easy-mtx

easy-mtx is a lightweight, easy-to-use JavaScript mutex and pool implementation for managing concurrent access to critical sections of code.

Note: This package is primarily intended for personal usage. Feel free to try it out, but be aware that it might not be suitable for all production scenarios.

Installation

Install the package via npm:

npm install easy-mtx

Usage

Example

import { Pool, Mutex } from "easy-mtx";
import express from "express";

// or use const { Pool, Mutex } = require('easy-mtx')

const app = express();

const pool = new Pool(5); // Create a pool with a concurrency level of 5
const mutex = new Mutex(); // Create a mutex instance

const obj = {
  count: 0,
};

// Route to increment obj.count in a mutex-protected context synchronously
app.get("/mutex-sync-context", async (req, res) => {
  const result = await mutex.runInContext(() => {
    return obj.count++;
  });

  res.json(obj);
});

// Route to increment obj.count in a mutex-protected context asynchronously
app.get("/mutex-async-context", async (req, res) => {
  const result = await mutex.runInAsyncContext(async () => {
    return obj.count++;
  });

  res.json(obj);
});

// Route to increment obj.count in a pool-protected context synchronously
app.get("/pool-sync-context", async (req, res) => {
  // Will start blocking when the number of requests exceeds the concurrency level of the pool
  const result = await pool.runInContext(() => {
    return obj.count++;
  });

  res.json(obj);
});

// Route to increment obj.count in a pool-protected context asynchronously
app.get("/pool-async-context", async (req, res) => {
  // Will start blocking when the number of requests exceeds the concurrency level of the pool
  const result = await pool.runInAsyncContext(async () => {
    return obj.count++;
  });

  res.json(obj);
});

app.listen(8000); // Start the server

API

Mutex

• Mutex() - Constructor function to create a new mutex instance.

Methods

• runInAsyncContext(asyncFunction): Runs the provided async function in a mutex-protected context.
• runInContext(syncFunction): Runs the provided synchronous function in a mutex-protected context.

Pool

• Pool(concurrency): Constructor function to create a new pool instance with the specified concurrency level.

Methods

• runInAsyncContext(asyncFunction): Runs the provided async function in a pool-protected context.
• runInContext(syncFunction): Runs the provided synchronous function in a pool-protected context.