C Specification

The VkBufferMemoryBarrier structure is defined as:

typedef struct VkBufferMemoryBarrier {
    VkStructureType    sType;
    const void*        pNext;
    VkAccessFlags      srcAccessMask;
    VkAccessFlags      dstAccessMask;
    uint32_t           srcQueueFamilyIndex;
    uint32_t           dstQueueFamilyIndex;
    VkBuffer           buffer;
    VkDeviceSize       offset;
    VkDeviceSize       size;
} VkBufferMemoryBarrier;

Members

  • sType is the type of this structure.

  • pNext is NULL or a pointer to an extension-specific structure.

  • srcAccessMask is a bitmask of VkAccessFlagBits specifying a source access mask.

  • dstAccessMask is a bitmask of VkAccessFlagBits specifying a destination access mask.

  • srcQueueFamilyIndex is the source queue family for a queue family ownership transfer.

  • dstQueueFamilyIndex is the destination queue family for a queue family ownership transfer.

  • buffer is a handle to the buffer whose backing memory is affected by the barrier.

  • offset is an offset in bytes into the backing memory for buffer; this is relative to the base offset as bound to the buffer (see vkBindBufferMemory).

  • size is a size in bytes of the affected area of backing memory for buffer, or VK_WHOLE_SIZE to use the range from offset to the end of the buffer.

Description

The first access scope is limited to access to memory through the specified buffer range, via access types in the source access mask specified by srcAccessMask. If srcAccessMask includes VK_ACCESS_HOST_WRITE_BIT, memory writes performed by that access type are also made visible, as that access type is not performed through a resource.

The second access scope is limited to access to memory through the specified buffer range, via access types in the destination access mask. specified by dstAccessMask. If dstAccessMask includes VK_ACCESS_HOST_WRITE_BIT or VK_ACCESS_HOST_READ_BIT, available memory writes are also made visible to accesses of those types, as those access types are not performed through a resource.

If srcQueueFamilyIndex is not equal to dstQueueFamilyIndex, and srcQueueFamilyIndex is equal to the current queue family, then the memory barrier defines a queue family release operation for the specified buffer range, and the second access scope includes no access, as if dstAccessMask was 0.

If dstQueueFamilyIndex is not equal to srcQueueFamilyIndex, and dstQueueFamilyIndex is equal to the current queue family, then the memory barrier defines a queue family acquire operation for the specified buffer range, and the first access scope includes no access, as if srcAccessMask was 0.

Valid Usage
  • offset must be less than the size of buffer

  • If size is not equal to VK_WHOLE_SIZE, size must be greater than 0

  • If size is not equal to VK_WHOLE_SIZE, size must be less than or equal to than the size of buffer minus offset

  • If buffer was created with a sharing mode of VK_SHARING_MODE_CONCURRENT, srcQueueFamilyIndex and dstQueueFamilyIndex must both be VK_QUEUE_FAMILY_IGNORED

  • If buffer was created with a sharing mode of VK_SHARING_MODE_EXCLUSIVE, srcQueueFamilyIndex and dstQueueFamilyIndex must either both be VK_QUEUE_FAMILY_IGNORED, or both be a valid queue family (see ../../html/vkspec.html#devsandqueues-queueprops)

  • If buffer was created with a sharing mode of VK_SHARING_MODE_EXCLUSIVE, and srcQueueFamilyIndex and dstQueueFamilyIndex are not VK_QUEUE_FAMILY_IGNORED, at least one of them must be the same as the family of the queue that will execute this barrier

Valid Usage (Implicit)
  • sType must be VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER

  • pNext must be NULL

  • srcAccessMask must be a valid combination of VkAccessFlagBits values

  • dstAccessMask must be a valid combination of VkAccessFlagBits values

  • buffer must be a valid VkBuffer handle

See Also

Document Notes

For more information, see the Vulkan Specification at URL

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2017 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.