{using Qt 4.7.0, Windows Xp, Visual Studio 2005}
hi, i've develope a Qt console project to implement a protocol which is up and running on the intended product for quite sometime now. But recently a problem has come up. The application is never meant to shutdown so there is nothing to quit it from inside the application. What it does is it implements a new thread for each client connection on the developed protocol and when the client disconnects, it ends the thread and continues polling for new connections, which is all fine. Now when the tester runs it in debug mode the console window pops up showing the logs of the ongoing activities. The problem is when this console window is manually closed it gives an error the instruction at 0xwhatever referenced memory at 0xwhatever which could not be read. Click Ok to terminate. I've identified this problem and it comes because one of the shutdown functions is not called.
How do i call this custom shutdown function whenever the application is closed in such a way? (by the way, if one "ends process" in the task manager this problem does not pop up and that's why the release mode shutdowns are always fine as they don't pop up a console window and only way to do is is through task manager)
p.s: i have tried using QCoreApplication's aboutToQuit() signal to call a custom slot which calls the shutdown functions indicated above. This does not seem to work. I don't know if the signal is fired up in such application shutdown events.
Related
When my spring aplication come up and makes an attempt to issue any command using send method NoHandlerForCommandException is observed. This exception is observed just after the startup of the application and after a few moments it can find the handler and everything works as expected.
How can I know if the command bus and all other command handling components are setup before initiating any command?
I have read somewhere on stackoverflow that in coming version of Axon Framework an event would be emitted after setting up or after receiving the start signal from command handling configuration, has that been introduced?
I believe the issue you are talking about is this one which is not done yet but you can follow it up there.
To your problem, the only way to do that right now is to wait a few seconds before you start your testing (not the best approach).
There are ways to check using Axon Server API if the command handlers are already registered there or not but that's not an easy task and not beautiful as well so I would stick with the wait approach by now until it gets properly fixed.
I am working on an app which has the web component (visited via browser) and background task processing component, to which web component delegates some long running stuff.
I've just hit an issue when I refreshed my web browser only to find it loading indefinitely (first spotted in AJAX, but later in normal request).
It did not really look apparent but as soon as I shut down the background Symfony command which also utilizes EntityManager the browser get unblocked and proceeds with request.
My app uses RabbitMQ to store job requests which are publish by web component. The Symfony command uses the same "backbone" to create RabbitMQ consumer and take consume those jobs.
I tried, without any result:
Restarting Apache
Restating RabbitMQ
Purging RabbitMQ queue
Using different EntityManagers for web and command
I use OldSoundRabbitMqBundle (link) to facilitate communication between those two.
The web component gets stuck regardless of action being called (not related to RabbitMQ producer).
Has anyone stumbled upon similar issue?
This happens on dev box, I haven't got around giving it a spin on a production server, nor would I until I find out more about this.
It would seem that I misused the locking mechanism in Postgres. Indeed the task processing component is a long-running task, but given that it is Symfony command, Doctrine connection is being established as early as possible.
Now comes the tricky part: I used the LOCK TABLE statement to lock some tables away from concurrent access (EXCLUSIVE type). Without closing the connection (not entity manager), those locks are left intact, until I restart the command (every 10th task).
This was the root cause.
I am still investigating some edge-cases, but since I moved away to advisory locking, I had no more lock-ups.
I am trying to construct a simple windows workflow to monitor a directory for inbound files and do some DB updates using Windows WF 4.0. Currently I am planning to build a 'WCF Workflow Service' and host it as a 'Windows service' running 24/7 (with a daily service shutdown and startup).
Further in the future I am planning to consume this service using an ASP.NET/WPF application to create a basic dashboard kind of stuff.
Considering the idea of directory polling for files with WF hosted on windows service, does it seems to be a good idea? What can be the cons of this?
Please advice if there are any drawbacks on this or can this achieved by better means?
I'm actually doing this, but it is a bit more complex than you think, and should be avoided if possible.
You should not be blocking from within an Activity; if it is expected to be a long running Activity that is waiting from input from the outside (FileSystemWatcher event, for instance), the workflow should idle itself and wait to be woken from the outside.
How I did this was I created a workflow extension that hosted the FileSystemWatcher. Once the Activity was ready to watch for a file, it created a bookmark and passed it to the extension.
The extension then started the FSW, holding onto the bookmark.
When a FSW event was fired, the extension resumed the bookmark, passing in an object that contained details about the event. The Activity did what was needed with the event, then re-scheduled itself.
Normally I wouldn't have done this, but I had some requirements that forced me to use WF4 to accomplish this goal. If I didn't have to use WF4, I would have just spun up the FSW within the service and consumed the events.
Unless you expect to have to be very flexible with your configuration detailing what you do with the FSW event, and expect this to change relatively often during deployment of the service, I'd skip WF4.
When i run it in Flash Builder (debug mode) the remote object called successfully. but whenever i build the application (AIR application), then the remote object will return no result nor fault, the busy cursor is showing about 3 seconds. then no clue at all.
Any idea how to get advance fault or something than regular fault event or result event?
or anyone have the same experience?
UPDATE:
Actually it was failed only for ONE service method, for other method (some of them took longer time to call) the service call is work fine.
CASE SOLVED
So the problem was not on the service call, but on my result conversion that cause the advanced datagrid failed to render.
Best regards
ktutnik.
Try using a software like Charles to see what happens during the network call.
NativeApplication.nativeApplication.exit(); - this method is used for exit the application of flex/air .
application.close(); - this method also used for exit the application of flex/air -
So what is different?
He is referring to NativeApplication.exit() vs WindowedApplication.close().
WindowedApplication.close() Closes the
application's NativeWindow (the
initial native window opened by the
application). This action is
cancelable.
Calling close() on the application window will effectively shut down the application, but using the exit() method on NativeApplication is the proper way to terminate it. See the following link for more info:
http://livedocs.adobe.com/flex/3/html/help.html?content=app_launch_1.html
I am not sure I am understanding your question entirely because I am not finding an application.close() method.
Here is the documentation on NativeApplication, an AIR only class: http://livedocs.adobe.com/flex/3/langref/flash/desktop/NativeApplication.html#exit()
It defines the exit method like this:
Terminates this application.
The call to the exit() method will
return; the shutdown sequence does not
begin until the currently executing
code (such as a current event handler)
has completed. Pending asynchronous
operations are canceled and may or may
not complete.
Note that an exiting event is not
dispatched. If an exiting event is
required by application logic, call
NativeApplication.nativeApplication.dispatchEvent(),
passing in an Event object of type
exiting. Likewise, closing and close
events are not dispatched before
application windows are closed. If
windows should be notified before your
application exits, you can dispatch
closing events for each open window.
If a window close event is required,
call the window's close() method
before exiting.
Here is the documetation on Application, a Flex class: http://livedocs.adobe.com/flex/3/langref/mx/core/Application.html#methodSummary
It does not seem to have a close() method associated with it. Are you possibly confusing the application class with a window class that you need to close before calling the NativeApplication.nativeApplication.exit() ?
I would be happy to help you research this further if you can clarify the question.
One completely exits the application, the other only closes the main window. It's important to understand the difference. On a Mac, for instance, closing all of an application's windows often leaves that application running in the dock. This is rarely the case on Windows, but if you have a dock icon, you should get similar behavior, I think.