JSON

require('something');

// 1. try something.js
// 2. try something.json
// 3. try something.node

Addons

> npm i node-gyp -g

 

> npm install --global --production windows-build-tools

Concurrency Model and Event Loop

Event Model

The Event Loop

Slow I/O Operations

What is I/O Anyway?

Handling Slow I/O

Event Loop

The Event Loop

The entity that handles external events and converts them into callback invocations

The Event Loop

A loop that picks events from the event queue and pushes their callbacks to the call stack

The Call Stack

anonymous()

printDouble(9)

double(9)

add(9, 9)

anonymous()

printDouble(9)

console.log(18)

add(9, 9)

double(9)

Handling Slow Operations

anonymous()

slowAdd(3, 3)

slowAdd(4, 4)

slowAdd(5, 5)

console.log(6)

console.log(8)

console.log(10)

How Callbacks Actually Work

anonymous()

slowAdd(3, 3)

setTimeout()

slowAdd(4, 4)

setTimeout()

console.log(6)

console.log(8)

Timer()

cb1

cb2

cb1

cb2

anonymous()

slowAdd(3, 3)

setTimeout(cb1, d)

Timer

cb1

slowAdd(4, 4)

setTimeout(cb2, d)

Timer

cb2

cb1

cb2

cb1

console.log(6)

cb2

console.log(8)

setImmediate & process.nextTick

anonymous()

slowAdd(3, 3)

setTimeout(cb1, d)

Timer

cb1

cb1

slowAdd(4, 4)

setTimeout(cb2, d)

Timer

cb2

cb2

cb1

console.log(6)

console.log(6)

cb2

Who Named These?

Concurrency Model

By Shuhratbek Mamadaliyev

Concurrency Model

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