chore(brain): ASTRA 성장 자산 동기화 — 기능 인벤토리·growth(약점프로필/학습큐)·일화기억·장기기억·회의록 원문

2026-06-12 16:37:41 +09:00
parent a97fc7be07
commit 89fb05a28a
781 changed files with 138546 additions and 47 deletions
@@ -0,0 +1,128 @@
+---
+id: wiki-2026-0508-v8-javascript-engine
+title: V8 JavaScript Engine
+category: 10_Wiki/Topics
+status: verified
+canonical_id: self
+aliases: [V8, V8 Engine, Chrome V8]
+duplicate_of: none
+source_trust_level: A
+confidence_score: 0.9
+verification_status: applied
+tags: [v8, javascript, engine, runtime, chrome, node]
+raw_sources: []
+last_reinforced: 2026-05-10
+github_commit: pending
+tech_stack:
+  language: C++
+  framework: V8
+---
+
+# V8 JavaScript Engine
+
+## 매 한 줄
+> **"매 Ignition interpreter + TurboFan / Maglev / Sparkplug 의 매 multi-tier JIT 으로 매 JS 를 native 수준에 도달시키는 엔진"**. 매 Chrome / Edge / Node.js / Deno 의 핵심. 매 2026 기준 Maglev (mid-tier JIT) 와 매 pointer compression 으로 매 startup + memory 모두 개선됨.
+
+## 매 핵심
+
+### 매 Multi-tier compilation
+- **Ignition** — bytecode interpreter (fastest startup).
+- **Sparkplug** — non-optimizing baseline JIT (V8 9.1+).
+- **Maglev** — mid-tier optimizing JIT (V8 11.5+, default 11.9+).
+- **TurboFan** — top-tier optimizer (slow compile, fast run).
+
+### 매 Hidden classes & inline caches
+- 매 JS object 의 매 shape 추적 (V8 internal "Map").
+- 매 same-shape access 는 매 monomorphic IC 로 매 native 속도.
+- 매 shape 변경 (속성 추가 순서 다름) 매 → polymorphic / megamorphic.
+
+### 매 GC
+- Generational: young (scavenger, Minor MC) + old (Mark-Compact, Mark-Sweep).
+- Orinoco — concurrent / parallel / incremental.
+- Pointer compression (V8 8.0+) — 35-40% heap 절감.
+
+### 매 응용
+1. Browser JS — Chrome, Edge.
+2. Server JS — Node.js, Deno (V8 기반).
+3. Embedded — Electron, CEF.
+
+## 💻 패턴
+
+### Hidden class 친화적 객체
+```javascript
+// Good — same shape
+function User(id, name) { this.id = id; this.name = name; }
+
+// Bad — shape diverges
+function User(id, name) { this.id = id; if (name) this.name = name; }
+```
+
+### Monomorphic call site
+```javascript
+function getX(point) { return point.x; }
+// pass only one shape consistently → IC stays monomorphic
+const points = Array.from({ length: 1e6 }, (_, i) => ({ x: i, y: i }));
+points.forEach(getX);
+```
+
+### Avoiding deopt
+```javascript
+function add(a, b) { return a + b; }
+add(1, 2);     // optimized for number
+add('a', 'b'); // deopt — TurboFan must reoptimize
+```
+
+### V8 inspector / profiling
+```bash
+node --inspect-brk app.js
+# Chrome devtools → Performance → JS samples
+```
+
+### V8 flags for diagnosis
+```bash
+node --trace-opt --trace-deopt app.js
+node --print-bytecode app.js
+node --allow-natives-syntax  # %OptimizeFunctionOnNextCall
+```
+
+### Pointer compression check
+```bash
+node -p "process.config.variables.v8_enable_pointer_compression"
+# 1 → enabled
+```
+
+## 매 결정 기준
+| 관심사 | Approach |
+|---|---|
+| Startup 빠름 | Ignition / Sparkplug 충분 |
+| Hot loop | Maglev / TurboFan 의 monomorphic 유지 |
+| Memory tight | pointer compression + young GC tuning |
+| Diagnose perf | `--trace-deopt`, `clinic flame` |
+
+**기본값**: 매 modern V8 default — 매 micro-opt 보다 매 algorithmic 우선.
+
+## 🔗 Graph
+- 부모: [[JavaScript]]
+- 변형: [[JavaScriptCore]] · [[Hermes]]
+- 응용: [[Node.js]] · [[Deno]] · [[Chrome]] · [[Electron]]
+- Adjacent: [[JIT Compilation]] · [[Garbage Collection]] · [[Inline Cache]]
+
+## 🤖 LLM 활용
+**언제**: 매 perf 분석 가설 세우기, 매 deopt 원인 추정.
+**언제 X**: 매 V8 internal 변경 빠름 — 매 매 latest blog 확인 필요.
+
+## ❌ 안티패턴
+- **Shape divergence**: 매 conditional property 추가 — 매 polymorphic 유발.
+- **delete 연산자**: 매 hidden class transition 강제.
+- **`arguments` 변형**: 매 deopt 유발.
+- **Try/catch in hot path**: 매 V8 ≤ 7.x 까진 deopt — 매 modern V8 은 ok 이나 매 case-by-case.
+
+## 🧪 검증 / 중복
+- Verified (V8 official blog v8.dev, "Maglev" announcement).
+- 신뢰도 A.
+
+## 🕓 Changelog
+| 날짜 | 변경 |
+|---|---|
+| 2026-05-08 | Phase 1 |
+| 2026-05-10 | Manual cleanup — Maglev + pointer compression 반영 |