Here is my first attempt to solve crash issue in iOS app. Sharing some crash logs here.
Exception Type: SIGSEGV
Exception Codes: SEGV_ACCERR at 0x97ad6beb8
Crashed Thread: 11
Application Specific Information:
objc_msgSend() selector name: length
and here is my 11th thread.
Thread 11 Crashed:
0 libobjc.A.dylib 0x0000000180558150 objc_msgSend + 16
1 Foundation 0x00000001824f3f60 -[NSString compare:] + 28
2 Foundation 0x00000001824d88e0 _NSCompareObject + 60
3 CoreFoundation 0x0000000181a99bd0 __CFSimpleMergeSort + 88
4 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
5 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
6 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
7 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
8 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
9 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
10 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
11 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
12 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
13 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
14 CoreFoundation 0x0000000181a99c60 __CFSimpleMergeSort + 232
15 CoreFoundation 0x00000001819c585c CFSortIndexes + 460
16 CoreFoundation 0x00000001819c6f9c CFMergeSortArray + 372
17 Foundation 0x00000001824d80e8 _sortedObjectsUsingDescriptors + 568
18 Foundation 0x00000001825c64e0 -[NSSet(NSKeyValueSorting) sortedArrayUsingDescriptors:] + 536
19 Eikon 0x0000000100198b98 __51-[EIKNewsHeadlineStoreManager saveHeadlines:block:]_block_invoke (EIKNewsHeadlineStoreManager.m:67)
20 CoreData 0x0000000183e5e214 developerSubmittedBlockToNSManagedObjectContextPerform + 148
21 libdispatch.dylib 0x000000018099a9a0 _dispatch_client_callout + 12
22 libdispatch.dylib 0x00000001809a8ad4 _dispatch_queue_serial_drain + 924
23 libdispatch.dylib 0x000000018099e2cc _dispatch_queue_invoke + 880
24 libdispatch.dylib 0x00000001809a8fa8 _dispatch_queue_override_invoke + 340
25 libdispatch.dylib 0x00000001809aaa50 _dispatch_root_queue_drain + 536
26 libdispatch.dylib 0x00000001809aa7d0 _dispatch_worker_thread3 + 120
27 libsystem_pthread.dylib 0x0000000180ba31d0 _pthread_wqthread + 1092
28 libsystem_pthread.dylib 0x0000000180ba2d7c start_wqthread + 0
What i am trying to do is get some news headlines from server every 5 or 10 secs, sort them in some order using NSSortDescriptors and then store them in my CoreData. And that is what exactly saveHeadlines:block method is doing inside my class.
What exactly objc_msgSend() selector name: length
mean here? Any help is appreciated.
Note: Its a sporadic issue. When i test in simulator or my devices its not crashing. But some users of our app are reporting this crash.
Edited question: inside saveHeadlines:block method
__weak typeof(self) weakSelf = self;
[self.privateMOC performBlock:^{
NSMutableArray *newsTopics = [[EIKNewsTopicStoreManager managedObjectsInManagedObjectContext:self.privateMOC] mutableCopy];
[newsTopics addObjectsFromArray:[EIKNewsTopicStoreManager topicsManagedObjectForNewsFeedInContext:self.privateMOC]];
weakSelf.storedHeadlines = [NSMutableSet set];
for (NSManagedObject *storedTopic in newsTopics) {
[weakSelf.storedHeadlines addObjectsFromArray:[[storedTopic valueForKey:EIKFeedTopicRelationshipItems] allObjects]];
}
NSArray *sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:EIKNewsHeadlineAttributeHeadlineId ascending:YES]];
NSArray *orderedItems = [items sortedArrayUsingDescriptors:sortDescriptors];
NSArray *orderedHeadlines = [weakSelf.storedHeadlines sortedArrayUsingDescriptors:sortDescriptors];
And the crash is happening on the last line. i.e
NSArray *orderedHeadlines = [weakSelf.storedHeadlines sortedArrayUsingDescriptors:sortDescriptors];
Not able to figure out why.!
My NSManagedObjectContext is initialised like this[i.e privateMOC as shown in above code]
NSManagedObjectContext *confinementContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
