PFNvkReallocate

PFNvkReallocate is a function-pointer type used in some Vulkan-like APIs to represent a memory or resource reallocation operation. It is not part of the official Vulkan specification; rather, it appears in certain extensions, sample implementations, or custom allocators to formalize the process of resizing an existing allocation or migrating to a new one.

In Vulkan naming conventions, PFN_ prefixes indicate a pointer-to-function type. The inclusion of vk suggests a relation to Vulkan concepts, while Reallocate describes the operation performed by the function. The exact naming and signature can vary between projects, but PFNvkReallocate generally signals an entry point used by an allocator or extension to perform dynamic resizing of a resource.

Typical usage patterns involve a function pointer of this type being provided by a memory allocator or device extension. A PFNvkReallocate entry would be invoked to request a new allocation size, reallocate the backing store, and migrate data if necessary. Because there is no standardized signature, implementations may differ in required inputs such as a device or allocator handle, a source memory or resource handle, the desired new size or new memory requirements, and outputs including a new resource handle and a status code.

Practical considerations include how reallocation is performed (in-place versus new allocation), data migration logic, alignment constraints, and synchronization requirements. Developers must refer to the specific extension or library documentation to determine the exact parameters, return codes, and semantics. PFNvkReallocate thus represents a concept used in certain Vulkan-related tooling rather than a canonical, universally defined API entry in the core specification.