UnAsync

Synchronously execute asynchronous functions on browsers, Node.js, and Deno. This package is a successor of synckit and sync-threads.

Features

• ✅ Zero dependencies - No external runtime dependencies
• ✅ Conditional exports - Automatically loads correct implementation for your environment
• ✅ ESM-only - Modern JavaScript modules
• ✅ Cross-platform - Works in Node.js, browsers, and Deno
• ✅ TypeScript support - Full type definitions included

Usage

https://jsr.io/@tani/unasync

This package provides two functions runAsWorker and createSyncFn.

1. Wrap an asynchronous function by runAsWorker
2. Create a synchronous function by createSyncFn

//worker.js
import { runAsWorker } from "unasync";
runAsWorker(async (x) => {
  await new Promise((resolve) => setTimeout(() => resolve(1), 1000));
  return x + 1;
});

//main.js
import { createSyncFn } from "unasync";
using syncFn = createSyncFn(import.meta.resolve("./worker.js"));
console.log(syncFn(1)); // 2

Technical Details

In the modern JavaScript platform, we can use shared memory SharedArrayBuffer. we employ it as a semaphore. First, we lock the semaphore to suspend the main thread and run the asyncrhonous function in the worker thread. After the execution, we unlock the semaphore to resume the main thread.

The strong point of this idea, we do not need to modify event-loop in the target virtual machine by FFI.

Copyright and License

(c) 2024 TANIGUCHI Masaya, MIT License