Objective-C methods not running - objective-c

Question

I'm messing around with using objects to launch background threads, however when I call an objects method to call the method that will spawn a background thread, nothing happens. I'm a bit puzzled as to why, and it looks like the -init function isn't even being called. Anyways, here's what I have:
ViewController.h
#import <UIKit/UIKit.h>
#import "Threader.h"
#interface ViewController : UIViewController
#property(nonatomic, strong) Thread* threadedObject;
- (IBAction)StartBackgroundThreadButtonClicked:(id)sender;
#end
ViewController.m
#import "ViewController.h"
#import "Threader.h"
#interface ViewController ()
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
_threadedObject = [[Threader alloc]init];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)StartBackgroundThreadButtonClicked:(id)sender {
NSLog(#"Clicked.");
[_threadedObject RunInBackground];
}
#end
Threader.h
#import <Foundation/Foundation.h>
#interface Threader : NSObject
#property(nonatomic) bool IsFinishedRunning;
#property(nonatomic) bool IsThreading;
//Constructor and Destructor
-(id)init;
-(void)dealloc;
-(void)RunInBackground;
-(void)WaitForTenSeconds;
#end
Threader.m
#import "Threader.h"
#implementation Threader
//constructor
-(id)init{
[super init];
if(self != nil)
{
_IsFinishedRunning = NO;
_IsThreading = NO;
}
return self;
}
//destructor
-(void)dealloc{
[super dealloc];
}
//Runs a thread in the background
-(void)RunInBackground{
NSLog(#"Initiating thread...");
[self performSelectorInBackground:#selector(WaitForTenSeconds) withObject:nil];
}
//Waits for 10 seconds, then sets IsFinishedRunning to YES
-(void)WaitForTenSeconds{
NSLog(#"Starting to run in the background.");
_IsThreading = YES;
sleep(10);
_IsFinishedRunning = YES;
NSLog(#"Finished running in the background.");
}
#end
When I run the program, this is my output(I clicked the button a few times)
2013-05-17 15:30:57.267 ThreadedObjects Clicked.
2013-05-17 15:30:59.003 ThreadedObjects Clicked.
2013-05-17 15:30:59.259 ThreadedObjects Clicked.
2013-05-17 15:30:59.443 ThreadedObjects Clicked.
2013-05-17 15:30:59.675 ThreadedObjects Clicked.
I should be getting messages telling me that the Threader object was created, and that it is preparing to launch a background thread, that the thread has been spawned and then after 10 seconds, that the thread is done running.
So, where's my glaring obvious error?

Answer 1

init isn't a constructor, it's for setup after construction. You need the class object to create an instance before you can send init, and, most importantly, you need to assign the results to your variable.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
threadedObject = [[Threader alloc] init];
}
You can't send alloc to an object that's not a class; instances don't respond to it. The only reason that this isn't crashing is that globals are initialized to 0/NULL/nil, and [nil someMessage] does nothing.
Not assigning the results to your variable is the same as:
int x = 0;
x + 10;
There's no change to x's value.
Additionally, you don't seem to have an ivar there, just a global variable. Ivars need to go into a curly-brace block at the head of the #implementation:
#implementation Threader
{
Threader * threadedObject;
}
// etc...

Answer 2

You never alloc the object.............
Also, this is curious:
#import <UIKit/UIKit.h>
#import "Threader.h"
#interface ViewController : UIViewController
- (IBAction)StartBackgroundThreadButtonClicked:(id)sender;
#end
Threader* threadedObject;
Where exactly did you declare the threadedObject? Like above? Use an iVar
or, better, a property for it!

Answer 3

A couple of reactions:
Show us where your definition and alloc/init of threadedObject.
I'm not sure what business problem you're trying to solve, but this smells like the precursor of some custom NSOperation solution. Operation queues are ideally suited for these sorts of implementations.
I'd be inclined to subclass NSOperation when trying to do something like this. See the custom NSOperation object in the Concurrency Programming Guide.
I'd suggest using camelCase for your method and variable names.
If you say with this, I'd steer you away from the "thread" name, as it might imply that you're doing something with NSThread, which you're not.