Debugger message - iphone

Question

I do webservice requests with a UISegmentedControl, when I change segmentedItem and request fast the application crashes with this message:
[Session started at 2011-05-12
10:58:50 +0200.] Terminating in
response to SpringBoard's termination.
[Session started at 2011-05-12
11:06:31 +0200.] GNU gdb
6.3.50-20050815 (Apple version gdb-1516) (Fri Feb 11 06:19:43 UTC
2011) Copyright 2004 Free Software
Foundation, Inc. GDB is free software,
covered by the GNU General Public
License, and you are welcome to change
it and/or distribute copies of it
under certain conditions. Type "show
copying" to see the conditions. There
is absolutely no warranty for GDB.
Type "show warranty" for details. This
GDB was configured as
"--host=i386-apple-darwin
--target=arm-apple-darwin".tty /dev/ttys001 Loading program into
debugger… Program loaded. target
remote-mobile
/tmp/.XcodeGDBRemote-239-58 Switching
to remote-macosx protocol mem 0x1000
0x3fffffff cache mem 0x40000000
0xffffffff none mem 0x00000000 0x0fff
none run Running… [Switching to thread
11779] [Switching to thread 11779]
sharedlibrary apply-load-rules all
continue Program received signal:
“SIGKILL”. warning: Unable to read
symbols for
/Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.3.3
(8J2)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib
(file not found). kill quit
The Debugger has exited with status
0.(gdb)
Does anybody have an idea of how can I fix this?
Is this a problem because I'm not using NSOperationQueue?
And if so any suggestions how I can fix this would be very welcomed.
I can not find any memory leaks when running.
Next time I ran it this message got logged:
Program received signal: “EXC_BAD_ACCESS”.
warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.3.3 (8J2)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib (file not found).
(gdb)
Here is the code for starting the connection:
Class header ServiceGetChildren:
#import <Foundation/Foundation.h>
#class Authentication;
#class AttendanceReportViewController;
#interface ServiceGetChildren : NSObject {
Authentication *authentication;
AttendanceReportViewController *attendanceReportViewController;
NSString *username;
NSString *password;
NSMutableString *authenticationString;
NSString *encodedLoginData;
NSMutableData *responseData;
NSMutableArray *childrensArray;
}
#property (nonatomic, retain) NSString *username;
#property (nonatomic, retain) NSString *password;
#property (nonatomic, retain) NSMutableString *authenticationString;
#property (nonatomic, retain) NSString *encodedLoginData;
#property (nonatomic, retain) NSMutableData *responseData;
#property (nonatomic, retain) NSMutableArray *childrensArray;
- (void)startService:(NSURL *)url :(NSString *)method withParent:(UIViewController *)controller;
#end
Class handling the request:
#import "ServiceGetChildren.h"
#import "JSON.h"
#import "Base64.h"
#import "AttendanceReportViewController.h"
#import "Authentication.h"
#implementation ServiceGetChildren
#synthesize appDelegate;
#synthesize username;
#synthesize password;
#synthesize authenticationString;
#synthesize encodedLoginData;
#synthesize responseData;
#synthesize childrensArray;
- (id) init {
if ((self = [super init])) {
}
return self;
}
- (void)startService:(NSURL *)url :(NSString *)method withParent:(UIViewController *)controller {
username = appDelegate.username;
password = appDelegate.password;
attendanceReportViewController = (AttendanceReportViewController *)controller;
Authentication *auth = [[Authentication alloc] init];
authenticationString = (NSMutableString*)[#"" stringByAppendingFormat:#"%#:%#", username, password];
encodedLoginData = [auth encodedAuthentication:authenticationString];
[auth release];
// Setup up the request with the url
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL: url
cachePolicy: NSURLRequestReloadIgnoringCacheData
timeoutInterval: 20.0];
[request setHTTPMethod:method];
[request setValue:[NSString stringWithFormat:#"Basic %#", encodedLoginData] forHTTPHeaderField:#"Authorization"];
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];
// Display the network indicator when the connection request started
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
// Check that the NSURLConnection was successful and then initialize the responseData
if(connection) {
NSLog(#"Connection made");
responseData = [[NSMutableData data] retain];
}
else {
NSLog(#"Connection could not be made");
}
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
[responseData setLength:0];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[responseData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSLog(#"Connection finished loading.");
// Dismiss the network indicator when connection finished loading
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
// Parse the responseData of json objects retrieved from the service
SBJSON *parser = [[SBJSON alloc] init];
NSString *jsonString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSDictionary *jsonData = [parser objectWithString:jsonString error:nil];
NSMutableArray *array = [jsonData objectForKey:#"Children"];
childrensArray = [NSMutableArray arrayWithArray:array];
// Callback to AttendanceReportViewController that the responseData finished loading
[attendanceReportViewController loadChildren];
[connection release];
[responseData release];
[jsonString release];
[parser release];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
NSLog(#"Connection failure.");
NSLog(#"ERROR%#", error);
// Dismiss the network indicator when connection failure occurred
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[connection release];
// Inform the user that the server was unavailable
}
- (void) dealloc {
[attendanceReportViewController release];
[super dealloc];
}
Class header for AttendanceReportViewController:
#import <UIKit/UIKit.h>
#class ServiceGetGroups;
#class ServiceGetChildren;
#class DetailViewController;
#interface AttendanceReportViewController : UIViewController <UITableViewDataSource, UITableViewDelegate> {
ServiceGetGroups *serviceGetGroups;
ServiceGetChildren *serviceGetChildren;
DetailViewController *detailViewController;
UISegmentedControl *segmentedControl;
IBOutlet UIToolbar *groupsToolbar;
NSMutableArray *btnArray;
NSInteger index;
IBOutlet UITableView *theTableView;
IBOutlet UILabel *attendanceLabel;
IBOutlet UILabel *abscentLabel;
IBOutlet UILabel *totalLabel;
NSMutableDictionary *selectRequestDictionary;
NSMutableDictionary *selectNameDictionary;
NSMutableArray *groupsArray;
NSMutableArray *childrensArray;
NSDictionary *childrensDictionary;
NSURL *url;
}
#property (nonatomic, retain) ServiceGetGroups *serviceGetGroups;
#property (nonatomic, retain) ServiceGetChildren *serviceGetChildren;
#property (nonatomic, retain) DetailViewController *detailViewController;
#property (nonatomic, retain) IBOutlet UIToolbar *groupsToolbar;
#property (nonatomic, retain) IBOutlet UITableView *theTableView;
#property (nonatomic, retain) IBOutlet UILabel *attendanceLabel;
#property (nonatomic, retain) IBOutlet UILabel *abscentLabel;
#property (nonatomic, retain) IBOutlet UILabel *totalLabel;
#property (nonatomic, retain) UISegmentedControl *segmentedControl;
#property (nonatomic) NSInteger index;
#property (nonatomic, retain) NSMutableArray *btnArray;
#property (nonatomic, retain) NSMutableDictionary *selectRequestDictionary;
#property (nonatomic, retain) NSMutableDictionary *selectNameDictionary;
#property (nonatomic, retain) NSMutableArray *groupsArray;
#property (nonatomic, retain) NSMutableArray *childrensArray;
#property (nonatomic, retain) NSDictionary *childrensDictionary;
#property (nonatomic, retain) NSURL *url;
- (void)setupSegmentedControl;
- (void)requestGroups;
- (void)requestChildren:(NSNumber *)groupId;
- (void)loadGroups;
- (void)loadChildren;
#end
Class that the Uses the UISegmentedControl:
#import "JSON.h"
#import "AttendanceReportViewController.h"
#import "CustomCellViewController.h"
#import "DetailViewController.h"
#import "ServiceGetGroups.h"
#import "ServiceGetChildren.h"
#import "Group.h"
#import "Child.h"
#implementation AttendanceReportViewController
#synthesize serviceGetGroups;
#synthesize serviceGetChildren;
#synthesize detailViewController;
#synthesize segmentedControl;
#synthesize groupsToolbar;
#synthesize index;
#synthesize btnArray;
#synthesize theTableView;
#synthesize attendanceLabel;
#synthesize abscentLabel;
#synthesize totalLabel;
#synthesize selectRequestDictionary;
#synthesize selectNameDictionary;
#synthesize groupsArray;
#synthesize childrensArray;
#synthesize childrensDictionary;
#synthesize url;
#pragma mark -
#pragma mark View lifecycle
// The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization.
}
return self;
}
- (void)requestGroups {
NSURL *groupsURL = [NSURL URLWithString:#"http://services/groups"];
[serviceGetGroups startService:groupsURL :#"GET" withParent:self];
}
- (void)requestChildren:(NSNumber *)groupId {
NSLog(#"%#", groupId);
NSString *baseURL = #"http://services/group/";
NSString *method = [NSString stringWithFormat:#"%#%#", groupId, #"/children"];
NSString *theURL = [NSString stringWithFormat:#"%#%#", baseURL, method];
self.url = [NSURL URLWithString:theURL];
NSLog(#"%#", self.url);
[serviceGetChildren startService:self.url :#"GET" withParent:self];
}
- (void)loadGroups {
// Retrieve a array with dictionaries of groups from ServiceGetGroups
self.groupsArray = [[serviceGetGroups.groupsArray copy] autorelease];
// The array to hold segmentedItems for the segmentedControl, representing groups buttons
btnArray = [NSMutableArray arrayWithObjects: #"Alla", nil];
for (NSDictionary *groupDict in groupsArray) {
// Add each groups name to the btnArray as segmentedItems for the segmentedControl
[btnArray addObject:[groupDict objectForKey:#"Name"]];
}
// Create a new NSMutableDictionary with group names as keys and group id´s as values
// used for reference to segementedControl items to make request to serviceGetChildren
self.selectRequestDictionary = [NSMutableDictionary dictionary];
for (NSDictionary *dict in groupsArray) {
[selectRequestDictionary setObject:[dict objectForKey:#"Id"] forKey:[dict objectForKey:#"Name"]];
}
// Create a new NSMutableDictionary with group id´s as keys and group names as values
// used for retrieving a groupName from a passed id
self.selectNameDictionary = [NSMutableDictionary dictionary];
for (NSDictionary *dict in groupsArray) {
[selectNameDictionary setObject:[dict objectForKey:#"Name"] forKey:[dict objectForKey:#"Id"]];
}
[self setupSegmentedControl];
}
- (void)setupSegmentedControl {
// Setup the UISegmentedControl as groups buttons
segmentedControl = nil;
segmentedControl = [[UISegmentedControl alloc] initWithItems:btnArray];
segmentedControl.tintColor = [UIColor darkGrayColor];
segmentedControl.selectedSegmentIndex = 0;
segmentedControl.autoresizingMask = UIViewAutoresizingFlexibleWidth;
segmentedControl.segmentedControlStyle = UISegmentedControlStyleBar;
segmentedControl.frame = CGRectMake(0, 0, 300, 30);
// Setup the target and actions for the segmentedControl
[segmentedControl addTarget:self
action:#selector(selectGroup:)
forControlEvents:UIControlEventValueChanged];
// Add the UISegmentedControl as a UIBarButtonItem subview to the UIToolbar
UIBarButtonItem *segmentedItem = [[[UIBarButtonItem alloc] initWithCustomView:segmentedControl] autorelease];
UIBarButtonItem *flexSpace = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
NSArray *groupsButtons = [NSArray arrayWithObjects:flexSpace, segmentedItem, flexSpace, nil];
[groupsToolbar setItems:groupsButtons];
[flexSpace release];
}
- (void)loadChildren {
// Retrieve a array with dictionaries of children from ServiceGetChildren
self.childrensArray = [[serviceGetChildren.childrensArray copy] autorelease];
// TODO create seperate method - Setup compilation bar values
int total = [childrensArray count];
totalLabel.text = [NSString stringWithFormat:#"%d", total];
[theTableView reloadData];
}
// Handles UIControlEventValueChanged for UISegmentedControl, retreives the name and id for a selected group
- (void)selectGroup:(UISegmentedControl *)theSegmentedControl {
NSString *selectedGroup = [segmentedControl titleForSegmentAtIndex: [segmentedControl selectedSegmentIndex]];
NSNumber *selectedId = [selectRequestDictionary objectForKey:selectedGroup];
// Persist the selectedSegmentIndex when view switches to detaildView
index = [segmentedControl selectedSegmentIndex];
// Request children based on the selected groupId
[self requestChildren:selectedId];
}
- (void)viewDidLoad {
[self requestGroups];
[super viewDidLoad];
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
//self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
#pragma mark -
#pragma mark Table view data source
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// Return the number of rows in the section.
return [childrensArray count];
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"CustomCell";
// Load from nib
CustomCellViewController *cell = (CustomCellViewController *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
NSArray *topLevelObjects = [[NSBundle mainBundle]
loadNibNamed:#"CustomCellView"
owner:nil
options:nil];
for (id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[UITableViewCell class]]) {
cell = (CustomCellViewController *) currentObject;
break;
}
}
}
// Set up a children dictionary for easy retrieving specific values to display in the UITableView
childrensDictionary = [childrensArray objectAtIndex:indexPath.row];
NSNumber *idForName = [childrensDictionary valueForKey:#"GroupId"];
NSString *name = [NSString stringWithFormat:#"%# %#",
[childrensDictionary valueForKey:#"Firstname"],
[childrensDictionary valueForKey:#"Surname"]];
NSString *group = [NSString stringWithFormat:#"%#",
[selectNameDictionary objectForKey:idForName]];
cell.childNameLabel.text = name;
cell.groupNameLabel.text = group;
cell.scheduleLabel.text = #"Schema";
cell.deviationLabel.text = #"Avvikelse";
return cell;
}
#pragma mark -
#pragma mark Table view delegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Navigation logic may go here. Create and push the detailedViewController.
if (detailViewController == nil) {
DetailViewController *_detailViewcontroller = [[DetailViewController alloc]
initWithNibName:#"DetailView" bundle:nil];
self.detailViewController = _detailViewcontroller;
[_detailViewcontroller release];
}
childrensDictionary = [childrensArray objectAtIndex:indexPath.row];
NSNumber *idForName = [childrensDictionary valueForKey:#"GroupId"];
NSString *group = [NSString stringWithFormat:#"%#",
[selectNameDictionary objectForKey:idForName]];
[self.detailViewController initWithDetailsSelected:childrensDictionary:group];
[self.navigationController pushViewController:detailViewController animated:YES];
}
#pragma mark -
#pragma mark Memory management
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Relinquish ownership any cached data, images, etc. that aren't in use.
}
- (void)viewDidUnload {
// Relinquish ownership of anything that can be recreated in viewDidLoad or on demand.
// For example: self.myOutlet = nil;
segmentedControl = nil;
}
- (void)dealloc {
[segmentedControl release];
[groupsArray release];
[childrensArray release];
[detailViewController release];
[super dealloc];
}
#end

Answer 1

OK here we go. First of all, I could not test the code, so I need your feedback.
The main problem with this class is, you only have one instance, which you reuse every time you hit the segmented control. This leads to creation of new instances of the NSURLConnection. So let's correct a bit in the header. I changed the NSString properties to copy. Have a look at this Q&A to know why, however this is not important for the improvement, just wanted to let you know.
I've removed Authentication *authentication; looked like you don't use it.
Added NSURLConnection as property so we keep a reference on it.
Header file
#class Authentication;
#class AttendanceReportViewController;
#interface ServiceGetChildren : NSObject {
AttendanceReportViewController *attendanceReportViewController;
NSString *username;
NSString *password;
NSMutableString *authenticationString;
NSString *encodedLoginData;
NSMutableData *responseData;
NSMutableArray *childrensArray;
NSURLConnection *connection;
}
#property (nonatomic, copy) NSString *username;
#property (nonatomic, copy) NSString *password;
#property (nonatomic, retain) NSMutableString *authenticationString;
#property (nonatomic, copy) NSString *encodedLoginData;
#property (nonatomic, retain) NSMutableData *responseData;
#property (nonatomic, retain) NSMutableArray *childrensArray;
#property (nonatomic, retain) NSURLConnection *connection
- (void)startService:(NSURL *)url :(NSString *)method withParent:(UIViewController *)controller;
#end
Next comes the Implementation file. I only altered the startService method and dealloc.
If you declare properties, use them :) Have a look at this Q&A for some explanations on synthesized properties.
Always release what you own, so I added release code in the dealloc.
Cancel the previous request!!! If there is none, the message is sent to nil, which causes no harm.
Implementation file
- (void)startService:(NSURL *)url:(NSString *)method withParent:(UIViewController *)controller
{
self.username = appDelegate.username;
self.password = appDelegate.password;
[connection cancel];
attendanceReportViewController = (AttendanceReportViewController *)controller;
Authentication *auth = [[Authentication alloc] init];
authenticationString = (NSMutableString *)[#"" stringByAppendingFormat:#"%#:%#", username, password];
self.encodedLoginData = [auth encodedAuthentication:authenticationString];
[auth release];
// Setup up the request with the url
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
cachePolicy:NSURLRequestReloadIgnoringCacheData
timeoutInterval:20.0];
[request setHTTPMethod:method];
[request setValue:[NSString stringWithFormat:#"Basic %#", encodedLoginData] forHTTPHeaderField:#"Authorization"];
self.connection = [[[NSURLConnection alloc] initWithRequest:request delegate:self] autorelease];
// Display the network indicator when the connection request started
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
// Check that the NSURLConnection was successful and then initialize the responseData
if (connection) {
NSLog(#"Connection made");
self.responseData = [NSMutableData data];
} else {
NSLog(#"Connection could not be made");
}
}
...
- (void) dealloc
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
[connection cancel];
[connection release];
[appDelegate release];
[responseData release];
[username release];
[password release];
[authenticationString release];
[encodedLoginData release];
[responseData release];
[childrensArray release];
[super dealloc];
}
Hope this helps for the next steps. However I think we will have to work a bit on the solution until it's final.