Re: gworkspace - ddbd connection problems

[Riccardo Mottola]

Hi Fred,

Fred Kiefer wrote:
> That is easy to explain. You get back an autoreleased array from 
> metadataForPath:. As there is an autorelease pool around that code, 
> this array will get released within the autorelease pool. Next you 
> return that now invalid object from your method. The caller will may 
> get an invalid pointer.
> This is the second basic memory management rule you have to learn when 
> coding Objective-C (the first being to match release and retain 
> calls), if you need to hold on to a variable retain it.
> I don't see why you would need an autorelease pool here, but if there 
> is reason for it, you need to retain usrdata when assigning it and 
> autorelease it in the return line.
thanks. I know that, but I missed it in that contxt. I had a closer 
look: it appears that all ddbd methods that return information for paths 
have the structure

create arp;
get information thorugh the path manager
retain information
release arp
return the information autoreleased.

Except that method found by Sebastian. I suppose Enrico or whoever wrote 
this was worried that some kind of recursion would bloat the autorelease 
pool too much due to some kind of recursion when thedding the data 
through the path manager. It can't be that the autorelease pool was 
missing, or the autorelease of the return information would not work either.

I think I will fix the mtehod which lack that  structure and for some 
reason lack the extra retain and autorelease of the retain information. 
However, probably, it makes only sense to do this if the information is 
gotten through something recursive (like an array of information), 
otherwise it is excessive optimization.

Riccardo