.NET bindings for the Gloo collective communications library from Facebook/Meta.

GlooSharp provides P/Invoke wrappers for native Gloo C++ operations, enabling high-performance distributed training from .NET applications.

• AllReduce - Combine data from all processes (gradient averaging)
• Broadcast - Distribute data from one process to all others
• AllGather - Gather data from all processes
• Barrier - Synchronize all processes
• ReduceScatter - Reduce and scatter in one operation
• TCP Transport - Works on any network
• InfiniBand Transport - RDMA support for HPC clusters

dotnet add package GlooSharp

Note: The native gloo_native library must be built separately. See Building the Native Library below.

using GlooSharp;

// Create context for this process
using var ctx = new GlooContext(rank: 0, worldSize: 4);

// Set up TCP transport
GlooTransport.CreateTCP(ctx, "localhost", 29500);

// AllReduce: sum gradients across all processes
var gradients = new float[] { 1.0f, 2.0f, 3.0f };
GlooCollectives.AllReduce(ctx, gradients, GlooReduceOp.Sum);
// gradients now contains the sum from all 4 processes

The managed bindings require a native C shim library (gloo_native) that wraps the Gloo C++ library.

• CMake 3.14+
• C++17 compiler
• Gloo library installed
• Optional: libibverbs for InfiniBand support

cd src/GlooSharp/native
mkdir build && cd build

# TCP only
cmake .. -DCMAKE_BUILD_TYPE=Release

# With InfiniBand support
cmake .. -DCMAKE_BUILD_TYPE=Release -DGLOO_USE_IBVERBS=ON

cmake --build . --config Release

Place the built library in the appropriate runtime directory for NuGet packaging:

src/GlooSharp/runtimes/
  win-x64/native/gloo_native.dll
  linux-x64/native/libgloo_native.so
  osx-arm64/native/libgloo_native.dylib

GlooSharp (Managed .NET)
    |
    | P/Invoke [DllImport("gloo_native")]
    v
gloo_native (C shim, extern "C")
    |
    | C++ calls
    v
Gloo C++ Library (Facebook)
    |
    v
TCP / InfiniBand Transport

GlooSharp is designed to be used by AiDotNet.DistributedTraining.GlooCommunicationBackend<T> for native Gloo support. When the GlooSharp NuGet package is installed, the backend automatically detects it and uses native collective operations instead of the built-in TCP fallback.

Apache-2.0. See LICENSE for details.