자바스크립트 스터디

A Tale of TurboFan: Four years that changed V8 forever

Inlining

Escape Analysis and Scalar Replacement

Making WebAssembly even faster: Firefox's new streaming and tiering compiler

Streaming compilation : Tier 1(or baseline compiler) and Tier 2 compiler

New bottleneck: CPU - main thread

Caching .wasm file

The Cost Of JavaScript

Bottleneck = Network(transmission size) + CPU(parse time)

JavaScript Startup Bytecode Cache

Optimizing hash tables: hiding the hash code

private symbol을 사용 -> symbol lookup이 필요

Backing store를 사용 -> lookup이 필요없게 되었다. 성능 향상!
: empty, array, dictionary

Fast Properties in V8

Named properties vs Indexed properties

Hidden classes and Descriptor arrays

In-object, fast, slow

Explaining JavaScript VMs in JavaScript - Inline Cached

Must-Watch JavaScript

In The Loop

Tasks - Animation callbacks - Microtasks

Tasks: 한번에 하나만 실행
Animation callbacks: 실행 시점에 큐에 있는 것은 모두 실행(실행 중 추가된 콜백은 다음번에 실행)
Microtasks: 큐가 빌때까지 계속 실행(따라서, 무한히 실행하는 것에 주의 필요)

자바스크립트와 이벤트 루프

Tasks, microtasks, queues and schedules

How JavaScript Timers Work

setTimeout vs setInterval

setInterval : 큐에 이전 핸들러가 실행되지 못하고 남아 있으면 새로 추가하지 않는다.

Elements kinds in V8

small integer -> PACKED_SMI_ELEMENTS
floating-point number -> PACKED_DOUBLE_ELEMENTS
regular element(string) -> PACKED_ELEMENTS

from PACKED to HOLEY

Avoid creating holes
Avoid reading beyond the length of the array
Avoid elements kind transitions
Prefer arrays over array-like objects
Avoid polymorphism

Bubbling and capturing

A cartoon guide to Flux