Comments on Captain Debug's Blog: Isn't Java a Civilised Language?

I made exactely the same experiences. I am a java ...

2012-03-01T06:54:52.481+00:00

I made exactely the same experiences. I am a java developer since 2005 and wrote an iPad-App at the end of the last year. The memory management was quite confusing for me but in this time ARC was even more confusing because on some parts I had do call retain/release-methods anyway (when using Core Graphics). And this inconsequence made me mad.
It seems to me that ARC is not completed jet.

I can see you point on circular references, which ...

2012-02-26T08:16:51.419+00:00

I can see you point on circular references, which I guess is something that Apple have thought about. Without going into detail, when using automatic reference counting, you can tell the compiler that a reference to an object maybe 'unsafe' and not reference count it; hence if A->B->A, object B knows that it's reference is unsafe, and it doesn't reference count it, it just has a copy of a pointer back to A.

In general terms - if you know a reference is unsafe, then your setter may look like this:

-(void) mySetter:(A *)myA {
_myA = myA;
}

If you know that the pointer is safe, then you do something like this:

-(void) mySetter:(A *)myA {
[_myA release];
_myA = myA;
[myA retain];
}

...where _myA is you instance variable and 'retain' gives you ownership.

What about circular references? A pointing to B an...

2012-02-24T17:18:48.301+00:00

What about circular references? A pointing to B and B pointing to A. Or a more complex path, A -> B -> C -> D -> B...

Does automatic compiler based retain/release calls just aggravate it?

I remember from way back when that COM and DCOM fell flat on its face because of circular references. It made any complicated application a complete nightmare, completely unacceptable to work with. You always get leaks eventually.

~Mike

Apple actually added garbage collection to Objecti...

2012-02-24T12:36:00.965+00:00

Apple actually added garbage collection to Objective-C before it added automatic reference counting. It never made it to iOS tho. And it has been abandoned again now.

Automatic reference counting is not really doing anything automatic at runtime tho. It simply adds the retain and release calls in the per-processor. So it can still be messed up by bad code.

This... String msg = new String().withFormat(&quo...

2012-02-23T18:42:39.277+00:00

This...

String msg = new String().withFormat("Processing an address page request for address with id: " + id);
logger.info(msg);
msg.release();

should be...

NSLog(@"blah %@",id);

Which logs to console and syslog. Also note that NSString can return autoreleased strings, and you don't retain parameters on sync code.

Here are the manual memory management rules of objc:

1. If you new, alloc init, retain, or copy (NARC) an object, you have to release it.
2. If a method doesn't start with any of these words it returns an autoreleased object.

You have to practice a bit, but it's just that.

Automatic Reference Counting (ARC) is a new featur...

2012-02-23T15:23:43.417+00:00

Automatic Reference Counting (ARC) is a new feature that Apple added to Objective-C which is supposed to generate the reference counting code for you. This is supposed to allow you to write simpler code without the slowdowns of a garbage collector.