Go ↔ Rust Async Demo

This repository contains a minimal example showing how Go can call into Rust where Rust exposes an async function. The Go side now serialises requests using the standard protowire helpers from google.golang.org/protobuf, and Rust decodes them with prost before running the async work on a Tokio runtime. Responses travel back as protobuf bytes as well, keeping the FFI surface to raw byte buffers.

Layout

• rustlib/: Rust static library exposing the FFI surface.
• g2r/: Go wrapper that handles cgo interop and exposes a friendly API.
• cmd/demo/: Small Go program demonstrating both blocking and non-blocking calls into Rust.

Build & Run

# Build the Rust static library
(cd rustlib && cargo build --release)

# Build or run the Go demo (make sure the Rust build step ran first)
GOCACHE=$(pwd)/.gocache go run ./cmd/demo

The demo prints responses from the Rust async function for both a blocking call and a non-blocking call that allows other work to proceed while Rust completes.

To keep the workspace clean you can remove the temporary Go build cache afterwards:

rm -rf .gocache