Library

import { Pool } from "waitlet";

const pool = new Pool({ name: "builds" });
pool.setLimit(2);
const lease = await pool.acquire({ key: "ISS-7", ttl: 20 * 60_000, onWait: (position) => console.log(`#${position}`) });
try {
  // ... the work
} finally {
  pool.release({ key: lease.key });
  pool.close();
}

acquire rejects with a WaitletError whose code is conflict, timeout, cancelled, aborted, or no-owner. The owner defaults to the current process; pass pid to tie the lease to another one.