vk::mem::virtual_block · Structs · V1

Uninterpreted consumer metadata; no ownership or dereference is inferred.

Set user_data and return the updated record.

Set offset and return the updated record.

Set size and return the updated record.

Observe checked virtual emptiness in constant time.

Set opaque per-allocation metadata, with no native pointer dereference or ownership.

Calculate explicit virtual allocation/free-span extrema.

Stream virtual JSON diagnostics; no native memory is accessed.

Create TLSF or linear host-only placement. No native storage is acquired.

use vk::{VirtualBlock, mem::{AllocationAlgorithm, PlacementStrategy}};
let mut block = VirtualBlock::new_with_algorithm(4096, AllocationAlgorithm::Linear)?;
let mut lower = block.allocate(64, 16, PlacementStrategy::Default)?;
let mut upper = block.allocate_upper(64, 16)?;
assert_eq!(block.allocation_info(&lower)?.offset, 0);
assert_eq!(block.allocation_info(&upper)?.offset, 4032);
block.free(&mut upper)?;
block.free(&mut lower)?;

Errors

Rejects a zero size or failed host metadata reservation.

Create host-only placement whose metadata uses borrowed Vulkan allocation callbacks.

TLSF/linear buffers, growth and detailed-JSON scratch storage use only this allocation/free pair, with SystemAllocationScope::OBJECT. The block value stays inline; tokens need no reference-count allocation. Reallocation and driver internal-allocation notifications are not invoked. Drop releases host metadata only; no Vulkan device or native memory is involved. The callback record cannot expire while the block still owns storage:

let mut block;
{
    let callbacks = vk::AllocationCallbacks::new();
    // SAFETY: demonstration of record lifetime; null functions are rejected at runtime.
    block = unsafe {
        VirtualBlock::new_with_callbacks(1024, AllocationAlgorithm::Tlsf, &callbacks)
    }.unwrap();
}
block.clear();

Errors

Rejects zero size, a missing allocation/free function or failed host storage.

Safety

Callbacks must return uniquely owned memory of the requested size/alignment, or null on failure, and free only their own allocations. They must not unwind or reenter this block. Their code and user data must remain valid through block Drop and support calls from any thread, including concurrent independent blocks. Borrowing retains the callback record, not ownership of its raw user data.

Allocate an aligned region. Linear placement ignores the TLSF search strategy.

Allocate downward in a linear block. Active ring mode rejects this request.

Errors

Rejects TLSF, invalid extents/alignment, exhausted space or host metadata.

Release a matching live identity. No native resource is destroyed or waited on.

Validate identity/generation and return the current offset/size snapshot.

Invalidate all tokens and restore the full range, retaining host capacity. Users of previously returned offsets must stop using them before reuse.

Calculate detailed free-span statistics; this is not a constant-time hot path.

Set statistics and return the updated record.

Set allocation_size_min and return the updated record.

Set allocation_size_max and return the updated record.

Set free_range_size_min and return the updated record.

Set free_range_size_max and return the updated record.

Set size and return the updated record.

Set allocation_count and return the updated record.

Set allocated_bytes and return the updated record.

Set free_bytes and return the updated record.

Set free_region_count and return the updated record.

Set largest_free_region and return the updated record.