Crate baracuda_nccl_sys 

Raw FFI + dynamic loader for NVIDIA NCCL (multi-GPU collective communication).

baracuda-nccl wraps this with a safe, typed API. Use this crate directly only if you need a function that the safe layer hasn’t wrapped yet (in which case please file a bug).

NCCL is primarily a Linux library; Windows support landed in later NCCL versions but is uncommon. This crate compiles everywhere and defers the “is NCCL actually installed?” question to runtime — nccl() returns LoaderError::LibraryNotFound on hosts without NCCL.

Structs

Nccl

Lazily-resolved NCCL function-pointer table.

ncclRedOp_t

NCCL reduction operation. Modeled as a transparent newtype rather than a closed enum because PFN_ncclRedOpCreatePreMulSum returns custom op IDs (≥ 5) that don’t fit a closed Rust enum.

ncclResult_t

Return code from an NCCL call.

ncclUniqueId

A 128-byte unique identifier for multi-process NCCL initialization.

Enums

ncclDataType_t

NCCL element data type.

Functions

nccl

Return the lazily-loaded NCCL library accessor.

Type Aliases

PFN_ncclAllGather

Function-pointer type for ncclAllGather (all-gather collective). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclAllReduce

Function-pointer type for ncclAllReduce (all-reduce collective). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclBroadcast

Function-pointer type for ncclBroadcast (broadcast-from-root collective). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommAbort

Function-pointer type for ncclCommAbort (abort outstanding ops on a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommCount

Function-pointer type for ncclCommCount (query rank count on a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommCuDevice

Function-pointer type for ncclCommCuDevice (query CUDA device backing a communicator rank). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommDeregister

Function-pointer type for ncclCommDeregister (deregister a user buffer from a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommDestroy

Function-pointer type for ncclCommDestroy (destroy a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommFinalize

Function-pointer type for ncclCommFinalize (finalize a non-blocking communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommGetAsyncError

Function-pointer type for ncclCommGetAsyncError (fetch a communicator’s last async error). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommInitAll

Function-pointer type for ncclCommInitAll (initialize all-local-GPU communicators in one call). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommInitRank

Function-pointer type for ncclCommInitRank (initialize a communicator rank). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommInitRankConfig

Function-pointer type for ncclCommInitRankConfig (initialize a communicator rank with config). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommRegister

Function-pointer type for ncclCommRegister (register a user buffer with a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommSplit

Function-pointer type for ncclCommSplit (split a communicator by color/key). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclCommUserRank

Function-pointer type for ncclCommUserRank (query this rank’s index on a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclGetErrorString

Function-pointer type for ncclGetErrorString (decode an ncclResult_t into a static C string). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclGetLastError

Function-pointer type for ncclGetLastError (fetch the last error string on a communicator). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclGetUniqueId

Function-pointer type for ncclGetUniqueId (generate a unique multi-rank initialization ID). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclGetVersion

Function-pointer type for ncclGetVersion (query NCCL library version). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclGroupEnd

Function-pointer type for ncclGroupEnd (end grouped collective ops and commit them). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclGroupStart

Function-pointer type for ncclGroupStart (start grouped collective ops). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclMemAlloc

Function-pointer type for ncclMemAlloc (allocate NCCL-registered device memory). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclMemFree

Function-pointer type for ncclMemFree (free NCCL-registered device memory). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclRecv

Function-pointer type for ncclRecv (point-to-point receive). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclRedOpCreatePreMulSum

Function-pointer type for ncclRedOpCreatePreMulSum (create a custom pre-multiplied-sum reduction op). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclRedOpDestroy

Function-pointer type for ncclRedOpDestroy (destroy a custom reduction op). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclReduce

Function-pointer type for ncclReduce (reduce-to-root collective). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclReduceScatter

Function-pointer type for ncclReduceScatter (reduce-scatter collective). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

PFN_ncclSend

Function-pointer type for ncclSend (point-to-point send). See https://docs.nvidia.com/deeplearning/nccl/user-guide/docs/api.html.

ncclComm_t

Opaque NCCL communicator.