Question

I wrote a Cocoa Application and I got EXC_BAD_ACCESS error when I’m closing an application window. I read that this error usually means problems with memory, but I have ARC mode on and I don’t need care about releasing e.t.c. (xCode forbids me to call this functions and manage memory automatically).

Error is pointing at line return NSApplicationMain(argc, (const char **)argv); in main function.

Here’s my application’s code:

.h file:

@interface MainDreamer : NSWindow <NSWindowDelegate> 
{    
    NSTextField *dreamField;
    NSTableView *dreamTable;    
    NSImageView *dreamview;

    NSMutableArray *dreamlist;  
    NSMutableArray *dataset;
}

@property (nonatomic, retain) IBOutlet NSTextField *dreamField;
@property (nonatomic, retain) IBOutlet NSTableView *dreamTable;
@property (nonatomic, retain) IBOutlet NSImageView *dreamview;
@property (nonatomic, retain) IBOutlet NSMutableArray *dreamlist;
@property (nonatomic, retain) IBOutlet NSMutableArray *dataset;
@property (assign) IBOutlet NSWindow *window;

@end

.m file:

@implementation MainDreamer

@synthesize window;
@synthesize dataset;
@synthesize dreamField;
@synthesize dreamlist;
@synthesize dreamview;
@synthesize dreamTable;

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification{
    NSString *applicationPath = [[NSBundle mainBundle] bundlePath];
    NSString *filename = [applicationPath stringByAppendingPathComponent:@"dreams"];
    NSLog(self.description);

    dreamlist = [[NSMutableArray alloc] init];  
    dataset = [[NSMutableArray alloc] init];
    dataset = [NSKeyedUnarchiver unarchiveObjectWithFile:filename];
    if([dataset count] != 0) {
        int i = 0;
        while (i < [dataset count]) { 
            Dream *dr = [[Dream alloc] init];
            dr = [dataset objectAtIndex:i];
            [dreamlist addObject: dr.dreamname];         
            i++;
        }
    }    
    [dreamTable reloadData]; 
}

-(void)applicationWillTerminate:(NSNotification *)notification{       
    NSString *applicationPath = [[NSBundle mainBundle] bundlePath];
    NSString *filename = [applicationPath stringByAppendingPathComponent:@"dreams"];
    [NSKeyedArchiver archiveRootObject:dataset toFile:filename];
    NSLog(@"finish");
}

- (void) mouseUp:(NSEvent *)theEvent{
    long index = [dreamTable selectedRow];
    Dream *dr = [[Dream alloc] init];
    dr = [dataset objectAtIndex:index];
    dr.dreampicture = dreamview.image;
    [dataset replaceObjectAtIndex:index withObject:dr];
    NSLog(self.description);
}

- (void) tableViewSelectionDidChange: (NSNotification *) notification{
    long row = [dreamTable selectedRow];
    Dream *dr = [[Dream alloc] init];
    dr = [dataset objectAtIndex: row];
    if(dr.dreampicture != NULL) 
        dreamview.image = dr.dreampicture;
    NSLog(@"selected row changed");
}

Class “Dream”:

@interface Dream : NSObject <NSCoding>
{
    NSString *dreamname;
    NSImage *dreampicture;
}

@property (retain) NSString* dreamname;
@property (retain) NSImage* dreampicture;

-(id)initWithCoder:(NSCoder *)aDecoder;
-(void)encodeWithCoder:(NSCoder *)aCoder;

@end

What is wrong, why EXC_BAD_ACCESS occurs?I remind that I have xCode 4 with Automatic Reference Counting (ARC)

Thanks

UPDATE

I used Profile to find zombie event. So I found out this: An Objective-C message was sent to a deallocated object(zombie( at adress 0x108d85230)

Responsible Caller – [NSApplication(NSWindowCache) _checkForTerminateAfterLastWindowClosed: saveWindows:]

I had this function in code:

- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)sender{
    return TRUE;
}

However after I putted it in comments, this zombie event continue to occur.

Answer 1

The crash is caused by the fact that you made the window your application’s delegate. When you close the window, that is the last release that kills it off, and if it’s the last window you had up, it causes the application to ask its delegate whether it should quit. Since the window you just killed off is the application’s delegate, you get that crash.

Longer explanation and suggestion of solution in my answer on your subsequent question.