CODEWITHSUNDEEP
iosobjective-cmemory-leaksweak-references
Hugues BR
Hugues BR

Reputation: 2258

weakSelf as an iVar

I'm aware of the fact that you should use weakSelf in block that may survive yourself to avoid retain memory cycle. like:

__weak id weakSelf = self;
self.block = ^{
    [weakSelf something];
}

But I'm trying to find a generic way. I could use a macro like:

#define Weakify(o) __weak __typeof__((__typeof__(o))o)
#define WeakifySelf(o) Weakify(self) o = self;

WeakifySelf(weakSelf)
self.block = ^{
    [weakSelf something];
}

Which simplify, but I wonder why I can't use an ivar on my viewController.

@interface YDViewController : UIViewController
{
    __weak id _weakSelf;
}

and then use this iVar

self.block = ^{
    [_weakSelf something];
}

Any idea?

Upvotes: 1

Views: 274

Answers (1)

Catfish_Man
Catfish_Man

Reputation: 41801

The issue that sinks this idea is that [_weakSelf something] is, under the hood, exactly the same as [self->_weakSelf something].

So even though you're trying to use a weak reference, you end up using the strong reference to get to the weak reference and capturing both.

Upvotes: 7

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