i have a static class witch has two property,like below ...
#interface Global : NSObject
{
BarcodeScanner* scanner;
NSInteger warehouseID;
}
#property(assign) BarcodeScanner* scanner;
#property(assign) NSInteger warehouseID;
+(Global *)sharedInstance;
#end
#import "Global.h"
#implementation Global
#synthesize scanner,warehouseID;
+ (Global *)sharedInstance
{
static Global *globalInstance = nil;
if (nil == globalInstance) {
globalInstance = [[Global alloc] init];
globalInstance.scanner = [[BarcodeScanner alloc] init];
globalInstance.warehouseID = 1;
}
return globalInstance;
}
-(void) dealloc
{
[super dealloc];
}
#end
now when i analyze project in Xcode i got warning for memory leak for scanner and warehouseID properties , and when i try to release them in dealloc method like ...
[[[Global sharedInstance] scanner]release];
i got warning "incorrect decrement of the reference count of an object..."
how should i resolve this problem.
so thanks for any help.
The warning is because your code does not match the rules Analyzer uses. To avoid the warning
make the scanner property retain
change the the instantiation or BarcodeScanner to be autorelease
add a release for scanner in dealloc
Example (reformatted just to save space):
#class BarcodeScanner;
#interface Global : NSObject {
BarcodeScanner* scanner;
NSInteger warehouseID;
}
#property(retain) BarcodeScanner* scanner;
#property(assign) NSInteger warehouseID;
+(Global *)sharedInstance;
#end
#implementation Global
#synthesize scanner,warehouseID;
+ (Global *)sharedInstance {
static Global *globalInstance = nil;
if (nil == globalInstance) {
globalInstance = [[Global alloc] init];
globalInstance.scanner = [[[BarcodeScanner alloc] init] autorelease];
globalInstance.warehouseID = 1;
}
return globalInstance;
}
-(void) dealloc {
[scanner release];
[super dealloc];
}
#end
just leave it to autorelease pool
globalInstance.scanner = [[[BarcodeScanner alloc] init] autorelease];
Related
This question already has answers here:
Under automatic reference counting, why are retain, release, and dealloc not allowed?
(4 answers)
Closed 9 years ago.
I'm using the latest xcode.
implementation file:
SimpleCar.m:
#import "SimpleCar.h"
#implementation SimpleCar
// set methods
- (void) setVin: (NSNumber*)newVin {
[vin release];
vin = [[NSNumber alloc] init];
vin = newVin;
}
- (void) setMake: (NSString*)newMake {
[make release];
make = [[NSString alloc] initWithString:newMake];
}
- (void) setModel: (NSString*)newModel {
[model release];
model = [[NSString alloc] initWithString:newModel];
}
// convenience method
- (void) setMake: (NSString*)newMake
andModel: (NSString*)newModel {
// Reuse our methods from earlier
[self setMake:newMake];
[self setModel:newModel];
}
//get methods
- (NSString*) make; {
return make;
}
- (NSString*) model;{
return model;
}
- (NSNumber*) vin;{
return vin;
}
-(void) dealloc
{
[vin release];
[make release];
[model release];
[super dealloc];
}
#end
interface file:
SimpleCar.h:
#import <Foundation/Foundation.h>
#interface SimpleCar : NSObject {
NSString* make;
NSString* model;
NSNumber* vin;
}
// set methods
- (void) setVin: (NSNumber*)newVin;
- (void) setMake: (NSString*)newMake;
- (void) setModel: (NSString*)newModel;
// convenience method
- (void) setMake: (NSString*)newMake
andModel: (NSString*)newModel;
// get methods
- (NSString*) make;
- (NSString*) model;
- (NSNumber*) vin;
#end
I get an error in the implementation file when I type "[vin release], [model release], [make release]" and I cannot run the program.
ARC is turned on, therefore memory management is automatic.
A modern definition of that class would be declared as:
#interface SimpleCar : NSObject
#property(copy) NSString *make;
#property(copy) NSString *model;
#property(copy) NSNumber *vin;
- initWithMake:(NSString*)make model:(NSString*)model vin:(NSNumber*)vin;
#end
And would be implemented as:
#implementation SimpleCar
- initWithMake:(NSString*)make model:(NSString*)model vin:(NSNumber*)vin
{
if (self = [super init]) {
_make = [make copy];
_model = [model copy];
_vin = [vin copy];
}
return self;
}
#end
You wouldn't typically implement a convenience method like setMake:andModel:. It just adds API footprint without really buying much in the way of convenience. It also raises questions like "What happens when I observe either make or model?".
I'm using an ItemController to provide a list of items to use in a tableview. I can't seem to populate the controller though, and I'm not sure why.
Here's the code for the controller class:
.h
#import <Foundation/Foundation.h>
#class Item;
#interface ItemController : NSObject
#property (nonatomic, copy) NSMutableArray *items;
- (NSUInteger)countOfList;
- (Item*)objectInListAtIndex:(NSUInteger)theIndex;
- (void)addItem:(Item *)item;
#end
.m
#import "ItemController.h"
#import "Item.h"
#interface ItemController ()
#end
#implementation ItemController
- (NSUInteger)countOfList {
return [self.items count];
}
- (Item *)objectInListAtIndex:(NSUInteger)theIndex {
return [self.items objectAtIndex:theIndex];
}
- (void)addItem:(Item *)item {
[self.items addObject:item];
}
#end
Item.m
#implementation Item
-(id)initWithName:(NSString *)name{
self = [super init];
if (self) {
_name = name;
return self;
}
return nil;
}
#end
I'm using the following code to populate the list:
ItemController* controller = [[ItemController alloc] init];
for (NSString* key in raw_data) {
NSLog(key); // This outputs the keys fine
[controller addItem:[[Item alloc] initWithName:key]];
}
NSLog([NSString stringWithFormat:#"%d",[controller countOfList]]); // Always 0
You need to initialize the array in the init methond.
- (id)init {
self = [super init];
if (self) {
self.items = [[NSMutableArray alloc] init];
}
return self;
}
You need to initialize your variable items. In your init method, call self.items = [NSMutableArray new]; and also change your array property from copy to retain.
I also believe your class ItemController should be of kind UIViewController and not NSObject.
#interface ItemController : UIViewController
You don't initialise the _items instance variable anywhere, so it's always nil. The result of any integer-returning method called on nil will be 0, so you see that the count is 0.
I've been stuck on this EXC_BAD_ACCESS error 2 days now. I have a reloadAnnotations method that removes all annotations before adding new annotations. Before removing the annotation this method should be checking to see if the new set contains the same location so it's not removed and re-added. But as soon as I try to trace out the current annotation title I get this error Thread 1: Program received signal: "EXC_BAD_ACCESS"
And when I view the annotation in the debugger the title property says "Invalid Summary". It must be caused by a value not being retained but I've tried everything and can't figure it out.
Why can't I log the annotation title to NSLog?
And why can't I compare each title and coords to other objects?
BrowseController.m
-(void)reloadAnnotations
{
NSMutableArray *toRemove = [NSMutableArray arrayWithCapacity:10];
for (id annotation in _mapView.annotations) {
if (annotation != _mapView.userLocation) {
//ParkAnnotation *pa = (ParkAnnotation *)annotation;
ParkAnnotation *pa = annotation;
NSLog(#"pa.title %#", pa.title); // Thread 1: Program received signal: "EXC_BAD_ACCESS"
[toRemove addObject:annotation];
}
}
// DON'T REMOVE IT IF IT'S ALREADY ON THE MAP!!!!!!
for(RKLocation *loc in locations)
{
CLLocationCoordinate2D location;
location.latitude = (double)[loc.lat doubleValue];
location.longitude = (double)[loc.lng doubleValue];
ParkAnnotation *parkAnnotation = [[ParkAnnotation alloc] initWithTitle:loc.name andCoordinate:location];
[_mapView addAnnotation:parkAnnotation];
}
[_mapView removeAnnotations:toRemove];
}
- (MKAnnotationView *)mapView:(MKMapView *)map viewForAnnotation:(id <MKAnnotation>)annotation
{
NSLog(#"BrowseViewController map viewForAnnotation");
MKPinAnnotationView *pin = (MKPinAnnotationView *)[_mapView dequeueReusableAnnotationViewWithIdentifier: #"anIdentifier"];
if (pin == nil){
pin = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation
reuseIdentifier: #"anIdentifier"] autorelease];
pin.pinColor = MKPinAnnotationColorRed;
pin.animatesDrop = YES;
pin.canShowCallout = YES;
}
else{
pin.annotation = annotation;
}
return pin;
}
ParkAnnotation.h
#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>
#interface ParkAnnotation : NSObject <MKAnnotation> {
NSString *title;
CLLocationCoordinate2D coordinate;
}
#property (nonatomic, copy) NSString *title;
#property (nonatomic, readonly) CLLocationCoordinate2D coordinate;
- (id)initWithTitle:(NSString *)ttl andCoordinate:(CLLocationCoordinate2D)c2d;
#end
ParkAnnotation.m (edited: see Wolfgangs comments below )
#import "ParkAnnotation.h"
#implementation ParkAnnotation
#synthesize title, coordinate;
- (id)initWithTitle:(NSString *)ttl andCoordinate:(CLLocationCoordinate2D)c2d {
self = [super init];
if (self) {
title = ttl;
coordinate = c2d;
}
return self;
}
- (void)dealloc {
[title release];
[super dealloc];
}
#end
Although you have declared title has a copy type property, it never is copied as you don't use the setter method and directly assigned. You are even releasing it without ownership. Change it like this,
title = [ttl copy];
The initializer in ParkAnnotation.m isn't written following ObjC conventions. The self variable is never set, the designated initializer of a class should follow the following pattern:
- (id)init
{
self = [super init];
if (self)
{
/* custom initialization here ... */
}
return self;
}
Since self is not set, the accessor methods used in the caller will fail; the container object (inside ParkAnnotation.m referenced with self) will be nil or some bogus value when trying to access a property inside the object from another class.
When I use Instruments to find memory leaks, a leak is detected on
Horaires *jour;
jour= [[Horaires alloc] init]; // memory leak reported here by Instruments
self.lundi = jour;
[jour release];
and I don't know why there is a leak at this point.
Does anyone can help me? Here's the code.
// HorairesCollection.h
#import <Foundation/Foundation.h>
#import "Horaires.h"
#interface HorairesCollection : NSObject < NSCopying > {
Horaires *lundi;
}
#property (nonatomic, retain) Horaires *lundi;
-init;
-(void)dealloc;
#end
// HorairesCollection.m
#import "HorairesCollection.h"
#implementation HorairesCollection
#synthesize lundi;
-(id)copyWithZone:(NSZone *)zone{
HorairesCollection *another = [[HorairesCollection alloc] init];
another.lundi = [lundi copyWithZone: zone];
[another autorelease];
return another;
}
-init{
self = [super init];
Horaires *jour;
jour= [[Horaires alloc] init]; // memory leak reported here by Instruments
self.lundi = jour;
[jour release];
return self;
}
- (void)dealloc {
[lundi release];
[super dealloc];
}
#end
// Horaires.h
#import <Foundation/Foundation.h>
#interface Horaires : NSObject <NSCopying>{
BOOL ferme;
BOOL h24;
NSString *h1;
}
#property (nonatomic, assign) BOOL ferme;
#property (nonatomic, assign) BOOL h24;
#property (nonatomic, retain) NSString *h1;
-init;
-(id)copyWithZone:(NSZone *)zone;
-(void)dealloc;
#end
// Horaires.m
#import "Horaires.h"
#implementation Horaires
-(BOOL) ferme {
return ferme;
}
-(void)setFerme:(BOOL)bFerme{
ferme = bFerme;
if (ferme) {
self.h1 = #"";
self.h24 = NO;
}
}
-(BOOL) h24 {
return h24;
}
-(void)setH24:(BOOL)bH24{
h24 = bH24;
if (h24) {
self.h1 = #"";
self.ferme = NO;
}
}
-(NSString *) h1 {
return h1;
}
-(void)setH1:(NSString *)horaire{
[horaire retain];
[h1 release];
h1 = horaire;
if (![h1 isEqualToString:#""]) {
self.h24 = NO;
self.ferme = NO;
}
}
-(id)copyWithZone:(NSZone *)zone{
Horaires *another = [[Horaires alloc] init];
another.ferme = self.ferme;
another.h24 = self.h24;
another.h1 = self.h1;
[another autorelease];
return another;
}
-init{
self = [super init];
return self;
}
-(void)dealloc {
[h1 release];
[super dealloc];
}
#end
You've set your property to retain and you alloc and release the variable, so from what I can see the code is okay and Instruments has given you a false warning.
I think your copyWithZone: might have a leak, though. [lundi copyWithZone:] will retain a copy of lundi but you never release it. So you need an extra release, something like this:
-(id)copyWithZone:(NSZone *)zone{
DefibHoraires *another = [[DefibHoraires alloc] init];
Horaires* makeCopy = [lundi copyWithZone: zone];
another.lundi = makeCopy;
[makeCopy release];
return another;
}
This is because copy and alloc both return retained object instances and you need to manually release them when you're finished with them. You did that correctly for your alloc'd objects but not the copy.
That init method looks ok, although it should be implemented (and typed) as
-(id)init
{
if (self = [super init])
{
...
}
return self;
}
or a similar pattern.
Your copyWithZone implementations are wrong, they need to return a retained object, so do not autorelease the returned value. But you need to release your copy of lundi, because you are using the retaining setter.
-(id)copyWithZone:(NSZone *)zone{
DefibHoraires *another = [[DefibHoraires alloc] init];
Horaires *lundiCopy = [lundi copyWithZone:zone];
another.lundi = lundiCopy;
[lundiCopy release];
return another;
}
I don't know why you return an instance of DefibHoraires here, shouldn't it be a HorairesCollection?
Maybe the wrong copyWithZone: method is responsible for the reported leak (it's a leak anyway).
One further note: It's a good defensive rule to use (copy) for NSString properties instead of (retain) to remove side effects when passing NSMutableString instead.
I don't have an answer but I do have some general comments:
In copyWithZone: you should use allocWithZone: (passing the same zone as a parameter) to allocate the object you are going to return.
copyWithZone: should return a retained object. Don't autorelease it.
You are not supposed to use properties in init. Your init should look something like:
-init
{
self = [super init];
if (self != nil)
{
lundi = [[Horaires alloc] init]; // assign the ivar directly
}
return self;
}
In your copyWithZone: for HorairesCollection you have a leak. It should look like:
-(id)copyWithZone:(NSZone *)zone{
DefibHoraires *another = [[DefibHoraires allocWithZone: zone] init];
another.lundi = [[lundi copyWithZone: zone] autorelease];
return another;
}
I have a user class that I use through the iPhone application, this is the init and initWithUser functions from my user class (A SUBCLASS OF NSobject), when I use the initWithUser function I get the warning described after the code. please advise.
// serialize.h
#import <Foundation/Foundation.h>
#protocol Serialize
// serialize the object to an xml string
-(NSString*)ToXML;
#end
// user.h
#import <Foundation/Foundation.h>
#import "Serialize.h"
#import "Contact.h"
#interface User : NSObject <Serialize> {
NSString *email;
NSString *firstName;
NSString *lastName;
NSString *userId;
NSString *userName;
NSString *password;
NSMutableArray *contactList;
}
#property (nonatomic,copy) NSString *email;
#property (nonatomic,copy) NSString *firstName;
#property (nonatomic,copy) NSString *lastName;
#property (nonatomic,copy) NSString *userId;
#property (nonatomic,copy) NSString *userName;
#property (nonatomic,copy) NSString *password;
#property (nonatomic, retain) NSMutableArray *contactList;
//-(id)init;
-(id)initWithUser:(User *)copyUser;
#end
// user.m
#import "user.h"
#implementation User
#synthesize email;
#synthesize firstName;
#synthesize lastName;
#synthesize userId;
#synthesize userName;
#synthesize password;
#synthesize contactList;
-(id)init
{
// call init in parent and assign to self
if( (self = [super init]) )
{
// do something specific
contactList = [[NSMutableArray alloc] init];
}
return self;
}
-(id)initWithUser:(User *)copyUser
{
if( (self = [self init]) ) {
email = copyUser.email;
firstName = copyUser.firstName;
lastName = copyUser.lastName;
userId = copyUser.userId;
userName = copyUser.userName;
password = copyUser.password;
// release contactList initialized in the init
[contactList release];
contactList = [copyUser.contactList mutableCopy];
}
return self;
}
- (void)dealloc
{
// TODO:
[contactList removeAllObjects];
[contactList release];
[super dealloc];
}
// implementation of serialize protocol
-(NSString*)ToXML
{
return #"";
}
and I use it in the main controller this way
- (void) registerNewUser {
RegistrationViewController *regController = [[RegistrationViewController alloc] init] ;
regController.newUser = [[User alloc] initWithUser:self.user];
[self.navigationController pushViewController:regController animated:YES];
[regController release];
}
the line
regController.newUser = [[User alloc] initWithUser:self.user];
gives me the following error, and its been driving me nuts for a couple of days:
incompatible Objective-c types 'struct User*', expected 'struct NSString *' when passing argument 1 of 'initWithUser:' from distinct Objective-c type
any help and guidance is appreciated
The problem is you have an ambiguous selector. Because alloc returns id, the call to initWithUser: has become ambiguous. NSUserDefaults also has an initWithUser: function which takes a string. The compiler thinks you're trying to use that one. Change the line to
regController.newUser = [(User*)[User alloc] initWithUser:self.user];
and everything should work as expected.
As mentioned in the comments, there are other problems with your implementation. In your initializer, reusing the -init is redundant and the assignments to ivars like email should be taking ownership of the data using -copy or -retain:
-(id)initWithUser:(User *)copyUser {
if((self = [super init])) {
// take ownership of the users data by copying or retaining:
email = [copyUser.email copy];
// ...
contactList = [copyUser.contactList mutableCopy];
}
return self;
}
In -dealloc, -removeAllObjects can be removed and the member data has to be released:
- (void)dealloc {
[email release];
// ...
[contactList release];
[super dealloc];
}
Note that you are also leaking the new User instance if newUser is a copy or retain property as there is a release missing:
User *user = [[User alloc] initWithUser:self.user];
regController.newUser = user;
[user release];