BackgroundWorker Thread in IIS7 - FAIL! - iis

Just wondering if anyone has had any trouble using a BackgroundWorker Thread in a site running under IIS 7 in Integrated Pipeline mode?
I am trying to use such a beast to update the database schema (admin function, obviously), and it works perfectly in Cassini, but when I deploy to IIS 7, the thread gets about one line of code in and silently ends. Is there a way to tell why a thread ended?
Thanks in advance.

It is probably an exception. Perhaps you're running with different set of rights between the two environments.

I don't know but I have to ask: why do you use BackgroundWorker in first place? Its main purpose is to ease the threading on UI elements.
Instead why don't you use a "normal" thread or any other non-UI mechanism?

You do not want to use BackgroundWorker, Thomas from ASP.NET team just posted some information about executing code in separate threads in ASP.NET: http://blogs.msdn.com/tmarq/archive/2010/04/14/performing-asynchronous-work-or-tasks-in-asp-net-applications.aspx

Related

Consequences of not calling WSACleanup

I'm in the process of designing an application that will run on a headless Windows CE 6.0 device. The idea is to make an application that will be started at startup and run until powered off. (Basically it will look like a service, but an application is easier to debug without the complete hassle to stop/deploy/start/attach to process procedure)
My concern is what will happen during development. If I debug/deploy the application I see no way of closing it in a friendly and easy way. (Feel free to suggest if this can be done in a better/user friendly way) I will just stop the debugger and the result will be WSACleanup is not called.
Now, the question. What is the consequence of not calling WSACleanup? Will I be able to start and run the winsock application again using the debugger? Or will there be a resource leak preventing me to do so?
Thanks in advance,
Jef
I think that Harry Johnston comment is correct.
Even if your application has no UI you can find a way to close it gracefully. I suppose that you have one or more threads in loops, you can add a named manual reset event that is checked (or can be used for waits instead of Sleep()) inside the loop condition and build a small application that opens the event using the same name, sets it and quits. This would force also your service app to close.
It may not be needed for debugging, but it may be useful also if you'll need to update your software and this requires that your main service is not running.

How to run the timer tasks asynchronously?

Hi am developing a windows phone 8 app using C# and xaml.
My previous team has developed some code, they have used many methods in timer control.
when it is updating all the methods are calling and its blocking the UI.
Is there any another way to use the timers asynchronously so that the UI can not be blocked.
Thanks in advance
you should use the "xaml binding" to updating the UI
There are several Timer classes in Windows Phone.
System.Windows.Threading.DispatcherTimer: runs on UI thread and makes UI unresponsive when executed.
System.Threading.Timer: executes on a ThreadPool thread, therefore can not update UI directly. For an example how to make a cross-thread call to update UI, see the example in the link.
There is also a ThreadPoolTimer, seems it works like a System.Threading.Timer - runs on ThreadPool thread, just has different methods. But I have not used it.
So to answer your question, if a timer event blocks UI, then it is likely a DispatcherTimer, replace it with System.Threading.Timer, reference the code sample in the previous link.
Did you try using the DispatcherTimer?
How to Increment timer asynchronously ?
Or else you could go with the CountdownTimer.
How do you run a synchronous timer in C#?
as #kennyzx said there are many ways to do it, but the choice is yours.
a sample on CountdownTimer from the Toolkit

Asynchronous call of inprocess COM-DLL from VSTO Excel Addin?

I am developing an application level VSTO 4 Addin for Microsoft Excel 2007 / 2010.
The result is a windows forms based DLL using .Net 4 Client Profile.
Now I have to use a legacy COM-DLL. It is no problem to set the reference and access the COM-Methods via COM-Interop from .Net.
But the the (synchronous) method I need to call can take a minute or longer to get back.
I know your answer:
Use a worker thread...
I have used The Task Parallel Library to put the long lasting operation in a worker task and keep the GUI (Excel) responding.
But: The inprocess COM-Call (in the worker task/thread) still seems to block my GUI-Thread.
Why? Is it because Excel is always running as STA (Single Thread
Apartment)?
How can I keep the Excel GUI responding?
Is there a way to make it really asynchronous?
Thanks for any answers,
Jörg
Finally, I've found an answer to this topic:
I've readed a lot about COM Threading Models and then spoke to the developer of the COM-DLL I am calling as an InProc-Server.
Together we changed the threading model of the COM-DLL:
OLD (blocking): Single-Threaded Apartment (STA), (ThreadingModel=Apartment)
NEW (working): Multi-Threaded Apartment (MTA), (ThreadingModel=Free)
Since we have our own synchronization mechanisms in the COM-DLL, there are no problems caused by the missing synchronization via the standard Windows message queue.
Problem was, that even the UI Thread was idle and even if it did DoEvents, the important windows messages (WM_Paint, etc.) were not delivered.
Now they are. The UI is responding at every time and the call to the COM-DLL is still done in a worker thread (as mentioned above, it's a ThreadPool thread which is used by the Task Parallel Library).

Multithread Form Application (.NET 4.0)

I'm currently working on a solution that has two projects, a console and a form application. The console application is the main entry point to my application, and from the console the user would run the form application.
The problem is, when the user boots the form application the rest of the business logic (from the console app) won't run until the form is closed. My first thought was to use a background worker for the form, but the business logic in the form project already uses a background worker (and I only have two CPUs...). Perhaps this could be my ignorance for multithreading, but is there a way to do this?
Any thoughts are much appreciated!
Cheers
Well, this is pretty unusual. In general, it doesn't make a lot of sense to provide the user with a nice GUI and still leave a console window up and interactive.
But yes, calling Application.Run() or Form.ShowDialog() is going to block the thread. It has to, the message loop needs to be running to keep the GUI alive. If you do this, be sure to put the [STAThread] attribute on the Main() method.
The only other decent alternative is to start a thread. This isn't a problem, a UI thread doesn't burn any CPU cycles. Code only ever runs when the user does something, it's otherwise idle 99% of the time. Be sure to call the thread's SetApartmentState() method before you start it, STA is required.

worker process in IIS shared hosting

Can anyone tell me, is there a way to run a process in IIS shared hosting service.
Suppose, the scenario is like "I want to send emails to a list of email id's after everywhere 3 hrs", so the challenge here is the process should not be invoked by a HTTP link. It should be automatic.
I think we can do this by IIS worker processes.
Also this all will be happening on a shared server(like GoDaddy) in IIS7, .NET 3.5
Please anyone give me a direction.
Thanks in advance.
This question was asked ages ago, but for what it's worth - I ended up using Hangfire to handle my long running tasks in my ASP app.
You can easily configure it for shared hosting and then for a dedicated server if you can scale up / out according to your needs.
It's super easy to use, just follow the doc step by step.
Cheers,
Andrew
You should write and run this as a Windows service, assuming you have access to install a service.
You could run a background worker thread from your asp.net code-behind but the problem is that IIS will terminate the thread after it is idle for a relatively short period of time. I tried going this route, trying to geocode a list of addresses (800+, from a SharePoint list) and IIS kept timing out my thread and stopping it. We ended up going with adding events to the SharePoint list that would geocode when the item was changed/added to the list.
One other option you could look into is using Windows Workflow API, it was designed for this kind of thing.

Resources