Vulkan Memory Allocator
Classes | Macros | Typedefs | Enumerations | Functions
vk_mem_alloc.h File Reference
#include <vulkan/vulkan.h>

Go to the source code of this file.

Classes

struct  VmaDeviceMemoryCallbacks
 Set of callbacks that the library will call for vkAllocateMemory and vkFreeMemory. More...
 
struct  VmaVulkanFunctions
 Pointers to some Vulkan functions - a subset used by the library. More...
 
struct  VmaAllocatorCreateInfo
 Description of a Allocator to be created. More...
 
struct  VmaStatInfo
 Calculated statistics of memory usage in entire allocator. More...
 
struct  VmaStats
 General statistics from current state of Allocator. More...
 
struct  VmaAllocationCreateInfo
 
struct  VmaPoolCreateInfo
 Describes parameter of created VmaPool. More...
 
struct  VmaPoolStats
 Describes parameter of existing VmaPool. More...
 
struct  VmaAllocationInfo
 Parameters of VmaAllocation objects, that can be retrieved using function vmaGetAllocationInfo(). More...
 
struct  VmaDefragmentationInfo
 Optional configuration parameters to be passed to function vmaDefragment(). More...
 
struct  VmaDefragmentationStats
 Statistics returned by function vmaDefragment(). More...
 

Macros

#define VMA_STATS_STRING_ENABLED   1
 

Typedefs

typedef void(VKAPI_PTR * PFN_vmaAllocateDeviceMemoryFunction) (VmaAllocator allocator, uint32_t memoryType, VkDeviceMemory memory, VkDeviceSize size)
 Callback function called after successful vkAllocateMemory. More...
 
typedef void(VKAPI_PTR * PFN_vmaFreeDeviceMemoryFunction) (VmaAllocator allocator, uint32_t memoryType, VkDeviceMemory memory, VkDeviceSize size)
 Callback function called before vkFreeMemory. More...
 
typedef struct VmaDeviceMemoryCallbacks VmaDeviceMemoryCallbacks
 Set of callbacks that the library will call for vkAllocateMemory and vkFreeMemory. More...
 
typedef enum VmaAllocatorCreateFlagBits VmaAllocatorCreateFlagBits
 Flags for created VmaAllocator. More...
 
typedef VkFlags VmaAllocatorCreateFlags
 
typedef struct VmaVulkanFunctions VmaVulkanFunctions
 Pointers to some Vulkan functions - a subset used by the library. More...
 
typedef struct VmaAllocatorCreateInfo VmaAllocatorCreateInfo
 Description of a Allocator to be created. More...
 
typedef struct VmaStatInfo VmaStatInfo
 Calculated statistics of memory usage in entire allocator. More...
 
typedef struct VmaStats VmaStats
 General statistics from current state of Allocator. More...
 
typedef enum VmaMemoryUsage VmaMemoryUsage
 
typedef enum VmaAllocationCreateFlagBits VmaAllocationCreateFlagBits
 Flags to be passed as VmaAllocationCreateInfo::flags. More...
 
typedef VkFlags VmaAllocationCreateFlags
 
typedef struct VmaAllocationCreateInfo VmaAllocationCreateInfo
 
typedef enum VmaPoolCreateFlagBits VmaPoolCreateFlagBits
 Flags to be passed as VmaPoolCreateInfo::flags. More...
 
typedef VkFlags VmaPoolCreateFlags
 
typedef struct VmaPoolCreateInfo VmaPoolCreateInfo
 Describes parameter of created VmaPool. More...
 
typedef struct VmaPoolStats VmaPoolStats
 Describes parameter of existing VmaPool. More...
 
typedef struct VmaAllocationInfo VmaAllocationInfo
 Parameters of VmaAllocation objects, that can be retrieved using function vmaGetAllocationInfo(). More...
 
typedef struct VmaDefragmentationInfo VmaDefragmentationInfo
 Optional configuration parameters to be passed to function vmaDefragment(). More...
 
typedef struct VmaDefragmentationStats VmaDefragmentationStats
 Statistics returned by function vmaDefragment(). More...
 

Enumerations

enum  VmaAllocatorCreateFlagBits { VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT = 0x00000001, VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT = 0x00000002, VMA_ALLOCATOR_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF }
 Flags for created VmaAllocator. More...
 
enum  VmaMemoryUsage {
  VMA_MEMORY_USAGE_UNKNOWN = 0, VMA_MEMORY_USAGE_GPU_ONLY = 1, VMA_MEMORY_USAGE_CPU_ONLY = 2, VMA_MEMORY_USAGE_CPU_TO_GPU = 3,
  VMA_MEMORY_USAGE_GPU_TO_CPU = 4, VMA_MEMORY_USAGE_MAX_ENUM = 0x7FFFFFFF
}
 
enum  VmaAllocationCreateFlagBits {
  VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT = 0x00000001, VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT = 0x00000002, VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT = 0x00000004, VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT = 0x00000008,
  VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT = 0x00000010, VMA_ALLOCATION_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
}
 Flags to be passed as VmaAllocationCreateInfo::flags. More...
 
enum  VmaPoolCreateFlagBits { VMA_POOL_CREATE_PERSISTENT_MAP_BIT = 0x00000001, VMA_POOL_CREATE_IGNORE_BUFFER_IMAGE_GRANULARITY_BIT = 0x00000002, VMA_POOL_CREATE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF }
 Flags to be passed as VmaPoolCreateInfo::flags. More...
 

Functions

VkResult vmaCreateAllocator (const VmaAllocatorCreateInfo *pCreateInfo, VmaAllocator *pAllocator)
 Creates Allocator object. More...
 
void vmaDestroyAllocator (VmaAllocator allocator)
 Destroys allocator object. More...
 
void vmaGetPhysicalDeviceProperties (VmaAllocator allocator, const VkPhysicalDeviceProperties **ppPhysicalDeviceProperties)
 
void vmaGetMemoryProperties (VmaAllocator allocator, const VkPhysicalDeviceMemoryProperties **ppPhysicalDeviceMemoryProperties)
 
void vmaGetMemoryTypeProperties (VmaAllocator allocator, uint32_t memoryTypeIndex, VkMemoryPropertyFlags *pFlags)
 Given Memory Type Index, returns Property Flags of this memory type. More...
 
void vmaSetCurrentFrameIndex (VmaAllocator allocator, uint32_t frameIndex)
 Sets index of the current frame. More...
 
void vmaCalculateStats (VmaAllocator allocator, VmaStats *pStats)
 Retrieves statistics from current state of the Allocator. More...
 
void vmaBuildStatsString (VmaAllocator allocator, char **ppStatsString, VkBool32 detailedMap)
 Builds and returns statistics as string in JSON format. More...
 
void vmaFreeStatsString (VmaAllocator allocator, char *pStatsString)
 
VkResult vmaFindMemoryTypeIndex (VmaAllocator allocator, uint32_t memoryTypeBits, const VmaAllocationCreateInfo *pAllocationCreateInfo, uint32_t *pMemoryTypeIndex)
 
VkResult vmaCreatePool (VmaAllocator allocator, const VmaPoolCreateInfo *pCreateInfo, VmaPool *pPool)
 Allocates Vulkan device memory and creates VmaPool object. More...
 
void vmaDestroyPool (VmaAllocator allocator, VmaPool pool)
 Destroys VmaPool object and frees Vulkan device memory. More...
 
void vmaGetPoolStats (VmaAllocator allocator, VmaPool pool, VmaPoolStats *pPoolStats)
 Retrieves statistics of existing VmaPool object. More...
 
void vmaMakePoolAllocationsLost (VmaAllocator allocator, VmaPool pool, size_t *pLostAllocationCount)
 Marks all allocations in given pool as lost if they are not used in current frame or VmaPoolCreateInfo::frameInUseCount back from now. More...
 
VkResult vmaAllocateMemory (VmaAllocator allocator, const VkMemoryRequirements *pVkMemoryRequirements, const VmaAllocationCreateInfo *pCreateInfo, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)
 General purpose memory allocation. More...
 
VkResult vmaAllocateMemoryForBuffer (VmaAllocator allocator, VkBuffer buffer, const VmaAllocationCreateInfo *pCreateInfo, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)
 
VkResult vmaAllocateMemoryForImage (VmaAllocator allocator, VkImage image, const VmaAllocationCreateInfo *pCreateInfo, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)
 Function similar to vmaAllocateMemoryForBuffer(). More...
 
void vmaFreeMemory (VmaAllocator allocator, VmaAllocation allocation)
 Frees memory previously allocated using vmaAllocateMemory(), vmaAllocateMemoryForBuffer(), or vmaAllocateMemoryForImage(). More...
 
void vmaGetAllocationInfo (VmaAllocator allocator, VmaAllocation allocation, VmaAllocationInfo *pAllocationInfo)
 Returns current information about specified allocation. More...
 
void vmaSetAllocationUserData (VmaAllocator allocator, VmaAllocation allocation, void *pUserData)
 Sets pUserData in given allocation to new value. More...
 
void vmaCreateLostAllocation (VmaAllocator allocator, VmaAllocation *pAllocation)
 Creates new allocation that is in lost state from the beginning. More...
 
VkResult vmaMapMemory (VmaAllocator allocator, VmaAllocation allocation, void **ppData)
 
void vmaUnmapMemory (VmaAllocator allocator, VmaAllocation allocation)
 
void vmaUnmapPersistentlyMappedMemory (VmaAllocator allocator)
 Unmaps persistently mapped memory of types that are HOST_COHERENT and DEVICE_LOCAL. More...
 
VkResult vmaMapPersistentlyMappedMemory (VmaAllocator allocator)
 Maps back persistently mapped memory of types that are HOST_COHERENT and DEVICE_LOCAL. More...
 
VkResult vmaDefragment (VmaAllocator allocator, VmaAllocation *pAllocations, size_t allocationCount, VkBool32 *pAllocationsChanged, const VmaDefragmentationInfo *pDefragmentationInfo, VmaDefragmentationStats *pDefragmentationStats)
 Compacts memory by moving allocations. More...
 
VkResult vmaCreateBuffer (VmaAllocator allocator, const VkBufferCreateInfo *pBufferCreateInfo, const VmaAllocationCreateInfo *pAllocationCreateInfo, VkBuffer *pBuffer, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)
 
void vmaDestroyBuffer (VmaAllocator allocator, VkBuffer buffer, VmaAllocation allocation)
 Destroys Vulkan buffer and frees allocated memory. More...
 
VkResult vmaCreateImage (VmaAllocator allocator, const VkImageCreateInfo *pImageCreateInfo, const VmaAllocationCreateInfo *pAllocationCreateInfo, VkImage *pImage, VmaAllocation *pAllocation, VmaAllocationInfo *pAllocationInfo)
 Function similar to vmaCreateBuffer(). More...
 
void vmaDestroyImage (VmaAllocator allocator, VkImage image, VmaAllocation allocation)
 Destroys Vulkan image and frees allocated memory. More...
 

Macro Definition Documentation

◆ VMA_STATS_STRING_ENABLED

#define VMA_STATS_STRING_ENABLED   1

Typedef Documentation

◆ PFN_vmaAllocateDeviceMemoryFunction

typedef void(VKAPI_PTR * PFN_vmaAllocateDeviceMemoryFunction) (VmaAllocator allocator, uint32_t memoryType, VkDeviceMemory memory, VkDeviceSize size)

Callback function called after successful vkAllocateMemory.

◆ PFN_vmaFreeDeviceMemoryFunction

typedef void(VKAPI_PTR * PFN_vmaFreeDeviceMemoryFunction) (VmaAllocator allocator, uint32_t memoryType, VkDeviceMemory memory, VkDeviceSize size)

Callback function called before vkFreeMemory.

◆ VmaAllocationCreateFlagBits

Flags to be passed as VmaAllocationCreateInfo::flags.

◆ VmaAllocationCreateFlags

typedef VkFlags VmaAllocationCreateFlags

◆ VmaAllocationCreateInfo

◆ VmaAllocationInfo

Parameters of VmaAllocation objects, that can be retrieved using function vmaGetAllocationInfo().

◆ VmaAllocatorCreateFlagBits

Flags for created VmaAllocator.

◆ VmaAllocatorCreateFlags

typedef VkFlags VmaAllocatorCreateFlags

◆ VmaAllocatorCreateInfo

Description of a Allocator to be created.

◆ VmaDefragmentationInfo

Optional configuration parameters to be passed to function vmaDefragment().

◆ VmaDefragmentationStats

Statistics returned by function vmaDefragment().

◆ VmaDeviceMemoryCallbacks

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.

◆ VmaMemoryUsage

◆ VmaPoolCreateFlagBits

Flags to be passed as VmaPoolCreateInfo::flags.

◆ VmaPoolCreateFlags

typedef VkFlags VmaPoolCreateFlags

◆ VmaPoolCreateInfo

Describes parameter of created VmaPool.

◆ VmaPoolStats

typedef struct VmaPoolStats VmaPoolStats

Describes parameter of existing VmaPool.

◆ VmaStatInfo

typedef struct VmaStatInfo VmaStatInfo

Calculated statistics of memory usage in entire allocator.

◆ VmaStats

typedef struct VmaStats VmaStats

General statistics from current state of Allocator.

◆ VmaVulkanFunctions

Pointers to some Vulkan functions - a subset used by the library.

Used in VmaAllocatorCreateInfo::pVulkanFunctions.

Enumeration Type Documentation

◆ VmaAllocationCreateFlagBits

Flags to be passed as VmaAllocationCreateInfo::flags.

Enumerator
VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT 

Set this flag if the allocation should have its own memory block.

Use it for special, big resources, like fullscreen images used as attachments.

This flag must also be used for host visible resources that you want to map simultaneously because otherwise they might end up as regions of the same VkDeviceMemory, while mapping same VkDeviceMemory multiple times simultaneously is illegal.

You should not use this flag if VmaAllocationCreateInfo::pool is not null.

VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT 

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_PERSISTENT_MAP_BIT 

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. You cannot map the memory on your own as multiple mappings of a single VkDeviceMemory are illegal.

If VmaAllocationCreateInfo::pool is not null, usage of this flag must match usage of flag VMA_POOL_CREATE_PERSISTENT_MAP_BIT used during pool creation.

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).

VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT 

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.

VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT 

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_FLAG_BITS_MAX_ENUM 

◆ VmaAllocatorCreateFlagBits

Flags for created VmaAllocator.

Enumerator
VMA_ALLOCATOR_CREATE_EXTERNALLY_SYNCHRONIZED_BIT 

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_KHR_DEDICATED_ALLOCATION_BIT 

Enables usage of VK_KHR_dedicated_allocation extension.

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
  • VK_KHR_dedicated_allocation

If this flag is enabled, you must also provide VmaAllocatorCreateInfo::pVulkanFunctions and fill at least members: VmaVulkanFunctions::vkGetBufferMemoryRequirements2KHR, VmaVulkanFunctions::vkGetImageMemoryRequirements2KHR, because they are never imported statically.

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_FLAG_BITS_MAX_ENUM 

◆ VmaMemoryUsage

Enumerator
VMA_MEMORY_USAGE_UNKNOWN 

No intended memory usage specified. Use other members of VmaAllocationCreateInfo to specify your requirements.

VMA_MEMORY_USAGE_GPU_ONLY 

Memory will be used on device only, so faster access from the device is preferred. No need to be mappable on host.

VMA_MEMORY_USAGE_CPU_ONLY 

Memory will be mapped on host. Could be used for transfer to/from device.

Guarantees to be HOST_VISIBLE and HOST_COHERENT.

VMA_MEMORY_USAGE_CPU_TO_GPU 

Memory will be used for frequent (dynamic) updates from host and reads on device (upload).

Guarantees to be HOST_VISIBLE.

VMA_MEMORY_USAGE_GPU_TO_CPU 

Memory will be used for frequent writing on device and readback on host (download).

Guarantees to be HOST_VISIBLE.

VMA_MEMORY_USAGE_MAX_ENUM 

◆ VmaPoolCreateFlagBits

Flags to be passed as VmaPoolCreateInfo::flags.

Enumerator
VMA_POOL_CREATE_PERSISTENT_MAP_BIT 

Set this flag to use a memory that will be persistently mapped.

Each allocation made from this pool will have VmaAllocationInfo::pMappedData available.

Usage of this flag must match usage of VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT flag for every allocation made from this pool.

VMA_POOL_CREATE_IGNORE_BUFFER_IMAGE_GRANULARITY_BIT 

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 na 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 more optimal.

VMA_POOL_CREATE_FLAG_BITS_MAX_ENUM 

Function Documentation

◆ vmaAllocateMemory()

VkResult vmaAllocateMemory ( VmaAllocator  allocator,
const VkMemoryRequirements *  pVkMemoryRequirements,
const VmaAllocationCreateInfo pCreateInfo,
VmaAllocation *  pAllocation,
VmaAllocationInfo pAllocationInfo 
)

General purpose memory allocation.

Parameters
[out]pAllocationHandle to allocated memory.
[out]pAllocationInfoOptional. Information about allocated memory. It can be later fetched using function vmaGetAllocationInfo().

You should free the memory using vmaFreeMemory().

It is recommended to use vmaAllocateMemoryForBuffer(), vmaAllocateMemoryForImage(), vmaCreateBuffer(), vmaCreateImage() instead whenever possible.

◆ vmaAllocateMemoryForBuffer()

VkResult vmaAllocateMemoryForBuffer ( VmaAllocator  allocator,
VkBuffer  buffer,
const VmaAllocationCreateInfo pCreateInfo,
VmaAllocation *  pAllocation,
VmaAllocationInfo pAllocationInfo 
)
Parameters
[out]pAllocationHandle to allocated memory.
[out]pAllocationInfoOptional. Information about allocated memory. It can be later fetched using function vmaGetAllocationInfo().

You should free the memory using vmaFreeMemory().

◆ vmaAllocateMemoryForImage()

VkResult vmaAllocateMemoryForImage ( VmaAllocator  allocator,
VkImage  image,
const VmaAllocationCreateInfo pCreateInfo,
VmaAllocation *  pAllocation,
VmaAllocationInfo pAllocationInfo 
)

Function similar to vmaAllocateMemoryForBuffer().

◆ vmaBuildStatsString()

void vmaBuildStatsString ( VmaAllocator  allocator,
char **  ppStatsString,
VkBool32  detailedMap 
)

Builds and returns statistics as string in JSON format.

Parameters
[out]ppStatsStringMust be freed using vmaFreeStatsString() function.

◆ vmaCalculateStats()

void vmaCalculateStats ( VmaAllocator  allocator,
VmaStats pStats 
)

Retrieves statistics from current state of the Allocator.

◆ vmaCreateAllocator()

VkResult vmaCreateAllocator ( const VmaAllocatorCreateInfo pCreateInfo,
VmaAllocator *  pAllocator 
)

Creates Allocator object.

◆ vmaCreateBuffer()

VkResult vmaCreateBuffer ( VmaAllocator  allocator,
const VkBufferCreateInfo *  pBufferCreateInfo,
const VmaAllocationCreateInfo pAllocationCreateInfo,
VkBuffer *  pBuffer,
VmaAllocation *  pAllocation,
VmaAllocationInfo pAllocationInfo 
)
Parameters
[out]pBufferBuffer that was created.
[out]pAllocationAllocation that was created.
[out]pAllocationInfoOptional. Information about allocated memory. It can be later fetched using function vmaGetAllocationInfo().

This function automatically:

  1. Creates buffer.
  2. Allocates appropriate memory for it.
  3. Binds the buffer with the memory.

If any of these operations fail, buffer and allocation are not created, returned value is negative error code, *pBuffer and *pAllocation are null.

If the function succeeded, you must destroy both buffer and allocation when you no longer need them using either convenience function vmaDestroyBuffer() or separately, using vkDestroyBuffer() and vmaFreeMemory().

If VMA_ALLOCATOR_CREATE_KHR_DEDICATED_ALLOCATION_BIT flag was used, VK_KHR_dedicated_allocation extension is used internally to query driver whether it requires or prefers the new buffer to have dedicated allocation. If yes, and if dedicated allocation is possible (VmaAllocationCreateInfo::pool is null and VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT is not used), it creates dedicated allocation for this buffer, just like when using VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT.

◆ vmaCreateImage()

VkResult vmaCreateImage ( VmaAllocator  allocator,
const VkImageCreateInfo *  pImageCreateInfo,
const VmaAllocationCreateInfo pAllocationCreateInfo,
VkImage *  pImage,
VmaAllocation *  pAllocation,
VmaAllocationInfo pAllocationInfo 
)

Function similar to vmaCreateBuffer().

◆ vmaCreateLostAllocation()

void vmaCreateLostAllocation ( VmaAllocator  allocator,
VmaAllocation *  pAllocation 
)

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.

◆ vmaCreatePool()

VkResult vmaCreatePool ( VmaAllocator  allocator,
const VmaPoolCreateInfo pCreateInfo,
VmaPool *  pPool 
)

Allocates Vulkan device memory and creates VmaPool object.

Parameters
allocatorAllocator object.
pCreateInfoParameters of pool to create.
[out]pPoolHandle to created pool.

◆ vmaDefragment()

VkResult vmaDefragment ( VmaAllocator  allocator,
VmaAllocation *  pAllocations,
size_t  allocationCount,
VkBool32 *  pAllocationsChanged,
const VmaDefragmentationInfo pDefragmentationInfo,
VmaDefragmentationStats pDefragmentationStats 
)

Compacts memory by moving allocations.

Parameters
pAllocationsArray of allocations that can be moved during this compation.
allocationCountNumber of elements in pAllocations and pAllocationsChanged arrays.
[out]pAllocationsChangedArray of boolean values that will indicate whether matching allocation in pAllocations array has been moved. This parameter is optional. Pass null if you don't need this information.
pDefragmentationInfoConfiguration parameters. Optional - pass null to use default values.
[out]pDefragmentationStatsStatistics returned by the function. Optional - pass null if you don't need this information.
Returns
VK_SUCCESS if completed, VK_INCOMPLETE if succeeded but didn't make all possible optimizations because limits specified in pDefragmentationInfo have been reached, negative error code in case of error.

This function works by moving allocations to different places (different VkDeviceMemory objects and/or different offsets) in order to optimize memory usage. Only allocations that are in pAllocations array can be moved. All other allocations are considered nonmovable in this call. Basic rules:

  • Only allocations made in memory types that have VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT flag can be compacted. You may pass other allocations but it makes no sense - these will never be moved.
  • You may pass allocations made with VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT but it makes no sense - they will never be moved.
  • Both allocations made with or without VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT flag can be compacted. If not persistently mapped, memory will be mapped temporarily inside this function if needed, so it shouldn't be mapped by you for the time of this call.
  • You must not pass same VmaAllocation object multiple times in pAllocations array.

The function also frees empty VkDeviceMemory blocks.

After allocation has been moved, its VmaAllocationInfo::deviceMemory and/or VmaAllocationInfo::offset changes. You must query them again using vmaGetAllocationInfo() if you need them.

If an allocation has been moved, data in memory is copied to new place automatically, but if it was bound to a buffer or an image, you must destroy that object yourself, create new one and bind it to the new memory pointed by the allocation. You must use vkDestroyBuffer(), vkDestroyImage(), vkCreateBuffer(), vkCreateImage() for that purpose and NOT vmaDestroyBuffer(), vmaDestroyImage(), vmaCreateBuffer(), vmaCreateImage()! Example:

VkDevice device = ...;
VmaAllocator allocator = ...;
std::vector<VkBuffer> buffers = ...;
std::vector<VmaAllocation> allocations = ...;
std::vector<VkBool32> allocationsChanged(allocations.size());
vmaDefragment(allocator, allocations.data(), allocations.size(), allocationsChanged.data(), nullptr, nullptr);
for(size_t i = 0; i < allocations.size(); ++i)
{
if(allocationsChanged[i])
{
VmaAllocationInfo allocInfo;
vmaGetAllocationInfo(allocator, allocations[i], &allocInfo);
vkDestroyBuffer(device, buffers[i], nullptr);
VkBufferCreateInfo bufferInfo = ...;
vkCreateBuffer(device, &bufferInfo, nullptr, &buffers[i]);
// You can make dummy call to vkGetBufferMemoryRequirements here to silence validation layer warning.
vkBindBufferMemory(device, buffers[i], allocInfo.deviceMemory, allocInfo.offset);
}
}

This function may be time-consuming, so you shouldn't call it too often (like every frame or after every resource creation/destruction), but rater you can call it on special occasions (like when reloading a game level, when you just destroyed a lot of objects).

◆ vmaDestroyAllocator()

void vmaDestroyAllocator ( VmaAllocator  allocator)

Destroys allocator object.

◆ vmaDestroyBuffer()

void vmaDestroyBuffer ( VmaAllocator  allocator,
VkBuffer  buffer,
VmaAllocation  allocation 
)

Destroys Vulkan buffer and frees allocated memory.

This is just a convenience function equivalent to:

vkDestroyBuffer(device, buffer, allocationCallbacks);
vmaFreeMemory(allocator, allocation);

It it safe to pass null as buffer and/or allocation.

◆ vmaDestroyImage()

void vmaDestroyImage ( VmaAllocator  allocator,
VkImage  image,
VmaAllocation  allocation 
)

Destroys Vulkan image and frees allocated memory.

This is just a convenience function equivalent to:

vkDestroyImage(device, image, allocationCallbacks);
vmaFreeMemory(allocator, allocation);

It it safe to pass null as image and/or allocation.

◆ vmaDestroyPool()

void vmaDestroyPool ( VmaAllocator  allocator,
VmaPool  pool 
)

Destroys VmaPool object and frees Vulkan device memory.

◆ vmaFindMemoryTypeIndex()

VkResult vmaFindMemoryTypeIndex ( VmaAllocator  allocator,
uint32_t  memoryTypeBits,
const VmaAllocationCreateInfo pAllocationCreateInfo,
uint32_t *  pMemoryTypeIndex 
)

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.
Returns
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.

◆ vmaFreeMemory()

void vmaFreeMemory ( VmaAllocator  allocator,
VmaAllocation  allocation 
)

Frees memory previously allocated using vmaAllocateMemory(), vmaAllocateMemoryForBuffer(), or vmaAllocateMemoryForImage().

◆ vmaFreeStatsString()

void vmaFreeStatsString ( VmaAllocator  allocator,
char *  pStatsString 
)

◆ vmaGetAllocationInfo()

void vmaGetAllocationInfo ( VmaAllocator  allocator,
VmaAllocation  allocation,
VmaAllocationInfo pAllocationInfo 
)

Returns current information about specified allocation.

◆ vmaGetMemoryProperties()

void vmaGetMemoryProperties ( VmaAllocator  allocator,
const VkPhysicalDeviceMemoryProperties **  ppPhysicalDeviceMemoryProperties 
)

PhysicalDeviceMemoryProperties are fetched from physicalDevice by the allocator. You can access it here, without fetching it again on your own.

◆ vmaGetMemoryTypeProperties()

void vmaGetMemoryTypeProperties ( VmaAllocator  allocator,
uint32_t  memoryTypeIndex,
VkMemoryPropertyFlags *  pFlags 
)

Given Memory Type Index, returns Property Flags of this memory type.

This is just a convenience function. Same information can be obtained using vmaGetMemoryProperties().

◆ vmaGetPhysicalDeviceProperties()

void vmaGetPhysicalDeviceProperties ( VmaAllocator  allocator,
const VkPhysicalDeviceProperties **  ppPhysicalDeviceProperties 
)

PhysicalDeviceProperties are fetched from physicalDevice by the allocator. You can access it here, without fetching it again on your own.

◆ vmaGetPoolStats()

void vmaGetPoolStats ( VmaAllocator  allocator,
VmaPool  pool,
VmaPoolStats pPoolStats 
)

Retrieves statistics of existing VmaPool object.

Parameters
allocatorAllocator object.
poolPool object.
[out]pPoolStatsStatistics of specified pool.

◆ vmaMakePoolAllocationsLost()

void vmaMakePoolAllocationsLost ( VmaAllocator  allocator,
VmaPool  pool,
size_t *  pLostAllocationCount 
)

Marks all allocations in given pool as lost if they are not used in current frame or VmaPoolCreateInfo::frameInUseCount back from now.

Parameters
allocatorAllocator object.
poolPool.
[out]pLostAllocationCountNumber of allocations marked as lost. Optional - pass null if you don't need this information.

◆ vmaMapMemory()

VkResult vmaMapMemory ( VmaAllocator  allocator,
VmaAllocation  allocation,
void **  ppData 
)

Feel free to use vkMapMemory on these memory blocks on you own if you want, but just for convenience and to make sure correct offset and size is always specified, usage of vmaMapMemory() / vmaUnmapMemory() is recommended.

Do not use it on memory allocated with VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT as multiple maps to same VkDeviceMemory is illegal.

◆ vmaMapPersistentlyMappedMemory()

VkResult vmaMapPersistentlyMappedMemory ( VmaAllocator  allocator)

Maps back persistently mapped memory of types that are HOST_COHERENT and DEVICE_LOCAL.

See vmaUnmapPersistentlyMappedMemory().

After this call VmaAllocationInfo::pMappedData of some allocation may have value different than before calling vmaUnmapPersistentlyMappedMemory().

◆ vmaSetAllocationUserData()

void vmaSetAllocationUserData ( VmaAllocator  allocator,
VmaAllocation  allocation,
void *  pUserData 
)

Sets pUserData in given allocation to new value.

◆ vmaSetCurrentFrameIndex()

void vmaSetCurrentFrameIndex ( VmaAllocator  allocator,
uint32_t  frameIndex 
)

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.

◆ vmaUnmapMemory()

void vmaUnmapMemory ( VmaAllocator  allocator,
VmaAllocation  allocation 
)

◆ vmaUnmapPersistentlyMappedMemory()

void vmaUnmapPersistentlyMappedMemory ( VmaAllocator  allocator)

Unmaps persistently mapped memory of types that are HOST_COHERENT and DEVICE_LOCAL.

This is optional performance optimization. On AMD GPUs on Windows, Vulkan memory from the type that has both DEVICE_LOCAL and HOST_VISIBLE flags should not be mapped for the time of any call to vkQueueSubmit() or vkQueuePresent(). Although legal, that would cause performance degradation because WDDM migrates such memory to system RAM. To ensure this, you can unmap all persistently mapped memory using this function. Example:

vkQueueSubmit(...)

After this call VmaAllocationInfo::pMappedData of some allocations may become null.

This call is reference-counted. Memory is mapped again after you call vmaMapPersistentlyMappedMemory() same number of times that you called vmaUnmapPersistentlyMappedMemory().