Iterate Asynchronously in Parallel

// Run a set of asynchronous tasks in parallel by spawning them all at once,
// and then wait for all of them to complete by counting the number of times
// their callbacks are invoked.

const tasks = []; // array of async tasks

let completed = 0;
tasks.forEach(function(task) {
    task(function() {
        // async callback: will execute when async task completes
        
        // if all tasks are completed, call finish()
        if(++completed === tasks.length) {
            finish();
        }
    });
});

function finish() {
    // all tasks completed
}

Posted on: Tue, 29 Jan 2019 08:21:00 GMT

Tags:

javascript

design pattern