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.
Update validation layer string to VK_LAYER_KHRONOS_validation.
While we are at it, properly check for available validation layers
before enabling them.
Check() can throw an exception if the Vulkan result isn't successful.
We remove the check so that std::terminate isn't outright called and
allows for better debugging (should it ever actually fail).
Drop MemoryBarrier from the buffer cache and use Maxwell3D's register
WaitForIdle.
To implement this on OpenGL we just call glMemoryBarrier with the
necessary bits.
Vulkan lacks this synchronization primitive, so we set an event and
immediately wait for it. This is not a pretty solution, but it's what
Vulkan can do without submitting the current command buffer to the queue
(which ends up being more expensive on the CPU).
Adds optional support for Nsight Aftermath. It is enabled through
ENABLE_NSIGHT_AFTERMATH in cmake. A path to the SDK has to be provided
by the environment variable NSIGHT_AFTERMATH_SDK.
Nsight Aftermath allows an application to generate "minidumps" of the
GPU state when a device loss happens. By analysing these on Nsight we
can know what a game was doing and why it triggered a device loss.
The dump is generated inside %APPDATA%\yuzu\log\gpucrash and this
directory is deleted every time a new instance is initialized with
Nsight enabled.
To enable it on yuzu there has a to be a driver and device capable of
running Nsight Aftermath on Vulkan. That means only Turing based GPUs
on the latest stable driver, beta drivers won't work for now.
It is manually enabled in Configuration>Debug>Enable Graphics Debugging
because when using all debugging capabilities there is a runtime cost.
The intention behind a Vulkan wrapper is to drop Vulkan-Hpp.
The issues with Vulkan-Hpp are:
- Regular breaks of the API.
- Copy constructors that do the same as the aggregates (fixed recently)
- External dynamic dispatch that is hard to remove
- Alias KHR handles with non-KHR handles making it impossible to use
smart handles on Vulkan 1.0 instances with extensions that were included
on Vulkan 1.1.
- Dynamic dispatchers silently change size depending on preprocessor
definitions. Different files will have different dispatch definitions,
generating all kinds of hard to debug memory issues.
In other words, Vulkan-Hpp is not "production ready" for our needs and
this wrapper aims to replace it without losing RAII and exception
safety.
