Struct GpuMappedBuffer 

pub struct GpuMappedBuffer<'a> { /* private fields */ }

GPU-visible memory region that io_uring is allowed to DMA into.

Compatibility constructors cover host-visible shared mappings. The BAR1 constructor covers the native GPUDirect path where NVMe DMA lands directly in GPU-owned memory.

Implementations

impl<'a> GpuMappedBuffer<'a>

pub unsafe fn from_host_visible_slice(slice: &'a mut [u8]) -> Self

Construct from a borrowed host-visible byte slice.

Safety

The caller asserts:

• slice aliases a device allocation created with host-visible host-shared usage bits by the concrete backend.
• No other code reads or writes through slice while the returned handle is alive.

pub unsafe fn from_host_visible_owner<O: ?Sized>( _owner: &'a mut O, ptr: *mut u8, len: usize, ) -> Self

Construct from a raw pointer + explicit owner anchor.

This is for GPU APIs that hand back a raw mapped pointer plus an owning handle rather than a Rust slice. The borrow on owner forces the mapped region to outlive every derived AsyncUringStream.

Safety

The caller asserts:

• ptr points into a GPU allocation owned by owner.
• The mapped region is len bytes long and host-visible.
• No other code reads or writes through ptr while the returned handle is alive.

pub unsafe fn duplicate(&self) -> Self

Duplicate the mapped-buffer handle for the same underlying region.

Safety

The caller must uphold the same aliasing and lifetime guarantees as GpuMappedBuffer::from_host_visible_slice. This does not clone memory; it creates another handle to the same mapped bytes.

pub fn sub_region( &self, offset: usize, len: usize, ) -> Result<Self, PipelineError>

Carve out a sub-region of this mapped buffer.

This preserves the original constructor contract: the returned handle aliases the same host-visible GPU allocation and carries no ownership of its own.

Errors

Returns PipelineError::QueueFull when offset + len exceeds the mapped buffer bounds.

pub fn len(&self) -> usize

Byte length of the mapped region.

pub fn is_empty(&self) -> bool

Whether the region is empty.

pub unsafe fn as_mut_slice(&mut self) -> &mut [u8]

Borrow the mapped bytes as a mutable slice.

Safety

The caller must ensure exclusive mutable access to the region for the lifetime of the returned slice.

pub unsafe fn from_bar1_peer_with_owner<O: ?Sized>( _owner: &'a mut O, peer_ptr: *mut u8, len: usize, ) -> Self

Construct from a PCIe peer-memory pointer GPUDirect Storage).

When paired with crate::PipelineError::NvmePassthroughDisabled via the uring-cmd-nvme feature, this lets NVMe DMA writes land directly in VRAM without crossing the host PCIe bridge.

Safety

The caller asserts:

• peer_ptr points at a region returned by nvidia_p2p_get_pages (Linux nvidia-fs) or cuMemAlloc + cuPointerSetAttribute CU_POINTER_ATTRIBUTE_SYNC_MEMOPS.
• The GPU allocation outlives the returned handle.
• The io_uring kernel and NVMe driver both have DMA-mapping capability (verified at runtime by checking /proc/driver/nvidia-fs/stats).

Trait Implementations

impl Send for GpuMappedBuffer<'_>

impl Sync for GpuMappedBuffer<'_>