Does NSValue free its value when freed?

Question

Have a look at this pseudocode:

void* magicpointer = malloc(OVER_NINE_THOUSAND);
NSValue* v = [NSValue valueWithPointer:magicpointer];
[v release];

When v is released, does magicpointer get freed as well, or do I have to do that manually? I am using manual reference counting.

score 5 · Accepted Answer · answered Apr 13 '12 at 06:20

5

It doesn't get freed - NSValue is just a wrapper so you can treat arbitrary values as objects. It doesn't do anything with the wrapped pointer.

answered Apr 13 '12 at 06:20

Sven

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score 5 · Answer 2 · answered Apr 13 '12 at 06:35

5

No, NSValue won't.

Sounds like you might want to use NSData, it can free it's pointer when it's released:

    void* magicpointer = malloc(OVER_NINE_THOUSAND);
    NSData *d = [NSData dataWithBytesNoCopy:magicpointer
                                     length:OVER_NINE_THOUSAND
                               freeWhenDone:YES];
    //d is autoreleased, so no need to -release it.

answered Apr 13 '12 at 06:35

Vincent Gable

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Much more useful answer since it introduces an alternative way, thanks Vincent! – F.X. Jul 16 '12 at 18:58

score 1 · Answer 3 · answered Apr 13 '12 at 06:27

NSValue does not free the pointer when the NSValue is released. The only thing the documentation says about the pointer stored in an NSValue is:

If you create an NSValue object with an allocated data item, don’t deallocate its memory while the NSValue object exists.

The main reason for using an NSValue is to box a value so that it can be placed into an NSArray or similar collection which only accept objects. It wouldn't make sense for the memory to be freed simply because the NSValue box is no longer needed.

Does NSValue free its value when freed?

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