javascriptのGCの概要

1. javascript
Garbage Collector
Overview

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

3. What is Garbage Collector?
Garbage Collector

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

5. What is Heap?
Stack
=
Heap

6. What is Heap?
Stack
Heap
javascript Heap Stack

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

8. What is Heap?
OUT OF MEMORY

9. Garbage Collector
Heap
Garbage Collector

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

11. Garbage Collector
Garbage Collector Heap
Heap
Global
x y

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

13. Garbage Collector
Garbage Collector Heap
Heap
Global
x y

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

15. Garbage Collector
Garbage Collector Heap
Heap
Global
x y

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

17. Garbage Collector
Garbage Collector Heap
Heap
Global
x y

18. Garbage Collector
Heap
Global
x y
Garbage Collector Heap

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

20. Garbage Collector
(Mark And Sweep)

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

22. Incremental Garbage Collection
Garbage Collector Heap
Heap
Global
x y
中断

23. Incremental Garbage Collection
Garbage Collector Heap
Heap
Global
x y
中断

24. Incremental Garbage Collection
Incremental GC Mark Phase
(WriteBarrier)

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

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

27. Incremental Garbage Collection
Incremental GC
GC

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