renderer_vulkan: Make unconditional use of VK_KHR_timeline_semaphore

This reworks how host<->device synchronization works on the Vulkan
backend. Instead of "protecting" resources with a fence and signalling
these as free when the fence is known to be signalled by the host GPU,
use timeline semaphores.

Vulkan timeline semaphores allow use to work on a subset of D3D12
fences. As far as we are concerned, timeline semaphores are a value set
by the host or the device that can be waited by either of them.

Taking advantange of this, we can have a monolithically increasing
atomic value for each submission to the graphics queue. Instead of
protecting resources with a fence, we simply store the current logical
tick (the atomic value stored in CPU memory). When we want to know if a
resource is free, it can be compared to the current GPU tick.

This greatly simplifies resource management code and the free status of
resources should have less false negatives.

To workaround bugs in validation layers, when these are attached there's
a thread waiting for timeline semaphores.

1 files changed, 5 insertions, 4 deletions

diff --git a/src/video_core/renderer_vulkan/vk_swapchain.h b/src/video_core/renderer_vulkan/vk_swapchain.h
index a35d61345..6b39befdf 100644
--- a/src/video_core/renderer_vulkan/vk_swapchain.h
+++ b/src/video_core/renderer_vulkan/vk_swapchain.h
@@ -16,11 +16,11 @@ struct FramebufferLayout;
 namespace Vulkan {
 
 class VKDevice;
-class VKFence;
+class VKScheduler;
 
 class VKSwapchain {
 public:
-    explicit VKSwapchain(VkSurfaceKHR surface, const VKDevice& device);
+    explicit VKSwapchain(VkSurfaceKHR surface, const VKDevice& device, VKScheduler& scheduler);
     ~VKSwapchain();
 
     /// Creates (or recreates) the swapchain with a given size.
@@ -31,7 +31,7 @@ public:
 
     /// Presents the rendered image to the swapchain. Returns true when the swapchains had to be
     /// recreated. Takes responsability for the ownership of fence.
-    bool Present(VkSemaphore render_semaphore, VKFence& fence);
+    bool Present(VkSemaphore render_semaphore);
 
     /// Returns true when the framebuffer layout has changed.
     bool HasFramebufferChanged(const Layout::FramebufferLayout& framebuffer) const;
@@ -74,6 +74,7 @@ private:
 
     const VkSurfaceKHR surface;
     const VKDevice& device;
+    VKScheduler& scheduler;
 
     vk::SwapchainKHR swapchain;
 
@@ -81,7 +82,7 @@ private:
     std::vector<VkImage> images;
     std::vector<vk::ImageView> image_views;
     std::vector<vk::Framebuffer> framebuffers;
-    std::vector<VKFence*> fences;
+    std::vector<u64> resource_ticks;
     std::vector<vk::Semaphore> present_semaphores;
 
     u32 image_index{};