iOS NSDate singleton.

[IDMah]

Hi all.

Accessing NSDate in singleton crashes, with Bad_Access!!
note: accessing any other parts of the singleton works fine. So not included.

SingletonCentre.h

@interface SingletonCentre : NSObject
{
      NSDate *lastUpdate;
}
@property (nonatomic, retain) NSDate *lastUpdate;

+ (SingletonCentre *)sharedSingleton; 
@end

SingletonCentre.m

//  Note this is a fragment so I might have missed a bracket or two //

#import "SingletonCentre.h"
@implementation SingletonCentre
static SingletonCentre *shared;
@synthesize lastUpdate;
 
- (id)init  
{  
    if ( self = [super init] )  
    {  
            NSData *HSEncodedObject = [NSKeyedArchiver    
            archivedDataWithRootObject:self.myHighScoreKeeperSingleton];
            
            NSString *dateString = @"02-Aug-04";
            NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
            dateFormatter.dateFormat = @"dd-MMM-yy";
            lastUpdate =  [dateFormatter dateFromString:dateString ];
            
            [def setObject:lastUpdate forKey:@"lastUpdate"];
            NSLog(@"lastupdate set to: %@",lastUpdate);
            [def synchronize];
    }else {  
     self.lastUpdate = [def objectForKey:@"lastUpdate"];
    }
return self;

}

+ (SingletonCentre *)sharedSingleton  
{  
    @synchronized(shared)  
    {  
        if ( !shared||shared==NULL)  
        {  
            // allocate the shared instance, because it hasn't been done yet  
            shared = [[SingletonCentre alloc] init];  
            NSLog(@"created Singleton");
        }  
        
        return shared;  
    }  
}  

- (void)dealloc  
{  
    NSLog(@"Deallocating singleton...");  
    [super dealloc];  
}  


-(void)saveSingletons
{
  [def setObject:lastUpdate forKey:@"lastUpdate"];
  NSLog(@"Single: date %@",lastUpdate);
}
@end

in Gettit.m

- (void)doStuff
{
SingletonCentre *sharedHSData = [SingletonCentre sharedSingleton];
//** Code fragment that crashes with EXC_BAD_ACCESS (code1, address  = 
 NSLog(@"sing: %@",sharedHSData.lastUpdate); // <---- this line -----
NSLog(@"sing: %@",[sharedHSData lastUpdate]);// <----or this -------
}

// more stuff
@end

** Also it seems to only crash when initializing of if I run it a few times it works.. WT???
thanks, for any help!
Ian

 

[ianray]

I would recommend distilling your code down to the smallest possible reproducible test case.

You may also wish to research some useful environment variables related to memory allocations and debugging:

OBJC_PRINT_EXCEPTIONS=YES
NSZombieEnabled=YES
MallocStackLogging
MallocGuardEdges
MallocScribble

Good luck

 

[dantastic]

You're not using ARC, are you? Not with that 'retain' in the property declaration.
And you are setting the ivar directly without retaining it.

Use the setter or retain the ivar.

 

[IDMah]

Thanks.

Thanks.
You are correct !! without arc.

so changed in singleton.m

           //NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
            NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] retain]; // <- do I need this ??? it works without.. 
            dateFormatter.dateFormat = @"dd-MMM-yy";
            //lastUpdate =  [dateFormatter dateFromString:dateString ]; From
            self.lastUpdate =  [dateFormatter dateFromString:dateString ]; // To

Seems stable now.. Thanks !!!