How to find, where is the crash happen - ios - ios

Question

I'm running my ios app in ipad 1, the following crash happen sometime while app is running, i don't know where the crash happen. This mostly happen in ios 5.1.1 . Here the crash log,
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0xf0000008
Crashed Thread: 0
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libobjc.A.dylib 0x3387ef78 objc_msgSend + 16
1 UIKit 0x333ffa3a -[UIViewController unloadViewForced:] + 254
2 UIKit 0x335473a6 -[UIViewController purgeMemoryForReason:] + 58
3 Foundation 0x3507a4f8 __57-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_0 + 12
4 CoreFoundation 0x35c2c540 ___CFXNotificationPost_block_invoke_0 + 64
5 CoreFoundation 0x35bb8090 _CFXNotificationPost + 1400
6 Foundation 0x34fee3e4 -[NSNotificationCenter postNotificationName:object:userInfo:] + 60
7 Foundation 0x34fefc14 -[NSNotificationCenter postNotificationName:object:] + 24
8 UIKit 0x335120e6 -[UIApplication _performMemoryWarning] + 74
9 UIKit 0x335121e0 -[UIApplication _receivedMemoryNotification] + 168
10 libdispatch.dylib 0x33ffb252 _dispatch_source_invoke + 510
11 libdispatch.dylib 0x33ff8b1e _dispatch_queue_invoke$VARIANT$up + 42
12 libdispatch.dylib 0x33ff8e64 _dispatch_main_queue_callback_4CF$VARIANT$up + 152
13 CoreFoundation 0x35c332a6 __CFRunLoopRun + 1262
14 CoreFoundation 0x35bb649e CFRunLoopRunSpecific + 294
15 CoreFoundation 0x35bb6366 CFRunLoopRunInMode + 98
16 GraphicsServices 0x33951432 GSEventRunModal + 130
17 UIKit 0x3338ecce UIApplicationMain + 1074
18 MY Game 0x00079a90 0x75000 + 19088
19 MY Game 0x00079a50 0x75000 + 19024
As i understand from crash log, crash not happen due to my code. It's due low memory. Is that correct? How to find where the crash happen? Any suggestions.

Answer 1

As i understand from crash log, crash not happen due to my code. It's due low memory. Is that correct?
No, that's not correct.
Low memory is being reported, but your view controller is not responding properly. The most common cause of this is a retain cycle - see UIViewController purgeMemoryForReason: Crashing on iOS 5. In that answer, the retain cycle is in SVPullToRefresh , but yours could be elsewhere. The most common cause of retain cycles is not setting a delegate property to weak.
Once you figure out where the issue is, you can set breakpoints in viewDidUnload and ``didReceiveMemoryWarning`, simulate a memory warning, and step through your code to find the error.
Symbolication
Additionally, this crash report isn't symbolicated. Typically you'll want to symbolicate your crash report first. For example, see these lines:
18 MY Game 0x00079a90 0x75000 + 19088
19 MY Game 0x00079a50 0x75000 + 19024
In this case, as pointed out by Kerni, those two will just show start and main, so they won't help you in this instance. But generally, you should symbolicate your crash reports. (Search for "Xccode symbolicate crash logs" if you don't know how to do this.)