⭐ Vulkan & CMake/Vulkan
[Vulkan] Command Pool
Designerd
2024. 8. 6. 12:02
목차
인프런 삼각형님의 '삼각형의 실전! Vulkan 중급' 강의를 참고하였습니다.
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Command Pool
Vulkan Command pool이란?
- Vulkan Command buffer를 할당하고 관리하는 객체다.
- Vulkan Command pool은 특정 Queue family에 바인딩된다.
- Vulkan Command pool은 스레드 안정성이 보장되지 않아 스레드마다 생성해야 한다.
- Vulkan은 최대한 오버헤드를 줄이기 위해 설계되었다
- 스레드 안정을 보장하는 것은 동기화 비용을 발생시키기 때문에, Vulkan의 경우 개발자가 명시적으로 Command Pool의 동기화를 직접 관리하게 했다. 이렇게 명시적으로 관리함으로써 더 효율적인 멀티스레딩 성능을 달성할 수 있다.
Vulkan Command pool 생성
Command Pool을 생성하기 위해서는 Queue family index가 필요하며 Command Pool이 어떻게 동작할지 결정해야 한다.
그 후 vkCreateCommandPool을 호출하여 Command Pool를 생성한다.
VkCommandPoolCreateInfo 구조체
typedef struct VkCommandPoolCreateInfo {
VkStructureType sType;
const void* pNext;
VkCommandPoolCreateFlags flags;
uint32_t queueFamilyIndex;
} VkCommandPoolCreateInfo;
| 매개 변수 | 설명 |
| sType | 구조체 타입 |
| pNext | NULL 또는 확장 기능 구조체의 포인터 |
| flags | Vulkan Command pool의 동작을 정의 |
| queueFamilyIndex | Queue family index |
VkCommandPoolCreateFlagBits 이해하기
typedef enum VkCommandPoolCreateFlagBits {
VK_COMMAND_POOL_CREATE_TRANSIENT_BIT = 0x00000001,
VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT = 0x00000002,
VK_COMMAND_POOL_CREATE_PROTECTED_BIT = 0x00000004,
} VkCommandPoolCreateFlagBits;
VK_COMMAND_POOL_CREATE_TRANSIENT_BIT은 Vulkan Command buffer가 자주 변경될 것임을 Vulkan 드라이버에 알려주어 메모리 할당을 보다 효율적으로 관리할 수 있도록 도와준다.
VK_COMMAND_POOL_RESET_COMMAND_BUFFER_BIT은 Vulkan Command buffer를 개별적으로 재설정할 수 있도록 한다.
- 기본적으로 Command buffer는 개별적으로 리셋을 할 수 없다. 대신 Command Pool을 리셋해서 모든 Command buffer를 한 번에 리셋한다.
- 반면에 Reset Command buffer를 사용하면 Command buffer를 개별적으로 리셋할 수 있어 더 유연한 Command buffer 관리가 가능하다.
VkCommandPoolCreateInfo 구조체
VkCommandPoolCreateInfo commandPoolCreateInfo{
.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO,
.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT,
.queueFamilyIndex = mQueueFamilyIndex
};
Vulkan Command pool 생성
VkResult vkCreateCommandPool(
VkDevice device,
const VkCommandPoolCreateInfo* pCreateInfo,
const VkAllocationCallbacks* pAllocator,
VkCommandPool* pCommandPool);
| 매개 변수 | 설명 |
| device | VkDevice |
| pCreateInfo | VkCommandPoolCreateInfo 변수의 포인터 |
| pAllocator | 일단 NULL을 사용 |
| pCommandPool | VkCommandPool 변수의 포인터 |
Vulkan Command pool 파괴
void vkDestroyCommandPool(
VkDevice device,
VkCommandPool commandPool,
const VkAllocationCallbacks* pAllocator);
| 매개 변수 | 설명 |
| device | VkDevice |
| pCommandPool | VkCommandPool 변수의 포인터 |
| pAllocator | 일단 NULL을 사용 |
#include ...
using namespace std;
VkRenderer::VkRenderer() {
// 1. VkInstance 생성
// 2. VkPhysicalDevice 선택
// 3. VkDevice 생성
// 4. VkSurface 생성
// 5. VkSwapchain 생성
// ================================================================================
// 6. VkCommandPool 생성
// ================================================================================
VkCommandPoolCreateInfo commandPoolCreateInfo{
.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO,
.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT, // command buffer를 개별적으로 초기화 가능하게 설정
.queueFamilyIndex = mQueueFamilyIndex
};
VK_CHECK_ERROR(vkCreateCommandPool(mDevice, &commandPoolCreateInfo, nullptr, &mCommandPool)); // mCommandPool 생성
}
VkRenderer::~VkRenderer() {
vkDestroyCommandPool(mDevice, mCommandPool, nullptr);
...
}
전체 코드
더보기
// MIT License
//
// Copyright (c) 2024 Daemyung Jang
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#include <cassert>
#include <array>
#include <vector>
#include "VkRenderer.h"
#include "VkUtil.h"
#include "AndroidOut.h"
using namespace std;
VkRenderer::VkRenderer() {
// ================================================================================
// 1. VkInstance 생성
// ================================================================================
// VkApplicationInfo 구조체 정의
VkApplicationInfo applicationInfo{
.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO,
.pApplicationName = "Practice Vulkan",
.applicationVersion = VK_MAKE_API_VERSION(0, 0, 1, 0),
.apiVersion = VK_MAKE_API_VERSION(0, 1, 3, 0)
};
// 사용할 수 있는 레이어를 얻어온다.
uint32_t instanceLayerCount;
VK_CHECK_ERROR(vkEnumerateInstanceLayerProperties(&instanceLayerCount, nullptr));
vector<VkLayerProperties> instanceLayerProperties(instanceLayerCount);
VK_CHECK_ERROR(vkEnumerateInstanceLayerProperties(&instanceLayerCount,
instanceLayerProperties.data()));
// 활성화할 레이어의 이름을 배열로 만든다.
vector<const char*> instanceLayerNames;
for (const auto &layerProperty : instanceLayerProperties) {
instanceLayerNames.push_back(layerProperty.layerName);
}
uint32_t instanceExtensionCount; // 사용 가능한 InstanceExtension 개수
VK_CHECK_ERROR(vkEnumerateInstanceExtensionProperties(nullptr,
&instanceExtensionCount,
nullptr));
vector<VkExtensionProperties> instanceExtensionProperties(instanceExtensionCount);
VK_CHECK_ERROR(vkEnumerateInstanceExtensionProperties(nullptr,
&instanceExtensionCount,
instanceExtensionProperties.data()));
vector<const char *> instanceExtensionNames; // instanceExtensionName을 담는 배열
for (const auto &properties: instanceExtensionProperties) {
if (properties.extensionName == string("VK_KHR_surface") ||
properties.extensionName == string("VK_KHR_android_surface")) {
instanceExtensionNames.push_back(properties.extensionName);
}
}
assert(instanceExtensionNames.size() == 2); // 반드시 2개의 이름이 필요하기 때문에 확인
// sType: 구조체의 타입, pApplicationInfo: 어플리케이션의 이름
// enabledLayerCount, ppEnableLayerNames: 사용할 레이어의 정보를 정의
VkInstanceCreateInfo instanceCreateInfo{
.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,
.pApplicationInfo = &applicationInfo,
.enabledLayerCount = static_cast<uint32_t>(instanceLayerNames.size()),
.ppEnabledLayerNames = instanceLayerNames.data(),
.enabledExtensionCount = static_cast<uint32_t>(instanceExtensionNames.size()),
.ppEnabledExtensionNames = instanceExtensionNames.data()
};
// vkCreateInstance로 인스턴스 생성. 생성된 인스턴스가 mInstance에 쓰여진다.
VK_CHECK_ERROR(vkCreateInstance(&instanceCreateInfo, nullptr, &mInstance));
// ================================================================================
// 2. VkPhysicalDevice 선택
// ================================================================================
uint32_t physicalDeviceCount;
VK_CHECK_ERROR(vkEnumeratePhysicalDevices(mInstance, &physicalDeviceCount, nullptr));
vector<VkPhysicalDevice> physicalDevices(physicalDeviceCount);
VK_CHECK_ERROR(vkEnumeratePhysicalDevices(mInstance, &physicalDeviceCount, physicalDevices.data()));
// 간단한 예제를 위해 첫 번째 VkPhysicalDevice를 사용
mPhysicalDevice = physicalDevices[0];
VkPhysicalDeviceProperties physicalDeviceProperties; // 이 구조체 안에 GPU에 필요한 모든 정보가 있다.
vkGetPhysicalDeviceProperties(mPhysicalDevice, &physicalDeviceProperties);
aout << "Selected Physical Device Information ↓" << endl;
aout << setw(16) << left << " - Device Name: "
<< string_view(physicalDeviceProperties.deviceName) << endl;
aout << setw(16) << left << " - Device Type: "
<< vkToString(physicalDeviceProperties.deviceType) << endl;
aout << std::hex;
aout << setw(16) << left << " - Device ID: " << physicalDeviceProperties.deviceID << endl;
aout << setw(16) << left << " - Vendor ID: " << physicalDeviceProperties.vendorID << endl;
aout << std::dec;
aout << setw(16) << left << " - API Version: "
<< VK_API_VERSION_MAJOR(physicalDeviceProperties.apiVersion) << "."
<< VK_API_VERSION_MINOR(physicalDeviceProperties.apiVersion);
aout << setw(16) << left << " - Driver Version: "
<< VK_API_VERSION_MAJOR(physicalDeviceProperties.driverVersion) << "."
<< VK_API_VERSION_MINOR(physicalDeviceProperties.driverVersion);
// ================================================================================
// 3. VkDevice 생성
// ================================================================================
uint32_t queueFamilyPropertiesCount;
//---------------------------------------------------------------------------------
//** queueFamily 속성을 조회
// 사용 가능한 queueFamily의 수(=queueFamilyPropertiesCount)를 얻어온다.
vkGetPhysicalDeviceQueueFamilyProperties(mPhysicalDevice, &queueFamilyPropertiesCount, nullptr);
vector<VkQueueFamilyProperties> queueFamilyProperties(queueFamilyPropertiesCount);
// 해당 queueFamily들의 속성을 배열에 얻어온다.
vkGetPhysicalDeviceQueueFamilyProperties(mPhysicalDevice, &queueFamilyPropertiesCount, queueFamilyProperties.data());
//---------------------------------------------------------------------------------
// 특정 queueFamilyProperties가 VK_QUEUE_GRAPHICS_BIT를 지원하는지 확인.
// 지원하는 queueFamilyProperties를 찾으면 break. queueFamily에 대한 정보는 mQueueFamilyIndex에 저장.
for (mQueueFamilyIndex = 0;
mQueueFamilyIndex != queueFamilyPropertiesCount; ++mQueueFamilyIndex) {
if (queueFamilyProperties[mQueueFamilyIndex].queueFlags & VK_QUEUE_GRAPHICS_BIT) {
break;
}
}
// 생성할 큐를 정의
const vector<float> queuePriorities{1.0};
VkDeviceQueueCreateInfo deviceQueueCreateInfo{
.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,
.queueFamilyIndex = mQueueFamilyIndex, // queueFamilyIndex
.queueCount = 1, // 생성할 큐의 개수
.pQueuePriorities = queuePriorities.data() // 큐의 우선순위
};
uint32_t deviceExtensionCount; // 사용 가능한 deviceExtension 개수
VK_CHECK_ERROR(vkEnumerateDeviceExtensionProperties(mPhysicalDevice,
nullptr,
&deviceExtensionCount,
nullptr));
vector<VkExtensionProperties> deviceExtensionProperties(deviceExtensionCount);
VK_CHECK_ERROR(vkEnumerateDeviceExtensionProperties(mPhysicalDevice,
nullptr,
&deviceExtensionCount,
deviceExtensionProperties.data()));
vector<const char *> deviceExtensionNames;
for (const auto &properties: deviceExtensionProperties) {
if (properties.extensionName == string("VK_KHR_swapchain")) {
deviceExtensionNames.push_back(properties.extensionName);
}
}
assert(deviceExtensionNames.size() == 1); // VK_KHR_swapchain이 반드시 필요하기 때문에 확인
// 생성할 Device 정의
VkDeviceCreateInfo deviceCreateInfo{
.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,
.queueCreateInfoCount = 1, // 큐의 개수
.pQueueCreateInfos = &deviceQueueCreateInfo, // 생성할 큐의 정보
.enabledExtensionCount = static_cast<uint32_t>(deviceExtensionNames.size()),
.ppEnabledExtensionNames = deviceExtensionNames.data() // 활성화하려는 deviceExtension들을 넘겨줌
};
// vkCreateDevice를 호출하여 Device 생성(= mDevice 생성)
VK_CHECK_ERROR(vkCreateDevice(mPhysicalDevice, &deviceCreateInfo, nullptr, &mDevice));
// 생성된 Device(= mDevice)로부터 큐를 vkGetDeviceQueue를 호출하여 얻어온다.
vkGetDeviceQueue(mDevice, mQueueFamilyIndex, 0, &mQueue);
// ================================================================================
// 4. VkSurface 생성
// ================================================================================
VkAndroidSurfaceCreateInfoKHR surfaceCreateInfo{
.sType = VK_STRUCTURE_TYPE_ANDROID_SURFACE_CREATE_INFO_KHR,
.window = window
};
// surface 생성.
VK_CHECK_ERROR(vkCreateAndroidSurfaceKHR(mInstance, &surfaceCreateInfo, nullptr, &mSurface));
VkBool32 supported; // surface 지원 여부
VK_CHECK_ERROR(vkGetPhysicalDeviceSurfaceSupportKHR(mPhysicalDevice,
mQueueFamilyIndex,
mSurface,
&supported)); // 지원 여부를 받아옴.
assert(supported);
// ================================================================================
// 5. VkSwapchain 생성
// ================================================================================
VkSurfaceCapabilitiesKHR surfaceCapabilities;
VK_CHECK_ERROR(vkGetPhysicalDeviceSurfaceCapabilitiesKHR(mPhysicalDevice,
mSurface,
&surfaceCapabilities));
VkCompositeAlphaFlagBitsKHR compositeAlpha = VK_COMPOSITE_ALPHA_FLAG_BITS_MAX_ENUM_KHR;
for (auto i = 0; i <= 4; ++i) {
if (auto flag = 0x1u << i; surfaceCapabilities.supportedCompositeAlpha & flag) {
compositeAlpha = static_cast<VkCompositeAlphaFlagBitsKHR>(flag);
break;
}
}
assert(compositeAlpha != VK_COMPOSITE_ALPHA_FLAG_BITS_MAX_ENUM_KHR);
VkImageUsageFlags imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
assert(surfaceCapabilities.supportedUsageFlags & imageUsage);
uint32_t surfaceFormatCount = 0;
VK_CHECK_ERROR(vkGetPhysicalDeviceSurfaceFormatsKHR(mPhysicalDevice,
mSurface,
&surfaceFormatCount,
nullptr));
vector<VkSurfaceFormatKHR> surfaceFormats(surfaceFormatCount);
VK_CHECK_ERROR(vkGetPhysicalDeviceSurfaceFormatsKHR(mPhysicalDevice,
mSurface,
&surfaceFormatCount,
surfaceFormats.data()));
uint32_t surfaceFormatIndex = VK_FORMAT_MAX_ENUM;
for (auto i = 0; i != surfaceFormatCount; ++i) {
if (surfaceFormats[i].format == VK_FORMAT_R8G8B8A8_UNORM) {
surfaceFormatIndex = i;
break;
}
}
assert(surfaceFormatIndex != VK_FORMAT_MAX_ENUM);
uint32_t presentModeCount;
VK_CHECK_ERROR(vkGetPhysicalDeviceSurfacePresentModesKHR(mPhysicalDevice,
mSurface,
&presentModeCount,
nullptr));
vector<VkPresentModeKHR> presentModes(presentModeCount);
VK_CHECK_ERROR(vkGetPhysicalDeviceSurfacePresentModesKHR(mPhysicalDevice,
mSurface,
&presentModeCount,
presentModes.data()));
uint32_t presentModeIndex = VK_PRESENT_MODE_MAX_ENUM_KHR;
for (auto i = 0; i != presentModeCount; ++i) {
if (presentModes[i] == VK_PRESENT_MODE_FIFO_KHR) {
presentModeIndex = i;
break;
}
}
assert(presentModeIndex != VK_PRESENT_MODE_MAX_ENUM_KHR);
VkSwapchainCreateInfoKHR swapchainCreateInfo{
.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR,
.surface = mSurface,
.minImageCount = surfaceCapabilities.minImageCount,
.imageFormat = surfaceFormats[surfaceFormatIndex].format,
.imageColorSpace = surfaceFormats[surfaceFormatIndex].colorSpace,
.imageExtent = surfaceCapabilities.currentExtent,
.imageArrayLayers = 1,
.imageUsage = imageUsage,
.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE,
.preTransform = surfaceCapabilities.currentTransform,
.compositeAlpha = compositeAlpha,
.presentMode = presentModes[presentModeIndex]
};
VK_CHECK_ERROR(vkCreateSwapchainKHR(mDevice, &swapchainCreateInfo, nullptr, &mSwapchain));
uint32_t swapchainImageCount;
VK_CHECK_ERROR(vkGetSwapchainImagesKHR(mDevice, mSwapchain, &swapchainImageCount, nullptr));
mSwapchainImages.resize(swapchainImageCount);
VK_CHECK_ERROR(vkGetSwapchainImagesKHR(mDevice,
mSwapchain,
&swapchainImageCount,
mSwapchainImages.data()));
// ================================================================================
// 6. VkCommandPool 생성
// ================================================================================
VkCommandPoolCreateInfo commandPoolCreateInfo{
.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO,
.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT, // command buffer를 개별적으로 초기화 가능하게 설정
.queueFamilyIndex = mQueueFamilyIndex
};
VK_CHECK_ERROR(vkCreateCommandPool(mDevice, &commandPoolCreateInfo, nullptr, &mCommandPool)); // mCommandPool 생성
}
VkRenderer::~VkRenderer() {
vkDestroyCommandPool(mDevice, mCommandPool, nullptr);
vkDestroySwapchainKHR(mDevice, mSwapchain, nullptr);
vkDestroySurfaceKHR(mInstance, mSurface, nullptr);
vkDestroyDevice(mDevice, nullptr); // Device 파괴. queue의 경우 Device를 생성하면서 생겼기 때문에 따로 파괴하는 API가 존재하지 않는다.
vkDestroyInstance(mInstance, nullptr);
}