Fix persistent buffer mapping balance and prevent double map#87
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Mrkol merged 3 commits intoMay 4, 2026
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| // make map() optional if allocationCreate has VMA_ALLOCATION_CREATE_MAPPED_BIT | ||
| mapped = reinterpret_cast<std::byte*>(allocInfo.pMappedData); | ||
| // make map() forbidden for the user if allocationCreate has VMA_ALLOCATION_CREATE_MAPPED_BIT | ||
| if (info.allocationCreate & VMA_ALLOCATION_CREATE_MAPPED_BIT) |
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warning: implicit conversion 'VmaAllocationCreateFlags' (aka 'unsigned int') -> 'bool' [readability-implicit-bool-conversion]
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| if (info.allocationCreate & VMA_ALLOCATION_CREATE_MAPPED_BIT) | |
| if ((info.allocationCreate & VMA_ALLOCATION_CREATE_MAPPED_BIT) != 0u) |
kzubatov
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May 13, 2026
* Revert "Fix persistent buffer mapping balance and prevent double map (#87)" This reverts commit e498aab. * buffer: do not call unmap in reset if VMA_ALLOCATION_CREATE_MAPPED_BIT is set, the buffer is always mapped and unmap should not be called in reset, see https://gpuopen-librariesandsdks.github.io/VulkanMemoryAllocator/html/group__group__alloc.html#ggad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f:~:text=It%20is%20also%20safe,to%20VMA%5FALLOCATION%5FCREATE%5FMAPPED%5FBIT%20flag If map is called explicitly, instead of creating the buffer using VMA_ALLOCATION_CREATE_MAPPED_BIT, unmap must also be called explicitly Removed map/unmap calls in helper functions, since buffers are created with VMA_ALLOCATION_CREATE_MAPPED_BIT
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Problem
Buffers created with
VMA_ALLOCATION_CREATE_MAPPED_BITreceive apersistently mapped pointer without an explicit
vmaMapMemorycall.The destructor's
unmap()then triggers a VMA assertion because thereis no matching explicit
vmaMapMemory.Solution
Explicitly call
map()in the constructor when the persistent flagis set, pairing with the
unmap()inreset().Forbid further
map()calls viaETNA_VERIFY(mapped == nullptr).If the user were allowed to call
map()/unmap()manually, a singleunmap()would setmapped = nullptr, breaking the pairing with thedestructor's
unmap()— the constructor'smap()would remainunmatched forever.