lock.js

const locks = {};

/**
 * @param {string} name the thing we want to have access to
 */
async function getLock(name) {
    while (locks[name]) await locks[name]
    let release;
    locks[name] = new Promise(resolve => {
        release = () => {
            delete locks[name];
            resolve();
        };
    });
    return { release }
}


const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));

async function unsafeWork(key) {
    // Simulate doing work
    console.log(key, "Start");
    await sleep(100);
    console.log(key, "End");
}

async function safeWork(key) {
    const lock = await getLock(key);
    await unsafeWork(key);
    lock.release();
}

// 
safeWork(1);
safeWork(2);
safeWork(1);
safeWork(2);
safeWork(3);
safeWork(3);
safeWork(1);

1 Start
2 Start
3 Start
1 End
1 Start
2 End
2 Start
3 End
3 Start
1 End
1 Start
2 End
3 End
1 End