Open Radar

 
Summary:
A mysterious crash has showed up on iOS11 (including 11.0.1, and 11.0.2), iPhone 5S/6/6+ since the first beta.

Here is what we know so far:
- The crash is specific to iOS11, iPhone 5S/6/6+. It doesn’t occur on 6S and up.
- The core of the OpenGL stack returns gpus_ReturnGuiltyForHardwareRestart
- It occurs when we attempt to invoke [EAGLContext presentRenderbuffer] from a CAEAGLLayer
- We don’t have a repro.
- This is currently the top iOS11 crash for the Instagram app, and second for the Facebook app (across all devices).

What we have tried so far:
- Remove any reference to VBO/VAO in our rendering stack. Didn’t help.
- We have tried reproing with a large range of drawing scenarios (rotation, resize, background/foreground). No luck.
- As far as we can tell, there is nothing specific in our application logic between the iPhone 6 family and the iPhone 6S family.

Some clues (that could be relevant but not necessarily):
- We know that when the presentRenderBuffer is invoked off main thread, and some CATransaction are occurring at the same time on the main thread, the crash rate goes up.
- When presentRenderBuffer is invoked on main thread (along with the whole drawing pipeline), the crash rate goes slightly down but not drastically.
- A substantial chunk (~20%) of the crashes occurs when the layer goes off screen and/or gets out of the view hierarchy.

Here is the stack trace:

libGPUSupportMercury.dylib gpus_ReturnGuiltyForHardwareRestart

1 AGXGLDriver gldUpdateDispatch
2 libGPUSupportMercury.dylib gpusSubmitDataBuffers
3 AGXGLDriver gldUpdateDispatch
4 GLEngine gliPresentViewES_Exec
5 OpenGLES -[EAGLContext presentRenderbuffer:]

Steps to Reproduce:
Unable to reproduce but we're seeing very large crash numbers in production

Expected Results:
N/A since we can not reproduce it

Actual Results:
N/A since we can not reproduce it

Version:
11.0.2

Notes:
- This is currently the top iOS11 crash for the Instagram app, and second for the Facebook app (across all devices).