Implement Fence Cycle, Memory Manager and Command Scheduler

Implements a wrapper over fences to track a single cycle of activation, implement a Vulkan memory manager that wraps the Vulkan-Memory-Allocator library and a command scheduler for scheduling Vulkan command buffers

app/src/main/cpp/skyline/gpu/command_scheduler.cpp

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2021 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#include <gpu.h>
+#include "command_scheduler.h"
+
+namespace skyline::gpu {
+    CommandScheduler::CommandBufferSlot::CommandBufferSlot(vk::raii::Device &device, vk::CommandBuffer commandBuffer, vk::raii::CommandPool &pool) : active(true), device(device), commandBuffer(device, commandBuffer, pool), fence(device, vk::FenceCreateInfo{}), cycle(std::make_shared<FenceCycle>(device, *fence)) {}
+
+    bool CommandScheduler::CommandBufferSlot::AllocateIfFree(CommandScheduler::CommandBufferSlot &slot) {
+        if (slot.active.test_and_set(std::memory_order_acq_rel)) {
+            if (slot.cycle->Poll()) {
+                slot.cycle = std::make_shared<FenceCycle>(slot.device, *slot.fence);
+                return true;
+            } else {
+                slot.active.clear(std::memory_order_release);
+            }
+        }
+        return false;
+    }
+
+    CommandScheduler::CommandScheduler(GPU &pGpu) : gpu(pGpu), vkCommandPool(pGpu.vkDevice, vk::CommandPoolCreateInfo{
+        .flags = vk::CommandPoolCreateFlagBits::eTransient | vk::CommandPoolCreateFlagBits::eResetCommandBuffer,
+        .queueFamilyIndex = pGpu.vkQueueFamilyIndex,
+    }) {}
+
+    CommandScheduler::ActiveCommandBuffer CommandScheduler::AllocateCommandBuffer() {
+        auto slot{std::find_if(commandBuffers.begin(), commandBuffers.end(), CommandBufferSlot::AllocateIfFree)};
+        if (slot != commandBuffers.end())
+            return ActiveCommandBuffer(*slot);
+
+        std::scoped_lock lock(mutex);
+        vk::CommandBuffer commandBuffer;
+        vk::CommandBufferAllocateInfo commandBufferAllocateInfo{
+            .commandPool = *vkCommandPool,
+            .level = vk::CommandBufferLevel::ePrimary,
+            .commandBufferCount = 1,
+        };
+
+        auto result{(*gpu.vkDevice).allocateCommandBuffers(&commandBufferAllocateInfo, &commandBuffer, *gpu.vkDevice.getDispatcher())};
+        if (result != vk::Result::eSuccess)
+            vk::throwResultException(result, __builtin_FUNCTION());
+        return ActiveCommandBuffer(commandBuffers.emplace_back(gpu.vkDevice, commandBuffer, vkCommandPool));
+    }
+
+    void CommandScheduler::SubmitCommandBuffer(const vk::raii::CommandBuffer &commandBuffer, vk::Fence fence) {
+        std::lock_guard lock(gpu.queueMutex);
+        gpu.vkQueue.submit(vk::SubmitInfo{
+            .commandBufferCount = 1,
+            .pCommandBuffers = &*commandBuffer,
+        }, fence);
+    }
+}