Managing Exception In Multithreaded Application?
Mar 20, 2009I started throwing exceptions on a multithreaded application, and got a mess.There is a good tutorial on managing exceptions in multithreaded applications?
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Chat Application NOT MultiThreaded
Mar 16, 2012I don't want it to be MultiThreaded. i read some tutorials and have a good idea. but unfortuantely all the tutorials on the web write code without explaining. so is anyone here has a good knowledge with Chat application ? I know it's about sockets and stuff but i just need an explaination with code ;)
View 5 RepliesCreate A Multithreaded Application?
Aug 20, 2009I am using Visual Basic 2008 Express Edition and I want to create a multithreaded application.
View 13 RepliesMake An Application Multithreaded?
Oct 14, 2010After trying to make an application multithreaded, almost towards the end of the processing of 10,000 records, I get a webexception - operation timeout.Now it seems to process around 8000 records just fine, for each record it is also doing some business logic and with it, performing a call to a webservice.
without threading, its fine - no problems. with threading, we hit the issue.so there are 10,000 records to go through. this is of course slow when done in sync mode (Single threading) but much faster when placing items in the threadpool and waiting until completion.
im not sure exactly why the problem happens. how should I debug this when multithreading? its just odd that for around 3/4 of records, the calls are doing very well, then on the last bit to go, it bombs out.
again - no issues when single threading.update: seems to be after around 1000 records that have been processed that it seems to happen.the application calls out to an internal webservice which then does the direct callout to the "outside world" webservice. The internal webservice does some caching but shouldnt have any effect really.
The outside service it is calling is httpBinding. ReceiveTimeout is set to 00:10:00 (10 minutes) and bypassProxyOnLocal="false"im still not quite understanding why it would timeout after 1000 records because it seems to process the others just fine and does come back (or so it seems) when its making a call to the service
Multithreaded Application And Crystal Reports
Nov 16, 2009I have developed a multithread Windows Application that requires to print various Docss/rpt's off. The problem is I get a "Load Report Failed" error message when creating a new instance of my embedded crystal report.
View 3 RepliesVS 2010 - Showing Forms On Multithreaded Application
Apr 17, 2011I've finally gotten multi-threading working on my application, but now I'm having trouble showing forms when I need to. I currently have three threads in my program: one for updating a textbox, one for transferring files, and one for displaying forms. Here's a snippet of code from my program:
[code]...
I'm getting the error: Control 'frmXCopy' accessed from a thread other than the thread it was created on. I know what this means, but I can't find a way to make the ShowForm Sub run off of the main application thread.
.net - Managing Connection To Database In An Asp.net Application?
Mar 17, 2009what would be the best way to manage a connection to a database in asp.net.My application is built using an N-Tier architecture.The DAL consists of static classes with methods such as
Public Shared Sub Delete( _
ByVal connection As MyConnectionClass, _
ByVal contact_id As Integer, _
ByVal contact_timestamp As Date _
[code]....
The point to note here, is that I pass the connection to the DAL from the BLL.Should I create the connections in the MasterPage, store it in an object, then pass it to my business objects as I create them (the thing I'm trying to avoid)Should I create a connection using a static class and calling a method like CreateConnection on it, from the constructor of my business objects (Something I'd like, but I don't want to have a connection per object, I'd like it to be shared for all instances of my objects, but since asp.net is multi-threaded, a static class doesn't make sense to store connections) the solution should also work well in a Windows Forms environment (So no connection storing in session, and retrieving it with a static method in a class, for the current context)?
VS 2008 Managing The Users Application Settings?
Oct 28, 2009I have a simple application with a main form and an options dialogue. The options dialogue has various TextBox's and drop downs where the user can make changes and OK/Cancel buttons for when they're done.On the FormClosing event of the main form, I save these settings to an XML file. When the program is first run, the settings are loaded back into the options dialogue. The application reads settings directly from the controls in the options dialogue during run time.
View 3 RepliesWindows - Vista Exception In Application "Exception Processing Message"?
Apr 5, 2012Background : I have built a VB .NET application on the 4.0 Framework, part of the primary functionality is the built in AxWMPLib.AxWindowsMediaPlayer which allows us to pass a file path as a URL to the player and then play it through the built in media player. My Development Platform is VS 2010 Pro on Windows 7.
View 1 RepliesCatch An Exception And Throw A New Exception Which Wraps The First Exception As An Inner Exception
May 8, 2009It is possible to catch an exception and throw a new exception which wraps the first exception as an inner exception: [URL] Also, if I call a function and it throws a certain error, but I catch it, will the calling code's catch handler execute? If so, and it is of a higher exception type, is this not wrapping the exception? eg I can throw exception ex of type IndexOutOfRange, log it but rethrow, catch a higher up exception and do something, or I can throw a new exception and wrap an inner exception like:
View 1 RepliesC# - Multithreaded Drawing In .NET?
Jul 24, 2010(Edit: to clarify, my main goal is concurrency, but not necessarily for multi-core machines)
I'm fairly new to all concepts on concurrency, but I figured out I needed to have parallel drawing routines, for a number of reasons:
I wanted to draw different portions of a graphic separatedly (background refreshed less often than foreground, kept on a buffer). I wanted control about priority (More priority to UI responsiveness than drawing a complex graph). I wanted to have per-frame drawing calculations multithreaded. I wanted to offer cancelling for complex on-buffer drawing routines.
However, being such a beginner, my code soon looked like a mess and refactoring or bug-fixing became so awkward that I decided I need to play more with it before doing anything serious.
So, I'd like to know how to make clean, easy to mantain .NET multithreaded code that makes sense when I look at it after waking up the next day. The bigest issue I had was structuring the application so all parts talk to each other in a smart (as opposed to awkward and hacky) way.
I have a preference for sources that I can digest in my free time (e.g., not a 500+ pages treatise on concurrency) and for C#/VB.NET, up to the latest version (since I see there have been advances). Basically I want something straight to the point so I can get started by playing with the concepts on my toy projects.
Can A Shared Method Be Multithreaded
Feb 28, 2012As the question states, can a shared method of an object be multithreaded? I don't quite having threading down in my skillset, otherwise I would test myself. On the other hand, I am involved in designing class that could be part of a multithreaded application in VB.Net.
View 3 RepliesDebugging The Multithreaded Programs?
Oct 29, 2008I have a background thread that waits for data to come in. When data arrives, it fires off a call to the GUI thread.All works just peachy, except if there's ever a run-time exception in the GUI thread. If that happens, the debugger always halts at the point in the worker thread that called the GUI thread. It never shows the proper line that the error occured on.How do I get the debugger to stop at the error in the GUI thread?
Here's the pertinent code from the worker thread:
Code:
Public NotInheritable Class UIThreadMarshal
Private Shared _MainForm As Form = Nothing
Public Shared WriteOnly Property MainForm() As Form
[code]....
Build A Multithreaded App - Catch The Returning Value?
Dec 26, 2010I'm trying to build a multithreaded app but I couldnt find anything on google on how to catch the value that the lambda function returns.
ThreadPool.QueueUserWorkItem(New WaitCallback(Function() As Integer
Value += 1
Return Value
End Function))
.net - Isolating Read And Write In Multithreaded
Mar 8, 2010In a multithreaded application. I have a bunch of function that loop through a collection to read the information. I also have a bunch of function that modifies that same collection.
I'm looking for a way to isolate all the read and the write together. I don't want a write to be done while a read is in progress. I was thinking of using SyncLock on the collection object but this will block multiple read trying to work in parallel.
Send Message To All Multithreaded Clients?
Aug 2, 2010Given the code, ss there a way to propagate messages send from any of the multithreaded chat client to all the other chat client:
First the main will call startClient:
Public Sub startClient(ByVal inClientSocket As TcpClient, _
ByVal clineNo As String)
[code]......
Sql - Stored Procedure For Multithreaded App - Timeout Expired
Jul 5, 2011I have an application using taskfactory that creates multiple tasks which insert records into the same table in a database. I have jobs that cleanup the table when it gets too large and have the execution time-out set to 0 in options in sql server management studio. I keep getting the following error on the tasks when trying to do an insert using a stored procedure and set an exception handling process to sleep and try again. This does not help as it seems it timeouts on almost every attempt.Not sure how to handle this and ensure the table handles all these inserts. Tried including connect timeout = 600 in one of the processes connectionstring but this did not help.Also set sqlquerytimeout value in registry to 90 but still not helping.
ERROR: timeout expired the timeout period elapsed prior to completion of the operation or the server is not responding...
could not see the details of the error since visual studio 2010 debug options had to be set that way, but I will set a responsestream and capture but I rebooted sql server and somehow everything is fine now...not sure why.
Errors have reoccurred.
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception,
Boolean breakConnection)
[code]....
VB 2005 - Sync Lock In Multithreaded Programs
May 16, 2010I have been reading through lots of sample code and explainations regaurding the uses of Sync lock in multithreaded programs but still am a little fuzzy on this.
Am I correct in assuming that if I have two or more threads running the same procedure which has a sync lock on a shared resource that the first thread to call the lock will complete its update of the resource and any of the other threads to try and lock this object would just wait in line until it is released by the first object?
I am also a bit fuzzy on what is actually locked by the sync lock.
Lets say I have code that uses sync lock and the object specified is the current thread. Does that also lock the shared resources that are referenced within the sync lock block or would I need to use another method to do this?
What if my shared resourses were all in another class and I issue a sync lock on that class before I try to modify the resources would that be the proper way to go about it?
And last but not least is there any need to use sync lock when the shared resource is in effect read only [meaning the program will read the value but will not change it during runtime]
WinForms - Writing To File In MultiThreaded App Fails
Jul 11, 2011I have a multi threaded app that writes log to file. occasionally, saving fails using this code:
Friend Sub SaveToText(ByVal FileName As String, ByVal Text As String)
'// create a writer and open the file
Dim objLock As New Object
SyncLock objLock
Dim tw As TextWriter = Nothing
[Code] .....
The error message I get:
The process cannot access the file 'error.log' because it is being used by another process.
Application Exit Without Exception?
Jan 25, 2012My application exits sometime without any exception. I am using loop in separate thread to read HID device.
Private Sub USBListenServer()
If (readHandle IsNot Nothing) AndAlso (Not readHandle.IsInvalid) Then
Try
[Code].....
Com Exception For Excel.Application?
Jan 2, 2012Com exception for Excel.Application?
View 3 RepliesRun Windows Application It Says That There Is An Inner Exception?
Mar 6, 2012When I try to run my windows application it says that there is an inner exception problem and I have no clue what this means,
View 3 RepliesCORRECTLY Implement A Multithreaded Progressbar During A LINQ Query?
Oct 31, 2011I have a linq query which loads approx. 1000 lines into a variable, during that process I want to display a progressbar, not necessarily stating the percentage, can be marquee style, doesnt matter.
This progressbar is on a modal form to precent the user from interacting with the app for the time the query's running.
[Code]...
Implement Multithreaded Crawler - Add A Unique Url To Each Thread To Go Process
Feb 1, 2010I would like to implement a mulithtreaded crawler using the single thread crawler code I have now. Basically I read the urls from a text file, take each one and crawl and parse it. I know how thread basics of creating a thread and assigning a process to it but not too sure how to implement in the following way:
I need at least 3 threads and need to assign a url to each thread from a list of urls, and then each needs to go and fetch it and parse it before adding contents to a database. [Code] Now the code maynot make sense but what I need to do is add a unique url to each thread to go process.
Add Application To Firewall Exception Through Regedit?
Feb 9, 2010Im trying to add my application to firewall exception through regedit but when i add the sub key it doesnt work.
I dont have to have an installer for a chat program because its only 1 file.
FireWall Dir:
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesSharedAccessParametersFirewallPolicyFirewall Rules
An Unhandled Exception Has Occurred In Application?
Jan 20, 2011An unhandled exception has occurred in your application??
View 3 RepliesApplication - Run It From The Exe In The Folder - Unhandled Exception
Feb 28, 2012I've been using it for three days, and tried to make my own application. Everything was going okay, it ran fine in the debugger and everything worked, so I assumed there would be no problems. But then when I went to run it from the exe in the folder, it shows me this:
Quote:
System.Threading.ThreadStateException: Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it.
at System.Windows.Forms.WebBrowserBase.OnHandleCreated(EventArgs e)
[CODE]............
I copied what I think to be the most important part of it. I've been searching around, and it says to do something with the main method, but I have no idea what that means.
JIT- Debugging - Unhandled Exception In My Application ?
Apr 18, 2010activating just In time (JIT) debugging-- I have a propmt that I have an unhandled exception in my application (??).
View 1 RepliesSystem.OutofMemory Exception In ASP.net Application
Mar 5, 2010I have a ASP.net 3.5 web application developed in VB.net I am using iTextsharp component to generate PDF document from the ASP.net page.
I am retreving the PDF documents stored in the db and merging them into one PDF. using the memorystream.
But when I try to merge around 1000 pdfs with each containing 2 pages, I am getting Outofmemory exception.
Unhandled Exception Has Occurred In Application?
Jan 2, 2011unhandled exception has occurred in your application
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