Struct NoOpCommunicator 

pub struct NoOpCommunicator;

No-op communicator for single-device operation (world_size=1).

• In-place collectives (all_reduce, broadcast): true no-ops
• Separate-buffer collectives (all_gather, reduce_scatter): memcpy send→recv
• Point-to-point (send, recv): no-ops (nothing to communicate)
• sync, barrier: no-ops

Trait Implementations

impl Clone for NoOpCommunicator

fn clone(&self) -> NoOpCommunicator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Communicator for NoOpCommunicator

fn world_size(&self) -> usize

Number of participants

fn rank(&self) -> usize

This participant’s rank (0-indexed)

unsafe fn all_reduce( &self, _ptr: u64, _count: usize, _dtype: DType, _op: ReduceOp, ) -> Result<()>

AllReduce in-place: reduce across all ranks, result on all ranks.

unsafe fn broadcast( &self, _ptr: u64, _count: usize, _dtype: DType, _root: usize, ) -> Result<()>

Broadcast from root rank to all other ranks.

unsafe fn all_gather( &self, send_ptr: u64, recv_ptr: u64, count: usize, dtype: DType, ) -> Result<()>

AllGather: each rank contributes count elements, result is count * world_size elements on all ranks.

unsafe fn reduce_scatter( &self, send_ptr: u64, recv_ptr: u64, count: usize, dtype: DType, _op: ReduceOp, ) -> Result<()>

ReduceScatter: reduce + scatter. Each rank gets a different slice of the reduced result.

unsafe fn send( &self, _ptr: u64, _count: usize, _dtype: DType, _dest: usize, _tag: u32, ) -> Result<()>

Point-to-point send to a specific rank (non-blocking).

unsafe fn recv( &self, _ptr: u64, _count: usize, _dtype: DType, _src: usize, _tag: u32, ) -> Result<()>

Point-to-point receive from a specific rank (non-blocking).

fn sync(&self) -> Result<()>

Wait for all pending operations to complete.

fn barrier(&self) -> Result<()>

Barrier: block until all ranks reach this point.

fn split(&self, _color: u32, _key: u32) -> Result<Option<Box<dyn Communicator>>>

Split this communicator into sub-communicators by color and key.

fn as_stream_sync(&self) -> Option<&dyn StreamSyncOps>

Downcast to StreamSyncOps if this communicator supports CUDA stream/event synchronization for compute-communication overlap.

impl Debug for NoOpCommunicator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for NoOpCommunicator

fn default() -> NoOpCommunicator

Returns the “default value” for a type.