javascript
Garbage Collector
Overview

: @brn ( )
: iOS
: Cyberagent RightSegment AI Messenger
: http://abcdef.gets.b6n.ch/

What is Garbage Collector?
Garbage Collector

What is Garbage Collector?
var x = {
a: 1,
b: 2
}
Object
Field a
Field b
Other Objects
Heap

What is Heap?
Stack
=
Heap

What is Heap?
Stack
Heap
javascript Heap Stack

What is Heap?
Stack
Process
Stack Heap
Process
Stack Heap
Process
( )

What is Heap?
OUT OF MEMORY

Garbage Collector
Heap
Garbage Collector

Garbage Collector
var x = {}
var y = {}
Heap
Global
x y

Garbage Collector
Garbage Collector Heap
Heap
Global
x y

Garbage Collector
var x = {}
var y = {}
y = null
Heap
Global
x y

Garbage Collector
Garbage Collector Heap
Heap
Global
x y

Garbage Collector
var x = {};
var y = {x: x};
x = null
y.x = null
Heap
Global
x y

Garbage Collector
Garbage Collector Heap
Heap
Global
x y

Garbage Collector
var x = {};
var y = {x: x};
x = null
y = null
Heap
Global
x y

Garbage Collector
Garbage Collector Heap
Heap
Global
x y

Garbage Collector
Heap
Global
x y
Garbage Collector Heap

Garbage Collector
Garbage Collector Heap
(Mark Phase)
Garbage Collector Heap
(Sweep Phase)

Garbage Collector
(Mark And Sweep)

Garbage Collector
MarkPhase SweepPhase
GC(Incremental GC)
Mark&Sweep
Stop the world

Incremental Garbage Collection
Garbage Collector Heap
Heap
Global
x y
中断

Incremental Garbage Collection
Garbage Collector Heap
Heap
Global
x y
中断

Incremental Garbage Collection
Incremental GC Mark Phase
(WriteBarrier)

Incremental Garbage Collection
var x = {}
var y = {}
y.x = x;
Object(x)
Heap
Object(y)
WRITED

Incremental Garbage Collection
Garbage Collector WriteBarrier
Heap
Global
x y
中断
WRITED
削除しない

Incremental Garbage Collection
Incremental GC
GC

Summary
GC
https://github.com/authorNari/minigc 449 miniGC
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