gistfile1.txt

@implementation MySingleton

static MySingleton* _instance = nil;

+(id)alloc {
	@synchronized([MySingleton class]) {
		NSAssert(_instance == nil, @"Error. Don't use alloc on singloetons.");
		_instance = [super alloc];
		return _instance;
	}
	return nil;
}

+(MySingleton*)init {
	@synchronized([MySingleton class]) {
		if (!_instance) {
			[[self alloc] _init];
        }
		return _instance;
	}
	return nil;
}

-(id)_init {
    NSLog(@"initing singleton");
}

@end