VS 2010 Multi Threading Access To Module Level SEQUENTIAL Counter?
Feb 22, 2012I've got this code
Public Class Form1
Dim m_listener As HttpListener = Nothing
Dim m_asyncCount As Integer = 0
[code].....
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Multi-threading Scoping - Enclosing The Test Module Portion That Hosts The Delay In A Synclock Results?
Jul 16, 2010I'm on my way to MSDN but thought I'd stop by here first because the answers are usually more cogent.I have a test bed that mimmicks my product app. The general architecture is a factory that builds/instantiates a number of objects (device controllers) that are scalable in number based on requirement. Each object has a threaded portion that reads a device. This way, each object can read its own device simultaneously with all the others. To perform the read, the object calls a routine in a Module that houses the device interfaces. Interestingly (and happily), it seems like each thread has its own copy of the Module routine.
The test bed seems to verify what I'm seeing in the app. In the testbed, a 500 mil second delay is substituted for the device call. Even enclosing the test module portion that hosts the delay in a Synclock results in multi-threaded execution of the pseudo device call. I haven't tested for data yet, but this seems to indicate that when the module routine is called from controller object, it too carries it's own copy of the data just like the calling object. As a long time c++ programmer...that don't quite seem right.
Creating Multi Level List Boxes In Access?
Oct 25, 2010The first list box contains the project name. Based on whatever is selected in the Projects list box, the 2nd list box is generated with Custodian names associated with that project. I am having problems generating the 3rd list box. This holds the data sources associated with whatever is selected in the 2nd list box (Custodians)
View 1 RepliesVS 2010 Having The Multi-Threading IP's?
Dec 11, 2010I've been raking my brain for quite some time on this. Is there any way with VB.NET that I can use multiple IP's in one instance of a program? For example, I want to be able to navigate to a web page 10 times at once, with each one using a different IP. I want them to be parallel (multi-threaded) rather than going sequentially. Going sequentially, I could just do the action, change the IP, do the action, change the IP.
View 5 RepliesVS 2010 Multi Threading The Right Way?
Jan 10, 2012I have a button and when it's clicked a HTTP request is sent out to a website to do a few things, but because its got to load the external resources it makes the interface frozen. I've moved the HTTP onto another thread using the follow
VB.NET Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim Thread1 As New System.Threading.Thread(AddressOf check_accounts)
[Code]...
When i want to update a label that is on my main form (from the check_accounts sub). I know that isn't the right way, but i have no idea what the right way is. All the documentation i can find is very (excuse me for this) nerdy and really doesn't offer much insight on how to incorporate it into a project.
I want to be able to have a numericupdown box that can let the user change the amount of threads they want to use. I assume more threads allow the http requests to be done faster and at the same time?Also if i wanted to pause the HTTP requests, would the best method to use be pausing the thread?
VS 2010 Multi-Threading Application?
Apr 5, 2011I am working on an application that is taking pretty long to execute. I started playing with mutli-threading and it seems to have greatly sped up my app. Problem is that threads are still executing and the rest of the code executes before the threads finish. Here is my
[Code]...
VS 2010 True Multi-threading?
Dec 20, 2010I'm having some issues with parsing a lot of information into controls using winforms. I've tried adding threads/backgroundworkers, but they don't seem to work properly. To avoid the cross-thread exception, I had to add an invocation checker:If Me.InvokeRequired Then Me.Invoke(New MethodInvoker(AddressOf ParseSub()))This just freezes the form as it would without threading, but without the invoke checker I get cross thread exceptions because information from one thread is trying to be sent to another.
View 6 RepliesVS 2010 - Multi-Threading Managing Threads
Aug 31, 2011I started a threading project and want to manage my code so that it waits for all the threads to be finished before displaying to the user on the main UI thread that it has completed the task and waiting for the user... I've created a List to manage the threads and a global Boolean, "blnStop"...
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VS 2008 Multi-threding - Adding Multi-threading Facilities - Cross-thread Operation Not Valid
Feb 10, 2010I'm adding multi-threading facilities for the first time. I have a function that is wrapped to be run in a separated thread. This function retrieves data (text) from a combobox and it works for sure without multi-threading.
When I call it as multi-threaded, I get the following error when I try to retrieve the data from the cmobobox: Cross-thread operation not valid: Control 'cmb1stBL' accessed from a thread other than the thread it was created on.
It looks like a restriction of thread-safety... I assume that the child thread cannot read from his parent, to make sure that he doesn't change his parent data. So how can I read the data from the combobox? Should I read the comoboxbox data before calling the child thread?
Accessing Multiple Sites Multi-threading Or Multi Browsers?
May 14, 2011I have a need to build an app that will access about 10 websites and pass data to them, etc.I've read about something called multi-threading when searching Google. I've also seen people say that they use multiple browsers.Which route is better to use? I figure if you have to do some sort of multi-threading that you would access a single browser?
View 2 RepliesChange Login Code To Support For Multi Access Level Login?
Dec 14, 2009 May i know how to change my below login code to support for multi access level login? So that i can differentiate between manager and normal employees login so that i can enable or disable certain features for different department? I have the below code that can serve as a basic login.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'login code can work
conn.Open()[code]......
VS 2010 Reading From A Sequential Access File And Storing It In An Array?
Feb 9, 2011what I have to do is read the 5 names inside the Sequential Access File and store them in an array. I'v encountered a problems in storing it in an array. Here's the code
Dim infile As IO.StreamReader
Dim names(4) As String
Dim filename As String = "names.txt"
[Code]....
Theres an error in the code saying that a string cannot be converted into a one dimensional array.
Multi-threading Or Multi Browsers?
May 14, 2011I have a need to build an app that will access about 10 websites and pass data to them, etc.I've read about something called multi-threading when searching Google. I've also seen people say that they use multiple browsers.Which route is better to use? I figure if you have to do some sort of multi-threading that you would access a single browser?Not sure which way I should approach this app.
View 2 RepliesBest Way Of Multi-threading?
Mar 3, 2009I need to be able to call a C++ dll that takes a long time (possibly infinte, it relies on user input)to execute. Im calling this through VB. My VB GUI freezes up when this happens, and I would like to keep the GUI responsive, so that the user can stop this possibly infinte loop. A bit of background, the C++ is trying to keep score on a snooker table using a webcam, and while the VB scoreboard updates easily, I would like to script it so that the analysis is almost continuous, while still allowing the user to interact. Currently the project requires the user to press a button to start the shot analysis, but it would be preferable if the program scripted itself. I have only realised this problem now and the deadline is very soon.
Update: Our lecturer suggested an option to solve the problem, but it would appear that most options here and the one he suggested will not work for us as the processing time required for the webcam image capture is too great to handle due to hardware constraints.
SMS Multi Threading
Jun 26, 2009SMS Multi Threading
View 4 RepliesVS 2010 Higher Level Of Access Makes Program Dysfunctional
Mar 13, 2011So I have this program which I can use to drag files in it and do something with it, and when I run it as administrator, it doesn't let me drag the files in at all, but when I run it normally it does. Is there a reason behind this? And how would I go about fixing it?
My code if it means anything:
Imports System.IO
Public Class Form1
Dim SetSU As Microsoft.Win32.RegistryKey
[Code]......
Low Level Keyboard Hook In A Module
Apr 16, 2010i am trying to create a keyboard hook so when i type out something my app will pop up, regardless of which app has focus at the time.i coded this already in a form which then opens up a second form but now i trying to make it so my module opens first, and then it will open up my secondary form.but the issue i am having is when the module loads and starts the keyhooking, i get an error on the following code saying"Overflow Exception was unhandled, Arthmetic operation resulted in an overflow".[code]
View 1 Replies.NET Perform Any Multi-threading On Its Own?
May 30, 2009I know .Net and C# pretty well, but never even looked at VB.My problem is: our Win32 COM library is used by a number of clients, and we see that the number of failures is higher for those who use the library from VB (both VB and VB.NET) than for those who use C++, C# or Delphi. One thing about our library is that it is supposed to be used from one thread only - can some threading magic by VB be the cause of failures?
Clients tell us the do not create any extra threads on their own.
Better Performance With Multi Threading?
Feb 15, 2009I'm creating a password hash recovery tool that uses brute force. I have the brute force algorithm run in a background worker. It all works, but some similar apps I tried out have performance ~100x bigger then my app. (mine does 50k keys/second, some others do 5m keys/second or more.)I realize this is partly caused by using a .Net language, but I suspect there are ways to significantly speed up the brute force. A lot of ppl say I should use multi threading, but how is this done in practice? Splitting up the passwords to check would slow down my app I think.
View 1 RepliesC# - .NET Multi Threading - Updating The UI On The Fly
Nov 12, 2010I have a button click event and inside I do a lot of work. While I am doing this work (not from the UI project) I want to send messages to the UI to display to the user.
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and inside DoMyWork which is in another assembly i can call SendMessage which writes to the textbox. The messages will only display though when DoMyWork is complete. How can I update TextBox1.Text on the fly without putting DoMyWork on a BackGround thread or do i have to put it on a BackGround thread? I do actually want to block the user from doing anything while DoMyWork is running
C# - Multi Threading A Web Application?
Sep 9, 2009I know there are many cases when it's best to multi thread an application but when is it best to multi thread a .net web Application?
View 5 RepliesMulti-threading In GUI Environment
Jun 22, 2010I made a simple Form1, with Text.Box1 (starting value=1) and Text.Box2 (starting value = 100000), as shown in the attachment: I wanted that, when the Form loads,value of Text.Box1 keeps on increasing by 2 and value of Text.Box2 keeps on
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Multi-Threading On Multiple CPU
Aug 20, 2009One of our products consists of two different services:
- main service that launched at the startup of Wndows
- GUI that launched manualy when needed
GUI is representing data from main service.Main service starts X amount of threads that do some work and gether data.Some minor data and adresses to threads are stored in chache memory, so that GUI will have access to them.Everything works fine in 99% cases, but in some rare cases GUI do not display any data when used on machines with multiple processors (not milti-core). My guess is that it can't access the memory -> probably OS "decided" to run main service on one processor and GUI on another one.Is there any way to access the memory alocated for one processor from the service that runs on another processor?Or is there simple and secure way (same application will be also runing on single processor machines) to specify both services to run on the same processor?
Synchronization In Multi Threading In .net?
Sep 10, 2010I have a question regarding the synchronization in multi threading.
I have a function called send which i am calling in a for loop for every data row.
This function creates threads to send emails to different people.
Public Sub send(ByVal Conn As Data.DataRow, ByVal job As Data.DataRow)
MyThread = New Thread(AddressOf Me.start)
MyThread.Start()
End Sub
But every thread created is writing to a log file at different points of time. So, there are very high chances that 2 threads write to the same file at the same time. So, do i need to use any kind of synchronization mechanisms here ? or is it fine without them ?
Adding Multi-threading To Application?
Jun 15, 2009I am working on adding multi-threading to my application. I have done two applications using multi-threading following a tutorial of sorts, and modifying the code to "get my feet wet."
This is the first time I am trying multi-threading within my own application, and I feel I should be beyond this type of problem, but after a 3 hour search on the forums, I can not find a solution, so I am posting this thread.
The section of code with the error
vb.net
Imports System.Threading
Imports SldWorks
Imports SwConst
[Code]......
Class Updates And Multi-threading?
Aug 29, 2010using multi-threading in my application.Basically what i am trying to do from within a form event is initiate a class instance and then run a function of that class (via a thread) that changes certain member values of that class.Those class member values are then used to update values on the main form.Ive created a simple example below but i cant seem to get it to work.The class values are not updating and im struggling to understand how this threading works.
Class FormMain
Private Sub BtnClick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles myformbtn.Click()
Dim myFileCounter As New FileCounter()
[code]....
Difference Between Multi-threading Vs. Backgroundworker?
Apr 12, 2011I'm creating an app that needs to navigate to multiple websites, logs me in and then submits my documentation.I've read that multi-threading can handle this task but then I've read something about backgroundworker.
View 1 RepliesDownload File Using Multi-threading?
Dec 18, 2010Download file using Multithreading
View 1 RepliesMulti Threading With Comm Object
Jun 20, 2012We working with a Modem type interface that use's the Comm port for two way communication. The App starts and sets up the Comm port, and sends config info to the 'Modem'. Trick here is you have specific timing issues that need to be considered, and we got it all sorted, by using Threading.
You send The Config command to the modem and wait X ms for the confirmation reply (Single Byte), If no reply, send a Wake up command, wait X ms and send Config command again. Once confirmed that the modem is in config mode, send parameters, Waiting for confirmation of each one. Once config is set, send the 'Return to normal mode' command and wait for confirmation. [Code]
The SwitchModemMode sub runs under the Comms thread and not the main thread, like the Checkmodem sub at the top. Mostly because the Comms thread Raises the Data Event, which in turn calls the SwitchModemMode. Now because of that the Thread that is supposed to be checking for the input and setting the Flag, is actually the one waiting for the Flag to be set. And Yes App.DoEvents could solve it here, however that can/will mess with the Timing needed with these commands. I'm looking for how to pass the Raised event to the Main thread.
Multi-threading Bad File Name Or Number
Apr 18, 2012I'm using VB2008 express under Windows XP.I have a complex program that processes digital maps. To speed things up I have started to use multiple threads.The program logs diagnostic information as it runs - a file is opened when the program starts, records are written (Printline) to it as required and it is closed when the program ends. All this worked fine until I introduced multiple threads.For the main program it still works fine - but if I try to print to the log file from the code in a started thread there is an IO exception "Bad file name or number". The number (1) is shown by the debugger and is correct.Does this mean that a file cannot be accessed by different threads without being opened and closed for each thread?
View 1 Replies