Re: +initialize and static (class) variables

[Richard Frith-Macdonald]

On Tuesday, September 4, 2001, at 03:55 PM, Aurelien wrote:

> Hi again,
>
> (My previous problem with exceptions actually boiled down to this one)
>
> I have an implementation like so:
>
> static NSArray *advRequiredConstructors;
> static AdvertisementFactory *advFactory;
>
> @implementation AdvertisementFactory
>
> + initialize
> {
>   NSLog ( @"Calling initialize" );
>   advFactory = [[AdvertisementFactory alloc] init];
>   advRequiredConstructors = [[NSArray alloc] initWithObjects: nil];
> }
> ....
>
> As you can see, this is a singleton class. It turns out, strangely, 
> that initializing advFactory works, but the program hangs when it's 
> advRequiredConstructors' turn (i.e. commenting out the last line gets 
> the job done)

Well, the above code looks fine, and works for me.
The only unusual thing about 'advRequiredConstructors = [[NSArray alloc] 
initWithObjects: nil]' is
that it is a varargs method ... so it does begin to sound as if you have 
compiler problems, or perhaps
you picked up an incorrect stdarg.h/varargs.h when you built the 
libraries?

> I have to mention that I *did* something wrong from the start, but 
> until now there was no problem with that. I still don't have my mind 
> set about the AutoreleasePool bits, so I didn't create one in the 
> beginning. Could that be the problem ? Also, it would be nice from one 
> of you to send me the snippet that sets up the AutoreleasePool !

Since you aren't using autorelease, I don't think that the lack of a 
pool can be a problem (in any case,
if you don't have a pool set up you should just leak memory and get 
warning messages logged - nothing
to cause a hang or crash).

However, FYI the simplest way to do a pool is -

{
  CREATE_AUTORELEASE_POOL(pool);

  // Your code here ...

  RELEASE(pool);
}

which is just a macro version (allowing for future use of boehm GC) of

{
  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

  // Your code here ...

  [pool release];
}