From 3e08494146d60c0c484d704bc141046e57df4e8b Mon Sep 17 00:00:00 2001
From: PixelyIon <pixelyion@protonmail.com>
Date: Sun, 5 Jun 2022 12:26:58 +0530
Subject: [PATCH] Minor `CommandScheduler` refactor

There was a lot of redundant code in the `CommandScheduler` when the same functionality could be achieved with much shorter and cleaner code which this commit fixes. This includes no changes to the user-facing API and does not require any changes on the user side as a result.
---
 .../cpp/skyline/gpu/command_scheduler.cpp     | 30 ++++++++-----------
 .../main/cpp/skyline/gpu/command_scheduler.h  |  6 ----
 2 files changed, 12 insertions(+), 24 deletions(-)

diff --git a/app/src/main/cpp/skyline/gpu/command_scheduler.cpp b/app/src/main/cpp/skyline/gpu/command_scheduler.cpp
index 91e7ae96..f41e9187 100644
--- a/app/src/main/cpp/skyline/gpu/command_scheduler.cpp
+++ b/app/src/main/cpp/skyline/gpu/command_scheduler.cpp
@@ -11,29 +11,23 @@ namespace skyline::gpu {
           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.commandBuffer.reset();
-                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), pool(std::ref(pGpu.vkDevice), vk::CommandPoolCreateInfo{
         .flags = vk::CommandPoolCreateFlagBits::eTransient | vk::CommandPoolCreateFlagBits::eResetCommandBuffer,
         .queueFamilyIndex = pGpu.vkQueueFamilyIndex,
     }) {}
 
     CommandScheduler::ActiveCommandBuffer CommandScheduler::AllocateCommandBuffer() {
-        auto slot{std::find_if(pool->buffers.begin(), pool->buffers.end(), CommandBufferSlot::AllocateIfFree)};
-        auto slotId{std::distance(pool->buffers.begin(), slot)};
-        if (slot != pool->buffers.end())
-            return ActiveCommandBuffer(*slot);
+        for (auto &slot : pool->buffers) {
+            if (!slot.active.test_and_set(std::memory_order_acq_rel)) {
+                if (slot.cycle->Poll()) {
+                    slot.commandBuffer.reset();
+                    slot.cycle = std::make_shared<FenceCycle>(slot.device, *slot.fence);
+                    return {slot};
+                } else {
+                    slot.active.clear(std::memory_order_release);
+                }
+            }
+        }
 
         vk::CommandBuffer commandBuffer;
         vk::CommandBufferAllocateInfo commandBufferAllocateInfo{
@@ -45,7 +39,7 @@ namespace skyline::gpu {
         auto result{(*gpu.vkDevice).allocateCommandBuffers(&commandBufferAllocateInfo, &commandBuffer, *gpu.vkDevice.getDispatcher())};
         if (result != vk::Result::eSuccess)
             vk::throwResultException(result, __builtin_FUNCTION());
-        return ActiveCommandBuffer(pool->buffers.emplace_back(gpu.vkDevice, commandBuffer, pool->vkCommandPool));
+        return {pool->buffers.emplace_back(gpu.vkDevice, commandBuffer, pool->vkCommandPool)};
     }
 
     void CommandScheduler::SubmitCommandBuffer(const vk::raii::CommandBuffer &commandBuffer, vk::Fence fence) {
diff --git a/app/src/main/cpp/skyline/gpu/command_scheduler.h b/app/src/main/cpp/skyline/gpu/command_scheduler.h
index 73a30bee..7ac4c6cf 100644
--- a/app/src/main/cpp/skyline/gpu/command_scheduler.h
+++ b/app/src/main/cpp/skyline/gpu/command_scheduler.h
@@ -23,12 +23,6 @@ namespace skyline::gpu {
             std::shared_ptr<FenceCycle> cycle; //!< The latest cycle on the fence, all waits must be performed through this
 
             CommandBufferSlot(vk::raii::Device &device, vk::CommandBuffer commandBuffer, vk::raii::CommandPool &pool);
-
-            /**
-             * @brief Attempts to allocate the buffer if it is free (Not being recorded/executing)
-             * @return If the allocation was successful or not
-             */
-            static bool AllocateIfFree(CommandBufferSlot &slot);
         };
 
         GPU &gpu;