I am working heavily on Memory Fineturning and most of the problems are solved with the help of stackoverflow. But finally I got struck with a serious memory leak with NSMutableArray initialization.
- (NSMutableArray *)children {
if (!_children) {
_children = [NSMutableArray new]; // <-- here is the memory leak
}
return _children;
}
I am working with a project where we are using 100% ARC.
Perticular class initialization is not triggered none other than the main thread (no threading has been used).
but... this is the only place where we are using recurtion
moreover the statments
#property (strong, nonatomic) NSMutableArray *children;
#synthesize children = _children;
are there in the respective .h and .m files...
Waht can be the problem....?
Thanks in advance for you effort...
more info...
- (id)init {
if (self = [super init]) {
[self setIsRoot:NO];
// [self setChildren:[NSMutableArray new]]; // <-- was before, but I moved to custom setter
}
return self;
}
- (id)initAsRoot
{
if (self = [self init]) {
self.level = -1;
self.index = -1;
self.isExpaned = YES;
self.value = #"Root";
self.isRoot = YES;
}
return self;
}
Related
I've tried to init/alloc it in initWithFrame but then objects wouldn't get added.
It'd only work in this method I'm calling but I call this method each time user refreshes the view so it'd init/alloc hundred times.
Not sure why it won't just work in initWithFrame.
I need to know the right way to init and add..!
-(void)queryParseMethod {
self.imageFilesArray = nil;
self.imageFilesArray = [[NSMutableArray alloc]init];
[self.imageFilesArray addObjectsFromArray:objects];
if (!error) {
for (PFObject *object in objects) {
int index = (int)[self.favArray indexOfObject:[object objectId]];
[self.imageFilesArray replaceObjectAtIndex:index withObject:object];
}
[self.favCV reloadData];
}}
Why not just:
if (self.imageFilesArray == nil) {
self.imageFilesArray = [[NSMutableArray alloc] init];
[self.imageFilesArray addObjectsFromArray:objects];
}
And make sure that imageFilesArray is a strong property.
Your most likely problem is that initWithFrame: isn't being called. If this view comes out of a storyboard, then you need to put this in awakeFromNib, since storyboard/nib-loaded objects initialize with initWithCoder:, not their designated initializer.
You generally don't want to try to do initialization in initWithCoder: because it's called too early. awakeFromNib is called after all your IBOutlets are assigned.
It is very common for experienced devs to break initialization out into its own method like this:
- (void)setup {
// Do your setup here
}
- (instancetype)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
[self setup];
}
}
- (void)awakeFromNib {
[self setup];
}
Doing it this way makes sure that the object is initialized in either case.
Another common solution is lazy initialization, particularly for things like NSMutableArray:
#interface MyView
#property (nonatomic, readonly, strong) NSMutableArray *imageFilesArray;
#end
#implementation MyView
- (NSMutableArray *)imageFilesArray {
if (_imageFilesArray == nil) {
_imageFilesArray = [NSMutableArray new];
}
return _imageFilesArray;
}
It's stepping into the ViewDidLoad of the main view controller, and hitting the line calling get all tweets, but I put a breakpoint in the getAllTweets of both the base and derived to see if it just wasn't hitting the derived like I expected.
#implementation WWMainViewControllerTests {
// system under test
WWMainViewController *viewController;
// dependencies
UITableView *tableViewForTests;
WWTweetServiceMock *tweetServiceMock;
}
- (void)setUp {
tweetServiceMock = [[WWTweetServiceMock alloc] init];
viewController = [[WWMainViewController alloc] init];
viewController.tweetService = tweetServiceMock;
tableViewForTests = [[UITableView alloc] init];
viewController.mainTableView = tableViewForTests;
tableViewForTests.dataSource = viewController;
tableViewForTests.delegate = viewController;
}
- (void)test_ViewLoadedShouldCallServiceLayer_GetAllTweets {
[viewController loadView];
STAssertTrue(tweetServiceMock.getAllTweetsCalled, #"Should call getAllTweets on tweetService dependency");
}
- (void)tearDown {
tableViewForTests = nil;
viewController = nil;
tweetServiceMock = nil;
}
The base tweet service:
#implementation WWTweetService {
NSMutableArray *tweetsToReturn;
}
- (id)init {
if (self = [super init]) {
tweetsToReturn = [[NSMutableArray alloc] init];
}
return self;
}
- (NSArray *)getAllTweets {
NSLog(#"here in the base of get all tweets");
return tweetsToReturn;
}
#end
The Mock tweet service:
#interface WWTweetServiceMock : WWTweetService
#property BOOL getAllTweetsCalled;
#end
#implementation WWTweetServiceMock
#synthesize getAllTweetsCalled;
- (id)init {
if (self = [super init]) {
getAllTweetsCalled = NO;
}
return self;
}
- (NSArray *)getAllTweets {
NSLog(#"here in the mock class.");
getAllTweetsCalled = YES;
return [NSArray array];
}
The main view controller under test:
#implementation WWMainViewController
#synthesize mainTableView = _mainTableView;
#synthesize tweetService;
NSArray *allTweets;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
allTweets = [tweetService getAllTweets];
NSLog(#"was here in view controller");
}
- (void)viewDidUnload
{
[self setMainTableView:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
Since you're able to break in the debugger in viewDidLoad, what's the value of the tweetService ivar? If it's nil, the getAllTweets message will just be a no op. Maybe the ivar isn't being set properly or overridden somewhere else.
You should probably use the property to access the tweetService (call self.tweetService) rather than its underlying ivar. You should only ever access the ivar directly in getters, setters, and init (also dealloc if aren't using ARC for some crazy reason).
You also should not call loadView yourself, rather just access the view property of the view controller. That will kick off the loading process and call viewDidLoad.
Also, if you're doing a lot of mocking, I highly recommend OCMock.
Updated post
Now, I have a EXC_BAD_ACCESS on the main 2 times out of 7 and I don't know why the heightOfPumpView result is 0 from the pumpCustomView class when the result of pumpViewHeight is 607.
PumpViewController.m
#import "PumpViewController.h"
#import "PumpModel.h"
#import "PumpCustomView.h"
#implementation PumpViewController
#synthesize labels;
#synthesize heightOfPumpView;
- (id)init
{
if (self = [super init])
{
labels = [[PumpModel alloc]init];
PumpCustomView* pumpView = [PumpCustomView alloc];
heightOfPumpView = [pumpView pumpViewHeight];
[labels pumpCreateLabel:heightOfPumpView];
labelsArray = [[NSMutableArray alloc]initWithArray:[labels labelsGroup]];
[labels release];
if (labelsArray!=nil)
{
[pumpView addSubview:[labelsArray objectAtIndex:2]];
}
[labelsArray release];
[pumpView release];
}
return self;
}
-(void) dealloc
{
[super dealloc];
}
#end
PumpModel.m
#import "PumpModel.h"
#import "PumpViewController.h"
#import "PumpCustomView.h"
#implementation PumpModel
#synthesize labelsGroup;
-(id)init
{
self = [super init];
return self;
}
-(void)pumpCreateLabel:(float)pumpViewHeight
{
theNumberOfPump = 8;
PumpViewController* pumpViewControllerAlloc = [PumpViewController alloc];
labelsGroup = [[NSMutableArray alloc]init];
for (int i = 0;i < theNumberOfPump; i++)
{
int pumpViewHeight = [pumpViewControllerAlloc heightOfPumpView];
int pumpViewWidthA = 259;
int resultHeight = pumpViewHeight/theNumberOfPump;
CGFloat resultWidth = pumpViewWidthA/2;
positionChart[i] = resultHeight * i;
newLabel[i] = [[NSTextField alloc] init] ;
[newLabel[i] setIntValue:i];
newLabel[i].frame = CGRectMake(resultWidth, positionChart[i], 300, 100);
newLabel[i].font= [NSFont fontWithName:#"Arial" size:12];
newLabel[i].textColor= [NSColor blackColor];
newLabel[i].backgroundColor= [NSColor whiteColor];
[labelsGroup addObject:newLabel[i]];
[newLabel[i] release];
NSLog(#"%# %d",[[labelsGroup objectAtIndex:i] stringValue],positionChart[i]);
}
[pumpViewControllerAlloc release];
}
-(void) dealloc
{
[labelsGroup release];
[super dealloc];
}
You shouldn't send messages to the object before [super init], e.g.:
- (id)init
{
if (self = [super init])
{
[self setNumberOfPump:8];
}
return self;
}
This is also true for:
-(id)initWithNumberOfPump:(int)numberOfPump
{
if (self = [super init]) {
theNumberOfPump = numberOfPump;
[self pumpCreateLabel];
}
return self ;
}
If you have a crash, post the backtrace of the crash.
Looking at your setNumberOfPump: method, it seems quite wrong.
labels is allocated, then released, likely leaving the instance variable as a dangling reference that'll crash later
labelsArray is leaked
your dealloc doesn't release any memory
You should try running Build and Analyze on your code, fixing any errors. The above issues combined with comments regarding the init patterns indicates that you should likely review the Objective-C documentation to gain a better understanding of both initialization and memory management patterns.
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 a singleton class here is the code
#import <Foundation/Foundation.h>
#import "CustomColor.h"
#interface Properties : NSObject {
UIColor *bgColor;
CustomColor *bggColor;
}
#property(retain) UIColor *bgColor;
#property (retain) CustomColor *bggColor;
+ (id)sharedProperties;
#end
#import "Properties.h"
static Properties *sharedMyProperties = nil;
#implementation Properties
#synthesize bgColor;
#synthesize bggColor;
#pragma mark Singleton Methods
+ (id)sharedProperties
{
#synchronized(self)
{
if(sharedMyProperties == nil)
[[self alloc] init];
}
return sharedMyProperties;
}
+ (id)allocWithZone:(NSZone *)zone
{
#synchronized(self)
{
if(sharedMyProperties == nil)
{
sharedMyProperties = [super allocWithZone:zone];
return sharedMyProperties;
}
}
return nil;
}
- (id)copyWithZone:(NSZone *)zone
{
return self;
}
- (id)retain {
return self;
}
- (unsigned)retainCount {
return UINT_MAX; //denotes an object that cannot be released
}
- (void)release {
// never release
}
- (id)autorelease {
return self;
}
- (id)init {
if (self = [super init])
{
bgColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:1.0];
FSColor *bc = [[FSColor alloc] init];
bc.red = bc.green = bc.blue = bc.hue = bc.sat = bc.bri = 0;
bggColor = bc;
}
return self;
}
- (void)dealloc
{
// Should never be called, but just here for clarity really.
[bgColor release];
[bggColor release];
[super dealloc];
}
#end
I have a UIView' subclass. in which i am using it. I am calling drawRect method after each second. It only run once and then app crashes.
- (void)drawRect:(CGRect)rect
{
Properties *sharedProprties = [Properties sharedProperties];
…...
….
CGContextSetFillColorWithColor(context, [[sharedProprties bgColor] CGColor]);
…..
}
What if you do self.bgColor = [UIColor colorWithRed:...]?
Without the self. I think you may be accessing the ivar directly, and therefore assigning it an autoreleased object which won't live very long (rather than using the synthesized property setter, which would retain it). I could be wrong about this, I'm stuck targeting older Mac OS X systems so I haven't been able to play much with Objective-C 2.0.
Your static sharedProperties gets never assigned. It is missing in the init method or in the sharedProperties static method.
Here's a sample pattern for singletons (last post)
Also accessing properties without self. may cause bad access errors too.
Regards
Not an answer, but note that a simple call to [Properties alloc] will mean it's no longer a singleton!
+ (id)sharedProperties
{
#synchronized(self)
{
if(sharedMyProperties == nil)
{
sharedMyProperties = [[self alloc] init];
}
}
return sharedMyProperties;
}