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Need to call a method in another class with timer and once done to return control to the main partial class (user control)

Please go through the following code which is an oversimplification of the code I have.
I need to know how once the timer is elapsed, how to return control to the main user control class, preferably to the same case within the switch statement.
public partial class ucClass : UserControl
{
int A;
Label labelTimer = new Label();
sec secObj = new sec();
public execute()
{
switch(A)
{
case 1:
secObj.initiate(labelTimer, 10);
break:
case 2:
......
}
}
}
class sec
{
public System.Windows.Forms.Timer timer;
private Label labelTimer = new Label();
private int expectedCount = 0;
private int actualCount = 0;
public void initiate(Label labelTimer, int count)
{
this.expectedCount = count;
this.labelTimer = labelTimer;
this.timer.Interval = 1000;
startTimer();
}
private void startTimer()
{
this.timer.Start();
this.timer.Tick += this.timerElapsed;
}
private void timerElapsed(object sender, EventArgs e)
{
this.timer.Dispose();
if(expectedCount > actualCount)
{
this.actualCount += 1;
this.labelTimer.Text = this.actualCount.ToString();
this.startTimer();
}
else
{
//this is where I need to notify the main class that timer has expired and go to case 2
}
}
}

You can achieve the behavior that you want with events:
public partial class ucClass : UserControl
{
int A;
Label labelTimer = new Label();
sec secObj = new sec();
public ucClass()
{
// Listen to event from timer
secObj.TimerExpired += (sender, args) =>
{
A = args.Count;
execute();
};
}
public void execute()
{
switch(A)
{
case 1:
secObj.initiate(labelTimer, 10);
break:
case 2:
......
}
}
}
class sec
{
public System.Windows.Forms.Timer timer;
public event EventHandler<TimerExpiredEventArgs> TimerExpired;
private Label labelTimer = new Label();
private int expectedCount = 0;
private int actualCount = 0;
public void initiate(Label labelTimer, int count)
{
this.expectedCount = count;
this.labelTimer = labelTimer;
this.timer.Interval = 1000;
startTimer();
}
private void startTimer()
{
this.timer.Start();
this.timer.Tick += this.timerElapsed;
}
private void timerElapsed(object sender, EventArgs e)
{
this.timer.Dispose();
if(expectedCount > actualCount)
{
this.actualCount += 1;
this.labelTimer.Text = this.actualCount.ToString();
this.startTimer();
}
else
{
// Send event with count
TimerExpired?.Invoke(this, new TimerExpiredEventArgs
{
Count = actualCount
});
}
}
}
public class TimerExpiredEventArgs
{
public int Count { get; set; }
}
I would recommend looking into the following;
The MVVM pattern
This will allow you to seperate the UI logic (passing around labels etc) and the control logic (timers etc).
Reactive Extensions (https://github.com/dotnet/reactive)
This would allow for a very simple timer:
Observable
.Interval(TimeSpan.FromSeconds(1))
.Subscribe(count => {
labelTimer.Text = count.ToString();
if (count > actualCount) {
A = args.Count;
execute();
}
});

How to control Thread because it work incorrect?

My problem is:
I want to run through all ListStudent; it has five rows.
I am using for() to loop through all element in ListStudent and start thread corresponding.
It must run StartProcess(dtStudent.Rows[0].ToString(), 1); to ``StartProcess(dtStudent.Rows[5].ToString(), 1);`
But when I tried to debug, at rows while (run_process[idxThread].bwIsRun == true) - variable idxThread always is 5.
And I want it only run first thread because I will input to a program. After, when I click again btnProcess it will continue to next dtStudent.Rows.
Have any method to do this? Thanks..
I don't have to know an issue with my code.
This all my code to do this:
LThread[] run_process =new LThread[0];
int num_process = 0;
public void btnProcess()
{
DataTable dtStudent = mysql_db.ExcelLoad("ListStudent");
int total_row_student = dtStudent.Rows.Count; // 5 rows
if (num_process != total_row_student)
{
run_process = new LThread[total_row_student];
for (int idx = 0; idx < total_row_student; idx++)
{
run_process[idx] = new LThread();
run_process[idx].StartedEvent += new LThread.startDelegate(delegate (string arg)
{
StartProcess(dtStudent.Rows[idx - 1]["number"].ToString(), idx - 1);
});
}
}
num_process = total_row_student;
if (num_process == 0)
return;
flag = true;
Start_all_thread();
}
private void Start_all_thread()
{
for (int i = 0; i < run_process.Length; i++)
if (run_process[i] != null)
run_process[i].Start();
}
private void Stop_all_thread()
{
for (int i = 0; i < run_process.Length; i++)
if (run_process[i] != null)
run_process[i].Stop();
}
private void StartProcess(string output, int idxThread)
{
while (run_process[idxThread].bwIsRun == true)
{
if (flag == false)
continue;
// some code at here
Stop_all_thread();
}
}
And class LThread.cs is define:
public class LThread2
{
public delegate void startDelegate(string ID);
public event startDelegate StartedEvent;
public Boolean bwIsRun;
MicroTimer microTimer = new MicroTimer();
public LThread2()
{
microTimer.MicroTimerElapsed +=
new MicroTimer.MicroTimerElapsedEventHandler(OnTimedEvent);
microTimer.Interval = 2000;
}
private static int RandNumber(int Low, int High)
{
Random rndNum = new Random(int.Parse(Guid.NewGuid().ToString().Substring(0, 8), System.Globalization.NumberStyles.HexNumber));
int rnd = rndNum.Next(Low, High);
return rnd;
}
public void Start()
{
try
{
bwIsRun = true;
microTimer.Enabled = true;
}
catch { }
}
public void Stop()
{
try
{
bwIsRun = false;
microTimer.Enabled = false;
}
catch { }
}
private void OnTimedEvent(object sender,MicroTimerEventArgs timerEventArgs)
{
StartedEvent(RandNumber(100, 10000).ToString());
}
}
/// <summary>
/// Class emulates long process which runs in worker thread
/// and makes synchronous user UI operations.
/// </summary>
public class LThread : BackgroundWorker
{
#region Members
public delegate void startDelegate(string ID);
public event startDelegate StartedEvent;
private static int RandNumber(int Low, int High)
{
Random rndNum = new Random(int.Parse(Guid.NewGuid().ToString().Substring(0, 8), System.Globalization.NumberStyles.HexNumber));
int rnd = rndNum.Next(Low, High);
return rnd;
}
protected override void OnDoWork(DoWorkEventArgs e)
{
StartedEvent(RandNumber(100,10000).ToString()); //put whatever parameter suits you or nothing
base.OnDoWork(e);
e.Result = e.Argument;
}
BackgroundWorker bwThread;
// Main thread sets this event to stop worker thread:
public Boolean bwIsRun;
int m_time_delay = 10000;
Delegate m_form_method_run;
Delegate m_form_method_stop;
Form m_type_form;
#endregion
#region Functions
public void Start()
{
try
{
bwIsRun = true;
this.RunWorkerAsync();
}
catch { }
}
public void Stop()
{
try
{
bwIsRun = false;
}
catch { }
}
private void StartToListen(object sender, DoWorkEventArgs e)
{
while (true)
{
Thread.Sleep(m_time_delay);
if (bwIsRun == true)
{
m_type_form.Invoke(m_form_method_run);
}
else
{
BackgroundWorker bwAsync = sender as BackgroundWorker;
if (bwAsync.CancellationPending)
{
e.Cancel = true;
return;
}
break;
}
}
}
#endregion
}

You issue is probably in the for (int idx = 0; idx < total_row_student; idx++) for-loop. You're starting threads that will start long after the loop is finished so the variable idx is already at 5 before any of the threads actually start.
Try changing the code to this to fix:
for (int idx = 0; idx < total_row_student; idx++)
{
int local_idx = idx;
run_process[idx] = new LThread();
run_process[idx].StartedEvent += new LThread.startDelegate(delegate (string arg)
{
StartProcess(dtStudent.Rows[local_idx - 1]["number"].ToString(), local_idx - 1);
});
}

switching from different timers c#

I'm creating an Windowns phone 8 app(c#), its a countdown interval timer, so there is prepare time(10 sec), work time(20 sec), rest time(10 sec). I have these variables
`TimeSpan prepInterval = new TimeSpan(0, 0, 0, 10);
TimeSpan workInterval = new TimeSpan(0, 0, 0, 20);
TimeSpan restInterval = new TimeSpan(0, 0, 0, 10);`
I can't wrap my head around having them implementing them one after another when they hit 0. So when prepare time is done, the work timer is to start and when thats finised, the rest timer is to start.

If you would like to have some more broken down logic in all of this, maybe you can create some classes based on a simple interface, like the following:
interface ITimerAction
{
int Seconds { get; set; }
bool Started { get; }
bool Completed { get; }
void OnStart();
void OnComplete();
}
interface ITimerActionList
{
void Add(ITimerAction action);
void Work();
event EventHandler OnCompletedEvent;
}
This would then allow you to create an abstract TimerAction class, and TimerActionList
abstract class TimerAction : ITimerAction
{
public virtual int Seconds
{
get;
set;
}
public virtual bool Completed
{
get;
protected set;
}
public virtual bool Started
{
get;
protected set;
}
public abstract void OnStart();
public abstract void OnComplete();
}
class TimerActionList : ITimerActionList
{
public event EventHandler OnCompletedEvent;
private readonly IList<ITimerAction> actions = new List<ITimerAction>();
private bool working = false;
private Thread myThread;
public void Add(ITimerAction action)
{
if (working)
{
throw new InvalidOperationException("Cannot add new timers when work is already in progress");
}
actions.Add(action);
}
protected virtual void DoWork()
{
working = true;
int currentStep = 0, maxSteps = actions.Count;
while (currentStep < maxSteps)
{
ITimerAction action = actions[currentStep];
if (!action.Started)
{
action.OnStart();
}
if (action.Completed)
{
currentStep++;
continue;
}
if (action.Seconds == 0)
{
action.OnComplete();
continue;
}
action.Seconds--;
Thread.Sleep(1000);
}
Completed();
}
public void Work()
{
if (working)
{
throw new InvalidOperationException("Already running!");
}
working = true;
myThread = new Thread(DoWork);
myThread.Start();
}
protected virtual void Completed()
{
myThread = null;
working = false;
actions.Clear();
var local = OnCompletedEvent;
if (local != null)
{
local.Invoke(this, EventArgs.Empty);
}
}
}
You could then write the classes that inherit from the TimerAction class, that could handle an action before and after the timer ran through :)
class PrepareTimer : TimerAction
{
public override void OnStart()
{
Console.WriteLine("Preparing");
Started = true;
}
public override void OnComplete()
{
Console.WriteLine("Prepare ready");
Completed = true;
}
}
class WorkTimer : TimerAction
{
public override void OnStart()
{
Console.WriteLine("Working");
Started = true;
}
public override void OnComplete()
{
Console.WriteLine("Work ready");
Completed = true;
}
}
class CoolDownTimer : TimerAction
{
public override void OnStart()
{
Console.WriteLine("Cooling down");
Started = true;
}
public override void OnComplete()
{
Console.WriteLine("Cooldown ready");
Completed = true;
}
}
And then you could test the code as such
static void Main(string[] args)
{
bool done = false;
ITimerActionList mylist = new TimerActionList();
mylist.Add(new PrepareTimer { Seconds = 1 });
mylist.Add(new WorkTimer { Seconds = 2 });
mylist.Add(new CoolDownTimer { Seconds = 1 });
mylist.OnCompletedEvent += (sender, e) =>
{
done = true;
};
mylist.Work();
while (!done)
{
// timer is running
}
Console.WriteLine("Done!");
}
(Console program, but i guess that also goes to demonstrate?)

Here's an example based on deathismyfriend's and Hans Passant's suggestions:
var start = new DateTime();
var stage = 0;
var timer = new System.Timers.Timer(100);
timer.Elapsed += (s, e) =>
{
var elapsed = DateTime.Now - start;
int duration = stage == 1 ? 20 : 10;
if (elapsed.TotalSeconds > duration)
{
start = DateTime.Now;
stage++;
if (stage > 2)
timer.Stop();
}
};
start = DateTime.Now;
stage = 0;
timer.Start();

refreshing UI elements in work threads

Question 1: I want to refresh a label by a work thread by delegate and invoke. It works well until i try to close the form. In closing event, I stop the work thread and then the UI thread while an exception occurs(Object disposed exception). It seems that form1 is disposed. I don't know what's wrong.
Question 2: When running this code, the memory usage keep increasing. I don't think it should take so much memory space. You can see find this by checking the task manager.
here's my code:
(.Net Framework 4, winforms)
Scheduler:
class Scheduler
{
private Thread[] workThreads = null;
//Scheduler started flag
public static bool bSchedulerStarted = false;
//Work threads stop event
public static EventWaitHandle stopWaitHandle = new EventWaitHandle(false, EventResetMode.ManualReset);
private static Scheduler self = null;
public static Scheduler getInstance()
{
if (self == null)
{
self = new Scheduler();
}
return self;
}
private Scheduler()
{
workThreads = new Thread[1];
}
private void CreateThread()
{
workThreads[0] = new Thread(Worker.doWork);
workThreads[0].IsBackground = true;
}
public void startUp()
{
if (!bSchedulerStarted)
{
stopWaitHandle.Reset();
CreateThread();
//Start all work threads
for (int i = 0; i < 1; i++)
{
workThreads[i].Start();
}
bSchedulerStarted = true;
}
}
public void stop()
{
if (!bSchedulerStarted)
return;
//Send stop event
stopWaitHandle.Set();
bSchedulerStarted = false;
if (workThreads != null)
{
//wait for all work threads to stop
for (int i = 0; i <1; i++)
{
if (workThreads[i] != null && workThreads[i].IsAlive)
workThreads[i].Join();
}
}
}
}
Worker:
class Worker
{
public static void doWork()
{
while (true)
{
if (Scheduler.stopWaitHandle.WaitOne(10, false) == true)
{
break;
}
Form1.count++;
Form1.sysMsgEvent.Set();
Thread.Sleep(10);
}
}
}
And form:
public partial class Form1 : Form
{
public static int count = 0;
public static EventWaitHandle sysMsgEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
public static EventWaitHandle stopEvent = new EventWaitHandle(false, EventResetMode.ManualReset);
private EventWaitHandle[] waitEvent = null;
Thread UIThread = null;
private delegate void ShowMsg();
public Form1()
{
InitializeComponent();
waitEvent = new EventWaitHandle[2];
waitEvent[0] = stopEvent;
waitEvent[1] = sysMsgEvent;
}
public void UpdateUI()
{
while (true)
{
switch (EventWaitHandle.WaitAny(waitEvent))
{
case 0: //Stop UI thread
return;
case 1: //Refresh UI elements
updateLabel();
break;
default:
return;
}//switch
}//while
}
private void updateLabel()
{
if (label1.InvokeRequired)
{
ShowMsg d = new ShowMsg(updateLabel);
this.Invoke(d, null);
}
else
{
label1.Text = count.ToString();
}
}
private void Form1_Load(object sender, EventArgs e)
{
UIThread = new Thread(new ThreadStart(UpdateUI));
UIThread.Start();
Scheduler sc = Scheduler.getInstance();
sc.startUp();
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
Scheduler sc = Scheduler.getInstance();
sc.stop();
//stop UI thread
Form1.stopEvent.Set();
}
}

Frequent lag spikes in multi-threaded code

I'm attempting to make my simple C# graphics library multi-threaded. However, after the introduction of this code:
/* foreach (IAffector affector in affectorLookup.Values)
affector.Update(timestep); */
taskManager.Value = timestep; taskManager.Start();
foreach (IAffector affector in affectorLookup.Values)
taskManager.AddToQueue(affector.Update);
taskManager.StopWhenDone();
taskManager.Wait();
the simulation starts experiencing sharp lag-spikes, which seem to originate in TaskHandler.Run (I can't tell for sure, because adding the previous code makes my code profiler ignore anything outside TaskHandler.Run).
The task manager:
public class TaskManager
{
public delegate void MethodDel(float timestep);
private Queue<MethodDel> queue;
private List<TaskHandler> handlers;
private float value;
public float Value
{
get
{
return value;
}
set
{
this.value = value;
}
}
public TaskManager()
{
this.queue = new Queue<MethodDel>();
this.handlers = new List<TaskHandler>(System.Environment.ProcessorCount);
for (int t = 0; t < this.handlers.Capacity; ++t)
this.handlers.Add(new TaskHandler(this));
this.value = 0;
}
public void Start()
{
foreach (var handler in handlers)
handler.Start();
}
public void Stop()
{
lock (queue)
queue.Clear();
foreach (var handler in handlers)
handler.StopWhenDone();
}
public void StopWhenDone()
{
foreach (var handler in handlers)
handler.StopWhenDone();
}
public void AddToQueue(MethodDel method)
{
lock (queue)
queue.Enqueue(method);
}
public bool GetFromQueue(out MethodDel method)
{
lock (queue)
{
if (queue.Count == 0) { method = null; return false; }
method = queue.Dequeue();
return true;
}
}
public int GetQueueCount()
{
return queue.Count;
}
internal void Wait()
{
// Have to wait for them one at a time because the main thread is STA.
WaitHandle[] waitHandles = new WaitHandle[1];
// for (int t = 0; t < handlers.Count; ++t)
// waitHandles[t] = handlers[t].WaitHandle;
// WaitHandle.WaitAll(waitHandles);
for (int t = 0; t < handlers.Count; ++t)
{ waitHandles[0] = handlers[t].WaitHandle; WaitHandle.WaitAll(waitHandles); }
}
}
And the task handler:
public class TaskHandler
{
private TaskManager manager;
private Thread thread;
private bool stopWhenDone;
private ManualResetEvent waitHandle;
public ManualResetEvent WaitHandle
{
get
{
return waitHandle;
}
}
public TaskHandler(TaskManager manager)
{
this.manager = manager;
}
public void Start()
{
waitHandle = new ManualResetEvent(false);
stopWhenDone = false;
thread = new Thread(Run);
thread.IsBackground = true;
thread.SetApartmentState(ApartmentState.MTA);
thread.Start();
}
public void StopWhenDone()
{
this.stopWhenDone = true;
}
// Possible source of slowdown
private void Run()
{
TaskManager.MethodDel curMethod;
while (!stopWhenDone || manager.GetQueueCount() > 0)
{
if (manager.GetFromQueue(out curMethod))
{
curMethod(manager.Value);
}
}
waitHandle.Set();
}
}

Starting a thread is a heavy operation. Not sure if it's as heavy as you are experiencing, but that could be it. Also, having all your processing run parallel can be putting a big strain on your system with possibly little benefit...

I'm going to venture that the spikes have something to do with waitHandle.Set();
I like the overall design, but I have not used WaitHandle before, so I am unsure how this interacts with your design.