Hi Joachim,
I really appreciate your response. Thank you very much!
Below my replies / notes:
Regarding tasks 179 and 172, I can confirm they are not sent to the same server. I haven't included them for privacy reasons. But for sure I could share the full trace with you privately.
About requests in general I cannot find a way to know where they were made using the network or handled by the local cache. Can you point me in the right direction in order to find such an information?
Finally, concerning the latest sentence I do not have clear what you mean with "take a closer look at the domain track for these tasks".
Since you are confirming those issues could be due to background state, I've started to implement a way to handle this using beginBackgroundTaskWithName:expirationHandler: and endBackgroundTask:.
In particular, when I need to perform a request, I create both a new background task identifier and session data task like the following.
// tell the system the work could continue in background
__block UIBackgroundTaskIdentifier backgroundTaskIdentifier = UIBackgroundTaskInvalid;
backgroundTaskIdentifier = [[UIApplication sharedApplication] beginBackgroundTaskWithName:taskName expirationHandler:^{
[self.internalLock lock];
for (NSURLSessionDataTask* dataTask in self.dataTasks) {
[dataTask cancel];
}
if ([self.dataTasks count] > 0) {
// manage failure here?
}
[self.dataTasks removeAllObjects];
[self.internalLock unlock];
cleanupBackgroundTaskIdentifier(backgroundTaskIdentifier);
}];
// create a data task to perform the request
__block NSURLSessionDataTask *task;
task = [self.urlSession dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
// handling the result here
cleanupBackgroundTaskIdentifier(backgroundTaskIdentifier);
sendResult(result);
[self.internalLock lock];
[self.dataTasks removeObject:task];
[self.internalLock unlock];
}];
[self.internalLock lock];
[self.dataTasks addObject:task];
[self.internalLock unlock];
task.taskDescription = taskName;
[task resume];
where
void(^cleanupBackgroundTaskIdentifier)(UIBackgroundTaskIdentifier) = ^void(UIBackgroundTaskIdentifier backgroundTaskIdentifier) {
[[UIApplication sharedApplication] endBackgroundTask:backgroundTaskIdentifier];
backgroundTaskIdentifier = UIBackgroundTaskInvalid;
};
It's a very old legacy code so I'm not sure this is the right way to handle such a scenario.
