When 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]...
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 RepliesEvery 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.
What is the best way to keep a thread alive
View 1 RepliesI am working in Visual Basic 2010 and need to check if a port is alive on an ip.I am currently using this code
If My.Computer.Network.Ping("85.250.180.71") Then
TextBox2.Text = "Server Online"
Else
TextBox2.Text = "Server Offline"
End If
I was trying to show an waiting icon when processing a time consuming operation (to let user know something is running behind), but no sure what's the good way to do it? for example, i have a picture box holding this animated Gif, and initially i set it to be invisible, but I want to show it and actually working (alive) when clicking a button, this button will trigger a do loop ending after 1min. [code]
View 17 RepliesI have an application that connects to an SQL Server, sometimes we have a networkinterruption of min 10secs during the openconnection , I get a General Network Error when I try to carry out any procedure that communicates with the database afterthe interruption. Even when the connection is closed and reopened, I still get General Network Error. The only way to get the application to function again is to close the Application and reopen it, is there any way I can keep the connection alive?
View 11 RepliesI am trying to make a basic server/client program but I ran in a problem.
[Code]....
When I click connect in the GUI the first state of sock.ctlstate is 6 , connecting then the connected event is triggered and after that the sock.ctlstate is 8 , "Peer is closing the connection". But I dont understand why it does this. I should keep the connection alive to communicate.
if i go to sql server configuration manager and shutdown the SQL server, the server will be down.
How do i detect for those changes using vb.
Public Sub CheckConnection()
Dim con As New SqlConnection
Dim objCmd As New SqlCommand
[Code]....
I cant make those work because the connection opens and close. WHat i want is to check if the server is alive or dead.
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]....
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 RepliesI 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 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 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 RepliesBeen 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?
I'm trying to setup sort of a LAN keep-alive proxy...Ex.: My Xbox 360 is connected strait to my computer via an ethernet cable. My computer is connected to the internet via a Wi-Fi adapter. Everything works fine and I can access the internet on the Xbox and computer.
Issue: Every time I start my Xbox I have to set up a "Home or Small Office Network" via the control panel to access the internet. What I would like to do is implement a proxy that when I shutdown the Xbox the LAN doesn't give the "Network Cable Unplugged" notification. I wasn't sure if there was a way to make the connection stay open for so long after it should say unplugged. Such as if I need to restart the system and don't want to have to re-setup the network on the computer.
This is my code to retrieve the network info:
Imports System.Net
Imports System.Net.NetworkInformation
Module Module1
[CODE]...
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]
I 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] .....
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?
