How to implement an error monitoring in audio_service?
It runs in isolate, but none of methods available expose Isolate to add error listener. Thus is there any other method for hooking it to error monitoring platform like ex. sentry?
Good news and bad news.
When the UI isolate is present and initiates the method call to the background isolate, any exception generated by the background task will be forwarded to the UI isolate where you can create an error zone or use something like sentry. For example, an error thrown by onPlay in the background isolate will be forwarded and thrown by play in the main UI isolate.
However, when the UI isolate is not around, or the media notification initiates the method call to the background isolate, the exception will be caught and discarded internally.
Making the latter case an uncaught exception would make a good feature request. Although note that the next version of audio_service will run under a single isolate which would also solve the problem.
Related
Please explain to me what is the difference between them. Can they be used together or only separately?
FlutterError.onError is a method that allows you to hook into the Flutter framework's error-handling mechanism, so you can receive callbacks when an error occurs during the build, layout, or painting phases.
runZonedGuarded is a utility function that allows you to run a block of code in a new zone with a custom error handler. The onError parameter is the error handler that will be called if an error occurs within the zone.
So, in summary:
FlutterError.onError is specific to the Flutter framework and is used
to handle errors during the build, layout, and painting phases.
runZonedGuarded.onError is more general and allows you to run a block
of code in a new zone with a custom error handler, which can be used
for a wider range of error-handling needs.
Yes, FlutterError.onError and runZonedGuarded.onError can be used together in a Flutter application.
For example, you can use FlutterError.onError to handle errors that occur during the build, layout, or painting phases, and use runZonedGuarded.onError to handle errors that occur within a specific block of code.
In this way, you can have multiple error handlers in your Flutter application to handle different types of errors in different parts of the code.
I am developing an app in C++ that uses UIAutomation to receive notification of significant events related to user interaction. I have tried anevent handler by calling AddAutomationEventHandler to listened for window opened events, but I am having problems stopping the notification and cleaning up before exiting. If the user has launched certain applications, such as Firefox, the call to RemoveAutomationEventHandlerhangs. (Calling RemoveAllEventHandlers also hangs in this case.) Note that all calls to add or remove event handlers are done in the context of the same non-UI thread.
Note: I am seeing this behavior on Windows 7 and on Windows 8.
Any ideas on why this is happening or how to fix it? What makes the structure changed event different from all the others?
Window open/close events are implemented via the kernel WinEvent handlers; the structure change events involve the client app. Does your non-ui thread pump messages? UI Automation needs to pump messages to get cross-process communications working.
I want to put an Abort Label or button below...the processing message is shown in ZK. or is there any way to load my custom components instead of the default Processing. message in ZK.
Want will happen if do abort while processing is it ideal to do that, I want to do that anyways as few times my application sleeps while loading
ZK is built on Servlets. When the busy button is shown on the ui awaiting the ajax response then the servlet thread is doing long running work on the server. Perhaps it would be possible to send another thread to interrupt the first thread but really that is high risk as all the servlet threads can end up doing long running work and no new ones will be available to cancel them.
The best solution is that long running work should not be on the servlet thread but handed off to a background thread or message queue. See zk-asynchronous-ui-updates-and-background-processing. In that example the work is offloaded to a java.util.concurrent.ExecutorService which has an API to cancel the work.
Note that cancelling of a working thread uses interruption and it is not guaranteed that code which doing the work will respond to the interrupt properly such that it is actually cancellable. The answers on the thread cancel with executor service outline some of the issues and you should test whether the work you are doing can be interrupted using the API.
I find the Post notification and delegate function are very useful in iOS. Once I finish a task I can notify another piece of code to do something. I am sending out notices for others to do the work.
Post Notification is when you sending notice right away, whereas delegate sometime down the line it will send a notice.
In Android I know there's event Listener, but that's only passive listening. What about me actively sending notices? Does Android have that equivalent?
Handler which can be fired right away or with postDelay() you can fire them later
You could either use a Handler to get notified from a running Thread or the AsyncTask which does run some code and after it's finished it notifies the UI Thread.
You are probably looking for a way to thread your application? Where there are other "worker" threads that do long computations (or do buffered IO stuff). The way you would do this is by creating an AsyncTask. Within an AsyncTask, there is a "doInBackground" method that seems to be what "delegate" is in your question. "onPostExecute" will handle whatever's returned in "doInBackground". More in the AsyncTask documentation.
Another option is to simply use a Handler and use postDelay() for later executions:
Am new to android, am developing application with websevices using json parsing with httpget method,cant use http post method in android actually.
It working fine normally, but many time it shows the error on emulator like activity not responding force close activity.when i put that url in browser it shows the result .but i don't know why this activity not responding error came.
I think the httprequest took more time to retrieve the data from server,but am not sure. any one help me to how to avoid this error or how to minimize this .
I want know what are the possibilities to get this activity not responding error.
Thanks,
Lakshmanan
You need to perform blocking operations such as I/O in a separate thread - see the below linked resource:
http://developer.android.com/guide/practices/design/responsiveness.html:
In Android, the system guards against applications that are insufficiently responsive for a period of time by displaying a dialog to the user, called the Application Not Responding (ANR) dialog, shown at right in Figure 1. The user can choose to let the application continue, but the user won't appreciate having to act on this dialog every time he or she uses your application. It's critical to design responsiveness into your application, so that the system never has cause to display an ANR dialog to the user.
To avoid ANR (Application Not Responding) dialog,
Your business logic code is inside doBackground() of AsyncTask and You may also need to override onPostExecute(),etc. After that it is better to invoke the async task in a Service (bound or normal service).
Service:
(bound service or normal service based on your requirement)
From, android office documentation:
A service is "bound" when an application component binds to it by calling bindService(). A bound service offers a client-server interface that allows components to interact with the service, send requests, get results, and even do so across processes with interprocess communication (IPC). A bound service runs only as long as another application component is bound to it. Multiple components can bind to the service at once, but when all of them unbind, the service is destroyed.