Crate spark_comm 

Communication backend abstraction (SBIO IORouter for collective ops).

All distributed communication flows through CommBackend. Business logic never calls NCCL or MPI directly.

• SingleGpuBackend — all ops are no-ops (single GPU).
• NcclBackend — real multi-GPU via NCCL (expert parallelism; available with the nccl feature).

Re-exports

pub use nccl_backend::NcclBackend;

Modules

nccl

Raw NCCL FFI bindings (minimal surface for EP all-reduce + broadcast).

nccl_backend

NCCL-based communication backend for expert parallelism.

Structs

SingleGpuBackend

Single-GPU backend: all collective ops are no-ops.

Traits

CommBackend

Communication backend trait for distributed operations.