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 // // Copyright (c) 2017-2020 Advanced Micro Devices, Inc. All rights reserved. // // 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. // #ifndef AMD_VULKAN_MEMORY_ALLOCATOR_H #define AMD_VULKAN_MEMORY_ALLOCATOR_H /** \mainpage Vulkan Memory Allocator Version 3.0.0-development (2020-06-24) Copyright (c) 2017-2020 Advanced Micro Devices, Inc. All rights reserved. \n License: MIT Documentation of all members: vk_mem_alloc.h \section main_table_of_contents Table of contents - User guide - \subpage quick_start - [Project setup](@ref quick_start_project_setup) - [Initialization](@ref quick_start_initialization) - [Resource allocation](@ref quick_start_resource_allocation) - \subpage choosing_memory_type - [Usage](@ref choosing_memory_type_usage) - [Required and preferred flags](@ref choosing_memory_type_required_preferred_flags) - [Explicit memory types](@ref choosing_memory_type_explicit_memory_types) - [Custom memory pools](@ref choosing_memory_type_custom_memory_pools) - [Dedicated allocations](@ref choosing_memory_type_dedicated_allocations) - \subpage memory_mapping - [Mapping functions](@ref memory_mapping_mapping_functions) - [Persistently mapped memory](@ref memory_mapping_persistently_mapped_memory) - [Cache flush and invalidate](@ref memory_mapping_cache_control) - [Finding out if memory is mappable](@ref memory_mapping_finding_if_memory_mappable) - \subpage staying_within_budget - [Querying for budget](@ref staying_within_budget_querying_for_budget) - [Controlling memory usage](@ref staying_within_budget_controlling_memory_usage) - \subpage custom_memory_pools - [Choosing memory type index](@ref custom_memory_pools_MemTypeIndex) - [Linear allocation algorithm](@ref linear_algorithm) - [Free-at-once](@ref linear_algorithm_free_at_once) - [Stack](@ref linear_algorithm_stack) - [Double stack](@ref linear_algorithm_double_stack) - [Ring buffer](@ref linear_algorithm_ring_buffer) - [Buddy allocation algorithm](@ref buddy_algorithm) - \subpage defragmentation - [Defragmenting CPU memory](@ref defragmentation_cpu) - [Defragmenting GPU memory](@ref defragmentation_gpu) - [Additional notes](@ref defragmentation_additional_notes) - [Writing custom allocation algorithm](@ref defragmentation_custom_algorithm) - \subpage lost_allocations - \subpage statistics - [Numeric statistics](@ref statistics_numeric_statistics) - [JSON dump](@ref statistics_json_dump) - \subpage allocation_annotation - [Allocation user data](@ref allocation_user_data) - [Allocation names](@ref allocation_names) - \subpage debugging_memory_usage - [Memory initialization](@ref debugging_memory_usage_initialization) - [Margins](@ref debugging_memory_usage_margins) - [Corruption detection](@ref debugging_memory_usage_corruption_detection) - \subpage record_and_replay - \subpage usage_patterns - [Common mistakes](@ref usage_patterns_common_mistakes) - [Simple patterns](@ref usage_patterns_simple) - [Advanced patterns](@ref usage_patterns_advanced) - \subpage configuration - [Pointers to Vulkan functions](@ref config_Vulkan_functions) - [Custom host memory allocator](@ref custom_memory_allocator) - [Device memory allocation callbacks](@ref allocation_callbacks) - [Device heap memory limit](@ref heap_memory_limit) - \subpage vk_khr_dedicated_allocation - \subpage enabling_buffer_device_address - \subpage vk_amd_device_coherent_memory - \subpage general_considerations - [Thread safety](@ref general_considerations_thread_safety) - [Validation layer warnings](@ref general_considerations_validation_layer_warnings) - [Allocation algorithm](@ref general_considerations_allocation_algorithm) - [Features not supported](@ref general_considerations_features_not_supported) \section main_see_also See also - [Product page on GPUOpen](https://gpuopen.com/gaming-product/vulkan-memory-allocator/) - [Source repository on GitHub](https://github.com/GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator) \page quick_start Quick start \section quick_start_project_setup Project setup Vulkan Memory Allocator comes in form of a "stb-style" single header file. You don't need to build it as a separate library project. You can add this file directly to your project and submit it to code repository next to your other source files. "Single header" doesn't mean that everything is contained in C/C++ declarations, like it tends to be in case of inline functions or C++ templates. It means that implementation is bundled with interface in a single file and needs to be extracted using preprocessor macro. If you don't do it properly, you will get linker errors. To do it properly: -# Include "vk_mem_alloc.h" file in each CPP file where you want to use the library. This includes declarations of all members of the library. -# In exacly one CPP file define following macro before this include. It enables also internal definitions. \code #define VMA_IMPLEMENTATION #include "vk_mem_alloc.h" \endcode It may be a good idea to create dedicated CPP file just for this purpose. Note on language: This library is written in C++, but has C-compatible interface. Thus you can include and use vk_mem_alloc.h in C or C++ code, but full implementation with VMA_IMPLEMENTATION macro must be compiled as C++, NOT as C. Please note that this library includes header , which in turn includes  on Windows. If you need some specific macros defined before including these headers (like WIN32_LEAN_AND_MEAN or WINVER for Windows, VK_USE_PLATFORM_WIN32_KHR for Vulkan), you must define them before every #include of this library. \section quick_start_initialization Initialization At program startup: -# Initialize Vulkan to have VkPhysicalDevice, VkDevice and VkInstance object. -# Fill VmaAllocatorCreateInfo structure and create #VmaAllocator object by calling vmaCreateAllocator(). \code VmaAllocatorCreateInfo allocatorInfo = {}; allocatorInfo.physicalDevice = physicalDevice; allocatorInfo.device = device; allocatorInfo.instance = instance; VmaAllocator allocator; vmaCreateAllocator(&allocatorInfo, &allocator); \endcode \section quick_start_resource_allocation Resource allocation When you want to create a buffer or image: -# Fill VkBufferCreateInfo / VkImageCreateInfo structure. -# Fill VmaAllocationCreateInfo structure. -# Call vmaCreateBuffer() / vmaCreateImage() to get VkBuffer/VkImage with memory already allocated and bound to it. \code VkBufferCreateInfo bufferInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufferInfo.size = 65536; bufferInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; VmaAllocationCreateInfo allocInfo = {}; allocInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; VkBuffer buffer; VmaAllocation allocation; vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr); \endcode Don't forget to destroy your objects when no longer needed: \code vmaDestroyBuffer(allocator, buffer, allocation); vmaDestroyAllocator(allocator); \endcode \page choosing_memory_type Choosing memory type Physical devices in Vulkan support various combinations of memory heaps and types. Help with choosing correct and optimal memory type for your specific resource is one of the key features of this library. You can use it by filling appropriate members of VmaAllocationCreateInfo structure, as described below. You can also combine multiple methods. -# If you just want to find memory type index that meets your requirements, you can use function: vmaFindMemoryTypeIndex(), vmaFindMemoryTypeIndexForBufferInfo(), vmaFindMemoryTypeIndexForImageInfo(). -# If you want to allocate a region of device memory without association with any specific image or buffer, you can use function vmaAllocateMemory(). Usage of this function is not recommended and usually not needed. vmaAllocateMemoryPages() function is also provided for creating multiple allocations at once, which may be useful for sparse binding. -# If you already have a buffer or an image created, you want to allocate memory for it and then you will bind it yourself, you can use function vmaAllocateMemoryForBuffer(), vmaAllocateMemoryForImage(). For binding you should use functions: vmaBindBufferMemory(), vmaBindImageMemory() or their extended versions: vmaBindBufferMemory2(), vmaBindImageMemory2(). -# If you want to create a buffer or an image, allocate memory for it and bind them together, all in one call, you can use function vmaCreateBuffer(), vmaCreateImage(). This is the easiest and recommended way to use this library. When using 3. or 4., the library internally queries Vulkan for memory types supported for that buffer or image (function vkGetBufferMemoryRequirements()) and uses only one of these types. If no memory type can be found that meets all the requirements, these functions return VK_ERROR_FEATURE_NOT_PRESENT. You can leave VmaAllocationCreateInfo structure completely filled with zeros. It means no requirements are specified for memory type. It is valid, although not very useful. \section choosing_memory_type_usage Usage The easiest way to specify memory requirements is to fill member VmaAllocationCreateInfo::usage using one of the values of enum #VmaMemoryUsage. It defines high level, common usage types. For more details, see description of this enum. For example, if you want to create a uniform buffer that will be filled using transfer only once or infrequently and used for rendering every frame, you can do it using following code: \code VkBufferCreateInfo bufferInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufferInfo.size = 65536; bufferInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; VmaAllocationCreateInfo allocInfo = {}; allocInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; VkBuffer buffer; VmaAllocation allocation; vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr); \endcode \section choosing_memory_type_required_preferred_flags Required and preferred flags You can specify more detailed requirements by filling members VmaAllocationCreateInfo::requiredFlags and VmaAllocationCreateInfo::preferredFlags with a combination of bits from enum VkMemoryPropertyFlags. For example, if you want to create a buffer that will be persistently mapped on host (so it must be HOST_VISIBLE) and preferably will also be HOST_COHERENT and HOST_CACHED, use following code: \code VmaAllocationCreateInfo allocInfo = {}; allocInfo.requiredFlags = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT; allocInfo.preferredFlags = VK_MEMORY_PROPERTY_HOST_COHERENT_BIT | VK_MEMORY_PROPERTY_HOST_CACHED_BIT; allocInfo.flags = VMA_ALLOCATION_CREATE_MAPPED_BIT; VkBuffer buffer; VmaAllocation allocation; vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr); \endcode A memory type is chosen that has all the required flags and as many preferred flags set as possible. If you use VmaAllocationCreateInfo::usage, it is just internally converted to a set of required and preferred flags. \section choosing_memory_type_explicit_memory_types Explicit memory types If you inspected memory types available on the physical device and you have a preference for memory types that you want to use, you can fill member VmaAllocationCreateInfo::memoryTypeBits. It is a bit mask, where each bit set means that a memory type with that index is allowed to be used for the allocation. Special value 0, just like UINT32_MAX, means there are no restrictions to memory type index. Please note that this member is NOT just a memory type index. Still you can use it to choose just one, specific memory type. For example, if you already determined that your buffer should be created in memory type 2, use following code: \code uint32_t memoryTypeIndex = 2; VmaAllocationCreateInfo allocInfo = {}; allocInfo.memoryTypeBits = 1u << memoryTypeIndex; VkBuffer buffer; VmaAllocation allocation; vmaCreateBuffer(allocator, &bufferInfo, &allocInfo, &buffer, &allocation, nullptr); \endcode \section choosing_memory_type_custom_memory_pools Custom memory pools If you allocate from custom memory pool, all the ways of specifying memory requirements described above are not applicable and the aforementioned members of VmaAllocationCreateInfo structure are ignored. Memory type is selected explicitly when creating the pool and then used to make all the allocations from that pool. For further details, see \ref custom_memory_pools. \section choosing_memory_type_dedicated_allocations Dedicated allocations Memory for allocations is reserved out of larger block of VkDeviceMemory allocated from Vulkan internally. That's the main feature of this whole library. You can still request a separate memory block to be created for an allocation, just like you would do in a trivial solution without using any allocator. In that case, a buffer or image is always bound to that memory at offset 0. This is called a "dedicated allocation". You can explicitly request it by using flag #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT. The library can also internally decide to use dedicated allocation in some cases, e.g.: - When the size of the allocation is large. - When [VK_KHR_dedicated_allocation](@ref vk_khr_dedicated_allocation) extension is enabled and it reports that dedicated allocation is required or recommended for the resource. - When allocation of next big memory block fails due to not enough device memory, but allocation with the exact requested size succeeds. \page memory_mapping Memory mapping To "map memory" in Vulkan means to obtain a CPU pointer to VkDeviceMemory, to be able to read from it or write to it in CPU code. Mapping is possible only of memory allocated from a memory type that has VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT flag. Functions vkMapMemory(), vkUnmapMemory() are designed for this purpose. You can use them directly with memory allocated by this library, but it is not recommended because of following issue: Mapping the same VkDeviceMemory block multiple times is illegal - only one mapping at a time is allowed. This includes mapping disjoint regions. Mapping is not reference-counted internally by Vulkan. Because of this, Vulkan Memory Allocator provides following facilities: \section memory_mapping_mapping_functions Mapping functions The library provides following functions for mapping of a specific #VmaAllocation: vmaMapMemory(), vmaUnmapMemory(). They are safer and more convenient to use than standard Vulkan functions. You can map an allocation multiple times simultaneously - mapping is reference-counted internally. You can also map different allocations simultaneously regardless of whether they use the same VkDeviceMemory block. The way it's implemented is that the library always maps entire memory block, not just region of the allocation. For further details, see description of vmaMapMemory() function. Example: \code // Having these objects initialized: struct ConstantBuffer { ... }; ConstantBuffer constantBufferData; VmaAllocator allocator; VkBuffer constantBuffer; VmaAllocation constantBufferAllocation; // You can map and fill your buffer using following code: void* mappedData; vmaMapMemory(allocator, constantBufferAllocation, &mappedData); memcpy(mappedData, &constantBufferData, sizeof(constantBufferData)); vmaUnmapMemory(allocator, constantBufferAllocation); \endcode When mapping, you may see a warning from Vulkan validation layer similar to this one: Mapping an image with layout VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL can result in undefined behavior if this memory is used by the device. Only GENERAL or PREINITIALIZED should be used. It happens because the library maps entire VkDeviceMemory block, where different types of images and buffers may end up together, especially on GPUs with unified memory like Intel. You can safely ignore it if you are sure you access only memory of the intended object that you wanted to map. \section memory_mapping_persistently_mapped_memory Persistently mapped memory Kepping your memory persistently mapped is generally OK in Vulkan. You don't need to unmap it before using its data on the GPU. The library provides a special feature designed for that: Allocations made with #VMA_ALLOCATION_CREATE_MAPPED_BIT flag set in VmaAllocationCreateInfo::flags stay mapped all the time, so you can just access CPU pointer to it any time without a need to call any "map" or "unmap" function. Example: \code VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufCreateInfo.size = sizeof(ConstantBuffer); bufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT; VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_CPU_ONLY; allocCreateInfo.flags = VMA_ALLOCATION_CREATE_MAPPED_BIT; VkBuffer buf; VmaAllocation alloc; VmaAllocationInfo allocInfo; vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo); // Buffer is already mapped. You can access its memory. memcpy(allocInfo.pMappedData, &constantBufferData, sizeof(constantBufferData)); \endcode There are some exceptions though, when you should consider mapping memory only for a short period of time: - When operating system is Windows 7 or 8.x (Windows 10 is not affected because it uses WDDM2), device is discrete AMD GPU, and memory type is the special 256 MiB pool of DEVICE_LOCAL + HOST_VISIBLE memory (selected when you use #VMA_MEMORY_USAGE_CPU_TO_GPU), then whenever a memory block allocated from this memory type stays mapped for the time of any call to vkQueueSubmit() or vkQueuePresentKHR(), this block is migrated by WDDM to system RAM, which degrades performance. It doesn't matter if that particular memory block is actually used by the command buffer being submitted. - On Mac/MoltenVK there is a known bug - [Issue #175](https://github.com/KhronosGroup/MoltenVK/issues/175) which requires unmapping before GPU can see updated texture. - Keeping many large memory blocks mapped may impact performance or stability of some debugging tools. \section memory_mapping_cache_control Cache flush and invalidate Memory in Vulkan doesn't need to be unmapped before using it on GPU, but unless a memory types has VK_MEMORY_PROPERTY_HOST_COHERENT_BIT flag set, you need to manually **invalidate** cache before reading of mapped pointer and **flush** cache after writing to mapped pointer. Map/unmap operations don't do that automatically. Vulkan provides following functions for this purpose vkFlushMappedMemoryRanges(), vkInvalidateMappedMemoryRanges(), but this library provides more convenient functions that refer to given allocation object: vmaFlushAllocation(), vmaInvalidateAllocation(), or multiple objects at once: vmaFlushAllocations(), vmaInvalidateAllocations(). Regions of memory specified for flush/invalidate must be aligned to VkPhysicalDeviceLimits::nonCoherentAtomSize. This is automatically ensured by the library. In any memory type that is HOST_VISIBLE but not HOST_COHERENT, all allocations within blocks are aligned to this value, so their offsets are always multiply of nonCoherentAtomSize and two different allocations never share same "line" of this size. Please note that memory allocated with #VMA_MEMORY_USAGE_CPU_ONLY is guaranteed to be HOST_COHERENT. Also, Windows drivers from all 3 **PC** GPU vendors (AMD, Intel, NVIDIA) currently provide HOST_COHERENT flag on all memory types that are HOST_VISIBLE, so on this platform you may not need to bother. \section memory_mapping_finding_if_memory_mappable Finding out if memory is mappable It may happen that your allocation ends up in memory that is HOST_VISIBLE (available for mapping) despite it wasn't explicitly requested. For example, application may work on integrated graphics with unified memory (like Intel) or allocation from video memory might have failed, so the library chose system memory as fallback. You can detect this case and map such allocation to access its memory on CPU directly, instead of launching a transfer operation. In order to do that: inspect allocInfo.memoryType, call vmaGetMemoryTypeProperties(), and look for VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT flag in properties of that memory type. \code VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufCreateInfo.size = sizeof(ConstantBuffer); bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; allocCreateInfo.preferredFlags = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT; VkBuffer buf; VmaAllocation alloc; VmaAllocationInfo allocInfo; vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo); VkMemoryPropertyFlags memFlags; vmaGetMemoryTypeProperties(allocator, allocInfo.memoryType, &memFlags); if((memFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) != 0) { // Allocation ended up in mappable memory. You can map it and access it directly. void* mappedData; vmaMapMemory(allocator, alloc, &mappedData); memcpy(mappedData, &constantBufferData, sizeof(constantBufferData)); vmaUnmapMemory(allocator, alloc); } else { // Allocation ended up in non-mappable memory. // You need to create CPU-side buffer in VMA_MEMORY_USAGE_CPU_ONLY and make a transfer. } \endcode You can even use #VMA_ALLOCATION_CREATE_MAPPED_BIT flag while creating allocations that are not necessarily HOST_VISIBLE (e.g. using #VMA_MEMORY_USAGE_GPU_ONLY). If the allocation ends up in memory type that is HOST_VISIBLE, it will be persistently mapped and you can use it directly. If not, the flag is just ignored. Example: \code VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufCreateInfo.size = sizeof(ConstantBuffer); bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; allocCreateInfo.flags = VMA_ALLOCATION_CREATE_MAPPED_BIT; VkBuffer buf; VmaAllocation alloc; VmaAllocationInfo allocInfo; vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo); if(allocInfo.pUserData != nullptr) { // Allocation ended up in mappable memory. // It's persistently mapped. You can access it directly. memcpy(allocInfo.pMappedData, &constantBufferData, sizeof(constantBufferData)); } else { // Allocation ended up in non-mappable memory. // You need to create CPU-side buffer in VMA_MEMORY_USAGE_CPU_ONLY and make a transfer. } \endcode \page staying_within_budget Staying within budget When developing a graphics-intensive game or program, it is important to avoid allocating more GPU memory than it's physically available. When the memory is over-committed, various bad things can happen, depending on the specific GPU, graphics driver, and operating system: - It may just work without any problems. - The application may slow down because some memory blocks are moved to system RAM and the GPU has to access them through PCI Express bus. - A new allocation may take very long time to complete, even few seconds, and possibly freeze entire system. - The new allocation may fail with VK_ERROR_OUT_OF_DEVICE_MEMORY. - It may even result in GPU crash (TDR), observed as VK_ERROR_DEVICE_LOST returned somewhere later. \section staying_within_budget_querying_for_budget Querying for budget To query for current memory usage and available budget, use function vmaGetBudget(). Returned structure #VmaBudget contains quantities expressed in bytes, per Vulkan memory heap. Please note that this function returns different information and works faster than vmaCalculateStats(). vmaGetBudget() can be called every frame or even before every allocation, while vmaCalculateStats() is intended to be used rarely, only to obtain statistical information, e.g. for debugging purposes. It is recommended to use VK_EXT_memory_budget device extension to obtain information about the budget from Vulkan device. VMA is able to use this extension automatically. When not enabled, the allocator behaves same way, but then it estimates current usage and available budget based on its internal information and Vulkan memory heap sizes, which may be less precise. In order to use this extension: 1. Make sure extensions VK_EXT_memory_budget and VK_KHR_get_physical_device_properties2 required by it are available and enable them. Please note that the first is a device extension and the second is instance extension! 2. Use flag #VMA_ALLOCATOR_CREATE_EXT_MEMORY_BUDGET_BIT when creating #VmaAllocator object. 3. Make sure to call vmaSetCurrentFrameIndex() every frame. Budget is queried from Vulkan inside of it to avoid overhead of querying it with every allocation. \section staying_within_budget_controlling_memory_usage Controlling memory usage There are many ways in which you can try to stay within the budget. First, when making new allocation requires allocating a new memory block, the library tries not to exceed the budget automatically. If a block with default recommended size (e.g. 256 MB) would go over budget, a smaller block is allocated, possibly even dedicated memory for just this resource. If the size of the requested resource plus current memory usage is more than the budget, by default the library still tries to create it, leaving it to the Vulkan implementation whether the allocation succeeds or fails. You can change this behavior by using #VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT flag. With it, the allocation is not made if it would exceed the budget or if the budget is already exceeded. Some other allocations become lost instead to make room for it, if the mechanism of [lost allocations](@ref lost_allocations) is used. If that is not possible, the allocation fails with VK_ERROR_OUT_OF_DEVICE_MEMORY. Example usage pattern may be to pass the #VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT flag when creating resources that are not essential for the application (e.g. the texture of a specific object) and not to pass it when creating critically important resources (e.g. render targets). Finally, you can also use #VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT flag to make sure a new allocation is created only when it fits inside one of the existing memory blocks. If it would require to allocate a new block, if fails instead with VK_ERROR_OUT_OF_DEVICE_MEMORY. This also ensures that the function call is very fast because it never goes to Vulkan to obtain a new block. Please note that creating \ref custom_memory_pools with VmaPoolCreateInfo::minBlockCount set to more than 0 will try to allocate memory blocks without checking whether they fit within budget. \page custom_memory_pools Custom memory pools A memory pool contains a number of VkDeviceMemory blocks. The library automatically creates and manages default pool for each memory type available on the device. Default memory pool automatically grows in size. Size of allocated blocks is also variable and managed automatically. You can create custom pool and allocate memory out of it. It can be useful if you want to: - Keep certain kind of allocations separate from others. - Enforce particular, fixed size of Vulkan memory blocks. - Limit maximum amount of Vulkan memory allocated for that pool. - Reserve minimum or fixed amount of Vulkan memory always preallocated for that pool. To use custom memory pools: -# Fill VmaPoolCreateInfo structure. -# Call vmaCreatePool() to obtain #VmaPool handle. -# When making an allocation, set VmaAllocationCreateInfo::pool to this handle. You don't need to specify any other parameters of this structure, like usage. Example: \code // Create a pool that can have at most 2 blocks, 128 MiB each. VmaPoolCreateInfo poolCreateInfo = {}; poolCreateInfo.memoryTypeIndex = ... poolCreateInfo.blockSize = 128ull * 1024 * 1024; poolCreateInfo.maxBlockCount = 2; VmaPool pool; vmaCreatePool(allocator, &poolCreateInfo, &pool); // Allocate a buffer out of it. VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufCreateInfo.size = 1024; bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.pool = pool; VkBuffer buf; VmaAllocation alloc; VmaAllocationInfo allocInfo; vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &buf, &alloc, &allocInfo); \endcode You have to free all allocations made from this pool before destroying it. \code vmaDestroyBuffer(allocator, buf, alloc); vmaDestroyPool(allocator, pool); \endcode \section custom_memory_pools_MemTypeIndex Choosing memory type index When creating a pool, you must explicitly specify memory type index. To find the one suitable for your buffers or images, you can use helper functions vmaFindMemoryTypeIndexForBufferInfo(), vmaFindMemoryTypeIndexForImageInfo(). You need to provide structures with example parameters of buffers or images that you are going to create in that pool. \code VkBufferCreateInfo exampleBufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; exampleBufCreateInfo.size = 1024; // Whatever. exampleBufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; // Change if needed. VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; // Change if needed. uint32_t memTypeIndex; vmaFindMemoryTypeIndexForBufferInfo(allocator, &exampleBufCreateInfo, &allocCreateInfo, &memTypeIndex); VmaPoolCreateInfo poolCreateInfo = {}; poolCreateInfo.memoryTypeIndex = memTypeIndex; // ... \endcode When creating buffers/images allocated in that pool, provide following parameters: - VkBufferCreateInfo: Prefer to pass same parameters as above. Otherwise you risk creating resources in a memory type that is not suitable for them, which may result in undefined behavior. Using different VK_BUFFER_USAGE_ flags may work, but you shouldn't create images in a pool intended for buffers or the other way around. - VmaAllocationCreateInfo: You don't need to pass same parameters. Fill only pool member. Other members are ignored anyway. \section linear_algorithm Linear allocation algorithm Each Vulkan memory block managed by this library has accompanying metadata that keeps track of used and unused regions. By default, the metadata structure and algorithm tries to find best place for new allocations among free regions to optimize memory usage. This way you can allocate and free objects in any order. ![Default allocation algorithm](../gfx/Linear_allocator_1_algo_default.png) Sometimes there is a need to use simpler, linear allocation algorithm. You can create custom pool that uses such algorithm by adding flag #VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT to VmaPoolCreateInfo::flags while creating #VmaPool object. Then an alternative metadata management is used. It always creates new allocations after last one and doesn't reuse free regions after allocations freed in the middle. It results in better allocation performance and less memory consumed by metadata. ![Linear allocation algorithm](../gfx/Linear_allocator_2_algo_linear.png) With this one flag, you can create a custom pool that can be used in many ways: free-at-once, stack, double stack, and ring buffer. See below for details. \subsection linear_algorithm_free_at_once Free-at-once In a pool that uses linear algorithm, you still need to free all the allocations individually, e.g. by using vmaFreeMemory() or vmaDestroyBuffer(). You can free them in any order. New allocations are always made after last one - free space in the middle is not reused. However, when you release all the allocation and the pool becomes empty, allocation starts from the beginning again. This way you can use linear algorithm to speed up creation of allocations that you are going to release all at once. ![Free-at-once](../gfx/Linear_allocator_3_free_at_once.png) This mode is also available for pools created with VmaPoolCreateInfo::maxBlockCount value that allows multiple memory blocks. \subsection linear_algorithm_stack Stack When you free an allocation that was created last, its space can be reused. Thanks to this, if you always release allocations in the order opposite to their creation (LIFO - Last In First Out), you can achieve behavior of a stack. ![Stack](../gfx/Linear_allocator_4_stack.png) This mode is also available for pools created with VmaPoolCreateInfo::maxBlockCount value that allows multiple memory blocks. \subsection linear_algorithm_double_stack Double stack The space reserved by a custom pool with linear algorithm may be used by two stacks: - First, default one, growing up from offset 0. - Second, "upper" one, growing down from the end towards lower offsets. To make allocation from upper stack, add flag #VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT to VmaAllocationCreateInfo::flags. ![Double stack](../gfx/Linear_allocator_7_double_stack.png) Double stack is available only in pools with one memory block - VmaPoolCreateInfo::maxBlockCount must be 1. Otherwise behavior is undefined. When the two stacks' ends meet so there is not enough space between them for a new allocation, such allocation fails with usual VK_ERROR_OUT_OF_DEVICE_MEMORY error. \subsection linear_algorithm_ring_buffer Ring buffer When you free some allocations from the beginning and there is not enough free space for a new one at the end of a pool, allocator's "cursor" wraps around to the beginning and starts allocation there. Thanks to this, if you always release allocations in the same order as you created them (FIFO - First In First Out), you can achieve behavior of a ring buffer / queue. ![Ring buffer](../gfx/Linear_allocator_5_ring_buffer.png) Pools with linear algorithm support [lost allocations](@ref lost_allocations) when used as ring buffer. If there is not enough free space for a new allocation, but existing allocations from the front of the queue can become lost, they become lost and the allocation succeeds. ![Ring buffer with lost allocations](../gfx/Linear_allocator_6_ring_buffer_lost.png) Ring buffer is available only in pools with one memory block - VmaPoolCreateInfo::maxBlockCount must be 1. Otherwise behavior is undefined. \section buddy_algorithm Buddy allocation algorithm There is another allocation algorithm that can be used with custom pools, called "buddy". Its internal data structure is based on a tree of blocks, each having size that is a power of two and a half of its parent's size. When you want to allocate memory of certain size, a free node in the tree is located. If it's too large, it is recursively split into two halves (called "buddies"). However, if requested allocation size is not a power of two, the size of a tree node is aligned up to the nearest power of two and the remaining space is wasted. When two buddy nodes become free, they are merged back into one larger node. ![Buddy allocator](../gfx/Buddy_allocator.png) The advantage of buddy allocation algorithm over default algorithm is faster allocation and deallocation, as well as smaller external fragmentation. The disadvantage is more wasted space (internal fragmentation). For more information, please read ["Buddy memory allocation" on Wikipedia](https://en.wikipedia.org/wiki/Buddy_memory_allocation) or other sources that describe this concept in general. To use buddy allocation algorithm with a custom pool, add flag #VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT to VmaPoolCreateInfo::flags while creating #VmaPool object. Several limitations apply to pools that use buddy algorithm: - It is recommended to use VmaPoolCreateInfo::blockSize that is a power of two. Otherwise, only largest power of two smaller than the size is used for allocations. The remaining space always stays unused. - [Margins](@ref debugging_memory_usage_margins) and [corruption detection](@ref debugging_memory_usage_corruption_detection) don't work in such pools. - [Lost allocations](@ref lost_allocations) don't work in such pools. You can use them, but they never become lost. Support may be added in the future. - [Defragmentation](@ref defragmentation) doesn't work with allocations made from such pool. \page defragmentation Defragmentation Interleaved allocations and deallocations of many objects of varying size can cause fragmentation over time, which can lead to a situation where the library is unable to find a continuous range of free memory for a new allocation despite there is enough free space, just scattered across many small free ranges between existing allocations. To mitigate this problem, you can use defragmentation feature: structure #VmaDefragmentationInfo2, function vmaDefragmentationBegin(), vmaDefragmentationEnd(). Given set of allocations, this function can move them to compact used memory, ensure more continuous free space and possibly also free some VkDeviceMemory blocks. What the defragmentation does is: - Updates #VmaAllocation objects to point to new VkDeviceMemory and offset. After allocation has been moved, its VmaAllocationInfo::deviceMemory and/or VmaAllocationInfo::offset changes. You must query them again using vmaGetAllocationInfo() if you need them. - Moves actual data in memory. What it doesn't do, so you need to do it yourself: - Recreate buffers and images that were bound to allocations that were defragmented and bind them with their new places in memory. You must use vkDestroyBuffer(), vkDestroyImage(), vkCreateBuffer(), vkCreateImage(), vmaBindBufferMemory(), vmaBindImageMemory() for that purpose and NOT vmaDestroyBuffer(), vmaDestroyImage(), vmaCreateBuffer(), vmaCreateImage(), because you don't need to destroy or create allocation objects! - Recreate views and update descriptors that point to these buffers and images. \section defragmentation_cpu Defragmenting CPU memory Following example demonstrates how you can run defragmentation on CPU. Only allocations created in memory types that are HOST_VISIBLE can be defragmented. Others are ignored. The way it works is: - It temporarily maps entire memory blocks when necessary. - It moves data using memmove() function. \code // Given following variables already initialized: VkDevice device; VmaAllocator allocator; std::vector buffers; std::vector allocations; const uint32_t allocCount = (uint32_t)allocations.size(); std::vector allocationsChanged(allocCount); VmaDefragmentationInfo2 defragInfo = {}; defragInfo.allocationCount = allocCount; defragInfo.pAllocations = allocations.data(); defragInfo.pAllocationsChanged = allocationsChanged.data(); defragInfo.maxCpuBytesToMove = VK_WHOLE_SIZE; // No limit. defragInfo.maxCpuAllocationsToMove = UINT32_MAX; // No limit. VmaDefragmentationContext defragCtx; vmaDefragmentationBegin(allocator, &defragInfo, nullptr, &defragCtx); vmaDefragmentationEnd(allocator, defragCtx); for(uint32_t i = 0; i < allocCount; ++i) { if(allocationsChanged[i]) { // Destroy buffer that is immutably bound to memory region which is no longer valid. vkDestroyBuffer(device, buffers[i], nullptr); // Create new buffer with same parameters. VkBufferCreateInfo bufferInfo = ...; vkCreateBuffer(device, &bufferInfo, nullptr, &buffers[i]); // You can make dummy call to vkGetBufferMemoryRequirements here to silence validation layer warning. // Bind new buffer to new memory region. Data contained in it is already moved. VmaAllocationInfo allocInfo; vmaGetAllocationInfo(allocator, allocations[i], &allocInfo); vmaBindBufferMemory(allocator, allocations[i], buffers[i]); } } \endcode Setting VmaDefragmentationInfo2::pAllocationsChanged is optional. This output array tells whether particular allocation in VmaDefragmentationInfo2::pAllocations at the same index has been modified during defragmentation. You can pass null, but you then need to query every allocation passed to defragmentation for new parameters using vmaGetAllocationInfo() if you might need to recreate and rebind a buffer or image associated with it. If you use [Custom memory pools](@ref choosing_memory_type_custom_memory_pools), you can fill VmaDefragmentationInfo2::poolCount and VmaDefragmentationInfo2::pPools instead of VmaDefragmentationInfo2::allocationCount and VmaDefragmentationInfo2::pAllocations to defragment all allocations in given pools. You cannot use VmaDefragmentationInfo2::pAllocationsChanged in that case. You can also combine both methods. \section defragmentation_gpu Defragmenting GPU memory It is also possible to defragment allocations created in memory types that are not HOST_VISIBLE. To do that, you need to pass a command buffer that meets requirements as described in VmaDefragmentationInfo2::commandBuffer. The way it works is: - It creates temporary buffers and binds them to entire memory blocks when necessary. - It issues vkCmdCopyBuffer() to passed command buffer. Example: \code // Given following variables already initialized: VkDevice device; VmaAllocator allocator; VkCommandBuffer commandBuffer; std::vector buffers; std::vector allocations; const uint32_t allocCount = (uint32_t)allocations.size(); std::vector allocationsChanged(allocCount); VkCommandBufferBeginInfo cmdBufBeginInfo = ...; vkBeginCommandBuffer(commandBuffer, &cmdBufBeginInfo); VmaDefragmentationInfo2 defragInfo = {}; defragInfo.allocationCount = allocCount; defragInfo.pAllocations = allocations.data(); defragInfo.pAllocationsChanged = allocationsChanged.data(); defragInfo.maxGpuBytesToMove = VK_WHOLE_SIZE; // Notice it's "GPU" this time. defragInfo.maxGpuAllocationsToMove = UINT32_MAX; // Notice it's "GPU" this time. defragInfo.commandBuffer = commandBuffer; VmaDefragmentationContext defragCtx; vmaDefragmentationBegin(allocator, &defragInfo, nullptr, &defragCtx); vkEndCommandBuffer(commandBuffer); // Submit commandBuffer. // Wait for a fence that ensures commandBuffer execution finished. vmaDefragmentationEnd(allocator, defragCtx); for(uint32_t i = 0; i < allocCount; ++i) { if(allocationsChanged[i]) { // Destroy buffer that is immutably bound to memory region which is no longer valid. vkDestroyBuffer(device, buffers[i], nullptr); // Create new buffer with same parameters. VkBufferCreateInfo bufferInfo = ...; vkCreateBuffer(device, &bufferInfo, nullptr, &buffers[i]); // You can make dummy call to vkGetBufferMemoryRequirements here to silence validation layer warning. // Bind new buffer to new memory region. Data contained in it is already moved. VmaAllocationInfo allocInfo; vmaGetAllocationInfo(allocator, allocations[i], &allocInfo); vmaBindBufferMemory(allocator, allocations[i], buffers[i]); } } \endcode You can combine these two methods by specifying non-zero maxGpu* as well as maxCpu* parameters. The library automatically chooses best method to defragment each memory pool. You may try not to block your entire program to wait until defragmentation finishes, but do it in the background, as long as you carefully fullfill requirements described in function vmaDefragmentationBegin(). \section defragmentation_additional_notes Additional notes It is only legal to defragment allocations bound to: - buffers - images created with VK_IMAGE_CREATE_ALIAS_BIT, VK_IMAGE_TILING_LINEAR, and being currently in VK_IMAGE_LAYOUT_GENERAL or VK_IMAGE_LAYOUT_PREINITIALIZED. Defragmentation of images created with VK_IMAGE_TILING_OPTIMAL or in any other layout may give undefined results. If you defragment allocations bound to images, new images to be bound to new memory region after defragmentation should be created with VK_IMAGE_LAYOUT_PREINITIALIZED and then transitioned to their original layout from before defragmentation if needed using an image memory barrier. While using defragmentation, you may experience validation layer warnings, which you just need to ignore. See [Validation layer warnings](@ref general_considerations_validation_layer_warnings). Please don't expect memory to be fully compacted after defragmentation. Algorithms inside are based on some heuristics that try to maximize number of Vulkan memory blocks to make totally empty to release them, as well as to maximimze continuous empty space inside remaining blocks, while minimizing the number and size of allocations that need to be moved. Some fragmentation may still remain - this is normal. \section defragmentation_custom_algorithm Writing custom defragmentation algorithm If you want to implement your own, custom defragmentation algorithm, there is infrastructure prepared for that, but it is not exposed through the library API - you need to hack its source code. Here are steps needed to do this: -# Main thing you need to do is to define your own class derived from base abstract class VmaDefragmentationAlgorithm and implement your version of its pure virtual methods. See definition and comments of this class for details. -# Your code needs to interact with device memory block metadata. If you need more access to its data than it's provided by its public interface, declare your new class as a friend class e.g. in class VmaBlockMetadata_Generic. -# If you want to create a flag that would enable your algorithm or pass some additional flags to configure it, add them to VmaDefragmentationFlagBits and use them in VmaDefragmentationInfo2::flags. -# Modify function VmaBlockVectorDefragmentationContext::Begin to create object of your new class whenever needed. \page lost_allocations Lost allocations If your game oversubscribes video memory, if may work OK in previous-generation graphics APIs (DirectX 9, 10, 11, OpenGL) because resources are automatically paged to system RAM. In Vulkan you can't do it because when you run out of memory, an allocation just fails. If you have more data (e.g. textures) that can fit into VRAM and you don't need it all at once, you may want to upload them to GPU on demand and "push out" ones that are not used for a long time to make room for the new ones, effectively using VRAM (or a cartain memory pool) as a form of cache. Vulkan Memory Allocator can help you with that by supporting a concept of "lost allocations". To create an allocation that can become lost, include #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag in VmaAllocationCreateInfo::flags. Before using a buffer or image bound to such allocation in every new frame, you need to query it if it's not lost. To check it, call vmaTouchAllocation(). If the allocation is lost, you should not use it or buffer/image bound to it. You mustn't forget to destroy this allocation and this buffer/image. vmaGetAllocationInfo() can also be used for checking status of the allocation. Allocation is lost when returned VmaAllocationInfo::deviceMemory == VK_NULL_HANDLE. To create an allocation that can make some other allocations lost to make room for it, use #VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT flag. You will usually use both flags #VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT and #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT at the same time. Warning! Current implementation uses quite naive, brute force algorithm, which can make allocation calls that use #VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT flag quite slow. A new, more optimal algorithm and data structure to speed this up is planned for the future. Q: When interleaving creation of new allocations with usage of existing ones, how do you make sure that an allocation won't become lost while it's used in the current frame? It is ensured because vmaTouchAllocation() / vmaGetAllocationInfo() not only returns allocation status/parameters and checks whether it's not lost, but when it's not, it also atomically marks it as used in the current frame, which makes it impossible to become lost in that frame. It uses lockless algorithm, so it works fast and doesn't involve locking any internal mutex. Q: What if my allocation may still be in use by the GPU when it's rendering a previous frame while I already submit new frame on the CPU? You can make sure that allocations "touched" by vmaTouchAllocation() / vmaGetAllocationInfo() will not become lost for a number of additional frames back from the current one by specifying this number as VmaAllocatorCreateInfo::frameInUseCount (for default memory pool) and VmaPoolCreateInfo::frameInUseCount (for custom pool). Q: How do you inform the library when new frame starts? You need to call function vmaSetCurrentFrameIndex(). Example code: \code struct MyBuffer { VkBuffer m_Buf = nullptr; VmaAllocation m_Alloc = nullptr; // Called when the buffer is really needed in the current frame. void EnsureBuffer(); }; void MyBuffer::EnsureBuffer() { // Buffer has been created. if(m_Buf != VK_NULL_HANDLE) { // Check if its allocation is not lost + mark it as used in current frame. if(vmaTouchAllocation(allocator, m_Alloc)) { // It's all OK - safe to use m_Buf. return; } } // Buffer not yet exists or lost - destroy and recreate it. vmaDestroyBuffer(allocator, m_Buf, m_Alloc); VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; bufCreateInfo.size = 1024; bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT; VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; allocCreateInfo.flags = VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT | VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT; vmaCreateBuffer(allocator, &bufCreateInfo, &allocCreateInfo, &m_Buf, &m_Alloc, nullptr); } \endcode When using lost allocations, you may see some Vulkan validation layer warnings about overlapping regions of memory bound to different kinds of buffers and images. This is still valid as long as you implement proper handling of lost allocations (like in the example above) and don't use them. You can create an allocation that is already in lost state from the beginning using function vmaCreateLostAllocation(). It may be useful if you need a "dummy" allocation that is not null. You can call function vmaMakePoolAllocationsLost() to set all eligible allocations in a specified custom pool to lost state. Allocations that have been "touched" in current frame or VmaPoolCreateInfo::frameInUseCount frames back cannot become lost. Q: Can I touch allocation that cannot become lost? Yes, although it has no visible effect. Calls to vmaGetAllocationInfo() and vmaTouchAllocation() update last use frame index also for allocations that cannot become lost, but the only way to observe it is to dump internal allocator state using vmaBuildStatsString(). You can use this feature for debugging purposes to explicitly mark allocations that you use in current frame and then analyze JSON dump to see for how long each allocation stays unused. \page statistics Statistics This library contains functions that return information about its internal state, especially the amount of memory allocated from Vulkan. Please keep in mind that these functions need to traverse all internal data structures to gather these information, so they may be quite time-consuming. Don't call them too often. \section statistics_numeric_statistics Numeric statistics You can query for overall statistics of the allocator using function vmaCalculateStats(). Information are returned using structure #VmaStats. It contains #VmaStatInfo - number of allocated blocks, number of allocations (occupied ranges in these blocks), number of unused (free) ranges in these blocks, number of bytes used and unused (but still allocated from Vulkan) and other information. They are summed across memory heaps, memory types and total for whole allocator. You can query for statistics of a custom pool using function vmaGetPoolStats(). Information are returned using structure #VmaPoolStats. You can query for information about specific allocation using function vmaGetAllocationInfo(). It fill structure #VmaAllocationInfo. \section statistics_json_dump JSON dump You can dump internal state of the allocator to a string in JSON format using function vmaBuildStatsString(). The result is guaranteed to be correct JSON. It uses ANSI encoding. Any strings provided by user (see [Allocation names](@ref allocation_names)) are copied as-is and properly escaped for JSON, so if they use UTF-8, ISO-8859-2 or any other encoding, this JSON string can be treated as using this encoding. It must be freed using function vmaFreeStatsString(). The format of this JSON string is not part of official documentation of the library, but it will not change in backward-incompatible way without increasing library major version number and appropriate mention in changelog. The JSON string contains all the data that can be obtained using vmaCalculateStats(). It can also contain detailed map of allocated memory blocks and their regions - free and occupied by allocations. This allows e.g. to visualize the memory or assess fragmentation. \page allocation_annotation Allocation names and user data \section allocation_user_data Allocation user data You can annotate allocations with your own information, e.g. for debugging purposes. To do that, fill VmaAllocationCreateInfo::pUserData field when creating an allocation. It's an opaque void* pointer. You can use it e.g. as a pointer, some handle, index, key, ordinal number or any other value that would associate the allocation with your custom metadata. \code VkBufferCreateInfo bufferInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO }; // Fill bufferInfo... MyBufferMetadata* pMetadata = CreateBufferMetadata(); VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; allocCreateInfo.pUserData = pMetadata; VkBuffer buffer; VmaAllocation allocation; vmaCreateBuffer(allocator, &bufferInfo, &allocCreateInfo, &buffer, &allocation, nullptr); \endcode The pointer may be later retrieved as VmaAllocationInfo::pUserData: \code VmaAllocationInfo allocInfo; vmaGetAllocationInfo(allocator, allocation, &allocInfo); MyBufferMetadata* pMetadata = (MyBufferMetadata*)allocInfo.pUserData; \endcode It can also be changed using function vmaSetAllocationUserData(). Values of (non-zero) allocations' pUserData are printed in JSON report created by vmaBuildStatsString(), in hexadecimal form. \section allocation_names Allocation names There is alternative mode available where pUserData pointer is used to point to a null-terminated string, giving a name to the allocation. To use this mode, set #VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT flag in VmaAllocationCreateInfo::flags. Then pUserData passed as VmaAllocationCreateInfo::pUserData or argument to vmaSetAllocationUserData() must be either null or pointer to a null-terminated string. The library creates internal copy of the string, so the pointer you pass doesn't need to be valid for whole lifetime of the allocation. You can free it after the call. \code VkImageCreateInfo imageInfo = { VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO }; // Fill imageInfo... std::string imageName = "Texture: "; imageName += fileName; VmaAllocationCreateInfo allocCreateInfo = {}; allocCreateInfo.usage = VMA_MEMORY_USAGE_GPU_ONLY; allocCreateInfo.flags = VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT; allocCreateInfo.pUserData = imageName.c_str(); VkImage image; VmaAllocation allocation; vmaCreateImage(allocator, &imageInfo, &allocCreateInfo, &image, &allocation, nullptr); \endcode The value of pUserData pointer of the allocation will be different than the one you passed when setting allocation's name - pointing to a buffer managed internally that holds copy of the string. \code VmaAllocationInfo allocInfo; vmaGetAllocationInfo(allocator, allocation, &allocInfo); const char* imageName = (const char*)allocInfo.pUserData; printf("Image name: %s\n", imageName); \endcode That string is also printed in JSON report created by vmaBuildStatsString(). \note Passing string name to VMA allocation doesn't automatically set it to the Vulkan buffer or image created with it. You must do it manually using an extension like VK_EXT_debug_utils, which is independent of this library. \page debugging_memory_usage Debugging incorrect memory usage If you suspect a bug with memory usage, like usage of uninitialized memory or memory being overwritten out of bounds of an allocation, you can use debug features of this library to verify this. \section debugging_memory_usage_initialization Memory initialization If you experience a bug with incorrect and nondeterministic data in your program and you suspect uninitialized memory to be used, you can enable automatic memory initialization to verify this. To do it, define macro VMA_DEBUG_INITIALIZE_ALLOCATIONS to 1. \code #define VMA_DEBUG_INITIALIZE_ALLOCATIONS 1 #include "vk_mem_alloc.h" \endcode It makes memory of all new allocations initialized to bit pattern 0xDCDCDCDC. Before an allocation is destroyed, its memory is filled with bit pattern 0xEFEFEFEF. Memory is automatically mapped and unmapped if necessary. If you find these values while debugging your program, good chances are that you incorrectly read Vulkan memory that is allocated but not initialized, or already freed, respectively. Memory initialization works only with memory types that are HOST_VISIBLE. It works also with dedicated allocations. It doesn't work with allocations created with #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag, as they cannot be mapped. \section debugging_memory_usage_margins Margins By default, allocations are laid out in memory blocks next to each other if possible (considering required alignment, bufferImageGranularity, and nonCoherentAtomSize). ![Allocations without margin](../gfx/Margins_1.png) Define macro VMA_DEBUG_MARGIN to some non-zero value (e.g. 16) to enforce specified number of bytes as a margin before and after every allocation. \code #define VMA_DEBUG_MARGIN 16 #include "vk_mem_alloc.h" \endcode ![Allocations with margin](../gfx/Margins_2.png) If your bug goes away after enabling margins, it means it may be caused by memory being overwritten outside of allocation boundaries. It is not 100% certain though. Change in application behavior may also be caused by different order and distribution of allocations across memory blocks after margins are applied. The margin is applied also before first and after last allocation in a block. It may occur only once between two adjacent allocations. Margins work with all types of memory. Margin is applied only to allocations made out of memory blocks and not to dedicated allocations, which have their own memory block of specific size. It is thus not applied to allocations made using #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT flag or those automatically decided to put into dedicated allocations, e.g. due to its large size or recommended by VK_KHR_dedicated_allocation extension. Margins are also not active in custom pools created with #VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT flag. Margins appear in [JSON dump](@ref statistics_json_dump) as part of free space. Note that enabling margins increases memory usage and fragmentation. \section debugging_memory_usage_corruption_detection Corruption detection You can additionally define macro VMA_DEBUG_DETECT_CORRUPTION to 1 to enable validation of contents of the margins. \code #define VMA_DEBUG_MARGIN 16 #define VMA_DEBUG_DETECT_CORRUPTION 1 #include "vk_mem_alloc.h" \endcode When this feature is enabled, number of bytes specified as VMA_DEBUG_MARGIN (it must be multiply of 4) before and after every allocation is filled with a magic number. This idea is also know as "canary". Memory is automatically mapped and unmapped if necessary. This number is validated automatically when the allocation is destroyed. If it's not equal to the expected value, VMA_ASSERT() is executed. It clearly means that either CPU or GPU overwritten the memory outside of boundaries of the allocation, which indicates a serious bug. You can also explicitly request checking margins of all allocations in all memory blocks that belong to specified memory types by using function vmaCheckCorruption(), or in memory blocks that belong to specified custom pool, by using function vmaCheckPoolCorruption(). Margin validation (corruption detection) works only for memory types that are HOST_VISIBLE and HOST_COHERENT. \page record_and_replay Record and replay \section record_and_replay_introduction Introduction While using the library, sequence of calls to its functions together with their parameters can be recorded to a file and later replayed using standalone player application. It can be useful to: - Test correctness - check if same sequence of calls will not cause crash or failures on a target platform. - Gather statistics - see number of allocations, peak memory usage, number of calls etc. - Benchmark performance - see how much time it takes to replay the whole sequence. \section record_and_replay_usage Usage Recording functionality is disabled by default. To enable it, define following macro before every include of this library: \code #define VMA_RECORDING_ENABLED 1 \endcode To record sequence of calls to a file: Fill in VmaAllocatorCreateInfo::pRecordSettings member while creating #VmaAllocator object. File is opened and written during whole lifetime of the allocator. To replay file: Use VmaReplay - standalone command-line program. Precompiled binary can be found in "bin" directory. Its source can be found in "src/VmaReplay" directory. Its project is generated by Premake. Command line syntax is printed when the program is launched without parameters. Basic usage: VmaReplay.exe MyRecording.csv Documentation of file format can be found in file: "docs/Recording file format.md". It's a human-readable, text file in CSV format (Comma Separated Values). \section record_and_replay_additional_considerations Additional considerations - Replaying file that was recorded on a different GPU (with different parameters like bufferImageGranularity, nonCoherentAtomSize, and especially different set of memory heaps and types) may give different performance and memory usage results, as well as issue some warnings and errors. - Current implementation of recording in VMA, as well as VmaReplay application, is coded and tested only on Windows. Inclusion of recording code is driven by VMA_RECORDING_ENABLED macro. Support for other platforms should be easy to add. Contributions are welcomed. \page usage_patterns Recommended usage patterns See also slides from talk: [Sawicki, Adam. Advanced Graphics Techniques Tutorial: Memory management in Vulkan and DX12. Game Developers Conference, 2018](https://www.gdcvault.com/play/1025458/Advanced-Graphics-Techniques-Tutorial-New) \section usage_patterns_common_mistakes Common mistakes Use of CPU_TO_GPU instead of CPU_ONLY memory #VMA_MEMORY_USAGE_CPU_TO_GPU is recommended only for resources that will be mapped and written by the CPU, as well as read directly by the GPU - like some buffers or textures updated every frame (dynamic). If you create a staging copy of a resource to be written by CPU and then used as a source of transfer to another resource placed in the GPU memory, that staging resource should be created with #VMA_MEMORY_USAGE_CPU_ONLY. Please read the descriptions of these enums carefully for details. Unnecessary use of custom pools \ref custom_memory_pools may be useful for special purposes - when you want to keep certain type of resources separate e.g. to reserve minimum amount of memory for them, limit maximum amount of memory they can occupy, or make some of them push out the other through the mechanism of \ref lost_allocations. For most resources this is not needed and so it is not recommended to create #VmaPool objects and allocations out of them. Allocating from the default pool is sufficient. \section usage_patterns_simple Simple patterns \subsection usage_patterns_simple_render_targets Render targets When: Any resources that you frequently write and read on GPU, e.g. images used as color attachments (aka "render targets"), depth-stencil attachments, images/buffers used as storage image/buffer (aka "Unordered Access View (UAV)"). What to do: Create them in video memory that is fastest to access from GPU using #VMA_MEMORY_USAGE_GPU_ONLY. Consider using [VK_KHR_dedicated_allocation](@ref vk_khr_dedicated_allocation) extension and/or manually creating them as dedicated allocations using #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT, especially if they are large or if you plan to destroy and recreate them e.g. when display resolution changes. Prefer to create such resources first and all other GPU resources (like textures and vertex buffers) later. \subsection usage_patterns_simple_immutable_resources Immutable resources When: Any resources that you fill on CPU only once (aka "immutable") or infrequently and then read frequently on GPU, e.g. textures, vertex and index buffers, constant buffers that don't change often. What to do: Create them in video memory that is fastest to access from GPU using #VMA_MEMORY_USAGE_GPU_ONLY. To initialize content of such resource, create a CPU-side (aka "staging") copy of it in system memory - #VMA_MEMORY_USAGE_CPU_ONLY, map it, fill it, and submit a transfer from it to the GPU resource. You can keep the staging copy if you need it for another upload transfer in the future. If you don't, you can destroy it or reuse this buffer for uploading different resource after the transfer finishes. Prefer to create just buffers in system memory rather than images, even for uploading textures. Use vkCmdCopyBufferToImage(). Dont use images with VK_IMAGE_TILING_LINEAR. \subsection usage_patterns_dynamic_resources Dynamic resources When: Any resources that change frequently (aka "dynamic"), e.g. every frame or every draw call, written on CPU, read on GPU. What to do: Create them using #VMA_MEMORY_USAGE_CPU_TO_GPU. You can map it and write to it directly on CPU, as well as read from it on GPU. This is a more complex situation. Different solutions are possible, and the best one depends on specific GPU type, but you can use this simple approach for the start. Prefer to write to such resource sequentially (e.g. using memcpy). Don't perform random access or any reads from it on CPU, as it may be very slow. Also note that textures written directly from the host through a mapped pointer need to be in LINEAR not OPTIMAL layout. \subsection usage_patterns_readback Readback When: Resources that contain data written by GPU that you want to read back on CPU, e.g. results of some computations. What to do: Create them using #VMA_MEMORY_USAGE_GPU_TO_CPU. You can write to them directly on GPU, as well as map and read them on CPU. \section usage_patterns_advanced Advanced patterns \subsection usage_patterns_integrated_graphics Detecting integrated graphics You can support integrated graphics (like Intel HD Graphics, AMD APU) better by detecting it in Vulkan. To do it, call vkGetPhysicalDeviceProperties(), inspect VkPhysicalDeviceProperties::deviceType and look for VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU. When you find it, you can assume that memory is unified and all memory types are comparably fast to access from GPU, regardless of VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT. You can then sum up sizes of all available memory heaps and treat them as useful for your GPU resources, instead of only DEVICE_LOCAL ones. You can also prefer to create your resources in memory types that are HOST_VISIBLE to map them directly instead of submitting explicit transfer (see below). \subsection usage_patterns_direct_vs_transfer Direct access versus transfer For resources that you frequently write on CPU and read on GPU, many solutions are possible: -# Create one copy in video memory using #VMA_MEMORY_USAGE_GPU_ONLY, second copy in system memory using #VMA_MEMORY_USAGE_CPU_ONLY and submit explicit transfer each time. -# Create just a single copy using #VMA_MEMORY_USAGE_CPU_TO_GPU, map it and fill it on CPU, read it directly on GPU. -# Create just a single copy using #VMA_MEMORY_USAGE_CPU_ONLY, map it and fill it on CPU, read it directly on GPU. Which solution is the most efficient depends on your resource and especially on the GPU. It is best to measure it and then make the decision. Some general recommendations: - On integrated graphics use (2) or (3) to avoid unnecesary time and memory overhead related to using a second copy and making transfer. - For small resources (e.g. constant buffers) use (2). Discrete AMD cards have special 256 MiB pool of video memory that is directly mappable. Even if the resource ends up in system memory, its data may be cached on GPU after first fetch over PCIe bus. - For larger resources (e.g. textures), decide between (1) and (2). You may want to differentiate NVIDIA and AMD, e.g. by looking for memory type that is both DEVICE_LOCAL and HOST_VISIBLE. When you find it, use (2), otherwise use (1). Similarly, for resources that you frequently write on GPU and read on CPU, multiple solutions are possible: -# Create one copy in video memory using #VMA_MEMORY_USAGE_GPU_ONLY, second copy in system memory using #VMA_MEMORY_USAGE_GPU_TO_CPU and submit explicit tranfer each time. -# Create just single copy using #VMA_MEMORY_USAGE_GPU_TO_CPU, write to it directly on GPU, map it and read it on CPU. You should take some measurements to decide which option is faster in case of your specific resource. Note that textures accessed directly from the host through a mapped pointer need to be in LINEAR layout, which may slow down their usage on the device. Textures accessed only by the device and transfer operations can use OPTIMAL layout. If you don't want to specialize your code for specific types of GPUs, you can still make an simple optimization for cases when your resource ends up in mappable memory to use it directly in this case instead of creating CPU-side staging copy. For details see [Finding out if memory is mappable](@ref memory_mapping_finding_if_memory_mappable). \page configuration Configuration Please check "CONFIGURATION SECTION" in the code to find macros that you can define before each include of this file or change directly in this file to provide your own implementation of basic facilities like assert, min() and max() functions, mutex, atomic etc. The library uses its own implementation of containers by default, but you can switch to using STL containers instead. For example, define VMA_ASSERT(expr) before including the library to provide custom implementation of the assertion, compatible with your project. By default it is defined to standard C assert(expr) in _DEBUG configuration and empty otherwise. \section config_Vulkan_functions Pointers to Vulkan functions There are multiple ways to import pointers to Vulkan functions in the library. In the simplest case you don't need to do anything. If the compilation or linking of your program or the initialization of the #VmaAllocator doesn't work for you, you can try to reconfigure it. First, the allocator tries to fetch pointers to Vulkan functions linked statically, like this: \code m_VulkanFunctions.vkAllocateMemory = (PFN_vkAllocateMemory)vkAllocateMemory; \endcode If you want to disable this feature, set configuration macro: #define VMA_STATIC_VULKAN_FUNCTIONS 0. Second, you can provide the pointers yourself by setting member VmaAllocatorCreateInfo::pVulkanFunctions. You can fetch them e.g. using functions vkGetInstanceProcAddr and vkGetDeviceProcAddr or by using a helper library like [volk](https://github.com/zeux/volk). Third, VMA tries to fetch remaining pointers that are still null by calling vkGetInstanceProcAddr and vkGetDeviceProcAddr on its own. If you want to disable this feature, set configuration macro: #define VMA_DYNAMIC_VULKAN_FUNCTIONS 0. Finally, all the function pointers required by the library (considering selected Vulkan version and enabled extensions) are checked with VMA_ASSERT if they are not null. \section custom_memory_allocator Custom host memory allocator If you use custom allocator for CPU memory rather than default operator new and delete from C++, you can make this library using your allocator as well by filling optional member VmaAllocatorCreateInfo::pAllocationCallbacks. These functions will be passed to Vulkan, as well as used by the library itself to make any CPU-side allocations. \section allocation_callbacks Device memory allocation callbacks The library makes calls to vkAllocateMemory() and vkFreeMemory() internally. You can setup callbacks to be informed about these calls, e.g. for the purpose of gathering some statistics. To do it, fill optional member VmaAllocatorCreateInfo::pDeviceMemoryCallbacks. \section heap_memory_limit Device heap memory limit When device memory of certain heap runs out of free space, new allocations may fail (returning error code) or they may succeed, silently pushing some existing memory blocks from GPU VRAM to system RAM (which degrades performance). This behavior is implementation-dependant - it depends on GPU vendor and graphics driver. On AMD cards it can be controlled while creating Vulkan device object by using VK_AMD_memory_overallocation_behavior extension, if available. Alternatively, if you want to test how your program behaves with limited amount of Vulkan device memory available without switching your graphics card to one that really has smaller VRAM, you can use a feature of this library intended for this purpose. To do it, fill optional member VmaAllocatorCreateInfo::pHeapSizeLimit. \page vk_khr_dedicated_allocation VK_KHR_dedicated_allocation VK_KHR_dedicated_allocation is a Vulkan extension which can be used to improve performance on some GPUs. It augments Vulkan API with possibility to query driver whether it prefers particular buffer or image to have its own, dedicated allocation (separate VkDeviceMemory block) for better efficiency - to be able to do some internal optimizations. The extension is supported by this library. It will be used automatically when enabled. To enable it: 1 . When creating Vulkan device, check if following 2 device extensions are supported (call vkEnumerateDeviceExtensionProperties()). If yes, enable them (fill VkDeviceCreateInfo::ppEnabledExtensionNames). - VK_KHR_get_memory_requirements2 - VK_KHR_dedicated_allocation If you enabled these extensions: 2 . Use #VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT flag when creating your #VmaAllocatorto inform the library that you enabled required extensions and you want the library to use them. \code allocatorInfo.flags |= VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT; vmaCreateAllocator(&allocatorInfo, &allocator); \endcode That's all. The extension will be automatically used whenever you create a buffer using vmaCreateBuffer() or image using vmaCreateImage(). When using the extension together with Vulkan Validation Layer, you will receive warnings like this: vkBindBufferMemory(): Binding memory to buffer 0x33 but vkGetBufferMemoryRequirements() has not been called on that buffer. It is OK, you should just ignore it. It happens because you use function vkGetBufferMemoryRequirements2KHR() instead of standard vkGetBufferMemoryRequirements(), while the validation layer seems to be unaware of it. To learn more about this extension, see: - [VK_KHR_dedicated_allocation in Vulkan specification](https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap44.html#VK_KHR_dedicated_allocation) - [VK_KHR_dedicated_allocation unofficial manual](http://asawicki.info/articles/VK_KHR_dedicated_allocation.php5) \page vk_amd_device_coherent_memory VK_AMD_device_coherent_memory VK_AMD_device_coherent_memory is a device extension that enables access to additional memory types with VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD and VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD flag. It is useful mostly for allocation of buffers intended for writing "breadcrumb markers" in between passes or draw calls, which in turn are useful for debugging GPU crash/hang/TDR cases. When the extension is available but has not been enabled, Vulkan physical device still exposes those memory types, but their usage is forbidden. VMA automatically takes care of that - it returns VK_ERROR_FEATURE_NOT_PRESENT when an attempt to allocate memory of such type is made. If you want to use this extension in connection with VMA, follow these steps: \section vk_amd_device_coherent_memory_initialization Initialization 1) Call vkEnumerateDeviceExtensionProperties for the physical device. Check if the extension is supported - if returned array of VkExtensionProperties contains "VK_AMD_device_coherent_memory". 2) Call vkGetPhysicalDeviceFeatures2 for the physical device instead of old vkGetPhysicalDeviceFeatures. Attach additional structure VkPhysicalDeviceCoherentMemoryFeaturesAMD to VkPhysicalDeviceFeatures2::pNext to be returned. Check if the device feature is really supported - check if VkPhysicalDeviceCoherentMemoryFeaturesAMD::deviceCoherentMemory is true. 3) While creating device with vkCreateDevice, enable this extension - add "VK_AMD_device_coherent_memory" to the list passed as VkDeviceCreateInfo::ppEnabledExtensionNames. 4) While creating the device, also don't set VkDeviceCreateInfo::pEnabledFeatures. Fill in VkPhysicalDeviceFeatures2 structure instead and pass it as VkDeviceCreateInfo::pNext. Enable this device feature - attach additional structure VkPhysicalDeviceCoherentMemoryFeaturesAMD to VkPhysicalDeviceFeatures2::pNext and set its member deviceCoherentMemory to VK_TRUE. 5) While creating #VmaAllocator with vmaCreateAllocator() inform VMA that you have enabled this extension and feature - add #VMA_ALLOCATOR_CREATE_AMD_DEVICE_COHERENT_MEMORY_BIT to VmaAllocatorCreateInfo::flags. \section vk_amd_device_coherent_memory_usage Usage After following steps described above, you can create VMA allocations and custom pools out of the special DEVICE_COHERENT and DEVICE_UNCACHED memory types on eligible devices. There are multiple ways to do it, for example: - You can request or prefer to allocate out of such memory types by adding VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD to VmaAllocationCreateInfo::requiredFlags or VmaAllocationCreateInfo::preferredFlags. Those flags can be freely mixed with other ways of \ref choosing_memory_type, like setting VmaAllocationCreateInfo::usage. - If you manually found memory type index to use for this purpose, force allocation from this specific index by setting VmaAllocationCreateInfo::memoryTypeBits = 1u << index. \section vk_amd_device_coherent_memory_more_information More information To learn more about this extension, see [VK_AMD_device_coherent_memory in Vulkan specification](https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap44.html#VK_AMD_device_coherent_memory) Example use of this extension can be found in the code of the sample and test suite accompanying this library. \page enabling_buffer_device_address Enabling buffer device address Device extension VK_KHR_buffer_device_address allow to fetch raw GPU pointer to a buffer and pass it for usage in a shader code. It is promoted to core Vulkan 1.2. If you want to use this feature in connection with VMA, follow these steps: \section enabling_buffer_device_address_initialization Initialization 1) (For Vulkan version < 1.2) Call vkEnumerateDeviceExtensionProperties for the physical device. Check if the extension is supported - if returned array of VkExtensionProperties contains "VK_KHR_buffer_device_address". 2) Call vkGetPhysicalDeviceFeatures2 for the physical device instead of old vkGetPhysicalDeviceFeatures. Attach additional structure VkPhysicalDeviceBufferDeviceAddressFeatures* to VkPhysicalDeviceFeatures2::pNext to be returned. Check if the device feature is really supported - check if VkPhysicalDeviceBufferDeviceAddressFeatures*::bufferDeviceAddress is true. 3) (For Vulkan version < 1.2) While creating device with vkCreateDevice, enable this extension - add "VK_KHR_buffer_device_address" to the list passed as VkDeviceCreateInfo::ppEnabledExtensionNames. 4) While creating the device, also don't set VkDeviceCreateInfo::pEnabledFeatures. Fill in VkPhysicalDeviceFeatures2 structure instead and pass it as VkDeviceCreateInfo::pNext. Enable this device feature - attach additional structure VkPhysicalDeviceBufferDeviceAddressFeatures* to VkPhysicalDeviceFeatures2::pNext and set its member bufferDeviceAddress to VK_TRUE. 5) While creating #VmaAllocator with vmaCreateAllocator() inform VMA that you have enabled this feature - add #VMA_ALLOCATOR_CREATE_BUFFER_DEVICE_ADDRESS_BIT to VmaAllocatorCreateInfo::flags. \section enabling_buffer_device_address_usage Usage After following steps described above, you can create buffers with VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT* using VMA. The library automatically adds VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT* to allocated memory blocks wherever it might be needed. Please note that the library supports only VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT*. The second part of this functionality related to "capture and replay" is not supported, as it is intended for usage in debugging tools like RenderDoc, not in everyday Vulkan usage. \section enabling_buffer_device_address_more_information More information To learn more about this extension, see [VK_KHR_buffer_device_address in Vulkan specification](https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap46.html#VK_KHR_buffer_device_address) Example use of this extension can be found in the code of the sample and test suite accompanying this library. \page general_considerations General considerations \section general_considerations_thread_safety Thread safety - The library has no global state, so separate #VmaAllocator objects can be used independently. There should be no need to create multiple such objects though - one per VkDevice is enough. - By default, all calls to functions that take #VmaAllocator as first parameter are safe to call from multiple threads simultaneously because they are synchronized internally when needed. - When the allocator is created with #VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT flag, calls to functions that take such #VmaAllocator object must be synchronized externally. - Access to a #VmaAllocation object must be externally synchronized. For example, you must not call vmaGetAllocationInfo() and vmaMapMemory() from different threads at the same time if you pass the same #VmaAllocation object to these functions. \section general_considerations_validation_layer_warnings Validation layer warnings When using this library, you can meet following types of warnings issued by Vulkan validation layer. They don't necessarily indicate a bug, so you may need to just ignore them. - *vkBindBufferMemory(): Binding memory to buffer 0xeb8e4 but vkGetBufferMemoryRequirements() has not been called on that buffer.* - It happens when VK_KHR_dedicated_allocation extension is enabled. vkGetBufferMemoryRequirements2KHR function is used instead, while validation layer seems to be unaware of it. - *Mapping an image with layout VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL can result in undefined behavior if this memory is used by the device. Only GENERAL or PREINITIALIZED should be used.* - It happens when you map a buffer or image, because the library maps entire VkDeviceMemory block, where different types of images and buffers may end up together, especially on GPUs with unified memory like Intel. - *Non-linear image 0xebc91 is aliased with linear buffer 0xeb8e4 which may indicate a bug.* - It happens when you use lost allocations, and a new image or buffer is created in place of an existing object that bacame lost. - It may happen also when you use [defragmentation](@ref defragmentation). \section general_considerations_allocation_algorithm Allocation algorithm The library uses following algorithm for allocation, in order: -# Try to find free range of memory in existing blocks. -# If failed, try to create a new block of VkDeviceMemory, with preferred block size. -# If failed, try to create such block with size/2, size/4, size/8. -# If failed and #VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT flag was specified, try to find space in existing blocks, possilby making some other allocations lost. -# If failed, try to allocate separate VkDeviceMemory for this allocation, just like when you use #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT. -# If failed, choose other memory type that meets the requirements specified in VmaAllocationCreateInfo and go to point 1. -# If failed, return VK_ERROR_OUT_OF_DEVICE_MEMORY. \section general_considerations_features_not_supported Features not supported Features deliberately excluded from the scope of this library: - Data transfer. Uploading (straming) and downloading data of buffers and images between CPU and GPU memory and related synchronization is responsibility of the user. Defining some "texture" object that would automatically stream its data from a staging copy in CPU memory to GPU memory would rather be a feature of another, higher-level library implemented on top of VMA. - Allocations for imported/exported external memory. They tend to require explicit memory type index and dedicated allocation anyway, so they don't interact with main features of this library. Such special purpose allocations should be made manually, using vkCreateBuffer() and vkAllocateMemory(). - Recreation of buffers and images. Although the library has functions for buffer and image creation (vmaCreateBuffer(), vmaCreateImage()), you need to recreate these objects yourself after defragmentation. That's because the big structures VkBufferCreateInfo, VkImageCreateInfo are not stored in #VmaAllocation object. - Handling CPU memory allocation failures. When dynamically creating small C++ objects in CPU memory (not Vulkan memory), allocation failures are not checked and handled gracefully, because that would complicate code significantly and is usually not needed in desktop PC applications anyway. Success of an allocation is just checked with an assert. - Code free of any compiler warnings. Maintaining the library to compile and work correctly on so many different platforms is hard enough. Being free of any warnings, on any version of any compiler, is simply not feasible. - This is a C++ library with C interface. Bindings or ports to any other programming languages are welcomed as external projects and are not going to be included into this repository. */ #if VMA_RECORDING_ENABLED #include #if defined(_WIN32) #include #else #include #include #endif #endif #ifdef __cplusplus extern "C" { #endif /* Define this macro to 0/1 to disable/enable support for recording functionality, available through VmaAllocatorCreateInfo::pRecordSettings. */ #ifndef VMA_RECORDING_ENABLED #define VMA_RECORDING_ENABLED 0 #endif #ifndef NOMINMAX #define NOMINMAX // For windows.h #endif #if defined(__ANDROID__) && defined(VK_NO_PROTOTYPES) && VMA_STATIC_VULKAN_FUNCTIONS extern PFN_vkGetInstanceProcAddr vkGetInstanceProcAddr; extern PFN_vkGetDeviceProcAddr vkGetDeviceProcAddr; extern PFN_vkGetPhysicalDeviceProperties vkGetPhysicalDeviceProperties; extern PFN_vkGetPhysicalDeviceMemoryProperties vkGetPhysicalDeviceMemoryProperties; extern PFN_vkAllocateMemory vkAllocateMemory; extern PFN_vkFreeMemory vkFreeMemory; extern PFN_vkMapMemory vkMapMemory; extern PFN_vkUnmapMemory vkUnmapMemory; extern PFN_vkFlushMappedMemoryRanges vkFlushMappedMemoryRanges; extern PFN_vkInvalidateMappedMemoryRanges vkInvalidateMappedMemoryRanges; extern PFN_vkBindBufferMemory vkBindBufferMemory; extern PFN_vkBindImageMemory vkBindImageMemory; extern PFN_vkGetBufferMemoryRequirements vkGetBufferMemoryRequirements; extern PFN_vkGetImageMemoryRequirements vkGetImageMemoryRequirements; extern PFN_vkCreateBuffer vkCreateBuffer; extern PFN_vkDestroyBuffer vkDestroyBuffer; extern PFN_vkCreateImage vkCreateImage; extern PFN_vkDestroyImage vkDestroyImage; extern PFN_vkCmdCopyBuffer vkCmdCopyBuffer; #if VMA_VULKAN_VERSION >= 1001000 extern PFN_vkGetBufferMemoryRequirements2 vkGetBufferMemoryRequirements2; extern PFN_vkGetImageMemoryRequirements2 vkGetImageMemoryRequirements2; extern PFN_vkBindBufferMemory2 vkBindBufferMemory2; extern PFN_vkBindImageMemory2 vkBindImageMemory2; extern PFN_vkGetPhysicalDeviceMemoryProperties2 vkGetPhysicalDeviceMemoryProperties2; #endif // #if VMA_VULKAN_VERSION >= 1001000 #endif // #if defined(__ANDROID__) && VMA_STATIC_VULKAN_FUNCTIONS && VK_NO_PROTOTYPES #ifndef VULKAN_H_ #include #endif // Define this macro to declare maximum supported Vulkan version in format AAABBBCCC, // where AAA = major, BBB = minor, CCC = patch. // If you want to use version > 1.0, it still needs to be enabled via VmaAllocatorCreateInfo::vulkanApiVersion. #if !defined(VMA_VULKAN_VERSION) #if defined(VK_VERSION_1_2) #define VMA_VULKAN_VERSION 1002000 #elif defined(VK_VERSION_1_1) #define VMA_VULKAN_VERSION 1001000 #else #define VMA_VULKAN_VERSION 1000000 #endif #endif #if !defined(VMA_DEDICATED_ALLOCATION) #if VK_KHR_get_memory_requirements2 && VK_KHR_dedicated_allocation #define VMA_DEDICATED_ALLOCATION 1 #else #define VMA_DEDICATED_ALLOCATION 0 #endif #endif #if !defined(VMA_BIND_MEMORY2) #if VK_KHR_bind_memory2 #define VMA_BIND_MEMORY2 1 #else #define VMA_BIND_MEMORY2 0 #endif #endif #if !defined(VMA_MEMORY_BUDGET) #if VK_EXT_memory_budget && (VK_KHR_get_physical_device_properties2 || VMA_VULKAN_VERSION >= 1001000) #define VMA_MEMORY_BUDGET 1 #else #define VMA_MEMORY_BUDGET 0 #endif #endif // Defined to 1 when VK_KHR_buffer_device_address device extension or equivalent core Vulkan 1.2 feature is defined in its headers. #if !defined(VMA_BUFFER_DEVICE_ADDRESS) #if VK_KHR_buffer_device_address || VMA_VULKAN_VERSION >= 1002000 #define VMA_BUFFER_DEVICE_ADDRESS 1 #else #define VMA_BUFFER_DEVICE_ADDRESS 0 #endif #endif // Define these macros to decorate all public functions with additional code, // before and after returned type, appropriately. This may be useful for // exporing the functions when compiling VMA as a separate library. Example: // #define VMA_CALL_PRE __declspec(dllexport) // #define VMA_CALL_POST __cdecl #ifndef VMA_CALL_PRE #define VMA_CALL_PRE #endif #ifndef VMA_CALL_POST #define VMA_CALL_POST #endif // Define this macro to decorate pointers with an attribute specifying the // length of the array they point to if they are not null. // // The length may be one of // - The name of another parameter in the argument list where the pointer is declared // - The name of another member in the struct where the pointer is declared // - The name of a member of a struct type, meaning the value of that member in // the context of the call. For example // VMA_LEN_IF_NOT_NULL("VkPhysicalDeviceMemoryProperties::memoryHeapCount"), // this means the number of memory heaps available in the device associated // with the VmaAllocator being dealt with. #ifndef VMA_LEN_IF_NOT_NULL #define VMA_LEN_IF_NOT_NULL(len) #endif // The VMA_NULLABLE macro is defined to be _Nullable when compiling with Clang. // see: https://clang.llvm.org/docs/AttributeReference.html#nullable #ifndef VMA_NULLABLE #ifdef __clang__ #define VMA_NULLABLE _Nullable #else #define VMA_NULLABLE #endif #endif // The VMA_NOT_NULL macro is defined to be _Nonnull when compiling with Clang. // see: https://clang.llvm.org/docs/AttributeReference.html#nonnull #ifndef VMA_NOT_NULL #ifdef __clang__ #define VMA_NOT_NULL _Nonnull #else #define VMA_NOT_NULL #endif #endif // If non-dispatchable handles are represented as pointers then we can give // then nullability annotations #ifndef VMA_NOT_NULL_NON_DISPATCHABLE #if defined(__LP64__) || defined(_WIN64) || (defined(__x86_64__) && !defined(__ILP32__) ) || defined(_M_X64) || defined(__ia64) || defined (_M_IA64) || defined(__aarch64__) || defined(__powerpc64__) #define VMA_NOT_NULL_NON_DISPATCHABLE VMA_NOT_NULL #else #define VMA_NOT_NULL_NON_DISPATCHABLE #endif #endif #ifndef VMA_NULLABLE_NON_DISPATCHABLE #if defined(__LP64__) || defined(_WIN64) || (defined(__x86_64__) && !defined(__ILP32__) ) || defined(_M_X64) || defined(__ia64) || defined (_M_IA64) || defined(__aarch64__) || defined(__powerpc64__) #define VMA_NULLABLE_NON_DISPATCHABLE VMA_NULLABLE #else #define VMA_NULLABLE_NON_DISPATCHABLE #endif #endif /** \struct VmaAllocator \brief Represents main object of this library initialized. Fill structure #VmaAllocatorCreateInfo and call function vmaCreateAllocator() to create it. Call function vmaDestroyAllocator() to destroy it. It is recommended to create just one object of this type per VkDevice object, right after Vulkan is initialized and keep it alive until before Vulkan device is destroyed. */ VK_DEFINE_HANDLE(VmaAllocator) /// Callback function called after successful vkAllocateMemory. typedef void (VKAPI_PTR *PFN_vmaAllocateDeviceMemoryFunction)( VmaAllocator VMA_NOT_NULL allocator, uint32_t memoryType, VkDeviceMemory VMA_NOT_NULL_NON_DISPATCHABLE memory, VkDeviceSize size, void* VMA_NULLABLE pUserData); /// Callback function called before vkFreeMemory. typedef void (VKAPI_PTR *PFN_vmaFreeDeviceMemoryFunction)( VmaAllocator VMA_NOT_NULL allocator, uint32_t memoryType, VkDeviceMemory VMA_NOT_NULL_NON_DISPATCHABLE memory, VkDeviceSize size, void* VMA_NULLABLE pUserData); /** \brief Set of callbacks that the library will call for vkAllocateMemory and vkFreeMemory. Provided for informative purpose, e.g. to gather statistics about number of allocations or total amount of memory allocated in Vulkan. Used in VmaAllocatorCreateInfo::pDeviceMemoryCallbacks. */ typedef struct VmaDeviceMemoryCallbacks { /// Optional, can be null. PFN_vmaAllocateDeviceMemoryFunction VMA_NULLABLE pfnAllocate; /// Optional, can be null. PFN_vmaFreeDeviceMemoryFunction VMA_NULLABLE pfnFree; /// Optional, can be null. void* VMA_NULLABLE pUserData; } VmaDeviceMemoryCallbacks; /// Flags for created #VmaAllocator. typedef enum VmaAllocatorCreateFlagBits { /** \brief Allocator and all objects created from it will not be synchronized internally, so you must guarantee they are used from only one thread at a time or synchronized externally by you. Using this flag may increase performance because internal mutexes are not used. */ VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT = 0x00000001, /** \brief Enables usage of VK_KHR_dedicated_allocation extension. The flag works only if VmaAllocatorCreateInfo::vulkanApiVersion == VK_API_VERSION_1_0. When it's VK_API_VERSION_1_1, the flag is ignored because the extension has been promoted to Vulkan 1.1. Using this extenion will automatically allocate dedicated blocks of memory for some buffers and images instead of suballocating place for them out of bigger memory blocks (as if you explicitly used #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT flag) when it is recommended by the driver. It may improve performance on some GPUs. You may set this flag only if you found out that following device extensions are supported, you enabled them while creating Vulkan device passed as VmaAllocatorCreateInfo::device, and you want them to be used internally by this library: - VK_KHR_get_memory_requirements2 (device extension) - VK_KHR_dedicated_allocation (device extension) When this flag is set, you can experience following warnings reported by Vulkan validation layer. You can ignore them. > vkBindBufferMemory(): Binding memory to buffer 0x2d but vkGetBufferMemoryRequirements() has not been called on that buffer. */ VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT = 0x00000002, /** Enables usage of VK_KHR_bind_memory2 extension. The flag works only if VmaAllocatorCreateInfo::vulkanApiVersion == VK_API_VERSION_1_0. When it's VK_API_VERSION_1_1, the flag is ignored because the extension has been promoted to Vulkan 1.1. You may set this flag only if you found out that this device extension is supported, you enabled it while creating Vulkan device passed as VmaAllocatorCreateInfo::device, and you want it to be used internally by this library. The extension provides functions vkBindBufferMemory2KHR and vkBindImageMemory2KHR, which allow to pass a chain of pNext structures while binding. This flag is required if you use pNext parameter in vmaBindBufferMemory2() or vmaBindImageMemory2(). */ VMA_ALLOCATOR_CREATE_KHR_BIND_MEMORY2_BIT = 0x00000004, /** Enables usage of VK_EXT_memory_budget extension. You may set this flag only if you found out that this device extension is supported, you enabled it while creating Vulkan device passed as VmaAllocatorCreateInfo::device, and you want it to be used internally by this library, along with another instance extension VK_KHR_get_physical_device_properties2, which is required by it (or Vulkan 1.1, where this extension is promoted). The extension provides query for current memory usage and budget, which will probably be more accurate than an estimation used by the library otherwise. */ VMA_ALLOCATOR_CREATE_EXT_MEMORY_BUDGET_BIT = 0x00000008, /** Enables usage of VK_AMD_device_coherent_memory extension. You may set this flag only if you: - found out that this device extension is supported and enabled it while creating Vulkan device passed as VmaAllocatorCreateInfo::device, - checked that VkPhysicalDeviceCoherentMemoryFeaturesAMD::deviceCoherentMemory is true and set it while creating the Vulkan device, - want it to be used internally by this library. The extension and accompanying device feature provide access to memory types with VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD and VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD flags. They are useful mostly for writing breadcrumb markers - a common method for debugging GPU crash/hang/TDR. When the extension is not enabled, such memory types are still enumerated, but their usage is illegal. To protect from this error, if you don't create the allocator with this flag, it will refuse to allocate any memory or create a custom pool in such memory type, returning VK_ERROR_FEATURE_NOT_PRESENT. */ VMA_ALLOCATOR_CREATE_AMD_DEVICE_COHERENT_MEMORY_BIT = 0x00000010, /** Enables usage of "buffer device address" feature, which allows you to use function vkGetBufferDeviceAddress* to get raw GPU pointer to a buffer and pass it for usage inside a shader. You may set this flag only if you: 1. (For Vulkan version < 1.2) Found as available and enabled device extension VK_KHR_buffer_device_address. This extension is promoted to core Vulkan 1.2. 2. Found as available and enabled device feature VkPhysicalDeviceBufferDeviceAddressFeatures*::bufferDeviceAddress. When this flag is set, you can create buffers with VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT* using VMA. The library automatically adds VK_MEMORY_ALLOCATE_DEVICE_ADDRESS_BIT* to allocated memory blocks wherever it might be needed. For more information, see documentation chapter \ref enabling_buffer_device_address. */ VMA_ALLOCATOR_CREATE_BUFFER_DEVICE_ADDRESS_BIT = 0x00000020, VMA_ALLOCATOR_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF } VmaAllocatorCreateFlagBits; typedef VkFlags VmaAllocatorCreateFlags; /** \brief Pointers to some Vulkan functions - a subset used by the library. Used in VmaAllocatorCreateInfo::pVulkanFunctions. */ typedef struct VmaVulkanFunctions { PFN_vkGetPhysicalDeviceProperties VMA_NULLABLE vkGetPhysicalDeviceProperties; PFN_vkGetPhysicalDeviceMemoryProperties VMA_NULLABLE vkGetPhysicalDeviceMemoryProperties; PFN_vkAllocateMemory VMA_NULLABLE vkAllocateMemory; PFN_vkFreeMemory VMA_NULLABLE vkFreeMemory; PFN_vkMapMemory VMA_NULLABLE vkMapMemory; PFN_vkUnmapMemory VMA_NULLABLE vkUnmapMemory; PFN_vkFlushMappedMemoryRanges VMA_NULLABLE vkFlushMappedMemoryRanges; PFN_vkInvalidateMappedMemoryRanges VMA_NULLABLE vkInvalidateMappedMemoryRanges; PFN_vkBindBufferMemory VMA_NULLABLE vkBindBufferMemory; PFN_vkBindImageMemory VMA_NULLABLE vkBindImageMemory; PFN_vkGetBufferMemoryRequirements VMA_NULLABLE vkGetBufferMemoryRequirements; PFN_vkGetImageMemoryRequirements VMA_NULLABLE vkGetImageMemoryRequirements; PFN_vkCreateBuffer VMA_NULLABLE vkCreateBuffer; PFN_vkDestroyBuffer VMA_NULLABLE vkDestroyBuffer; PFN_vkCreateImage VMA_NULLABLE vkCreateImage; PFN_vkDestroyImage VMA_NULLABLE vkDestroyImage; PFN_vkCmdCopyBuffer VMA_NULLABLE vkCmdCopyBuffer; #if VMA_DEDICATED_ALLOCATION || VMA_VULKAN_VERSION >= 1001000 PFN_vkGetBufferMemoryRequirements2KHR VMA_NULLABLE vkGetBufferMemoryRequirements2KHR; PFN_vkGetImageMemoryRequirements2KHR VMA_NULLABLE vkGetImageMemoryRequirements2KHR; #endif #if VMA_BIND_MEMORY2 || VMA_VULKAN_VERSION >= 1001000 PFN_vkBindBufferMemory2KHR VMA_NULLABLE vkBindBufferMemory2KHR; PFN_vkBindImageMemory2KHR VMA_NULLABLE vkBindImageMemory2KHR; #endif #if VMA_MEMORY_BUDGET || VMA_VULKAN_VERSION >= 1001000 PFN_vkGetPhysicalDeviceMemoryProperties2KHR VMA_NULLABLE vkGetPhysicalDeviceMemoryProperties2KHR; #endif } VmaVulkanFunctions; /// Flags to be used in VmaRecordSettings::flags. typedef enum VmaRecordFlagBits { /** \brief Enables flush after recording every function call. Enable it if you expect your application to crash, which may leave recording file truncated. It may degrade performance though. */ VMA_RECORD_FLUSH_AFTER_CALL_BIT = 0x00000001, VMA_RECORD_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF } VmaRecordFlagBits; typedef VkFlags VmaRecordFlags; /// Parameters for recording calls to VMA functions. To be used in VmaAllocatorCreateInfo::pRecordSettings. typedef struct VmaRecordSettings { /// Flags for recording. Use #VmaRecordFlagBits enum. VmaRecordFlags flags; /** \brief Path to the file that should be written by the recording. Suggested extension: "csv". If the file already exists, it will be overwritten. It will be opened for the whole time #VmaAllocator object is alive. If opening this file fails, creation of the whole allocator object fails. */ const char* VMA_NOT_NULL pFilePath; } VmaRecordSettings; /// Description of a Allocator to be created. typedef struct VmaAllocatorCreateInfo { /// Flags for created allocator. Use #VmaAllocatorCreateFlagBits enum. VmaAllocatorCreateFlags flags; /// Vulkan physical device. /** It must be valid throughout whole lifetime of created allocator. */ VkPhysicalDevice VMA_NOT_NULL physicalDevice; /// Vulkan device. /** It must be valid throughout whole lifetime of created allocator. */ VkDevice VMA_NOT_NULL device; /// Preferred size of a single VkDeviceMemory block to be allocated from large heaps > 1 GiB. Optional. /** Set to 0 to use default, which is currently 256 MiB. */ VkDeviceSize preferredLargeHeapBlockSize; /// Custom CPU memory allocation callbacks. Optional. /** Optional, can be null. When specified, will also be used for all CPU-side memory allocations. */ const VkAllocationCallbacks* VMA_NULLABLE pAllocationCallbacks; /// Informative callbacks for vkAllocateMemory, vkFreeMemory. Optional. /** Optional, can be null. */ const VmaDeviceMemoryCallbacks* VMA_NULLABLE pDeviceMemoryCallbacks; /** \brief Maximum number of additional frames that are in use at the same time as current frame. This value is used only when you make allocations with VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag. Such allocation cannot become lost if allocation.lastUseFrameIndex >= allocator.currentFrameIndex - frameInUseCount. For example, if you double-buffer your command buffers, so resources used for rendering in previous frame may still be in use by the GPU at the moment you allocate resources needed for the current frame, set this value to 1. If you want to allow any allocations other than used in the current frame to become lost, set this value to 0. */ uint32_t frameInUseCount; /** \brief Either null or a pointer to an array of limits on maximum number of bytes that can be allocated out of particular Vulkan memory heap. If not NULL, it must be a pointer to an array of VkPhysicalDeviceMemoryProperties::memoryHeapCount elements, defining limit on maximum number of bytes that can be allocated out of particular Vulkan memory heap. Any of the elements may be equal to VK_WHOLE_SIZE, which means no limit on that heap. This is also the default in case of pHeapSizeLimit = NULL. If there is a limit defined for a heap: - If user tries to allocate more memory from that heap using this allocator, the allocation fails with VK_ERROR_OUT_OF_DEVICE_MEMORY. - If the limit is smaller than heap size reported in VkMemoryHeap::size, the value of this limit will be reported instead when using vmaGetMemoryProperties(). Warning! Using this feature may not be equivalent to installing a GPU with smaller amount of memory, because graphics driver doesn't necessary fail new allocations with VK_ERROR_OUT_OF_DEVICE_MEMORY result when memory capacity is exceeded. It may return success and just silently migrate some device memory blocks to system RAM. This driver behavior can also be controlled using VK_AMD_memory_overallocation_behavior extension. */ const VkDeviceSize* VMA_NULLABLE VMA_LEN_IF_NOT_NULL("VkPhysicalDeviceMemoryProperties::memoryHeapCount") pHeapSizeLimit; /** \brief Pointers to Vulkan functions. Can be null. For details see [Pointers to Vulkan functions](@ref config_Vulkan_functions). */ const VmaVulkanFunctions* VMA_NULLABLE pVulkanFunctions; /** \brief Parameters for recording of VMA calls. Can be null. If not null, it enables recording of calls to VMA functions to a file. If support for recording is not enabled using VMA_RECORDING_ENABLED macro, creation of the allocator object fails with VK_ERROR_FEATURE_NOT_PRESENT. */ const VmaRecordSettings* VMA_NULLABLE pRecordSettings; /** \brief Handle to Vulkan instance object. Starting from version 3.0.0 this member is no longer optional, it must be set! */ VkInstance VMA_NOT_NULL instance; /** \brief Optional. The highest version of Vulkan that the application is designed to use. It must be a value in the format as created by macro VK_MAKE_VERSION or a constant like: VK_API_VERSION_1_1, VK_API_VERSION_1_0. The patch version number specified is ignored. Only the major and minor versions are considered. It must be less or equal (preferably equal) to value as passed to vkCreateInstance as VkApplicationInfo::apiVersion. Only versions 1.0 and 1.1 are supported by the current implementation. Leaving it initialized to zero is equivalent to VK_API_VERSION_1_0. */ uint32_t vulkanApiVersion; } VmaAllocatorCreateInfo; /// Creates Allocator object. VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreateAllocator( const VmaAllocatorCreateInfo* VMA_NOT_NULL pCreateInfo, VmaAllocator VMA_NULLABLE * VMA_NOT_NULL pAllocator); /// Destroys allocator object. VMA_CALL_PRE void VMA_CALL_POST vmaDestroyAllocator( VmaAllocator VMA_NULLABLE allocator); /** \brief Information about existing #VmaAllocator object. */ typedef struct VmaAllocatorInfo { /** \brief Handle to Vulkan instance object. This is the same value as has been passed through VmaAllocatorCreateInfo::instance. */ VkInstance VMA_NOT_NULL instance; /** \brief Handle to Vulkan physical device object. This is the same value as has been passed through VmaAllocatorCreateInfo::physicalDevice. */ VkPhysicalDevice VMA_NOT_NULL physicalDevice; /** \brief Handle to Vulkan device object. This is the same value as has been passed through VmaAllocatorCreateInfo::device. */ VkDevice VMA_NOT_NULL device; } VmaAllocatorInfo; /** \brief Returns information about existing #VmaAllocator object - handle to Vulkan device etc. It might be useful if you want to keep just the #VmaAllocator handle and fetch other required handles to VkPhysicalDevice, VkDevice etc. every time using this function. */ VMA_CALL_PRE void VMA_CALL_POST vmaGetAllocatorInfo(VmaAllocator VMA_NOT_NULL allocator, VmaAllocatorInfo* VMA_NOT_NULL pAllocatorInfo); /** PhysicalDeviceProperties are fetched from physicalDevice by the allocator. You can access it here, without fetching it again on your own. */ VMA_CALL_PRE void VMA_CALL_POST vmaGetPhysicalDeviceProperties( VmaAllocator VMA_NOT_NULL allocator, const VkPhysicalDeviceProperties* VMA_NULLABLE * VMA_NOT_NULL ppPhysicalDeviceProperties); /** PhysicalDeviceMemoryProperties are fetched from physicalDevice by the allocator. You can access it here, without fetching it again on your own. */ VMA_CALL_PRE void VMA_CALL_POST vmaGetMemoryProperties( VmaAllocator VMA_NOT_NULL allocator, const VkPhysicalDeviceMemoryProperties* VMA_NULLABLE * VMA_NOT_NULL ppPhysicalDeviceMemoryProperties); /** \brief Given Memory Type Index, returns Property Flags of this memory type. This is just a convenience function. Same information can be obtained using vmaGetMemoryProperties(). */ VMA_CALL_PRE void VMA_CALL_POST vmaGetMemoryTypeProperties( VmaAllocator VMA_NOT_NULL allocator, uint32_t memoryTypeIndex, VkMemoryPropertyFlags* VMA_NOT_NULL pFlags); /** \brief Sets index of the current frame. This function must be used if you make allocations with #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT and #VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT flags to inform the allocator when a new frame begins. Allocations queried using vmaGetAllocationInfo() cannot become lost in the current frame. */ VMA_CALL_PRE void VMA_CALL_POST vmaSetCurrentFrameIndex( VmaAllocator VMA_NOT_NULL allocator, uint32_t frameIndex); /** \brief Calculated statistics of memory usage in entire allocator. */ typedef struct VmaStatInfo { /// Number of VkDeviceMemory Vulkan memory blocks allocated. uint32_t blockCount; /// Number of #VmaAllocation allocation objects allocated. uint32_t allocationCount; /// Number of free ranges of memory between allocations. uint32_t unusedRangeCount; /// Total number of bytes occupied by all allocations. VkDeviceSize usedBytes; /// Total number of bytes occupied by unused ranges. VkDeviceSize unusedBytes; VkDeviceSize allocationSizeMin, allocationSizeAvg, allocationSizeMax; VkDeviceSize unusedRangeSizeMin, unusedRangeSizeAvg, unusedRangeSizeMax; } VmaStatInfo; /// General statistics from current state of Allocator. typedef struct VmaStats { VmaStatInfo memoryType[VK_MAX_MEMORY_TYPES]; VmaStatInfo memoryHeap[VK_MAX_MEMORY_HEAPS]; VmaStatInfo total; } VmaStats; /** \brief Retrieves statistics from current state of the Allocator. This function is called "calculate" not "get" because it has to traverse all internal data structures, so it may be quite slow. For faster but more brief statistics suitable to be called every frame or every allocation, use vmaGetBudget(). Note that when using allocator from multiple threads, returned information may immediately become outdated. */ VMA_CALL_PRE void VMA_CALL_POST vmaCalculateStats( VmaAllocator VMA_NOT_NULL allocator, VmaStats* VMA_NOT_NULL pStats); /** \brief Statistics of current memory usage and available budget, in bytes, for specific memory heap. */ typedef struct VmaBudget { /** \brief Sum size of all VkDeviceMemory blocks allocated from particular heap, in bytes. */ VkDeviceSize blockBytes; /** \brief Sum size of all allocations created in particular heap, in bytes. Usually less or equal than blockBytes. Difference blockBytes - allocationBytes is the amount of memory allocated but unused - available for new allocations or wasted due to fragmentation. It might be greater than blockBytes if there are some allocations in lost state, as they account to this value as well. */ VkDeviceSize allocationBytes; /** \brief Estimated current memory usage of the program, in bytes. Fetched from system using VK_EXT_memory_budget extension if enabled. It might be different than blockBytes (usually higher) due to additional implicit objects also occupying the memory, like swapchain, pipelines, descriptor heaps, command buffers, or VkDeviceMemory blocks allocated outside of this library, if any. */ VkDeviceSize usage; /** \brief Estimated amount of memory available to the program, in bytes. Fetched from system using VK_EXT_memory_budget extension if enabled. It might be different (most probably smaller) than VkMemoryHeap::size[heapIndex] due to factors external to the program, like other programs also consuming system resources. Difference budget - usage is the amount of additional memory that can probably be allocated without problems. Exceeding the budget may result in various problems. */ VkDeviceSize budget; } VmaBudget; /** \brief Retrieves information about current memory budget for all memory heaps. \param[out] pBudget Must point to array with number of elements at least equal to number of memory heaps in physical device used. This function is called "get" not "calculate" because it is very fast, suitable to be called every frame or every allocation. For more detailed statistics use vmaCalculateStats(). Note that when using allocator from multiple threads, returned information may immediately become outdated. */ VMA_CALL_PRE void VMA_CALL_POST vmaGetBudget( VmaAllocator VMA_NOT_NULL allocator, VmaBudget* VMA_NOT_NULL pBudget); #ifndef VMA_STATS_STRING_ENABLED #define VMA_STATS_STRING_ENABLED 1 #endif #if VMA_STATS_STRING_ENABLED /// Builds and returns statistics as string in JSON format. /** @param[out] ppStatsString Must be freed using vmaFreeStatsString() function. */ VMA_CALL_PRE void VMA_CALL_POST vmaBuildStatsString( VmaAllocator VMA_NOT_NULL allocator, char* VMA_NULLABLE * VMA_NOT_NULL ppStatsString, VkBool32 detailedMap); VMA_CALL_PRE void VMA_CALL_POST vmaFreeStatsString( VmaAllocator VMA_NOT_NULL allocator, char* VMA_NULLABLE pStatsString); #endif // #if VMA_STATS_STRING_ENABLED /** \struct VmaPool \brief Represents custom memory pool Fill structure VmaPoolCreateInfo and call function vmaCreatePool() to create it. Call function vmaDestroyPool() to destroy it. For more information see [Custom memory pools](@ref choosing_memory_type_custom_memory_pools). */ VK_DEFINE_HANDLE(VmaPool) typedef enum VmaMemoryUsage { /** No intended memory usage specified. Use other members of VmaAllocationCreateInfo to specify your requirements. */ VMA_MEMORY_USAGE_UNKNOWN = 0, /** Memory will be used on device only, so fast access from the device is preferred. It usually means device-local GPU (video) memory. No need to be mappable on host. It is roughly equivalent of D3D12_HEAP_TYPE_DEFAULT. Usage: - Resources written and read by device, e.g. images used as attachments. - Resources transferred from host once (immutable) or infrequently and read by device multiple times, e.g. textures to be sampled, vertex buffers, uniform (constant) buffers, and majority of other types of resources used on GPU. Allocation may still end up in HOST_VISIBLE memory on some implementations. In such case, you are free to map it. You can use #VMA_ALLOCATION_CREATE_MAPPED_BIT with this usage type. */ VMA_MEMORY_USAGE_GPU_ONLY = 1, /** Memory will be mappable on host. It usually means CPU (system) memory. Guarantees to be HOST_VISIBLE and HOST_COHERENT. CPU access is typically uncached. Writes may be write-combined. Resources created in this pool may still be accessible to the device, but access to them can be slow. It is roughly equivalent of D3D12_HEAP_TYPE_UPLOAD. Usage: Staging copy of resources used as transfer source. */ VMA_MEMORY_USAGE_CPU_ONLY = 2, /** Memory that is both mappable on host (guarantees to be HOST_VISIBLE) and preferably fast to access by GPU. CPU access is typically uncached. Writes may be write-combined. Usage: Resources written frequently by host (dynamic), read by device. E.g. textures (with LINEAR layout), vertex buffers, uniform buffers updated every frame or every draw call. */ VMA_MEMORY_USAGE_CPU_TO_GPU = 3, /** Memory mappable on host (guarantees to be HOST_VISIBLE) and cached. It is roughly equivalent of D3D12_HEAP_TYPE_READBACK. Usage: - Resources written by device, read by host - results of some computations, e.g. screen capture, average scene luminance for HDR tone mapping. - Any resources read or accessed randomly on host, e.g. CPU-side copy of vertex buffer used as source of transfer, but also used for collision detection. */ VMA_MEMORY_USAGE_GPU_TO_CPU = 4, /** CPU memory - memory that is preferably not DEVICE_LOCAL, but also not guaranteed to be HOST_VISIBLE. Usage: Staging copy of resources moved from GPU memory to CPU memory as part of custom paging/residency mechanism, to be moved back to GPU memory when needed. */ VMA_MEMORY_USAGE_CPU_COPY = 5, /** Lazily allocated GPU memory having VK_MEMORY_PROPERTY_LAZILY_ALLOCATED_BIT. Exists mostly on mobile platforms. Using it on desktop PC or other GPUs with no such memory type present will fail the allocation. Usage: Memory for transient attachment images (color attachments, depth attachments etc.), created with VK_IMAGE_USAGE_TRANSIENT_ATTACHMENT_BIT. Allocations with this usage are always created as dedicated - it implies #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT. */ VMA_MEMORY_USAGE_GPU_LAZILY_ALLOCATED = 6, VMA_MEMORY_USAGE_MAX_ENUM = 0x7FFFFFFF } VmaMemoryUsage; /// Flags to be passed as VmaAllocationCreateInfo::flags. typedef enum VmaAllocationCreateFlagBits { /** \brief Set this flag if the allocation should have its own memory block. Use it for special, big resources, like fullscreen images used as attachments. You should not use this flag if VmaAllocationCreateInfo::pool is not null. */ VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT = 0x00000001, /** \brief Set this flag to only try to allocate from existing VkDeviceMemory blocks and never create new such block. If new allocation cannot be placed in any of the existing blocks, allocation fails with VK_ERROR_OUT_OF_DEVICE_MEMORY error. You should not use #VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT and #VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT at the same time. It makes no sense. If VmaAllocationCreateInfo::pool is not null, this flag is implied and ignored. */ VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT = 0x00000002, /** \brief Set this flag to use a memory that will be persistently mapped and retrieve pointer to it. Pointer to mapped memory will be returned through VmaAllocationInfo::pMappedData. Is it valid to use this flag for allocation made from memory type that is not HOST_VISIBLE. This flag is then ignored and memory is not mapped. This is useful if you need an allocation that is efficient to use on GPU (DEVICE_LOCAL) and still want to map it directly if possible on platforms that support it (e.g. Intel GPU). You should not use this flag together with #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT. */ VMA_ALLOCATION_CREATE_MAPPED_BIT = 0x00000004, /** Allocation created with this flag can become lost as a result of another allocation with #VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT flag, so you must check it before use. To check if allocation is not lost, call vmaGetAllocationInfo() and check if VmaAllocationInfo::deviceMemory is not VK_NULL_HANDLE. For details about supporting lost allocations, see Lost Allocations chapter of User Guide on Main Page. You should not use this flag together with #VMA_ALLOCATION_CREATE_MAPPED_BIT. */ VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT = 0x00000008, /** While creating allocation using this flag, other allocations that were created with flag #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT can become lost. For details about supporting lost allocations, see Lost Allocations chapter of User Guide on Main Page. */ VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT = 0x00000010, /** Set this flag to treat VmaAllocationCreateInfo::pUserData as pointer to a null-terminated string. Instead of copying pointer value, a local copy of the string is made and stored in allocation's pUserData. The string is automatically freed together with the allocation. It is also used in vmaBuildStatsString(). */ VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT = 0x00000020, /** Allocation will be created from upper stack in a double stack pool. This flag is only allowed for custom pools created with #VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT flag. */ VMA_ALLOCATION_CREATE_UPPER_ADDRESS_BIT = 0x00000040, /** Create both buffer/image and allocation, but don't bind them together. It is useful when you want to bind yourself to do some more advanced binding, e.g. using some extensions. The flag is meaningful only with functions that bind by default: vmaCreateBuffer(), vmaCreateImage(). Otherwise it is ignored. */ VMA_ALLOCATION_CREATE_DONT_BIND_BIT = 0x00000080, /** Create allocation only if additional device memory required for it, if any, won't exceed memory budget. Otherwise return VK_ERROR_OUT_OF_DEVICE_MEMORY. */ VMA_ALLOCATION_CREATE_WITHIN_BUDGET_BIT = 0x00000100, /** Allocation strategy that chooses smallest possible free range for the allocation. */ VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT = 0x00010000, /** Allocation strategy that chooses biggest possible free range for the allocation. */ VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT = 0x00020000, /** Allocation strategy that chooses first suitable free range for the allocation. "First" doesn't necessarily means the one with smallest offset in memory, but rather the one that is easiest and fastest to find. */ VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT = 0x00040000, /** Allocation strategy that tries to minimize memory usage. */ VMA_ALLOCATION_CREATE_STRATEGY_MIN_MEMORY_BIT = VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT, /** Allocation strategy that tries to minimize allocation time. */ VMA_ALLOCATION_CREATE_STRATEGY_MIN_TIME_BIT = VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT, /** Allocation strategy that tries to minimize memory fragmentation. */ VMA_ALLOCATION_CREATE_STRATEGY_MIN_FRAGMENTATION_BIT = VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT, /** A bit mask to extract only STRATEGY bits from entire set of flags. */ VMA_ALLOCATION_CREATE_STRATEGY_MASK = VMA_ALLOCATION_CREATE_STRATEGY_BEST_FIT_BIT | VMA_ALLOCATION_CREATE_STRATEGY_WORST_FIT_BIT | VMA_ALLOCATION_CREATE_STRATEGY_FIRST_FIT_BIT, VMA_ALLOCATION_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF } VmaAllocationCreateFlagBits; typedef VkFlags VmaAllocationCreateFlags; typedef struct VmaAllocationCreateInfo { /// Use #VmaAllocationCreateFlagBits enum. VmaAllocationCreateFlags flags; /** \brief Intended usage of memory. You can leave #VMA_MEMORY_USAGE_UNKNOWN if you specify memory requirements in other way. \n If pool is not null, this member is ignored. */ VmaMemoryUsage usage; /** \brief Flags that must be set in a Memory Type chosen for an allocation. Leave 0 if you specify memory requirements in other way. \n If pool is not null, this member is ignored.*/ VkMemoryPropertyFlags requiredFlags; /** \brief Flags that preferably should be set in a memory type chosen for an allocation. Set to 0 if no additional flags are prefered. \n If pool is not null, this member is ignored. */ VkMemoryPropertyFlags preferredFlags; /** \brief Bitmask containing one bit set for every memory type acceptable for this allocation. Value 0 is equivalent to UINT32_MAX - it means any memory type is accepted if it meets other requirements specified by this structure, with no further restrictions on memory type index. \n If pool is not null, this member is ignored. */ uint32_t memoryTypeBits; /** \brief Pool that this allocation should be created in. Leave VK_NULL_HANDLE to allocate from default pool. If not null, members: usage, requiredFlags, preferredFlags, memoryTypeBits are ignored. */ VmaPool VMA_NULLABLE pool; /** \brief Custom general-purpose pointer that will be stored in #VmaAllocation, can be read as VmaAllocationInfo::pUserData and changed using vmaSetAllocationUserData(). If #VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT is used, it must be either null or pointer to a null-terminated string. The string will be then copied to internal buffer, so it doesn't need to be valid after allocation call. */ void* VMA_NULLABLE pUserData; } VmaAllocationCreateInfo; /** \brief Helps to find memoryTypeIndex, given memoryTypeBits and VmaAllocationCreateInfo. This algorithm tries to find a memory type that: - Is allowed by memoryTypeBits. - Contains all the flags from pAllocationCreateInfo->requiredFlags. - Matches intended usage. - Has as many flags from pAllocationCreateInfo->preferredFlags as possible. \return Returns VK_ERROR_FEATURE_NOT_PRESENT if not found. Receiving such result from this function or any other allocating function probably means that your device doesn't support any memory type with requested features for the specific type of resource you want to use it for. Please check parameters of your resource, like image layout (OPTIMAL versus LINEAR) or mip level count. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaFindMemoryTypeIndex( VmaAllocator VMA_NOT_NULL allocator, uint32_t memoryTypeBits, const VmaAllocationCreateInfo* VMA_NOT_NULL pAllocationCreateInfo, uint32_t* VMA_NOT_NULL pMemoryTypeIndex); /** \brief Helps to find memoryTypeIndex, given VkBufferCreateInfo and VmaAllocationCreateInfo. It can be useful e.g. to determine value to be used as VmaPoolCreateInfo::memoryTypeIndex. It internally creates a temporary, dummy buffer that never has memory bound. It is just a convenience function, equivalent to calling: - vkCreateBuffer - vkGetBufferMemoryRequirements - vmaFindMemoryTypeIndex - vkDestroyBuffer */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaFindMemoryTypeIndexForBufferInfo( VmaAllocator VMA_NOT_NULL allocator, const VkBufferCreateInfo* VMA_NOT_NULL pBufferCreateInfo, const VmaAllocationCreateInfo* VMA_NOT_NULL pAllocationCreateInfo, uint32_t* VMA_NOT_NULL pMemoryTypeIndex); /** \brief Helps to find memoryTypeIndex, given VkImageCreateInfo and VmaAllocationCreateInfo. It can be useful e.g. to determine value to be used as VmaPoolCreateInfo::memoryTypeIndex. It internally creates a temporary, dummy image that never has memory bound. It is just a convenience function, equivalent to calling: - vkCreateImage - vkGetImageMemoryRequirements - vmaFindMemoryTypeIndex - vkDestroyImage */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaFindMemoryTypeIndexForImageInfo( VmaAllocator VMA_NOT_NULL allocator, const VkImageCreateInfo* VMA_NOT_NULL pImageCreateInfo, const VmaAllocationCreateInfo* VMA_NOT_NULL pAllocationCreateInfo, uint32_t* VMA_NOT_NULL pMemoryTypeIndex); /// Flags to be passed as VmaPoolCreateInfo::flags. typedef enum VmaPoolCreateFlagBits { /** \brief Use this flag if you always allocate only buffers and linear images or only optimal images out of this pool and so Buffer-Image Granularity can be ignored. This is an optional optimization flag. If you always allocate using vmaCreateBuffer(), vmaCreateImage(), vmaAllocateMemoryForBuffer(), then you don't need to use it because allocator knows exact type of your allocations so it can handle Buffer-Image Granularity in the optimal way. If you also allocate using vmaAllocateMemoryForImage() or vmaAllocateMemory(), exact type of such allocations is not known, so allocator must be conservative in handling Buffer-Image Granularity, which can lead to suboptimal allocation (wasted memory). In that case, if you can make sure you always allocate only buffers and linear images or only optimal images out of this pool, use this flag to make allocator disregard Buffer-Image Granularity and so make allocations faster and more optimal. */ VMA_POOL_CREATE_IGNORE_BUFFER_IMAGE_GRANULARITY_BIT = 0x00000002, /** \brief Enables alternative, linear allocation algorithm in this pool. Specify this flag to enable linear allocation algorithm, which always creates new allocations after last one and doesn't reuse space from allocations freed in between. It trades memory consumption for simplified algorithm and data structure, which has better performance and uses less memory for metadata. By using this flag, you can achieve behavior of free-at-once, stack, ring buffer, and double stack. For details, see documentation chapter \ref linear_algorithm. When using this flag, you must specify VmaPoolCreateInfo::maxBlockCount == 1 (or 0 for default). For more details, see [Linear allocation algorithm](@ref linear_algorithm). */ VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT = 0x00000004, /** \brief Enables alternative, buddy allocation algorithm in this pool. It operates on a tree of blocks, each having size that is a power of two and a half of its parent's size. Comparing to default algorithm, this one provides faster allocation and deallocation and decreased external fragmentation, at the expense of more memory wasted (internal fragmentation). For more details, see [Buddy allocation algorithm](@ref buddy_algorithm). */ VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT = 0x00000008, /** Bit mask to extract only ALGORITHM bits from entire set of flags. */ VMA_POOL_CREATE_ALGORITHM_MASK = VMA_POOL_CREATE_LINEAR_ALGORITHM_BIT | VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT, VMA_POOL_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF } VmaPoolCreateFlagBits; typedef VkFlags VmaPoolCreateFlags; /** \brief Describes parameter of created #VmaPool. */ typedef struct VmaPoolCreateInfo { /** \brief Vulkan memory type index to allocate this pool from. */ uint32_t memoryTypeIndex; /** \brief Use combination of #VmaPoolCreateFlagBits. */ VmaPoolCreateFlags flags; /** \brief Size of a single VkDeviceMemory block to be allocated as part of this pool, in bytes. Optional. Specify nonzero to set explicit, constant size of memory blocks used by this pool. Leave 0 to use default and let the library manage block sizes automatically. Sizes of particular blocks may vary. */ VkDeviceSize blockSize; /** \brief Minimum number of blocks to be always allocated in this pool, even if they stay empty. Set to 0 to have no preallocated blocks and allow the pool be completely empty. */ size_t minBlockCount; /** \brief Maximum number of blocks that can be allocated in this pool. Optional. Set to 0 to use default, which is SIZE_MAX, which means no limit. Set to same value as VmaPoolCreateInfo::minBlockCount to have fixed amount of memory allocated throughout whole lifetime of this pool. */ size_t maxBlockCount; /** \brief Maximum number of additional frames that are in use at the same time as current frame. This value is used only when you make allocations with #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag. Such allocation cannot become lost if allocation.lastUseFrameIndex >= allocator.currentFrameIndex - frameInUseCount. For example, if you double-buffer your command buffers, so resources used for rendering in previous frame may still be in use by the GPU at the moment you allocate resources needed for the current frame, set this value to 1. If you want to allow any allocations other than used in the current frame to become lost, set this value to 0. */ uint32_t frameInUseCount; } VmaPoolCreateInfo; /** \brief Describes parameter of existing #VmaPool. */ typedef struct VmaPoolStats { /** \brief Total amount of VkDeviceMemory allocated from Vulkan for this pool, in bytes. */ VkDeviceSize size; /** \brief Total number of bytes in the pool not used by any #VmaAllocation. */ VkDeviceSize unusedSize; /** \brief Number of #VmaAllocation objects created from this pool that were not destroyed or lost. */ size_t allocationCount; /** \brief Number of continuous memory ranges in the pool not used by any #VmaAllocation. */ size_t unusedRangeCount; /** \brief Size of the largest continuous free memory region available for new allocation. Making a new allocation of that size is not guaranteed to succeed because of possible additional margin required to respect alignment and buffer/image granularity. */ VkDeviceSize unusedRangeSizeMax; /** \brief Number of VkDeviceMemory blocks allocated for this pool. */ size_t blockCount; } VmaPoolStats; /** \brief Allocates Vulkan device memory and creates #VmaPool object. @param allocator Allocator object. @param pCreateInfo Parameters of pool to create. @param[out] pPool Handle to created pool. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaCreatePool( VmaAllocator VMA_NOT_NULL allocator, const VmaPoolCreateInfo* VMA_NOT_NULL pCreateInfo, VmaPool VMA_NULLABLE * VMA_NOT_NULL pPool); /** \brief Destroys #VmaPool object and frees Vulkan device memory. */ VMA_CALL_PRE void VMA_CALL_POST vmaDestroyPool( VmaAllocator VMA_NOT_NULL allocator, VmaPool VMA_NULLABLE pool); /** \brief Retrieves statistics of existing #VmaPool object. @param allocator Allocator object. @param pool Pool object. @param[out] pPoolStats Statistics of specified pool. */ VMA_CALL_PRE void VMA_CALL_POST vmaGetPoolStats( VmaAllocator VMA_NOT_NULL allocator, VmaPool VMA_NOT_NULL pool, VmaPoolStats* VMA_NOT_NULL pPoolStats); /** \brief Marks all allocations in given pool as lost if they are not used in current frame or VmaPoolCreateInfo::frameInUseCount back from now. @param allocator Allocator object. @param pool Pool. @param[out] pLostAllocationCount Number of allocations marked as lost. Optional - pass null if you don't need this information. */ VMA_CALL_PRE void VMA_CALL_POST vmaMakePoolAllocationsLost( VmaAllocator VMA_NOT_NULL allocator, VmaPool VMA_NOT_NULL pool, size_t* VMA_NULLABLE pLostAllocationCount); /** \brief Checks magic number in margins around all allocations in given memory pool in search for corruptions. Corruption detection is enabled only when VMA_DEBUG_DETECT_CORRUPTION macro is defined to nonzero, VMA_DEBUG_MARGIN is defined to nonzero and the pool is created in memory type that is HOST_VISIBLE and HOST_COHERENT. For more information, see [Corruption detection](@ref debugging_memory_usage_corruption_detection). Possible return values: - VK_ERROR_FEATURE_NOT_PRESENT - corruption detection is not enabled for specified pool. - VK_SUCCESS - corruption detection has been performed and succeeded. - VK_ERROR_VALIDATION_FAILED_EXT - corruption detection has been performed and found memory corruptions around one of the allocations. VMA_ASSERT is also fired in that case. - Other value: Error returned by Vulkan, e.g. memory mapping failure. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaCheckPoolCorruption(VmaAllocator VMA_NOT_NULL allocator, VmaPool VMA_NOT_NULL pool); /** \brief Retrieves name of a custom pool. After the call ppName is either null or points to an internally-owned null-terminated string containing name of the pool that was previously set. The pointer becomes invalid when the pool is destroyed or its name is changed using vmaSetPoolName(). */ VMA_CALL_PRE void VMA_CALL_POST vmaGetPoolName( VmaAllocator VMA_NOT_NULL allocator, VmaPool VMA_NOT_NULL pool, const char* VMA_NULLABLE * VMA_NOT_NULL ppName); /** \brief Sets name of a custom pool. pName can be either null or pointer to a null-terminated string with new name for the pool. Function makes internal copy of the string, so it can be changed or freed immediately after this call. */ VMA_CALL_PRE void VMA_CALL_POST vmaSetPoolName( VmaAllocator VMA_NOT_NULL allocator, VmaPool VMA_NOT_NULL pool, const char* VMA_NULLABLE pName); /** \struct VmaAllocation \brief Represents single memory allocation. It may be either dedicated block of VkDeviceMemory or a specific region of a bigger block of this type plus unique offset. There are multiple ways to create such object. You need to fill structure VmaAllocationCreateInfo. For more information see [Choosing memory type](@ref choosing_memory_type). Although the library provides convenience functions that create Vulkan buffer or image, allocate memory for it and bind them together, binding of the allocation to a buffer or an image is out of scope of the allocation itself. Allocation object can exist without buffer/image bound, binding can be done manually by the user, and destruction of it can be done independently of destruction of the allocation. The object also remembers its size and some other information. To retrieve this information, use function vmaGetAllocationInfo() and inspect returned structure VmaAllocationInfo. Some kinds allocations can be in lost state. For more information, see [Lost allocations](@ref lost_allocations). */ VK_DEFINE_HANDLE(VmaAllocation) /** \brief Parameters of #VmaAllocation objects, that can be retrieved using function vmaGetAllocationInfo(). */ typedef struct VmaAllocationInfo { /** \brief Memory type index that this allocation was allocated from. It never changes. */ uint32_t memoryType; /** \brief Handle to Vulkan memory object. Same memory object can be shared by multiple allocations. It can change after call to vmaDefragment() if this allocation is passed to the function, or if allocation is lost. If the allocation is lost, it is equal to VK_NULL_HANDLE. */ VkDeviceMemory VMA_NULLABLE_NON_DISPATCHABLE deviceMemory; /** \brief Offset into deviceMemory object to the beginning of this allocation, in bytes. (deviceMemory, offset) pair is unique to this allocation. It can change after call to vmaDefragment() if this allocation is passed to the function, or if allocation is lost. */ VkDeviceSize offset; /** \brief Size of this allocation, in bytes. It never changes, unless allocation is lost. \note Allocation size returned in this variable may be greater than the size requested for the resource e.g. as VkBufferCreateInfo::size. Whole size of the allocation is accessible for operations on memory e.g. using a pointer after mapping with vmaMapMemory(), but operations on the resource e.g. using vkCmdCopyBuffer must be limited to the size of the resource. */ VkDeviceSize size; /** \brief Pointer to the beginning of this allocation as mapped data. If the allocation hasn't been mapped using vmaMapMemory() and hasn't been created with #VMA_ALLOCATION_CREATE_MAPPED_BIT flag, this value is null. It can change after call to vmaMapMemory(), vmaUnmapMemory(). It can also change after call to vmaDefragment() if this allocation is passed to the function. */ void* VMA_NULLABLE pMappedData; /** \brief Custom general-purpose pointer that was passed as VmaAllocationCreateInfo::pUserData or set using vmaSetAllocationUserData(). It can change after call to vmaSetAllocationUserData() for this allocation. */ void* VMA_NULLABLE pUserData; } VmaAllocationInfo; /** \brief General purpose memory allocation. @param[out] pAllocation Handle to allocated memory. @param[out] pAllocationInfo Optional. Information about allocated memory. It can be later fetched using function vmaGetAllocationInfo(). You should free the memory using vmaFreeMemory() or vmaFreeMemoryPages(). It is recommended to use vmaAllocateMemoryForBuffer(), vmaAllocateMemoryForImage(), vmaCreateBuffer(), vmaCreateImage() instead whenever possible. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemory( VmaAllocator VMA_NOT_NULL allocator, const VkMemoryRequirements* VMA_NOT_NULL pVkMemoryRequirements, const VmaAllocationCreateInfo* VMA_NOT_NULL pCreateInfo, VmaAllocation VMA_NULLABLE * VMA_NOT_NULL pAllocation, VmaAllocationInfo* VMA_NULLABLE pAllocationInfo); /** \brief General purpose memory allocation for multiple allocation objects at once. @param allocator Allocator object. @param pVkMemoryRequirements Memory requirements for each allocation. @param pCreateInfo Creation parameters for each alloction. @param allocationCount Number of allocations to make. @param[out] pAllocations Pointer to array that will be filled with handles to created allocations. @param[out] pAllocationInfo Optional. Pointer to array that will be filled with parameters of created allocations. You should free the memory using vmaFreeMemory() or vmaFreeMemoryPages(). Word "pages" is just a suggestion to use this function to allocate pieces of memory needed for sparse binding. It is just a general purpose allocation function able to make multiple allocations at once. It may be internally optimized to be more efficient than calling vmaAllocateMemory() allocationCount times. All allocations are made using same parameters. All of them are created out of the same memory pool and type. If any allocation fails, all allocations already made within this function call are also freed, so that when returned result is not VK_SUCCESS, pAllocation array is always entirely filled with VK_NULL_HANDLE. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemoryPages( VmaAllocator VMA_NOT_NULL allocator, const VkMemoryRequirements* VMA_NOT_NULL VMA_LEN_IF_NOT_NULL(allocationCount) pVkMemoryRequirements, const VmaAllocationCreateInfo* VMA_NOT_NULL VMA_LEN_IF_NOT_NULL(allocationCount) pCreateInfo, size_t allocationCount, VmaAllocation VMA_NULLABLE * VMA_NOT_NULL VMA_LEN_IF_NOT_NULL(allocationCount) pAllocations, VmaAllocationInfo* VMA_NULLABLE VMA_LEN_IF_NOT_NULL(allocationCount) pAllocationInfo); /** @param[out] pAllocation Handle to allocated memory. @param[out] pAllocationInfo Optional. Information about allocated memory. It can be later fetched using function vmaGetAllocationInfo(). You should free the memory using vmaFreeMemory(). */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemoryForBuffer( VmaAllocator VMA_NOT_NULL allocator, VkBuffer VMA_NOT_NULL_NON_DISPATCHABLE buffer, const VmaAllocationCreateInfo* VMA_NOT_NULL pCreateInfo, VmaAllocation VMA_NULLABLE * VMA_NOT_NULL pAllocation, VmaAllocationInfo* VMA_NULLABLE pAllocationInfo); /// Function similar to vmaAllocateMemoryForBuffer(). VMA_CALL_PRE VkResult VMA_CALL_POST vmaAllocateMemoryForImage( VmaAllocator VMA_NOT_NULL allocator, VkImage VMA_NOT_NULL_NON_DISPATCHABLE image, const VmaAllocationCreateInfo* VMA_NOT_NULL pCreateInfo, VmaAllocation VMA_NULLABLE * VMA_NOT_NULL pAllocation, VmaAllocationInfo* VMA_NULLABLE pAllocationInfo); /** \brief Frees memory previously allocated using vmaAllocateMemory(), vmaAllocateMemoryForBuffer(), or vmaAllocateMemoryForImage(). Passing VK_NULL_HANDLE as allocation is valid. Such function call is just skipped. */ VMA_CALL_PRE void VMA_CALL_POST vmaFreeMemory( VmaAllocator VMA_NOT_NULL allocator, const VmaAllocation VMA_NULLABLE allocation); /** \brief Frees memory and destroys multiple allocations. Word "pages" is just a suggestion to use this function to free pieces of memory used for sparse binding. It is just a general purpose function to free memory and destroy allocations made using e.g. vmaAllocateMemory(), vmaAllocateMemoryPages() and other functions. It may be internally optimized to be more efficient than calling vmaFreeMemory() allocationCount times. Allocations in pAllocations array can come from any memory pools and types. Passing VK_NULL_HANDLE as elements of pAllocations array is valid. Such entries are just skipped. */ VMA_CALL_PRE void VMA_CALL_POST vmaFreeMemoryPages( VmaAllocator VMA_NOT_NULL allocator, size_t allocationCount, const VmaAllocation VMA_NULLABLE * VMA_NOT_NULL VMA_LEN_IF_NOT_NULL(allocationCount) pAllocations); /** \brief Deprecated. \deprecated In version 2.2.0 it used to try to change allocation's size without moving or reallocating it. In current version it returns VK_SUCCESS only if newSize equals current allocation's size. Otherwise returns VK_ERROR_OUT_OF_POOL_MEMORY, indicating that allocation's size could not be changed. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaResizeAllocation( VmaAllocator VMA_NOT_NULL allocator, VmaAllocation VMA_NOT_NULL allocation, VkDeviceSize newSize); /** \brief Returns current information about specified allocation and atomically marks it as used in current frame. Current paramters of given allocation are returned in pAllocationInfo. This function also atomically "touches" allocation - marks it as used in current frame, just like vmaTouchAllocation(). If the allocation is in lost state, pAllocationInfo->deviceMemory == VK_NULL_HANDLE. Although this function uses atomics and doesn't lock any mutex, so it should be quite efficient, you can avoid calling it too often. - You can retrieve same VmaAllocationInfo structure while creating your resource, from function vmaCreateBuffer(), vmaCreateImage(). You can remember it if you are sure parameters don't change (e.g. due to defragmentation or allocation becoming lost). - If you just want to check if allocation is not lost, vmaTouchAllocation() will work faster. */ VMA_CALL_PRE void VMA_CALL_POST vmaGetAllocationInfo( VmaAllocator VMA_NOT_NULL allocator, VmaAllocation VMA_NOT_NULL allocation, VmaAllocationInfo* VMA_NOT_NULL pAllocationInfo); /** \brief Returns VK_TRUE if allocation is not lost and atomically marks it as used in current frame. If the allocation has been created with #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag, this function returns VK_TRUE if it's not in lost state, so it can still be used. It then also atomically "touches" the allocation - marks it as used in current frame, so that you can be sure it won't become lost in current frame or next frameInUseCount frames. If the allocation is in lost state, the function returns VK_FALSE. Memory of such allocation, as well as buffer or image bound to it, should not be used. Lost allocation and the buffer/image still need to be destroyed. If the allocation has been created without #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag, this function always returns VK_TRUE. */ VMA_CALL_PRE VkBool32 VMA_CALL_POST vmaTouchAllocation( VmaAllocator VMA_NOT_NULL allocator, VmaAllocation VMA_NOT_NULL allocation); /** \brief Sets pUserData in given allocation to new value. If the allocation was created with VMA_ALLOCATION_CREATE_USER_DATA_COPY_STRING_BIT, pUserData must be either null, or pointer to a null-terminated string. The function makes local copy of the string and sets it as allocation's pUserData. String passed as pUserData doesn't need to be valid for whole lifetime of the allocation - you can free it after this call. String previously pointed by allocation's pUserData is freed from memory. If the flag was not used, the value of pointer pUserData is just copied to allocation's pUserData. It is opaque, so you can use it however you want - e.g. as a pointer, ordinal number or some handle to you own data. */ VMA_CALL_PRE void VMA_CALL_POST vmaSetAllocationUserData( VmaAllocator VMA_NOT_NULL allocator, VmaAllocation VMA_NOT_NULL allocation, void* VMA_NULLABLE pUserData); /** \brief Creates new allocation that is in lost state from the beginning. It can be useful if you need a dummy, non-null allocation. You still need to destroy created object using vmaFreeMemory(). Returned allocation is not tied to any specific memory pool or memory type and not bound to any image or buffer. It has size = 0. It cannot be turned into a real, non-empty allocation. */ VMA_CALL_PRE void VMA_CALL_POST vmaCreateLostAllocation( VmaAllocator VMA_NOT_NULL allocator, VmaAllocation VMA_NULLABLE * VMA_NOT_NULL pAllocation); /** \brief Maps memory represented by given allocation and returns pointer to it. Maps memory represented by given allocation to make it accessible to CPU code. When succeeded, *ppData contains pointer to first byte of this memory. If the allocation is part of bigger VkDeviceMemory block, the pointer is correctly offseted to the beginning of region assigned to this particular allocation. Mapping is internally reference-counted and synchronized, so despite raw Vulkan function vkMapMemory() cannot be used to map same block of VkDeviceMemory multiple times simultaneously, it is safe to call this function on allocations assigned to the same memory block. Actual Vulkan memory will be mapped on first mapping and unmapped on last unmapping. If the function succeeded, you must call vmaUnmapMemory() to unmap the allocation when mapping is no longer needed or before freeing the allocation, at the latest. It also safe to call this function multiple times on the same allocation. You must call vmaUnmapMemory() same number of times as you called vmaMapMemory(). It is also safe to call this function on allocation created with #VMA_ALLOCATION_CREATE_MAPPED_BIT flag. Its memory stays mapped all the time. You must still call vmaUnmapMemory() same number of times as you called vmaMapMemory(). You must not call vmaUnmapMemory() additional time to free the "0-th" mapping made automatically due to #VMA_ALLOCATION_CREATE_MAPPED_BIT flag. This function fails when used on allocation made in memory type that is not HOST_VISIBLE. This function always fails when called for allocation that was created with #VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT flag. Such allocations cannot be mapped. This function doesn't automatically flush or invalidate caches. If the allocation is made from a memory types that is not HOST_COHERENT`, you also need to use vmaInvalidateAllocation() / vmaFlushAllocation(), as required by Vulkan specification. */ VMA_CALL_PRE VkResult VMA_CALL_POST vmaMapMemory(