Wasm and Cap'n Proto integration in Rust

Run Cap'n Proto clients and servers within WASM programs, directly over stdin and stdout.

Proof of Concept

This project sets up a WASM runtime in a Linux/MacOS host and provides Cap'n Proto capabilities to guest WASM processes through their stdin/stout by:

• Configuring WASIp2 in the guest; then carefully handling its polling capabilities to obtain non-blocking streams.
• Mapping async pipes to the host side of the WASM process stdin/stdout.
• Bootstrapping object capabilities over a transport based on the async pipes built upon the now async stdin/stdout.

The WASM guest will:

1. Bootstrap an EchoerProvider capability.
2. Ask the EchoerProvider for an Echoer capability by calling a capnp method: EchoerProvider.echoer(). This will return a new Echoer capability.
3. Call the echo method of the newly obtained Echoer and verify the result: Echoer.echo("<some message>").

Steps 2 and 3 are performed many times concurrently, producing multiple (different) Echoer objects and verifying that the transport is capable of handling multiple concurrent read/write requests under pressure.

Usage

Build the project with make, then run it with make run.