To flush ranges of non-coherent memory from the host caches, call:
VkResult vkFlushMappedMemoryRanges( VkDevice device, uint32_t memoryRangeCount, const VkMappedMemoryRange* pMemoryRanges);
deviceis the logical device that owns the memory ranges.
memoryRangeCountis the length of the
pMemoryRangesis a pointer to an array of VkMappedMemoryRange structures describing the memory ranges to flush.
vkFlushMappedMemoryRanges guarantees that host writes to the memory
ranges described by
pMemoryRanges are made available to the host
memory domain, such that they can be made available to the device memory
domain via memory
domain operations using the
Within each range described by
pMemoryRanges, each set of
nonCoherentAtomSize bytes in that range is flushed if any byte in that
set has been written by the host since it was first host mapped, or the last
time it was flushed.
pMemoryRanges includes sets of
where no bytes have been written by the host, those bytes must not be
Unmapping non-coherent memory does not implicitly flush the host mapped memory, and host writes that have not been flushed may not ever be visible to the device. However, implementations must ensure that writes that have not been flushed do not become visible to any other memory.
The above guarantee avoids a potential memory corruption in scenarios where host writes to a mapped memory object have not been flushed before the memory is unmapped (or freed), and the virtual address range is subsequently reused for a different mapping (or memory allocation).
For more information, see the Vulkan Specification
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.
Copyright (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.