Hang on swapchain destruction

[acgaudette]

Likely related to #19?

I have noticed for awhile that occasionally my app hangs in debug mode at exit (and never closes). I did some digging. This also occurs in the hello.rs example for me as well, i.e. after "Goodbye!" the application never closes.

I was unable to check with the address sanitizer since it only dumps output after program completion. However, I did trace the method calls. The hang occurs in the Drop implementation for the Swapchain KHR, which then calls device.destroy_swapchain_khr(), which hangs on vkDestroySwapchainKHR() (I have confirmed it is this method). At that point, we're in vks, and I hit a dead end.

I confirmed that the swapchain and device handles were legitimate--they match the values at create time. On my end, there is a single refresh of the swapchain, so two swapchains are created. The first is dropped successfully, and the second one hangs. Because of this, the device, instance, etc. are never dropped.

For reference, I'm on linux with an intel UHD graphics 620.

[c0gent]

I've been neglecting this repo a bit lately (lots on the plate). I'll take a look at this asap.

Thanks for the detailed report!