Thread 1:EXC_BAD_ACCESS code = 1 float *

Question

I know that there are a tons of question with same question, but no one helped me.

I have Object DimensionItemHolder and property :

@property(nonatomic) float *  sum;

in recursion function I have :

DimensionItemHolder * holder = [self getDimensionItemWhitIndex:[dimensionItem.dimItemID shortValue]];

if (holder)
{

    NSLog(@"%f , %f , %f , %f , %f  : %p", holder.sum[0],holder.sum[1],holder.sum[2],holder.sum[3],holder.sum[4] , holder.sum);

    [self.itemOrderdArray removeObject:holder];
    [self substractSum:holder.sum];
    NSLog(@"%p", holder.sum);
    return holder.sum;
}

And after few iteration xcode throw

Thread 1: EXC_BAD_ACCESS(code = 1, address 0xc080000c)

at line

NSLog(@"%p", holder.sum);

I figer it out that it has to do whit function

[self substractSum:holder.sum];

(if I comment it it works)

the function is :

-(void)substractSum:(float *)subSum{
if (subSum) {
    self.sum[0] = self.sum[0] - subSum[0];
    self.sum[1] = self.sum[1] - subSum[1];
    self.sum[2] = self.sum[2] - subSum[2];
    self.sum[3] = self.sum[3] - subSum[3];
    self.sum[4] = self.sum[4] - subSum[4];
}

}

Can you please show us where you malloc/free the array? Also, try explicitly marking the property as `(nonatomic, assign)`, I wonder if that would make a difference. — Guy Kogus, Dec 02 '13 at 10:06
Try executing code with NSZombie enabled which will give you a log of which released object is being referenced. How to enable NSZmobie? check [here](http://stackoverflow.com/questions/2190227/how-do-i-set-up-nszombieenabled-in-xcode-4). — dispatchMain, Dec 02 '13 at 10:08
I malloc it at the init state of the object and free it at -(void)dealloc — Marko Zadravec, Dec 02 '13 at 10:15
Ad-J, I would like to use NSZombie, but problem is that I do samo very memory intensive work, and if I enable NSZombies it go out of memory — Marko Zadravec, Dec 02 '13 at 10:19
Does adding an exceptions breakpoint help pinpoint the breaking line of code? — Guy Kogus, Dec 02 '13 at 10:29
I'm guessing your problem is not anywhere in the posted code, as it all looks kosher. — Guy Kogus, Dec 02 '13 at 10:49

score 0 · Answer 1 · answered Dec 02 '13 at 10:00

0

I guess you're using float * to enjoy C pointer characteristics and do sum[i]. But here you are in objectiveC, use NSArray filled with floats.

answered Dec 02 '13 at 10:00

shinyuX

1,519
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Yes that is the reason of float *. I use it because of performance issue. But there is no reason why should use NSArray for this bug – Marko Zadravec Dec 02 '13 at 10:05
1

An `NSArray` object can't hold floats. You'd need to use `NSNumber`s with float values. Same same but different :) – Guy Kogus Dec 02 '13 at 10:05
as Guy Kongus say, nsarray needs objects and those object must be created as NSArray and that needs time. If you fill 500 000 data in the data set there is a diference in a 4 min of using NSArray or float *. But this stil dont answer my question. – Marko Zadravec Dec 02 '13 at 10:12

score 0 · Accepted Answer · answered Dec 02 '13 at 11:29

0

I finally figure it out.

It was stupid thing. I malloc memory for 4 floats and I ask him for holder[4] which is 5 element.

Thanks all for help

answered Dec 02 '13 at 11:29

Marko Zadravec

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Thread 1:EXC_BAD_ACCESS code = 1 float *

2 Answers2