timer.Enabled=false;
}
}
but kept getting a cannot resolve symbol error message.
namespace Engine
{
internal class Program
{
public static DbConnect DbObject = new DbConnect();
private static void Main()
{
SettingsComponent.LoadSettings();
while (true)
{
try
{
for (int x = 0; x < 4; x++)
{
GenerateRandomBooking();
}
Thread.Sleep(2000);
GenerateRandomBids();
AllocateBids();
Thread.Sleep(2000);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
}
}
If you are using .Net 4.5 or later, you can use await instead of a Timer.
For example:
using System;
using System.Threading;
using System.Threading.Tasks;
namespace Demo
{
public static class Program
{
private static void Main()
{
Console.WriteLine("Generating bids for 30 seconds...");
using (var cancellationTokenSource = new CancellationTokenSource(TimeSpan.FromSeconds(30)))
{
var task = GenerateBids(cancellationTokenSource.Token);
// You can do other work here as required.
task.Wait();
}
Console.WriteLine("\nTask finished.");
}
private static async Task GenerateBids(CancellationToken cancel)
{
while (!cancel.IsCancellationRequested)
{
Console.WriteLine("");
try
{
for (int x = 0; x < 4; x++)
GenerateRandomBooking();
await Task.Delay(2000);
if (cancel.IsCancellationRequested)
return;
GenerateRandomBids();
AllocateBids();
await Task.Delay(2000);
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
}
private static void AllocateBids()
{
Console.WriteLine("AllocateBids()");
}
private static void GenerateRandomBids()
{
Console.WriteLine("GenerateRandomBids()");
}
private static void GenerateRandomBooking()
{
Console.WriteLine("GenerateRandomBooking()");
}
}
}
you can convert your code this one without using Thread.Sleep()
private static void Main()
{
SettingsComponent.LoadSettings();
//while (true)
{
try
{
RaiseRandomBooking(null);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
}
static void RaiseRandomBooking(object state)
{
for (int x = 0; x < 4; x++)
{
GenerateRandomBooking();
}
System.Threading.Timer tmr = new System.Threading.Timer(RaiseRandomBids, null, 0, 2000);
}
static void RaiseRandomBids(object state)
{
GenerateRandomBids();
AllocateBids();
System.Threading.Timer tmr = new System.Threading.Timer(RaiseRandomBooking, null, 0, 2000);
}
I have custom thread which parses WiFi networks and updates the UI (DataGridView and graphs). Here is the thread method:
private void RefreshThread()
{
var watch = Stopwatch.StartNew();
while (true)
{
UpdateAllNetworks();
UpdateAllInterferences();
UpdateAllColors();
switch (ActivePage)
{
case Page.Start:
break;
case Page.Networks:
this.Invoke((MethodInvoker)delegate
{
UpdateDataGridWithNetworks();
ClearGraphs();
Draw24GHzGraph();
DrawSignalsOverTimeGraph();
});
break;
case Page.Channels:
break;
case Page.Analyze:
break;
default:
break;
}
watch.Stop();
int elapsedMs = (int) watch.ElapsedMilliseconds;
if (elapsedMs < Constants.NetworksRefreshThreadInterval)
Thread.Sleep(Constants.NetworksRefreshThreadInterval - elapsedMs);
}
}
Custom DataGridView:
public class CustomDataGridView : DataGridView
{
...
protected override void OnCellClick(DataGridViewCellEventArgs e)
{
base.OnCellClick(e);
int Index = e.RowIndex;
if (Index != -1)
{
DataGridViewRow row = Rows[Index];
PrimaryKeyForSelectedRow = row.Cells[KeyName].Value.ToString();
}
}
}
The DataGridView is my custom DataGrid where I have a click event handler. I have observed that sometimes the event handler isn't called but in most cases it is.
What could be the problem? Is it related to multithreading or the event isn't queued?
Your code blocks main thread, use separate thread for your network details update. Here is quick sample how it done.
class Program
{
static void Main(string[] args)
{
var helper = new Looper(5000, YourMethod_RefreshThread);
helper.Start();
}
private static void YourMethod_RefreshThread()
{
Console.WriteLine(DateTime.Now);
}
}
public class Looper
{
private readonly Action _callback;
private readonly int _interval;
public Looper(int interval, Action callback)
{
if(interval <=0)
{
throw new ArgumentOutOfRangeException("interval");
}
if(callback == null)
{
throw new ArgumentNullException("callback");
}
_interval = interval;
_callback = callback;
}
private void Work()
{
var next = Environment.TickCount;
do
{
if (Environment.TickCount >= next)
{
_callback();
next = Environment.TickCount + _interval;
}
Thread.Sleep(_interval);
} while (IsRunning);
}
public void Start()
{
if (IsRunning)
{
return;
}
var thread = new Thread(Work);
thread.Start();
IsRunning = true;
}
public void Stop()
{
this.IsRunning = false;
}
public bool IsRunning { get; private set; }