Since most modern kernels are multi-threaded, they can handle multiple operations executing in the background. When one of these operations completes, the kernel tells Node.js so that the appropriate callback may be added to the poll queue to eventually be executed.

What is Node.js?

Why does Node.js exists?

Blocking is when the execution of additional JavaScript in the Node.js process must wait until a non-JavaScript operation completes. This happens because the event loop is unable to continue running JavaScript while a blocking operation is occurring.

Blocking methods execute synchronously and non-blocking methods execute asynchronously.

JavaScript execution in Node.js is single threaded, so concurrency refers to the event loop's capacity to execute JavaScript callback functions after completing other work. Any code that is expected to run in a concurrent manner must allow the event loop to continue running as non-JavaScript operations, like I/O.

Node is similar in design to, and influenced by, systems like Ruby's Event Machine or Python's Twisted. Node takes the event model a bit further. It presents an event loop as a runtime construct instead of as a library.

In Node there is no such start-the-event-loop call. Node simply enters the event loop after executing the input script. Node exits the event loop when there are no more callbacks to perform. This behavior is like browser JavaScript

The event loop is what allows Node.js to perform non-blocking I/O operations — despite the fact that JavaScript is single-threaded — by offloading operations to the system kernel whenever possible.

When Node.js starts, it initializes the event loop, processes the provided input script (or drops into the REPL) which may make async API calls, schedule timers, or call process.nextTick(), then begins processing the event loop.

These are the phases of the event loop. Each phase has his own queue. timers pending callbacks idle, prepare poll <- incoming: connections, data etc. check close callbacks

Each phase has a FIFO queue of callbacks to execute.

While each phase is special in its own way, generally, when the event loop enters a given phase, it will perform any operations specific to that phase, then execute callbacks in that phase's queue until the queue has been exhausted or the maximum number of callbacks has executed

12:33 > This diagram looks basically identical for node, instead of web APIs we have C++ APIs and the threading is being hidden from you by C++

Just because Node is designed without threads, doesn't mean you cannot take advantage of multiple cores in your environment. Child processes can be spawned by using our child_process.fork() API

V8 The V8 library provides Node.js with a JavaScript engine, which Node.js controls via the V8 C++ API. V8 is maintained by Google, for use in Chrome.

V8 is Google’s open source high-performance JavaScript and WebAssembly engine, written in C++. It is used in Google Chrome, the open source browser from Google, and in Node.js, among others.

V8 implements ECMAScript and WebAssembly. Can run standalone, or can be embedded into any C++ application

Libuv, a C library that is used to abstract non-blocking I/O operations to a consistent interface across all supported platforms. It provides mechanisms to handle file system, DNS, network, child processes, pipes, signal handling, polling and streaming.

I learned the way a monkey learns by watching its parents.

Architecture struck me between the eye and the eyeball.

I try to create some stupid entertainment for really smart people that they don't feel too stupid watching. In 'Xanadu,' the biggest laugh was a reference to Achilles.

I like to wear dresses and skirts when I go onstage because the attitude that I have is, 'I'm so excited to introduce myself to you.' And I want to be wearing what I'd be wearing to a date or a dinner party.

I'm a bass player from way back and Paul is a guitar player and we've been in many bands.

I'm one of the few people in this world who can do anything I choose. I can't tell you how good I'm feeling.

When you're doing a series, you're really in a zone. You're thinking about those characters and their situations in a free-floating way all the time. They live with you all the time. So it's just as natural as breathing to be having ideas and thinking about what they're thinking about.

I'm not spitting in my own soup, I love having spent my life thinking about these things-but you don't have to know anything about his life, even though I've just written a biography!

'Black Swan' was absolutely unbelievable. I had always dreamed of working with Darren Aronofsky, and Natalie Portman, Winona Ryder, Barbara Hershey, Mila Kunis and Vincent Cassel. The entire cast was really a dream cast, and it was amazing to work with these powerhouse women that I've just admired for so many years.

Habituation is indeed a fact of human psychology. That's one reason we like novelty, including different cuts of jeans.

What a grand thing, to be loved! What a grander thing still, to love!

I didn't want o do metal work and get my hands all nicked up and be around guys. So I took drama because there were a lot of girls.

Sharing food with another human being is an intimate act that should not be indulged in lightly.

My father has been my role model. And I always looked up to him - be it his management philosophy or his approach towards life.

I would hope we would begin a series of projects that would do more to bring the different parts of the university together in the study of Asia, for example, in the study of the professions in Asia.

It is not uncommon in modern times to see governments straining every nerve to keep the peace, and the people whom they represent, with patriotic enthusiasm and resentment over real or fancied wrongs, urging them forward to war.

My first published novel was 'Mother of Demons,' which is simply 'The High Crusade' standing on its head. Poul Anderson placed his medieval human heroes in a futuristic alien setting; I placed my futuristic human heroes in a bronze age alien setting.

The nice thing about 'Morning Joe' is that I do get to do serious news sometimes.

I worked as a lawyer; as a member of the teaching staff of a technical college; and then I worked principally as legal adviser to Adolf Hitler and the National Socialist German Workers Party.

Equity is the cushion that protects financial institutions from unexpected changes in the value of their assets. The greater the leverage, the smaller the losses required to wipe out a company's equity, leaving it without enough money to repay the people who hold its debt.

I don't go to war for the adrenaline rush. I cover wars because that's what I've ended up doing.

Man's greatness consists in his ability to do and the proper application of his powers to things needed to be done.

It requires genius to make a good pun - some men of bright parts can't reach it.

A good idea for lyrics and a melody to expand on.