Re: Is +[NSMutableArray initialize] completely implemented?

[Philip Mötteli]

Am 22.02.2004 um 01:10 schrieb Richard Frith-Macdonald:
> On 21 Feb 2004, at 23:49, Philip Mötteli wrote:

> The runtime should ensure that [NSArray+initialize] is called before 
> [NSMutableArray+initialize]

Is that sure? As I understood, the first time, a class receives a 
message, +initialize is called by the runtime. So if NSArray didn't 
receive a message before NSMutableArray receives its first message, it 
shouldn't be initialized.


> and that [NSMutableArray+initialize] is called before any other method 
> of the class, so I don't know how -initWithCapacity: could be called 
> without NSMutableArrayClass being initialised.
> or step through in debug yourself to find out what is going on?

I set a breakpoint in both +initialize, in NSMutableArray and NSArray 
and NSArray's initialize is clearly not called.


Re
Phil




> > I'm trying to track down a strange exception, that I never had before 
> > the last CVS update:
> >
> > : Uncaught exception NSGenericException, reason: subclass 
> > NSMutableArray(instance) should override initWithCapacity:
> >
> >
> > The backtrace, that leads to that is the following:
> >
> > +[NSException raise:format:arguments:]
> > +[NSException raise:format:]
> > -[NSObject(GSCategories) subclassResponsibility:]
> > -[NSMutableArray initWithCapacity:]
> > -[NSMutableArray initWithObjects:count:]
> > -[NSArray init]
> > -[EDStack init]
> > +[EDStack stack]
> >
> >
> > So all happens during a very early phase of the program. Most classes 
> > haven't been called once yet.
> > I'm not sure, but I have the impression, that the problem could 
> > perhaps be situated here:
> >
> >
> > @implementation NSMutableArray
> >
> > + (void) initialize
> > {
> >   if (self == [NSMutableArray class])
> >     {
> >     }
> > }
> >
> > + (id) allocWithZone: (NSZone*)z
> > {
> >   if (self == NSMutableArrayClass)
> >     {
> >       return NSAllocateObject(GSMutableArrayClass, 0, z);
> >     }
> >   else
> >     {
> >       return NSAllocateObject(self, 0, z);
> >     }
> > }
> > ...
> >
> >
> > Shouldn't there be some more code in + initialize? Because in the 
> > debugger the variable NSMutableArrayClass is been shown as having the 
> > value nil.
> > Probably, the problem is because +[NSArray initialize] has not yet 
> > been called, is it? There should be a mechanisme, that assures that 
> > or that initializes the same data.