iOS Global Array?

@interface MySingleton : NSObject
{
	NSMutableArray *array;
}
//
// Singleton object accessor.  All access to this object should be done via this object.  Do not use [[MySingleton alloc] init];
+ (MySingleton *) sharedSingleton;
@property (retain, nonatomic) array;

@implementation MySingleton
@synthesize array;
static MySingleton *_sharedMySingleton = nil;
// Factory method.  Basically copied from http://developer.apple.com/documentation/Cocoa/Conceptual/CocoaFundamentals/CocoaObjects/chapter_3_section_10.html
+ (MySingleton *) sharedSingleton
{
    @synchronized(self)
	{
        if (_sharedMySingleton == nil) 
		{
            [[self alloc] init]; // assignment not done here
            self.array  = [NSMutableArray array];
        }
    }
    return _sharedMySingleton;
}
//
// Allocation method.  Basically copied from http://developer.apple.com/documentation/Cocoa/Conceptual/CocoaFundamentals/CocoaObjects/chapter_3_section_10.html
+ (id)allocWithZone:(NSZone *)zone
{
    @synchronized(self)
	{
        if (_sharedMySingleton == nil)
		{
            _sharedMySingleton = [super allocWithZone:zone];
            return _sharedMySingleton;  // assignment and return on first allocation
        }
    }
    return nil; //on subsequent allocation attempts return nil
}
//
// Cleans up the instance
- (void) dealloc
{
	self.array = nil;
	[super dealloc];
}
@end