Lock - Task Queue

A super simple locking mechanism. Works like a task queue.

Install

npm i --save lock-taskqueue

Example

const Lock = require("lock-taskqueue");

const lock = Lock();

async function asyncFunction() {
    lock(() => {
        // Do work
    })
}

The lock can also return values from the passed function. If the value from the code in the lock is a Promise - it will be awaited.

async function getValue() {
    return await lock(() => somewhere.getValueAsync())
}

// these calls will run in a queue
getValue().then(console.log)
getValue().then(console.log)
getValue().then(console.log)
getValue().then(console.log)

You can have more than one lock object.

const Lock = require("lock-taskqueue");

const dbLock = Lock();
const fileLock = Lock();

async function useFile() {
    return await lock(() => {
        // Do work on file
    })
}

async function useDb() {
    return await lock(() => {
        // Do work on DB
    })
}

Lastly, here are some details about how it actually works:

await   lock(getValue).then(console.log)        // 1 task in queue, awaited
        lock(getValue).then(console.log)        // 1 tasks in queue
        lock(getValue).then(console.log)        // 2 tasks in queue
await   lock(getValue).then(console.log)        // 3 tasks in queue, all awaited.
        lock(getValue).then(console.log)        // 1 task in queue
await   lock(getValue).then(console.log)        // 2 tasks in queue, all awaited.