Memory Leak on iOS: FastImage not released from memory when callbacks onLoad is set

[StevenMasini]

Changelog

Solution to the open issue #371

• Use a weak reference to self to call sendOnLoad in the sd_setImageWithPreviousCachedImageWithURL:placeholderImage:options:progress:completed:

Holding a strong reference to self in a block can lead to memory leaks as the block will hold the reference until it is called.

Always pass weak reference of self into block in ARC?

[adammcarth]

I seem to be getting two compile errors in XCode when running these changes:

1. Implicit conversion of an Objective-C pointer to 'FFFastImageView *const __weak *' is disallowed with ARC.

__weak typeof(self) *weakSelf = self;

2. Bad receiver type 'FFFastImageView *const __weak *'.

[weakSelf sendOnLoad:image];

[StevenMasini]

@adammcarth Okay I will have a look at it. Sound weird tho, you are not supposed to pass a strong pointer into a block.

[marf]

I seem to be getting two compile errors in XCode when running these changes:

1. Implicit conversion of an Objective-C pointer to 'FFFastImageView *const __weak *' is disallowed with ARC.

__weak typeof(self) *weakSelf = self;

1. Bad receiver type 'FFFastImageView *const __weak *'.

[weakSelf sendOnLoad:image];

Hello @adammcarth I have the same problem trying to applying the fix.
What should we do?

Thank you,
Marco

[marf]

I have tried also to change from __weak typeof(self) *weakSelf = self; to __weak FFFastImageView *weakSelf = self; and it compiles but the problem of the memory leak does not disappear.

[StevenMasini]

Yeah sorry guys my bad, the correct syntax is __weak typeof(self) weakSelf = self;. It's been a while since I wrote Objective C, I forgot that typeof(self) will already define the type as a pointer. So no need *.

But still this fix isn't enough to fix the memory leaks.

[StevenMasini]

Well okay I am stupid, I have been chasing a ghost 😓

Actually if you implement onLoadStart, onError or onLoadEnd and you try to retrieve a parameter from it. Then you will end up with a huge memory leak.

I was trying to retrieve error from onError, but actually the native part doesn't return it at all.

Well at least I have discovered that you can't retrieve a parameter that doesn't exist from a callback.

Anyway we still need to give a weak pointer of self to the completion block of SDWebImage.

[marf]

Hello, @StevenMasini and thank you.
So has this change fixed the memory leaks?

Also changing from RTCBubblingEventBlock to RTCDirectEventBlock fixes the fact of the parameters to the callback which may generate memory leaks?

Thank you,
Marco

[StevenMasini]

I am preparing another Pull Request with more fixes. I am closing this Pull Request as the new Pull Request will contain these fixes and more.