Add KVO to NSURLSessionTask may cause crash.

[zjmdp]

The crashes are here: http://crashes.to/s/45830cf8ec3

I found the same issue discussed about AFNetworking. https://github.com/AFNetworking/AFNetworking/issues/1477

I searched all the code in my project that the category NSURLSessionTask+Timing with the observer on the property of NSURLSessionTask may cause the crash.

[garrettmoon]

@zjmdp well that's just… terrible :( How frequently are you seeing this crash?

[zjmdp]

Not very frequent, but it's the most frequently crash for my app.

[garrettmoon]

Ok, it'll probably be a bit before I can look at this, but if you decide to jump in before then, happy to review a pull request!

[zjmdp]

I just come back to beta.9 for work round. Maybe I need sometime to learn the code before attempting to fix it.

[xilin]

@garrettmoon Same problem happens on my app, the top 1 crash.
After reading on the AF issue 1477 and 2638, it seems that in the end they decided to use method swizzle instead of KVO (PR 2702) to fix it.
I'll try to create a pull request to fix it.

[workhardupc]

@zjmdp, We use 3.0.0-beta.11 has this problem, Does 3.0.0-beta.9 has this problem?

[garrettmoon]

@xilin Thank you for your heroic efforts attempting to fix this! It's really too bad this bug exists. Does anyone have confirmation it still exists in iOS 11?

[hovox]

It only happens on iOS 10.x, no iOS 9 or iOS 11.

[workhardupc]

@hovox same as us

[garrettmoon]

Aweeeeesome! I think I may suggest we wait this one out then 😬

[luohui8891]

Got same issue on iOS 11, see detail here

[workhardupc]

@garrettmoon Is there any way to use Texture, but not use PINRemoteImage?

[garrettmoon]

@workhardupc yes, I wrote the integration into Texture to be entirely pluggable.

[garrettmoon]

Hopefully the PR I put up addresses this. It's a pretty significant change but removes the need for KVO with the limitation that iOS 9 users and below don't get the benefits of knowing time to first byte.

[luohui8891]

@garrettmoon which PR? Would you mind to provide the URL?

[xilin]

@luohui8891 See PR#410

[luohui8891]

@xilin got it, thanks.