I'm writing a scripter using VBScript, that should be able to execute multiple scripts at same time, running on own threads.
The issue is, I DO start those scripts on different threads, but their sleeps still seem to affect the other threads too.
For example, let's say I start 2 scripts
In the Main event
NewScript1
NewScript2
[code]....
I just had a new, last-minute idea on to take on a task, so I am running to StackExchange for quick help.
What I want to do is execute a series of methods right in a row, each in their own threads. I want the application to wait until all of these threads are completed, after which the program will resume. It also has to use managed threading (thread pool).
What quick examples could you provide to help me along the way? If it's too complex, what things should I know about so that I can Google it on my own?
In the past few weeks, to speed up our database freshening process, I've created a couple of extra programs, basically copies of the exe file. The program itself, accesses web pages, images etc and uses threads to do so. The second program uses LIMIT 300,100 and the third LIMIT 600,100, to make sure they don't work on the same records.
Before the last few weeks, one occurrence of the program used to run without problem, from the task scheduler all through the day. Only one occurrence of each exe can run at a time.Since theres now three programs running, .net 2.0, on xp, the program often seems to get stuck and never ends. I have to kill it from task manager.
It runs fine in the IDE I just wonder if there would be any benefit from upgrading to vb.net 2010 ?
How to I run multiple threads in VB.NET? Say I need 2 threads - one that prints 100 numbers in a loop and the second one that asks for the user's name and prints it inside a message box.
View 1 RepliesI have a sub-procedure which I want to run a different process, depending on what is currently running. I thought the easiest way to do this was by using an ArrayList of each of the campaign details & adding an 'Inuse' field to check to see if the Inuse field is set to 0 or 1. The problem that I have is that when running the process it is all happening at once & the integer hasn't been changed before the next thread kicks in so my threads are running the same campaigns. I tried to avoid the problem by adding a Thread.Sleep(100) delay inbetween starting threads but this led to exactly the same problem.
Here's an example of what I am trying to do:
Imports System.Threading
Public Class Form1
Private Campaigns As New ArrayList
Private ProcessRunning As Boolean = False
Friend StopProcess As Boolean = False
[Code] .....
I have an application, running multiple threads, and in many of these threads, Outlook is being called, some mails read, attachments downloaded, and then the outlook instance closed. But it is possible that there are a number of threads trying to do the same thing at the same time. There is of course a lock at the beginning and end of the process, so that no two threads try to access the outlook application at the same time.
"Sometimes" i get an error message : Creating an instance of the COM component with CLSID {0006F03A-0000-0000-C000-000000000046} from the IClassFactory failed due to the following error: 80010108
Say I have a code with 3 methods that do some pretty intensive work. Would executing these methods on 3 seperate threads be faster then executing them one after the other on a single core cpu? And what if it's a dual core or HT?
View 8 RepliesI have only managed to use an STA to run a long running excel process with a background worker and 2 delegates.
What I want to do now is have the whole application running outside of the main thread to make sure the UI is always available, I then want to create new threads from the thread I have outside of the main to run the various processes. I will need to have some form of syncronisation in there for certain things to be done once a thread is completed and also I will need to change the button states on the main form to stop certain process being called whilst other processes are running.
This is my code so far, basically this loads in a csv file to a datatable adding manager employee ID and email address, filters it and displays the resultant data in a listview. There eventually will be some filter options as well. There are then 2 options for processing the data, it will produce individual bradford factor reports and email them to each manager or will produce a summary spreadsheet that is sent to HR.
Currently because there are around 8000 lines of data, it was the summary option that required the background worker as a long running process time out error was occuring whilst in the main.
What it does is write the data from the list view to an excel sheet and colour co-ordinates the summary rows according to the absense policy. It then copied bottom to top, the summary value the next blank column against all the lines for that individual and then uses this column to decide which sheet to move the row to, copying the row to the new sheet then deleting it from the master list and shifting the cells up.
This works well, but the process of loading the data in to the list view locks up the main thread where it currently runs. I also wanted to make this slightly more complicate as far as threading is concerned, as more of a learning curve than a practical application of the function.
Here is my code so far: [URL]
I have two forms running in the same application but on different threads. HdForm and DataForm. I have a class library whit datasets and a stack in it. Cause both forms (different threads try to rad from the same class library i use a synclock to syncronize. But it seems like the synclock dont work.I get random errors in the HdForm while reading from myAr dataset. It says index out of range. But i know for sure that the index exist (i have make sure of that). When i click on the visual studio play button then, it goes again.If the index was realy out of range then it couldn't go further. So i think the synclock does not work and thus the dataset is changed in time while im the loop reading from MyAr.
[Code]...
I want to have three classes running three simoultaineous threads. I have started out with one class that looks like this:
Imports System.ThreadingPublic Class C_EventCollector Dim oThread As Thread Public Sub New() oThread = New Thread(AddressOf Me.BackgroundProcess) End Sub Private Sub BackgroundProcess() Console.WriteLine(Now.ToString) oThread.Sleep(10000) End SubEnd Class
What I want is execute BackgroundProcess() every tenth second. For testing purpose I print out current date and time to the console. Using this thread BackgroundProcess() only executes once.
I have a loop that creates several threads as such[code]...
View 1 RepliesI have several threads in my WinForm and I am running them via Thread.Pool, what I need to know is that how can I run them sequentially.
example:
Thread1 => me.label1.text = "Thread1"
Thread2 => me.label2.text = "Thread2"
Thread3 => me.label3.text = "Thread3"
In my Form_Load event, I have a line as follows:
[Code]...
it would be best if I just copy and pasted the code (it's very trivial).
Private Sub Main() Handles MyBase.Shown
timer.Interval = 10
timer.Enabled = True
End Sub
[code]....
An exception, "The object is currently in use elsewhere", is raised during the tick event.
Threads a + b, (both are trying to delete files).a gets called first, then b while a is still running.b deletes the file successfully but a doesn't.If I run a on its own, a's file deletes fine.
When I step through the code I can see that a's MultiAttemptFilename gets overwritten with b's.
I don't understand.I have an ajax call pointing to a generic handler which passes the filename along with it.In my handler I have the following code:
[Code]...
I am writing a project in Visual Basic where I need to run several instances of the same method in parallel. I can do this using BackgrooundWorker by having several (4) copies of my code module (modules 1, 2, 3 and 4) with a call to background worker in each. I then have a Main form which invoke the 4 modules which setup 4 simultaneous background threads. Seeing as the code is the same I want to simply invoke the same module 4 times.
However when I do this I get an error from Backgroounworker that it is already busy. As I understand it this means that it is being shared. However, I have specifically instantiated it as "private" (private with events worker as new backgroundworker). I have tried running the same code in a Class instead of a Module but unless I make it public I have no way of invoking it from Main. I need to be able to pass each thread data from main for it to work on and if the class is private I cant invoke it.
This code will show you how I started multiple threads:
For i As Integer = 0 To 10
Dim MyThread As New System.Threading.Thread(New System.Threading.ThreadStart(AddressOf MySub))
MyThread.Start()
Next
Now I'm trying to stop the threads before closing my application but I don't know how to do that?
how to convert videos files using vb.net and ffmpeg. But as far as i know we cannot use multiple threads to run same exe file to convert files. Do you know how i can convert multiple videos using one external exe file (ffmpeg)?
I have not tried because my computer time was over. So iam just asking a general doubt whether if we attach it to one process then wouldn't the process get locked? Then can we multi-thread this application or not ?
I'm testing here something, but i don't know what's the best way to do this.I have a var that tells the application the number of threads that will be started, inside the thread/function that i call i need to return/get two values i have two sub functions, each one returns an integer.Then in the end i need to sum the values.
Example:
Thread1/Function
SF1 - Returns 2
SF2 - Returns 3
Thread2/Function
SF1 - Returns 1
SF2 - Returns 5
After all threads are over, i get the
SF1Total = 2 + 1 and
SF2Total = 3 + 5.
I'm thinking in using shared vars, and inside the function/subfunctions update the values. It's this a correct way to do it? Other question, the threads are assync, but i need to know when the last one finishes. How do i control this? The order they finish doesn't need to be the order they were called....
This may be a strange question and have no answer but I thought I would post it to see how you would go about doing it. I have a line of code:
Grade = Math.Round((Math.Abs(CorrectAnswers) / TotalQuestions) * 100)
Basically that line just figures out the grade no major code work there, what I want to do is execute that specific line with different variables without running the whole application and navigating to the point in the application which for this segment would be completing a 150 question exam, or coding some #temp page and running it from there.
I have this class and I have a loop that launches multiple threads from the same class. This is all done from the main form.Now I want to update the richtextbox on the main from these classes.I have tried those begininvokes etc etc and nothing worked, no error but no output as well.Here the code for launching the threads :
Private PingObjects(100000) As Account 'Account is the class and login is the sub in it...
PingObjects(I) = New Account
Threads(I) = New Threading.Thread(AddressOf PingObjects(I).login)
[code]....
And to update the rtb, im using MainForm.log.text = "....." Nothing happens, no error.I have tried using the begin invoker method as well.
To get pass the cross referencing error when running a thread, I use this code
[Code]...
But the AddressOf doesn't accept parameters... So how do I get pass that? Or is there another way to use delegate?
I've read a lot of different questions on SO about multithreaded applications and how to split work up between them, but none really seem to fit what I need for this. Here's how my program currently basically works:
Module Module1
'string X declared out here
Sub Main()
[Code]....
This is only a rough outline of what actually happens in my code by the way.
My problem being that if multiple threads start running Main2(), they're dealing with the same X value as in the other threads. The loop inside of main2 executes multiple times per millisecond, so I can't just stagger the loops. There is often duplication of work done.
How can I properly divide up the work so that the two threads running simultaneously never have the same work to run?
I need help to implement multiple threads in application.Assume ds.table(0) has 5 and sometime 6 rows rows for i=0 to ds.tables(0).rows.count-1.I have to apply multiple threads, means all five/six rows should start at once using thead and "Process 1" .."Process 4" should also handled by threads.This is hierarchy that I have to apply with threads, how can I do it. It is requested to put piece of code so I can understand better.
View 13 RepliesI know a little about threading and delegates, as well as socket programming. I'm working with a VB.NET-compatible SDK called TrueVision3D to create a small online game for me and my friends. The problem is that I cannot for the life of me figure out how to pass data from one thread to another. I've created 2 seperate threads on seperate forms.
The first thread is created on a form titled FrmLogin, and it contains all the socket code. I need to be able to update variables in the second thread, which mainly consists of a render loop. The second thread is created on a form titled FrmMain. I'm not quite sure if it matters what forms the threads are created on, I'm just trying to give as much information about the issue as I can. I've tried using delegates and events to pass information from the thread back to the form it was created on, which works fine, but how do I pass data to the second thread from the first?
I have an application that needs to perform a series of different actions at specific points in time.To do this I have a timer with various actions that occur in its tick event.One possible action is to send out a few messages via a serial port and then wait (between 1- 300 mins typically) for the next timer tick.Another possible action is to continuously toggle one of the control lines on the serial port until the next tick (again 1-300 mins).
In most instances, i'm happy for everything to run on the main thread, but in the case of toggling the line endlessly, I thought it better to give it its own thread.My problem is that for the new thread to use the Serial Port, it must open the port. Likewise, it must close it before the main thread can have it back.
Here are 2 code snippets
Private Sub activityTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles activityTimer.Tick
Dim some variables here
activityTimer.Stop()
If speedThread.ThreadState = ThreadState.Running Then
[code]....
I have a map image with data associated with the map indicated by RGB index. The data has been populated into an MS Access database. I imported the information in the database into my program as an array and sorted them to go in the order I want the program to run.
I want the program to find the nearest pixel that has a different color from the incumbent pixel being compared. (Colors are stored as string attributes of object Pixel)
First question: Should I use integers to represent my colors instead of string? Would this make the comparison function run significantly faster?
In order to find the nearest pixel of different color, the program begins with all 8 adjacent pixels around the incumbent. If a nonMatch is not found, it then continues onto the next "degree", and in this fashion, it spirals out from the incumbent pixel until it hits a nonMatch. When found, the color of the nonMatch is saved as an attribute of incumbent. After I find the nonMatch for each of the Pixels, the data is re-inserted into the database
The program accomplishes what I want in the manner I've written it, but it is very very slow. After 24 hours, I am only about 3% through with execution.
Question Two: Does my program behavior sound about right? Is this algorithm you would use if you had to accomplish this task?
Question Three: Would it be appropriate for me to use threads in order to finish execution of the program faster? How exactly does that work?
Question Four: Would it be more "intelligent" for my program to find the nonMatch for each pixel and insert it into the database immediately after finding it? (I'm making a guess that this would be good in multi-threading, because while one record is accessing the database (to insert), another record is accessing the array of pixels (shared global variable in program).
Question Five: If threading is a good idea, I'm guessing I would split the records up into more manageable chunks (i.e. quarters), and have each thread run the same functions for their specified number of records? Am I close at all?
In the same line of this thread Now i have a problem with the control of the ending threads. This is my
vb.net threadsEnded = 0 For j As Integer = 0 To numThreads - 1
[Code]...
Some times the application doesn't finish and if i pause the application i see that the threadEnded var doesn't have the correct value, seems like some thread doesn't update the value of the var.
I have a created a class, which contains a sub routine.This sub routine, should ideally be accessable by objects which are not members of the class, so I would like to make the sub, a 'shared sub' (call it Sub1).
Question: I am using many threads and there will be possibly 100s of 1000s of threads all wanting to use Sub1 (which is at present, is not shared).At present Sub1 , is not a shared sub, so every time a thread wishes to use Sub1 , I am creating a (dummy) instance of the class and then applying Sub1, to that instance.
My program works flawlessly using the above technique.Question: If I were to turn Sub1 (which is not currently shared) into a shared sub, and directly had various threads calling Sub1, would there be any issues with locking, ie. would it possible for 2 threads to enter that thread and start overwriting variables, which another thread has written to?
NOTE: there are no shared variables/properties in Sub1 and all variables used in Sub1 are declared within the sub itself.
I've used mutiple threads in a VB.NET program but I don't know if I did it right.I would like to start about 3 threads.Can they all use the same methods?Will a separate instance of each method automatically be created for each thread?If not, how do you make sure that the data within the method that is used by one thread is not used by another thread?I would like some data to be shared by all threads.How is data shared among threads?What is the protocol for changing the data and checking for changed data?Is there a good tutorial / website that explains how to handle methods and data when using multiple threads?
View 3 RepliesI have a application that use threadpool, and each thread stores data in the same textfile. I now want to have each thread store the data in the same array instead and use a timer to store all current data in the array into the text file after every couple of minutes.
So what I want to do is:
1. All threads store data in one array that they all have access to
2. After every couple of minutes the data in the array is stored into the text file.
I know number 2 can be done with a timer, but is the first one possible? If so how do I accomplish this task?