hello_triangle sample should avoid referencing a retired swapchain #1015

[yaman-lunarg]

Description

By obtaining the image_count prior to the retirement of old_swapchain, Android warning is prevented.

Fixes #1015

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[asuessenbach]

As I don't have an Android environment to test, I can't tell if this change is valid. But it looks a bit strange... If it actually is an issue, could you please adjust hpp_hello_triangle accordingly?

[marty-johnson59]

HI @yaman-lunarg, this is still labeled "draft". Any thoughts on next steps? Thanks

[bradgrantham-lunarg]

Yaman no longer is available at that login. We probably won't carry forward this PR, we don't have any resource to handle the long to-do list.

We noted this failure on Android in logcat:

Running some vulkan samples, for example Hello Triangle on android with gfxr enabled a warning is issued:

02-27 19:12:17.625 31072 31130 W vulkan : getting images for non-active swapchain 0xb400007a8dd3ef70; only dequeued image handles are valid

It comes from here: https://android.googlesource.com/platform/frameworks/native/+/android-8.1.0_r9/vulkan/libvulkan/swapchain.cpp#1173

I've gotten this on Pixel 6, to reproduce just run Vulkan Samples and choose the Hello Triangle sample, with gfxr enabled

In reply to @asuessenbach the current code is incorrect under the spec (but there may not be a VUID). Passing old_swapchain to CreateSwapchainKHR makes old_swapchain retired, and images cannot then be acquired from that swapchain. This PR makes sure the images are acquired before the swapchain is retired.

Retired Swapchain A swapchain that has been used as the oldSwapchain parameter to vkCreateSwapchainKHR. Images cannot be acquired from a retired swapchain, however images that were acquired (but not presented) before the swapchain was retired can be presented.