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


This package provides two functions runAsWroekr and createSyncFn.

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

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

import { createSyncFn } from "unasync";
const syncFn = createSyncFn(new URL("./worker.mjs", import.meta.url))
console.log(syncFn(1)) // 2
syncFn.dispose() // terminate the worker thread

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) 2022 TANIGUCHI Masaya, MIT License


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