@hortemo/semaphore

Promise-based FIFO semaphore for JavaScript and TypeScript.

Install

npm install @hortemo/semaphore

Use

import Semaphore from "@hortemo/semaphore";

const semaphore = new Semaphore(5);

async function processItem(item: string): Promise<void> {
  const release = await semaphore.acquire();
  try {
    await doWork(item);
  } finally {
    release();
  }
}

await Promise.all(items.map(processItem));

API

• new Semaphore(permits: number): Create a semaphore with permits available.
• await semaphore.acquire(): Wait for a permit and receive a Releaser. Call it to free the permit.
• type Releaser = () => void