Question

Code in my controller:

CalcBorderBlocks *calcBB = [[CalcBorderBlocks alloc] init];
NSMutableArray *blockArray = [calcBB calc:341241133];
[calcBB release]; // Releases calcBB.

Code in CalcBorderBlocks.h:

#import <Foundation/Foundation.h>

@interface CalcBorderBlocks : NSObject {
 @private
  NSMutableArray *blockArray_;
}
@property(nonatomic, retain) NSMutableArray *blockArray;

- (NSMutableArray *)calc:(int)blockID;

@end

Code in CalcBorderBlocks.m:

#import "CalcBorderBlocks.h"

@implementation CalcBorderBlocks
@synthesize blockArray = blockArray_;

- (id)init {
  self = [super init];
  if (self) {
    blockArray_ = [[NSMutableArray alloc] init]; // Retain count should be 1
  }
  return self;
}

- (NSMutableArray *)calc:(int)blockID {
// Do stuff
return self.blockArray;
}

- (void)dealloc {
  [blockArray_ release]; // Normal cleanup, yet crashes! Works fine if I comment out this line.
  [super dealloc];
}

@end

Answer 1

If you’re doing anything with blockArray after this line:

[calcBB release]; // Releases calcBB.

Then that’s the cause of the crash.

You’re releasing calcBB which in turn releases blockArray in dealloc.

I suspect you need to retain blockArray, process it as required then release it afterwards.

CalcBorderBlocks *calcBB = [[CalcBorderBlocks alloc] init];
NSMutableArray *blockArray = [[calcBB calc:341241133] retain];
[calcBB release]; // Releases calcBB.

// Process blockArray as needed

[blockArray release];