how do i make sense of this crash report(SIGABRT)? Regarding parsing an xml file on another host computer + iPad

Question

Basically, imagine this. i have an iPad , a Windows computer with apache http server which is hosting an xml file, and a wifi network that connects them both together

The xml parser im using is NSXMLParser

in my - (void)parseXMLFileAtURL method this is my code

NSError * error;
NSURLResponse * response;    

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://%@/UserBedData.xml",[appDelegate.hostipadd objectAtIndex:0]]] cachePolicy :NSURLRequestReloadIgnoringCacheData timeoutInterval:6.0];
[request setHTTPMethod:@"GET"];
NSData * responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error] ;

xmlParser = [[[NSXMLParser alloc] initWithData:responseData] autorelease];

[xmlParser setDelegate:self];

// Depending on the XML document you're parsing, you may want to enable these features of NSXMLParser.
[xmlParser setShouldProcessNamespaces:NO];
[xmlParser setShouldReportNamespacePrefixes:NO];
[xmlParser setShouldResolveExternalEntities:NO];

[xmlParser parse];

If i have very little data in the xml file (which is on the windows computer) the parsing works fine and i would get the data and store them etc. After Parsing , i would request for another file which is a .php file that would when upon requested, delete('unlink') the xml file. Sort of for data consistancy. The method goes like this.

- (void)parserDidEndDocument:(NSXMLParser *)parser 

NSError * error;
NSURLResponse * response;   
//HTTPREQUEST to delete send a GET request to the server to a PHP file with pw = md5hash of a password. This is to delete the XML file
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://%@/delete.php",[appDelegate.hostipadd objectAtIndex:0]]] cachePolicy :NSURLRequestReloadIgnoringCacheData timeoutInterval:5.0];
NSData * responseData = [[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error] autorelease] ;}

now when it successfuly parses it, i can see on the PC that the XMLFile has been deleted. But here comes the problem now, when i have several hundreds of records in the XMLFile, im thinking that it takes too long to parses the data and crashes for whatever reason. The Error log is below. Im sure that the error occurs WHILE parsing because the XMLFile was NOT deleted. This means that the parserDidEndDocument method was not invoked.

So now i have no idea on how i should solve this . any ideas would be much appreciated and helpful. Thanks for reading guys

Date/Time:       2010-08-20 13:40:30.047 +0800

OS Version:      iPhone OS 3.2.1 (7B405)
Report Version:  104

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x00000000, 0x00000000
Crashed Thread:  0

Thread 0 Crashed:
0   libSystem.B.dylib               0x000790a0 __kill + 8
1   libSystem.B.dylib               0x00079090 kill + 4
2   libSystem.B.dylib               0x00079082 raise + 10
3   libSystem.B.dylib               0x0008d20a abort + 50
4   libstdc++.6.dylib               0x00044a1c __gnu_cxx::__verbose_terminate_handler() + 376
5   libobjc.A.dylib                 0x000057c4 _objc_terminate + 104
6   libstdc++.6.dylib               0x00042dee __cxxabiv1::__terminate(void (*)()) + 46
7   libstdc++.6.dylib               0x00042e42 std::terminate() + 10
8   libstdc++.6.dylib               0x00042f12 __cxa_throw + 78
9   libobjc.A.dylib                 0x000046a4 objc_exception_throw + 64
10  CoreFoundation                  0x00090c6e +[NSException raise:format:arguments:] + 74
11  CoreFoundation                  0x00090d38 +[NSException raise:format:] + 28
12  UIKit                           0x0010327a -[UIViewController _loadViewFromNibNamed:bundle:] + 178
13  UIKit                           0x0006317a -[UIViewController loadView] + 74
14  UIKit                           0x000693f2 -[UITableViewController loadView] + 46
15  UIKit                           0x0005b2c0 -[UIViewController view] + 24
16  MedicalBed                      0x0000ce7e -[SelectionScreen btnRefresh:] (SelectionScreen.m:188)
17  CoreFoundation                  0x00025166 -[NSObject performSelector:withObject:withObject:] + 18
18  UIKit                           0x000550ce -[UIApplication sendAction:to:from:forEvent:] + 78
19  UIKit                           0x0005506e -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 26
20  UIKit                           0x00055040 -[UIControl sendAction:to:forEvent:] + 32
21  UIKit                           0x00054d92 -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 350
22  UIKit                           0x000553e0 -[UIControl touchesEnded:withEvent:] + 336
23  UIKit                           0x00053db6 -[UIWindow _sendTouchesForEvent:] + 322
24  UIKit                           0x000536fe -[UIWindow sendEvent:] + 74
25  UIKit                           0x0004f320 -[UIApplication sendEvent:] + 260
26  UIKit                           0x0004ec8c _UIApplicationHandleEvent + 4772
27  GraphicsServices                0x00003b2c PurpleEventCallback + 660
28  CoreFoundation                  0x00022d96 CFRunLoopRunSpecific + 2214
29  CoreFoundation                  0x000224da CFRunLoopRunInMode + 42
30  GraphicsServices                0x000030d4 GSEventRunModal + 108
31  GraphicsServices                0x00003180 GSEventRun + 56
32  UIKit                           0x0000342a -[UIApplication _run] + 374
33  UIKit                           0x00001954 UIApplicationMain + 636
34  MedicalBed                      0x0000219c main (main.m:14)
35  MedicalBed                      0x00002150 start + 32

Thread 1:
0   libSystem.B.dylib               0x00001668 mach_msg_trap + 20
1   libSystem.B.dylib               0x00003734 mach_msg + 44
2   CoreFoundation                  0x0002296e CFRunLoopRunSpecific + 1150
3   CoreFoundation                  0x000224da CFRunLoopRunInMode + 42
4   WebCore                         0x0000268a RunWebThread(void*) + 286
5   libSystem.B.dylib               0x0007a786 _pthread_start + 242
6   libSystem.B.dylib               0x00070070 thread_start + 0

Thread 2:
0   libSystem.B.dylib               0x00001668 mach_msg_trap + 20
1   libSystem.B.dylib               0x00003734 mach_msg + 44
2   CoreFoundation                  0x0002296e CFRunLoopRunSpecific + 1150
3   CoreFoundation                  0x000224da CFRunLoopRunInMode + 42
4   Foundation                      0x00017a4c +[NSURLConnection(NSURLConnectionReallyInternal) _resourceLoadLoop:] + 164
5   Foundation                      0x00010bca -[NSThread main] + 38
6   Foundation                      0x0007ccf8 __NSThread__main__ + 896
7   libSystem.B.dylib               0x0007a786 _pthread_start + 242
8   libSystem.B.dylib               0x00070070 thread_start + 0

Thread 3:
0   libSystem.B.dylib               0x00025968 select$DARWIN_EXTSN + 20
1   CoreFoundation                  0x00072d7c __CFSocketManager + 552
2   libSystem.B.dylib               0x0007a786 _pthread_start + 242
3   libSystem.B.dylib               0x00070070 thread_start + 0

Thread 0 crashed with ARM Thread State:
    r0: 0x00000000    r1: 0x00000000      r2: 0x00000001      r3: 0x381ac6d0
    r4: 0x00000006    r5: 0x087411cc      r6: 0x2fffe910      r7: 0x2fffe920
    r8: 0x38029708    r9: 0x00000065     r10: 0x00000000     r11: 0x30ed3644
    ip: 0x00000025    sp: 0x2fffe920      lr: 0x3167c097      pc: 0x3167c0a0
  cpsr: 0x000f0010

Answer 1

It doesn't seem like this directly relates to XML parsing. Instead it appears to be loading of a view that have some inconsistencies:

Looking at line 14-16 of thread 0, it happens directly as a result of loading a view as a response to handling a button push in btnRefresh: (line 188 of SelectionScreen.m).

14  UIKit         0x000693f2 -[UITableViewController loadView] + 46 
15  UIKit         0x0005b2c0 -[UIViewController view] + 24 
16  MedicalBed    0x0000ce7e -[SelectionScreen btnRefresh:] (SelectionScreen.m:188) 

This method calls a view method which triggers the load of the nib. And this is where it all goes wrong.

So, try to check your nib file for inconsistencies.

Another hint pointing at this, is that thread 2 still have some active NSURLConnection. Unless you have more than one connection, this could point to the XML still being loaded.

Hope this helps.