My app includes crash reporting library that using NSSetUncaughtExceptionHandler in order to catch the crashes.
I need to implement custom action (log crash and display alert view) before\after the crash reporting implementation.
To achieve this behavior, first I'm keep a reference to previous UncaughtExceptionHandler using NSGetUncaughtExceptionHandler(), and than registering my custom exception handler and signals handler. In my custom handler I tried to execute previous handler before\after my custom actions, but this throws a signal SIGABRT for previousHandler(exception) (in both cases).
Here is the code example :
static NSUncaughtExceptionHandler *previousHandler;
void InstallUncaughtExceptionHandler()
{
// keep reference to previous handler
previousHandler = NSGetUncaughtExceptionHandler();
// register my custom exception handler
NSSetUncaughtExceptionHandler(&HandleException);
signal(SIGABRT, SignalHandler);
signal(SIGILL, SignalHandler);
signal(SIGSEGV, SignalHandler);
signal(SIGFPE, SignalHandler);
signal(SIGBUS, SignalHandler);
signal(SIGPIPE, SignalHandler);
}
void HandleException(NSException *exception)
{
// execute previous handler
previousHandler(exception);
// my custom actions
}
void SignalHandler(int signal)
{
NSLog(#"SignalHandler");
}
How can I execute previous handler without throws a signal ?
Any ideas why SignalHandler doesn't called when system throws a signal ?
Don't register the signal handlers. I have to obfuscate a bit the code presented below, but it's from a production app that's on the App Store:
AppDelegate application:didFinishLaunchingWithOptions:
fabricHandler = NSGetUncaughtExceptionHandler();
NSSetUncaughtExceptionHandler(&customUncaughtExceptionHandler);
Handler:
void customUncaughtExceptionHandler(NSException *exception) {
// Custom handling
if (fabricHandler) {
fabricHandler(exception);
}
}
The PreviousSignalHandler might
1) Reset all set signal handlers
2) Call abort
One of the reasons it will abort.
So you can do all the stuff you want to do and call the previous handler.
HTH
Related
The iOS ATT Alert needs to be shown on startup before an app starts, so the remaining app code needs to be run in the completion handler (eg initialising advert code and starting the main game).
However, this crashes because the completion handler callback is not on the main thread (after the alert is actually shown and Allow or Ask App Not to Track is selected).
In iOS (Xamarin C# code):
public override void OnActivated(UIApplication application) // RequestTrackingAuthorization must be called when app is Active
{
if (!this.shownAlert)
{
this.shownAlert=true;
Debug.WriteLine("1) ThreadId={0}", Environment.CurrentManagedThreadId); // ThreadId=1
ATTrackingManager.RequestTrackingAuthorization(delegate (ATTrackingManagerAuthorizationStatus trackingManagerAuthorizationStatus)
{
Debug.WriteLine("2) ThreadId={0}", Environment.CurrentManagedThreadId); // ThreadId=7
});
}
}
Prints:
1) ThreadId=1
2) ThreadId=7
And the similarly in Unity:
Debug.WriteLine("1) ThreadId={0}", Environment.CurrentManagedThreadId); // ThreadId=1
ATTrackingStatusBinding.RequestAuthorizationTracking(delegate (int status)
{
Debug.WriteLine("2) ThreadId={0}", Environment.CurrentManagedThreadId); // ThreadId=4
});
This seems like a bug to me. So how do all the apps and games out there get this to work? Somehow switch to the main thread in the callback? I don’t see any examples of this.
I have a callback handler registered that listens to changes in the iOS Address Book.This is how I register the callback
ABAddressBookRegisterExternalChangeCallback(address_book, adressBookChanged,self);
What I want is to perform all the commutation in background thread when callback method is called.This is how I structured my callback :
void adressBookChanged(ABAddressBookRef ab, CFDictionaryRef info, void
*context)
{
//Perform all commutation in background thread
}
As we can not use one addressbook ref in multiple threads .How can I perform this.Please help me out what I am doing wrong?
I am developing an app in swift. I integrated test-flight SDK for remote logging. Now I want to use other test-flgiht SDK provided features. One of them is crash reporting. In the test-flight provided sample code c functions are there. How can I implement those c calls
The sample code test-flight provided
/*
My Apps Custom uncaught exception catcher, we do special stuff here, and TestFlight takes care of the rest
*/
void HandleExceptions(NSException *exception) {
NSLog(#"This is where we save the application data during a exception");
// Save application data on crash
}
/*
My Apps Custom signal catcher, we do special stuff here, and TestFlight takes care of the rest
*/
void SignalHandler(int sig) {
NSLog(#"This is where we save the application data during a signal");
// Save application data on crash
}
-(BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// installs HandleExceptions as the Uncaught Exception Handler
NSSetUncaughtExceptionHandler(&HandleExceptions);
// create the signal action structure
struct sigaction newSignalAction;
// initialize the signal action structure
memset(&newSignalAction, 0, sizeof(newSignalAction));
// set SignalHandler as the handler in the signal action structure
newSignalAction.sa_handler = &SignalHandler;
// set SignalHandler as the handlers for SIGABRT, SIGILL and SIGBUS
sigaction(SIGABRT, &newSignalAction, NULL);
sigaction(SIGILL, &newSignalAction, NULL);
sigaction(SIGBUS, &newSignalAction, NULL);
// Call takeOff after install your own unhandled exception and signal handlers
[TestFlight takeOff:#"Insert your Application Token here"];
// continue with your application initialization
}
Link for the above code:http://help.testflightapp.com/customer/portal/articles/829558-how-do-i-implement-crash-reporting-
Any help would be appreciated.
I am using a ListField Control to display data returned from xml webservice. I want to refresh the ListField or the screen every minute to update the ListField with new records or data.
I tried using the code below but it is not working properly (It is hanging).
public MyApp() {
// Push a screen onto the UI stack for rendering.
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
UiApplication.getUiApplication().pushScreen(new MyScreen());
}
},5000,true);
}
ResponseHandler handler = new ResponseHandler();
ListField listUsers = new ListField(handler.getItem().size());
public MyScreen() {
setTitle("yQAforum");
//Fetch the xml from the web service
String wsReturnString = GlobalV.Fetch_Webservice("myDs");
//Parse returned xml
SAXParserImpl saxparser = new SAXParserImpl();
ByteArrayInputStream stream = new ByteArrayInputStream(wsReturnString.getBytes());
try {
saxparser.parse( stream, handler );
}
catch ( Exception e ) {
response.setText( "Unable to parse response.");
}
//Return vector sze from the handler class
listUsers.setSize(handler.getItem().size());
listUsers.setCallback(this);
listUsers.setEmptyString("No Users found", 0);
add(listUsers);
}
You are attempting to fetch data from your webservice on the UI thread. That's almost always the wrong thing to do.
The UI thread (also known as the main thread) is responsible for drawing the UI, and tracking user actions, like touches, or navigation via a trackpad/trackball. If the UI thread is blocked waiting for a remote web server to respond, it cannot service the UI.
There's a couple changes you should make:
public MyApp() {
// Push a screen onto the UI stack for rendering.
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
UiApplication.getUiApplication().pushScreen(new MyScreen());
}
},5000,true);
}
should be changed to
public MyApp() {
// Push a screen onto the UI stack for rendering.
pushScreen(new MyScreen());
}
The MyApp() constructor will already be called on the UI thread, so there is no need to use invokeLater() to perform the pushScreen() call on the UI thread. It already will be called on the UI thread, if run from within the MyApp constructor. Also, the 5000 msec delay isn't really helpful. This will just delay the startup of your app by 5 seconds, which users will hate.
If you are trying to implement a splash screen, or something similar, when the app starts up, please search stack overflow for "BlackBerry splash screen", and I'm sure you'll find results.
Now, once your MyScreen class is created, you should take care not to fetch web service results from the UI thread. The MyScreen constructor will be run on the UI thread. If you want, you can initiate a web service request on a background thread, once the screen is shown. One way to do that is to use onUiEngineAttached():
protected void onUiEngineAttached(boolean attached) {
if (attached) {
// TODO: you might want to show some sort of animated
// progress UI here, so the user knows you are fetching data
Timer timer = new Timer();
// schedule the web service task to run every minute
timer.schedule(new WebServiceTask(), 0, 60*1000);
}
}
public MyScreen() {
setTitle("yQAforum");
listUsers.setEmptyString("No Users found", 0);
listUsers.setCallback(this);
add(listUsers);
}
private class WebServiceTask extends TimerTask {
public void run() {
//Fetch the xml from the web service
String wsReturnString = GlobalV.Fetch_Webservice("myDs");
//Parse returned xml
SAXParserImpl saxparser = new SAXParserImpl();
ByteArrayInputStream stream = new ByteArrayInputStream(wsReturnString.getBytes());
try {
saxparser.parse( stream, handler );
}
catch ( Exception e ) {
response.setText( "Unable to parse response.");
}
// now, update the UI back on the UI thread:
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
// TODO: record the currently selected, or focused, row
//Return vector sze from the handler class
listUsers.setSize(handler.getItem().size());
// Note: if you don't see the list content update, you might need to call
// listUsers.invalidate();
// here to force a refresh. I can't remember if calling setSize() is enough.
// TODO: set the previously selected, or focused, row
}
});
}
}
You'll need to add some error handling, in case the web service doesn't respond, or takes longer than a minute (you wouldn't want to be making a new request, if the last one hadn't finished).
But, this should get you started.
Note: once you fix the problem with running network code on the UI thread, you may still find that your code doesn't work. There could be problems fetching the web service data. You'll have to debug that. I am only showing you one problem with the code posted. If you still have problems with the web service fetch, post another question (with the UI thread problem fixed). Thanks.
I have an app that is listening in background and when the user clicks "send" it displays a dialogue. However I need to bring my app to foreground so the user answers some questions before letting the message go. but I haven't been able to do this, this is the code in my SendListener:
SendListener sl = new SendListener(){
public boolean sendMessage(Message msg){
Dialog myDialog = new Dialog(Dialog.D_OK,
"message from within SendListener",
Dialog.OK,Bitmap.getPredefinedBitmap(Bitmap.EXCLAMATION),
Dialog.GLOBAL_STATUS)
{
//Override inHolster to prevent the Dialog from being dismissed
//when a user holsters their BlackBerry. This can
//cause a deadlock situation as the Messages
//application tries to save a draft of the message
//while the SendListener is waiting for the user to
//dismiss the Dialog.
public void inHolster()
{
}
};
//Obtain the application triggering the SendListener.
Application currentApp = Application.getApplication();
//Detect if the application is a UiApplication (has a GUI).
if( currentApp instanceof UiApplication )
{
//The sendMessage method is being triggered from
//within a UiApplication.
//Display the dialog using is show method.
myDialog.show();
App.requestForeground();
}
else
{
//The sendMessage method is being triggered from
// within an application (background application).
Ui.getUiEngine().pushGlobalScreen( myDialog, 1,
UiEngine.GLOBAL_MODAL );
}
return true;
}
};
store.addSendListener(sl);
App is an object I created above:
Application App = Application.getApplication();
I have also tried to invoke the App to foreground using its processID but so far no luck.
i have managed to achieve something similar to what you're describing but the difference is, my dialogs are displayed asynchronously, which might actually be easier... so in your case..
the first i could suggest you try is get the event lock before pushing the screen, ala:
synchronized(Application.getEventLock()){
final UiEngine ui = Ui.getUiEngine();
ui.pushGlobalScreen(theScreen, 1, UiEngine.GLOBAL_MODAL);
}
I would also just create a custom class of type MainScreen and push that instead of plain Dialog.
There, that's better (now with code formatting).
public class MYSendListener implements SendListener {
private UiApplication _myApp;
public MySendListener(UiApplication myApp) {
_myApp = myApp;
}
public boolean sendMessage(Message m) {
...
_myApp.requestForeground();
}
}
Cache your app instance inside your send listener when you construct it, and use that when sendMessage is fired.
Application.getApplication() only gets you the app of the calling thread.