Static Web Sample

This experimental sample demonstrates one way to target the web platform with IREE. The output artifact is a web page containing an interactive MNIST digits classifier.

The MNIST ML model is compiled statically together with the IREE runtime into a single .js + .wasm bundle.

Quickstart

Install IREE's host tools (e.g. by building the install target with CMake)
Install the Emscripten SDK by following these directions
Initialize your Emscripten environment (e.g. run emsdk_env.bat)
From this directory, run bash ./build_sample.sh [path to install] && bash ./serve_sample.sh
Open the localhost address linked in the script output

To rebuild most parts of the sample (C runtime, sample HTML, CMake config, etc.), just control + C to stop the local webserver and rerun the script.

How it works

This MNIST model, also used in the Vision sample, is compiled using the “static library” output setting of IREE's compiler (see the Static library sample). The resulting .h and .o files are compiled together with main.c, while the .vmfb is embedded into a C file that is similarly linked in.

Emscripten is used (via the emcmake CMake wrapper) to compile the output binary into WebAssembly and JavaScript files.

The provided index.html file can be served together with the output .js and .wasm files.

Asynchronous API

iree_api.js exposes a Promise-based API to the hosting application in index.html
iree_api.js creates a worker running iree_worker.js, which includes Emscripten's JS code and instantiates the WebAssembly module
messages are passed back and forth between iree_api.js and iree_worker.js internally

Multithreading

The sample supports running both single-threaded using device_sync.c (backed by the local HAL‘s ‘sync’ device) and multi-threaded using device_multithreaded.c (backed by the local HAL’s ‘task’ device).

Each configuration is offered as a CMake target, then iree_worker.js specifies which script URL to load.

Multithreading requires Web Workers and SharedArrayBuffer: