I have problem with multithreading.
For:
Code:
and multithreading to loop for:
Code:
How can I speed up this loop through additional threads?
I tried:
Code:
How can I do?
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?
I have a main thread which is designed to be a batch processor - it spawns a series of 'child' threads from a loop (which can vary in terms of the no of items) - see below
[Code]...
However, each of the 'child' threads could take anywhere from milliseconds to about a minute to process - depending on the complexity of each calculation. There may also be a large number of child threads - e.g 100s. Creating large numbers of child threads is not efficient. I therefore want some way to effectively queue each child thread (and cancel if the process is taking too long to complete). Autoevents seems like one way of doing this, but the only examples I can find seem to assume there are two different processes on seperate threads, not one process being repeated.
My question is to add two numbers up using threads or multithreading. Here is what I have:
Module Module1
Sub ThreadA()
Dim I As Integer[code].....
Is there a way I can use this somehow to add two numbers up?
I have 10 threads each using the same sub to do work. This sub is calling a function to save the results. How are the threads accessing the sub? Is each one getting a fresh copy of the sub to do its thing or are they using the same piece of code and need to wait for each other to finish processing? I don't get any hits when searching for such a specific scenario. I am wondering because it is about using sockets (usually lightweight stuff) to retrieve a resource and the cpu is working at 100% all the time. Still it is very fast, 900 internet queries finish in about 3 minutes.
View 4 RepliesHow 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 some test code which i run at every load of a page in my asp.net website [Code] the "dotrace" simply add a record to a log table in the db. now the right result would be that i should have the entries in the db in order "entered","exiting","exited" but actually when i look in the db i see first 2 "entered" then 2 "exiting" etc. meaning that the multi-threading is working ok, but not the synclock. is that correct?
and how can this be fixed? the real code will be adding records to the db and might be called from several pages of different sessions, but the same code must not run twice concurrently. if i open multiple pages at once, they still clash some times. but if i'm correct, the issue is now not with the synclock as much as with the httpruntime.cache, because when using a standard property, on one page, the code works 100%. so how can i make sure that 2 threads, even from totally different sessions never run the trylock simultaneously?
I have the following multithreading function to implement threads fetching from a list of urls to parse content. The code was suggested by a user and I just want to know if this is an efficient way of implementing what I need to do. I am running the code now and getting errors on all functions that worked fine doing single thread.for example now for the list that I use to check visited urls; I am getting the 'argumentoutofrangeexception - capacity was less than the current size'/Does everything now need to be synchronized?
Dim startwatch As New Stopwatch
Dim elapsedTime As Long = 0
Dim urlCompleteList As String = String.Empty
[code]...
Basically I am making a proxy testing program. A user can supply a list of proxies to test. What i want to be able to do is have them be able to specify how many threads they want to run. Then have the program go through the list testing each one using the amount of threads supplied. Really not sure even where to start on this. Threadpooling?
View 3 RepliesI am looking into using a producerconsumer threading pattern to run through a list of strings that i retrieve from a database and then am going to run powershell commands against. As the powershell commands can be quite intensive i only want to spawn 3 threads at a time and then wait for one thread to finish before doing anymore. I looked into the treadpool but it looks like it is used for more lightweight processing.
View 3 RepliesCode:
Private Sub Start_Left_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Start_Left.Click
[code].....
It reads from the port once every 1 millisecond, but the cursor still moves very slowly. Is there anything I can do to increase the speed?
Im using Vb.net visual studio 2008. i have got a process(system.diagnostics.process) to be run in background and it updates the Ui thread progressbar and a label and i have worked it using backgroundworker.runworkerAsync. Now the problem is i have to work the same process for a number of time with different inputs.
The code block is :
Private Sub fnStartEvent(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStart.click
Dim inputFolder = Directory.GetFiles(textboxSourceFolder.text)
Dim currentNumberOfFile As Integer=1
[code]....
The problem in here is the fnStartEvent method once gets started, it calls BackgroundWorker1.runWorkerAsync process and that runs in a seperate thread and does not wait for the thread to complete and it moves to the next line of code i.e loops to the next item and it returns to same BackgroundWorker1.runWorkerAsync line and throws exception that it is already running.
Tried
1.
Private Sub fnStartEvent(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStart.click
Dim inputFolder = Directory.GetFiles(textboxSourceFolder.text)
Dim currentNumberOfFile As Integer=1
[code]....
But this does not updates the Ui thread used to denote progress.
2.Put the whole process inside the DoWork thread and loop for each file in there itself, but that to returns the cross thread error in progress bar updation.what is the standard procedure in executing a loop for the backgroundworker to wait for finishing as well as update the UI without blocking it.
threads that watch folders and process files. This works fine, but every time needs change to add a new folder or just change some existing rules I have to go in and change the program. I want to builda front end that storesprocessing infofor each watchfolder. The program would then read the configs and build the threads based on them. I cannot find a way to loop through creating the threads.
View 8 RepliesI have ran into a situation where it would be a lot faster to create a thread by the users demand. Basically, what I have is some kind of downloading program which grabs URLs from the clipboard into a DataGridView. Now when multiple URL's have been added, it becomes really inefficient since only one URL is being processed at a time.Now what I wanted to do is, create a thread for each URL. The parameter for each thread are the URLs which are stored as strings inside the DataGridView rows.[code]
View 3 RepliesSomeone had coded a project in Java. THis was just a calculation that looped through 1000 iterations. We had done the same thing in Vb.net.Does anyone know the speed difference between Java and Vb.net for a long calculation loop? I had heard Java was very slow.
View 4 RepliesBasically with the code below I would like to create multiple threads. Let's say user input was the number 100 for the "userVal" variable of type integer. With the first pass of the loop, starting with 1, I would like to[code]...
View 10 RepliesI am trying to stop the following piece of code from taking up too much processing power of the PC by using threads. But I keep getting errors when I use threads:
[Code]...
I've got the following code:
[code]...
The problem is that, when I call the "SetStatusBarText" sub from another thread, InvokeRequired is True (as it should be), but then my threads stall on the Me.Invoke statement - pausing execution shows them all just sitting there, not actually invoking anything.
How do i exactly check internet connection speed.I have searched around google and found out a method w/c will Download a file like 1mb size, then it will calculate the speed.
View 1 Replieshow do i check the bandwidth (download speed and possible upload speed) of a user in vb.net or php that uses my app or visits my site resp?
View 1 RepliesI have a codes that calculates DownLoad speed and UpLoad speed kb/s. I would like to implement this kind. I also want to put such kind of graph. Any article or links where can I start building my own like that.
View 2 Repliesi want to monitor the speed at which my system is currently Downloading and uploading. I dont have any idea how will it can be done.
View 6 Repliesi want to check for the lan speed and put this speed value in a progress bar.
for example:
[==== ] the lan speed now is 23 KB/s
and there is another problem is if there are a LAN and a WiFi adapter in the same time how do i check for the speed for both adapters
how would i go about getting the of a fan of a computer that my program is running on in rps(revolutions per second) using vb.net?
View 4 RepliesMakes the following statement about the code below:
**"The computer evaluates the loop condition in the Do...Loop statment to determine whether the loop instructions should be processed. In this case, the inputsales <> String.Empty condition compares the contenst of the input sales variable to the String.Empty value. As you know the String.Empty value represents a zero length, or empty, string if the inputsales variable is empty, the loop condition evaluates to True and the computer process the loop instructions. *If on the other hand the inputsales variable is not empty, the loop condition evaluates to false and the computer skips over the loop instructions.
Based on the code I think it is the opposite: ...that while the inputsales value is not empty it should evaluate to true and process the loop and if it is empty it should evaluate to false and skip the loop?
See below.
Option Explicit On
Option Strict On
Imports System.Globalization
[CODE]...
I'm working myself thru the sandcastle documentation and found this C# sample.[code]...
View 2 RepliesI have a parent/child relation I am trying to create fow 2 datasets.The parent ds consusts of a range of PO Header information
After I fill this dataset I loop through it getting the PO number. I then take that value and execute another sql statement on the DETAIL file and fill a dataset(dtlDS) for EACH row in the parent. How do I add to this dtlDS for each row? I am getting no CHILD data in the merge. Should I be filling to a datatable and do an add.row and THEN dump into the dtlDS?
adding certain functionality to an existing ASP.NET application running on IIS 6.0 programmed in VB.NET.To aid in future development the client wants the additional functionality to be as future proof as possible. Ideally i have said that I would like to push for a solution using ASP.NET MVC3, running off IIs 7.5 and .NET 4, written in C#. This solution would act as a seemless addition to the current web-portal appearing probably just as an extra tabbed page.
But they will be completely seperate web-apps. Which is crucial.The main problems i can forsee are firstly sharing session particulars between the asp.net web app and the new application. Particularly with regard to maintaining session state (and not having IIS timing out on one of the apps). Also, conjoining the two "apps" appears problematic in my head, although this may be far simpler than i fear.
1) Embed the new fuctionality into the existing codebase (not a great option). This would mean losing any potential future upgrade-ability and also means not following better OO conventions by utilising the MVC framework.
2) Using an iFrame to link to the razor pages of a seperate MVC3 app (the one im favouring currently). Allows uses of all new technologies, however downside is sharing session data. Either through iFrame "attributes" through persisting a session state to a db? (slow?) or even some kind of web service interaction between the applications to push/pull user/session data?
Im practicing a database and I have a 3-column table. Im using binary formatting to save/open the file. I cant see what is wrong with my code“
I can display records ok when I press the save button
I can also save the records ok when the save/close button is pressed.
When I reopen the programme and press the reload button to reload the dataset, additional records will not be displayed nor saved though original records will be showing.[code]...
Im trying to get a sales percentage program to work and im having trouble on the last part. My homework is to get the original price from the customer and then take the sales percentage off and show how much it is. Then after the first percentage is off take an additional percentage off part and then show the grand total. I got all the way up to the additional percentage off part to work right. I dont understand why I cant add an additional percentage of and the program wont recognize it and work right.
Public Class Form1
Dim Num1 As Integer
Dim Num2 As Integer
Dim Num3 As Integer
[code]....