I have a app that gathers and store updated data from a list of websites. My app use threadpool and each thread visits a site within the list and gathers the data. I want to create a stop button to stop/ prevent threadpool from running once it is clicked. How do I go about doing this?
View 1 RepliesI have a simple application that use thread pool to read a file and input the data into a listbox. I want to be able to stop threadpool from running after clicking a stop button. How do I stop threadpool? Here is the code for my application below:
Imports System.Threading
Public Class Form1
Private Delegate Sub StringDelegate(ByVal text As String)
[Code]....
I m trying to move all my drive's files into h drive firstly i have added all drives in threadpool for scanning and when scanning of any drive finish (Without waiting for other drive's complete ) it will move file's to h drive but it is not working as i wanted that's why i need two threadpool - one threadpool for scanning files and second threadpool for moving file's into drive's
View 11 RepliesIs there any direct way to stop a threadpool when user press Cancel Task button? I got SmartThreadPool but using that i could not arrange my code. Its becoming difficult.
Here is my simple code:
'Delegaet to update UI
Public Delegate Sub updateClassDelegate(ByVal index As Integer, ByVal status As String)
[Code].....
can somebody give ThreadPool example for application thats needs to get information to datagridview from thousands of sources? My application needs to work fast and without freezing and lag, but I cant figure out this threadpool thing. And would be nice if you could add this thing to example that when I set domainupdown value to 25 as example, it sets threads to 25. So its making work 25x faster. I haven't find any good example for this, only some C# examples but they haven't work after i converted those to vb.net.
View 1 Repliescurrently i am using a threadpool that contain a number of thread. This number of thread can be different everytime, sometimes 5, sometimes 10, sometimes 15 and so on (multiple of 5). So now i have it working good by using for loop to queue the thread into threadpool. Now the problems is i do not know how to make the progress bar depending on my threadpool. I want my progress bar to complete only when all the thread are done. After searching google, i found that maybe it can be solve by using AutoResetEvent(false), but after i apply to my program, it still did not work, my program hang at xEvent.WaitOne() method and didnt proceed further, anyone can explain to me how to solve the problem? Or got any other ways? For your information, only 5 threads can be running at the same time as the requirement state so (so i set the setmaxthread to 5 already).
View 2 RepliesI am doing one web scraper which loops user set list of urls. Lists can be huge and that's why I need Threadpool for it.
My code so far (Scrape code missing)
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ThreadingEvents(20) As ManualResetEvent
Dim iCounter As Integer = 0
For Each item As Object In ListBox1.Items
[Code] .....
how this is written in VB.NET? This was an example I found on [URL]
ThreadPool.QueueUserWorkItem(delegate
{
var channelFactory = new ChannelFactory<ISimpleService>("*");
var simpleService = channelFactory.CreateChannel();
var asyncResult = simpleService.BeginGetGreeting("Daniel", null, null);
[code]....
i have this code which i run with queued 10,000, even when a max of 50 is set but the threadpool counts goes to high.
Public Sub DoWork(ByVal objItem As Object)
Dim objUrl as String = DirectCast(objItem, string)
Try
If objUrl Is Nothing Then
[code]....
EDIT:i use a this code to check the number of runing threads each second
Sub Timer1Tick(sender As Object, e As EventArgs)
tsslthreads.Text=string.Format ("Threads: {0}", Process.GetCurrentProcess().Threads.Count)
End Sub
I have a bunch of operations that need to be executed simultaneously. For this I'm using the thread pool to execute the tasks. I'd like to know if it's possible to consume some sort of Async Callback (similar to BackgroundWorker.DoWorkComplete) when each thread is finished. The reasoning behind this is that I have a windows service running that uses IPC to update a GUI and I need to know the time at which each specific thread finishes I've used background workers to do a set of tasks and they work perfectly, however, they take longer than I would like. I've timed the execution on my BGW method for a designated number of said tasks and it took 27 seconds, and the same set of tasks takes 4 seconds using the threadpool method. I've also tried using managed threads, to the same effect as the background workers.
View 5 RepliesI'm currently writing an application that is used to automate a certain task. Currently, it uses the threadpool (using up to 25 threads per the enduser's option). Each thread calls a function which will usually take about two minutes to finish, but it uses a While loop in order to repeat the process. This is my code to start the threads:
Private Sub ProcessAllItems()
For i As Integer = 1 To Me.numThreads.Value Step 1
Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf ProcessItem), i)
Next i
End Sub
The function "ProcessItem()" is the function that contains the While loop. The control "Me.numThreads" is a NumericUpDown control whose max value is set to 25. My question is...is this a good method to follow? To my knowledge after .NET Framework SP1 there is a max of 250 threads/CPU. However I've read the the threadpool is normally used for processing short-lived tasks. Should I be using background workers instead? If so, how could I start up to 25 background workers during runtime depending on the value of "Me.numThreads"?
currently i am using a threadpool that contain a number of thread. This number of thread can be different everytime, sometimes 5, sometimes 10, sometimes 15 and so on (multiple of 5). So now i have it working good by using for loop to queue the thread into threadpool. Now the problems is i do not know how to make the progress bar depending on my threadpool. I want my progress bar to complete only when all the thread are done. After searching google, i found that maybe it can be solve by using AutoResetEvent(false), but after i apply to my program, it still did not work, my program hang at xEvent.WaitOne() method and didnt proceed further, anyone can explain to me how to solve the problem? Or got any other ways? For your information, only 5 threads can be running at the same time as the requirement state so (so i set the setmaxthread to 5 already).
View 1 Repliesanybody familiar with these error? "There were not enough free threads in the ThreadPool object to complete the operation".im calling a web service in my windows application client.
View 16 Replieswhipped up this code real quick which uses a ThreadPool on Form Load to iterate through my subnet and tell me if there's a device communicating at each IP address.
some questions: Why am I able to update BOTH my label at the top AND the listbox, but I'm only using an .Invoke on the Listbox?How can I know how many threads are currently being used while that is executing?
What does the SyncLock do?I'm aware some people don't like the use of Application.DoEvents(). Is it ok to be using it in this instance or is there a better practice?For those wanting to try it out, drag a Label and a Listbox to a new form. Label is called "currentIPTextbox", Listbox is default name.
[Code]...
I prepare data to be processed, and saved to file. Since this process is slow, I want to delegate it to a parallel thread, so the main routine can end his work faster. The data is processed and saved to file by the "Sub ProcesarDatos", a routine on his instance of "FileProcessor class".
I call the code this way:
Dim
fp As
New
FileProcessor(DatosDeArchivo, Archivo & ".txt", Me)
ThreadPool.QueueUserWorkItem
(NewSystem.Threading.WaitCallback _
AddressOffp.ProcesarDatos))
I am using VB.NET 2008.Every now and then, ThreadPool.QueueUserWorkItem can take up to 500 msI checked the available thread, and it's not 0.What can cause ThreadPool.QueueUserWorkItem to take long sometimes, and how can I make it faster ?
Do While Not TerminateRisk
While qRiskSync.Count > 0
sItem = qRiskSync.Dequeue
[code]....
I want to open a VB.net form using a ThreadPool with a maximum of 10 threads. I need to do this because, the form should open based on a live event and i need atmost 10 forms on the desktop at a time. If i open the form on every live event without using a ThreadPool, the desktop will be floaded with many forms. I am using QueueUserWorkItem method of threadpool to queue a method which opens the form. In this queued method, there is form1.show() statement called. But after displaying the form, this method finishes execution and again we have 10 threads available in the system. I somehow want to either keep this method running so that 1 thread is occupied or i want to keep the thread alive till the form1 is closed by the user. I want the 11th form to appear on the desktop, only when any of the existing forms out of the 10 (already on desktop) is closed.
View 2 RepliesWhen using teh system.threading.timer or threading.threadpool. queueuserworkitem, you are able to pass an object.
But wouldn't the garbage collector destroy the object even before the callback can be executed?[code]...
Been trying to implementing ThreadPool over a large and variable amount of data like the following:
public sub ProcessWorkItem(byval state as object)
Dim originalState as CustomStateInfo = CType(state, CustomStateInfo)
'Do stuff
[Code]....
This of course will bomb out if we have more than 64 items/threads being placed on the ThreadPool.
So, how would one process say x amount of items until there are no more items left to process?
Every time that I want to make a thread in the ThreadPool I make a stupid little function like Worker_O below.[code]...
Is there a way in VB .net to cast from Sub(i as integer) to Sub(o as object) without making Worker_O? Worker_O is ugly to me.
I have a task that needs to be executed many times in a thread, so as to keep my GUI responsive. Right now I'm using the ThreadPool to accomplish the tasks, and it works perfectly. I get all the data I expect back from the threads, life's good. When those tasks are finished, I then fire off another set of threads to accomplish another set of tasks, in the same fashion. The work method of these threads uses a call to RegistryKey.OpenRemoteBaseKey, which does exactly that, opens a remote registry key. The problem is: if the user running the application does not have permission to open the remote registry the call will throw an IOException, but I expect this behaviour because the user does not have permission to do it. However, the call itself can take FOREVER.
I wrote the application initially to use delegate methods and used the WaitHandle.WaitOne() method on AutoResetEvents in a state object I passed to each delegate. I tried the WaitOne method using a timeout, which worked fine until I realized that even though the WaitOne timed out, the thread was still running. This is a problem because (from what I understand) processes are only given a certain number of ThreadPool threads and, once used, they must be finished in order to be released back to the threadpool. In my work method, I also have a variable that can be signalled when the thread should be stopped, but that (obviously) only works on code that I've written.how can I cancel a thread that's stuck on a .NET method? Is there some sort of garbage collection method I can call if I give it a handle?
The error is:
Method 'Private Sub ProcessToolWork()'
does not have a signature compatible
with delegate 'Delegate Sub
[code].....
Learning about threads at the moment, barely managing to wrap my head around it, anyway I was wondering how you would go about making threads run sequentially from threadpool if you added them with
threadpool.queueuserworkitem()
In my code currently I know it is not running sequentially as I set it up to call a function and print a number each call. I gather this could be achieved with using synch lock but not quite sure how.
what is the best way of detecting if all the threads in the threadpool have finished working,
is there anyway to stop all the threads?
[URL]
Alright, so I'm still working on the slot machine. I have three timers all independently going for my three "wheels" of the slot machine.
My issue, is that I'm trying to make a Stop button to stop each timer one at a time, and I'm not understanding why this code isn't working. The logic completely makes sense, and the first "wheel" stops when I click the button, however, it doesnt appear to stop the other two timers.
CODE:
I have a code which adds each line of a textfile to a List(Of String).I have around 1.5 million entries in the textfile. It adds it to the list in like 1 second. However, I'm trying to add all the users to a threadpool to do a certain function. So I try:
For i as integer = 0 to list.count - 1
The list has like 1.5 million entries so the GUI freezes untill it all finishes in like 5 minutes. How can I make it go faster and not freeze the GUI?
I am working on uses the ThreadPool class and specifically the QueueUserWorkItem method to launch its background tasks. I am however having an issue related to SqlConnection timeouts. My error is this: "Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached."
This code is using all available ThreadPool threads because it is processing nearly 100,000 items, each on a threadpool thread, and updating an SQL database. So my question is this? Has anyone ran into a similar problem or could shed some light on a resolution to this issue? In testing, if I use the threadpool. setmaxthreads function and give it a value of 100 (to match the default Sql connection pooling count) then all runs just fine, but much to slow to process this much data.
[Code]
I created a form and have the variable inputs for 4 motor run statements. Then with a start button the script starts and it is surrounded by a for next statement to loop 10 times. It works fine but if i need to stop the execution of the script with a stop button. I put the stop in a new section but of course does not work to do a motor stop. It just causes the exe to not respond till the loop is complete. Just need to be able to stop the Run1_Click button section.
Edit:I do not mind if it finishes the 4 motor run commands and then stops execution of the loop. So need to figure out a way to trigger a stop from a button on the form to stop the cycle. For the future the loop will be a variable integer input so 10 will not be the standard.
Edit::Does a ' Do ' statement sound like the thing to use? If so how and where would I place that? Have a Stop button on the form and it would stop after the 4th motor run command.
#End Region
Declare Function InitStp Lib "stp.dll" () As Integer
Declare Function RunMotor1 Lib "stp.dll" (ByVal steps As Integer, ByVal interval As Integer, ByVal direction As Integer, ByVal outputs As Integer) As Boolean
[code]....
Problem Fixed. Mod please delete this thread, .
View 2 RepliesI have created a small program but the code is quite big.
I have a start button that when clicked it runs the script in a private sub called start(), when it gets the the ens it calls the start() again to loop it and restart the script.
I have added a stop button, but how do i make the script stop ?