I am working on an iPhone application which is crashing after the routine tied to a button call is completed. I am popping the view which is at position index 1 on the navigation controller stack. The current view on which i clicked the button is on index 5.
The code I use for popping the view is as follows:
id callListController = [[self.navigationController viewControllers] objectAtIndex:1];
if(nil != callListController)
{
[self.navigationController popToViewController:callListController animated:YES];
}
I have tried setting break points in the above code and also in the code of the view to be loaded at index 1. Nothing works. Something is happening in between.
I used the crash report from the iphone (symbolicated) to analyze the issue. Honestly, I cannot make sense of symbolicated file. Here is the dump of main portion of the file since I could not attach with this questionnaire:
Incident Identifier: BDE0FFE7-D74F-46B5-A9BD-89AA4F483300
CrashReporter Key: fbe272c09f9d46b3e962f897e0d8a5e3de9793e1
Hardware Model: iPhone1,2
Process: iwf [151]
Path: /var/mobile/Applications/F50D0AED-94A4-48A8-8B5D-0D88B2D4D36F/iwf.app/iwf
Identifier: iwf
Version: ??? (???)
Code Type: ARM (Native)
Parent Process: launchd [1]
Date/Time: 2011-02-22 20:43:10.614 -0700
OS Version: iPhone OS 4.0.1 (8A306)
Report Version: 104
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x00000000, 0x00000000
Crashed Thread: 0
Thread 0 Crashed:
0 libSystem.B.dylib 0x00088c24 __kill + 8
1 libSystem.B.dylib 0x00088c12 kill + 4
2 libSystem.B.dylib 0x00088c06 raise + 10
3 libSystem.B.dylib 0x0009f902 abort + 54
4 libSystem.B.dylib 0x0008e6de szone_error + 230
5 libSystem.B.dylib 0x0008e7ac free_tiny_botch + 60
6 libSystem.B.dylib 0x00001fe8 szone_free + 302
7 libSystem.B.dylib 0x00001ea0 malloc_zone_free + 64
8 CoreFoundation 0x00053cc8 __CFAllocatorSystemDeallocate + 8
9 CoreFoundation 0x000019d6 CFAllocatorDeallocate + 74
10 CoreFoundation 0x000036c4 _CFRelease + 288
11 CoreFoundation 0x00003566 CFRelease + 74
12 CoreFoundation 0x00015898 _CFAutoreleasePoolPop + 124
13 Foundation 0x00004822 -[NSAutoreleasePool release] + 98
14 UIKit 0x0007bc18 _UIApplicationHandleEvent + 7776
15 GraphicsServices 0x00004edc PurpleEventCallback + 1024
16 CoreFoundation 0x000742ac __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 22
17 CoreFoundation 0x000761d6 __CFRunLoopDoSource1 + 158
18 CoreFoundation 0x0007718e __CFRunLoopRun + 574
19 CoreFoundation 0x0001e0bc CFRunLoopRunSpecific + 220
20 CoreFoundation 0x0001dfca CFRunLoopRunInMode + 54
21 GraphicsServices 0x00003f88 GSEventRunModal + 188
22 UIKit 0x00007b40 -[UIApplication _run] + 564
23 UIKit 0x00005fb8 UIApplicationMain + 964
24 iwf 0x0000d434 main (main.m:14)
25 iwf 0x0000d404 start + 32
Thread 1:
0 libSystem.B.dylib 0x00034e84 kevent + 24
1 libSystem.B.dylib 0x00102a48 _dispatch_mgr_invoke + 88
2 libSystem.B.dylib 0x00102494 _dispatch_queue_invoke + 96
3 libSystem.B.dylib 0x00102634 _dispatch_worker_thread2 + 120
4 libSystem.B.dylib 0x0008b53c _pthread_wqthread + 392
5 libSystem.B.dylib 0x00082b6c start_wqthread + 0
Thread 2:
0 libSystem.B.dylib 0x00000ab0 mach_msg_trap + 20
1 libSystem.B.dylib 0x00002f94 mach_msg + 60
2 CoreFoundation 0x00074b18 __CFRunLoopServiceMachPort + 88
3 CoreFoundation 0x000770e0 __CFRunLoopRun + 400
4 CoreFoundation 0x0001e0bc CFRunLoopRunSpecific + 220
5 CoreFoundation 0x0001dfca CFRunLoopRunInMode + 54
6 WebCore 0x0000370c RunWebThread(void*) + 552
7 libSystem.B.dylib 0x0008af80 _pthread_start + 364
8 libSystem.B.dylib 0x0007d014 thread_start + 0
Thread 3:
0 libSystem.B.dylib 0x00000ab0 mach_msg_trap + 20
1 libSystem.B.dylib 0x00002f94 mach_msg + 60
2 CoreFoundation 0x00074b18 __CFRunLoopServiceMachPort + 88
3 CoreFoundation 0x000770e0 __CFRunLoopRun + 400
4 CoreFoundation 0x0001e0bc CFRunLoopRunSpecific + 220
5 CoreFoundation 0x0001dfca CFRunLoopRunInMode + 54
6 Foundation 0x0003c316 +[NSURLConnection(NSURLConnectionReallyInternal) _resourceLoadLoop:] + 210
7 Foundation 0x0000c612 -[NSThread main] + 42
8 Foundation 0x00092140 __NSThread__main__ + 908
9 libSystem.B.dylib 0x0008af80 _pthread_start + 364
10 libSystem.B.dylib 0x0007d014 thread_start + 0
Thread 4:
0 libSystem.B.dylib 0x00029f24 select$DARWIN_EXTSN + 20
1 CoreFoundation 0x0007aa54 __CFSocketManager + 340
2 libSystem.B.dylib 0x0008af80 _pthread_start + 364
3 libSystem.B.dylib 0x0007d014 thread_start + 0
Thread 5:
0 libSystem.B.dylib 0x0008c3b4 __workq_kernreturn + 8
1 libSystem.B.dylib 0x0008b718 _pthread_wqthread + 868
2 libSystem.B.dylib 0x00082b6c start_wqthread + 0
Thread 6:
0 libSystem.B.dylib 0x0008c3b4 __workq_kernreturn + 8
1 libSystem.B.dylib 0x0008b718 _pthread_wqthread + 868
2 libSystem.B.dylib 0x00082b6c start_wqthread + 0
Thread 0 crashed with ARM Thread State:
r0: 0x00000000 r1: 0x00000000 r2: 0x00000001 r3: 0x3e73926c
r4: 0x00000006 r5: 0x067a9e50 r6: 0x0013f000 r7: 0x2fffe464
r8: 0x05559084 r9: 0x00000888 r10: 0x00000001 r11: 0x0013f000
ip: 0x00000025 sp: 0x2fffe464 lr: 0x3483fc19 pc: 0x3483fc24
cpsr: 0x000f0010
I have a basic understanding that this error is happening when I shift views but I am little lost at this point.
Any advice will be helpful.
Thanks in advance.
Subbu
As Izzy said, this is usually caused by releasing an autorelease object, a pretty common problem until you get a handle on memory management in Objective-C.
If you are not sure specifically where to look for the problem, you might want to start by commenting out all of the releases in viewWillDisappear/dealloc in your views, and assuming it works without crashing, start to put back in the releases until you narrow down an ivar that is causing a problem. Most likely, you will find that the ivar is given an object that is an autorelease object, so you will either not release the object, retain the object, or use a method that gives you back a retained object.
Check this link for more background:
http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/MemoryMgmt/Articles/mmObjectOwnership.html