Re: More GC. Now with NSData

FROM : Paul Sargent
DATE : Mon Nov 26 21:38:10 2007

On 26 Nov 2007, at 17:44, Alastair Houghton wrote:

> On 26 Nov 2007, at 17:20, Paul Sargent wrote:
>

>> My question is this, I've created these NSDatas without copying the 
>> bytes, so have I put myself in a position where the garbage 
>> collector could release the memory beneath them if the original 
>> fullDataDump NSData was released?

>
> Yes.  The garbage collector doesn't support interior pointers.  You 
> need to keep the original object around by holding on to a reference 
> to it until you're done with all of your data objects.
>
> A better approach to the problem would be to use NSData's -
> subdataWithRange: method; that will avoid having to do pointer 
> arithmetic and will also avoid entirely the problem with the garbage 
> collector.


Ahh, Thanks. Still not 100% familiar with all the functionality 
available.

Just to be clear, -subdataWithRange will make a copy of the data into 
it's own buffer, which the new NSData will own. Hence it'll be safe. 
Right?