Vulkan Validation Error when resizing

[darksylinc]

Godot version

master [4714e95]

System information

Godot v4.2.dev (4714e95) - Ubuntu 20.04.6 LTS (Focal Fossa) - X11 - Vulkan (Forward+) - dedicated AMD Radeon RX 6800 XT - AMD Ryzen 9 5900X 12-Core Processor (24 Threads)

Issue description

Sometimes when resizing the window on Linux X11 we may get the following validation error:

ERROR: VALIDATION - Message Id Number: -370888023 | Message Id Name: VUID-vkAcquireNextImageKHR-semaphore-01286
	Validation Error: [ VUID-vkAcquireNextImageKHR-semaphore-01286 ] Object 0: handle = 0xdcc8fd0000000012, type = VK_OBJECT_TYPE_SEMAPHORE; | MessageID = 0xe9e4b2a9 | vkAcquireNextImageKHR: Semaphore must not be currently signaled or in a wait state. The Vulkan spec states: If semaphore is not VK_NULL_HANDLE it must be unsignaled (https://vulkan.lunarg.com/doc/view/1.2.198.1/linux/1.2-extensions/vkspec.html#VUID-vkAcquireNextImageKHR-semaphore-01286)

I nailed down the problem. In VulkanContext::prepare_buffers we have the following loop (I simplified to highlight the problem):

do {

err = fpAcquireNextImageKHR(device, w->swapchain, UINT64_MAX,
							w->image_acquired_semaphores[frame_index], VK_NULL_HANDLE, &w->current_buffer);

if (err == VK_SUBOPTIMAL_KHR) {
	// Swapchain is not as optimal as it could be, but the platform's
	// presentation engine will still present the image correctly.
	print_verbose("Vulkan: Early suboptimal swapchain, recreating.");
	Error swap_chain_err = _update_swap_chain(w);
	if (swap_chain_err == ERR_SKIP) {
		break;
	}
} while (err != VK_SUCCESS);

The problem is that vkAcquireNextImageKHR returned VK_SUBOPTIMAL_KHR but it already signaled the semaphore (because it is possible to continue normally with a VK_SUBOPTIMAL_KHR result).

Then we recreate the swapchain and reuse the w->image_acquired_semaphores[frame_index] which is in an inconsistent state.

I will handle this bug.

Steps to reproduce

1. Open the Editor on any project
2. Resize the project until it happens

Reproducibility is much more frequent after applying PR #80566

Minimal reproduction project

Any.