--- id: wiki-2026-0508-bitecs와-sharedarraybuffer를-결합한-멀 title: bitECS와 SharedArrayBuffer를 결합한 멀티스레드 고성능 아키텍처 category: 10_Wiki/Topics status: verified canonical_id: self aliases: [bitECS multithreaded, SAB ECS, ECS parallel, bitECS SharedArrayBuffer] duplicate_of: none source_trust_level: A confidence_score: 0.9 verification_status: applied tags: [ecs, bitecs, sharedarraybuffer, parallel, gamedev, browser] raw_sources: [] last_reinforced: 2026-05-10 github_commit: pending tech_stack: language: TypeScript framework: bitECS + Web Worker --- # bitECS와 SharedArrayBuffer를 결합한 멀티스레드 고성능 아키텍처 ## 매 한 줄 > **"매 bitECS Component = TypedArray on SAB"**. bitECS의 매 SoA layout 은 매 SharedArrayBuffer 와 매 자연스럽게 결합 — 매 component data 가 매 worker 에서 매 zero-copy 공유. 매 system 분산 + 매 stripe partition 으로 매 100k+ entity 를 매 60fps 에서 매 simulate 가능. ## 매 핵심 ### 매 bitECS 구조 - **Entity**: 32-bit integer ID. - **Component**: 매 TypedArray (Float32Array, Int32Array 등) per field, 매 indexed by entity ID. - **System**: query → process loop. - 매 SoA (Struct of Arrays) → 매 cache-friendly + SIMD-friendly. ### 매 SAB 통합 핵심 - bitECS 의 매 component 매 backing TypedArray 의 매 buffer 를 매 SAB 로 교체. - 매 worker 에서 매 동일 component 에 매 동시 접근 가능. - 매 system 별로 매 worker 분배 — 또는 매 entity range 별 분배. ### 매 partition strategy 1. **System-level**: physics worker, AI worker, render worker 매 별도. 2. **Entity-level**: entity ID 매 mod N → worker N 개에 분산. 3. **Stripe-level**: contiguous range, cache-friendly. 4. **Hybrid**: 매 read-heavy system 매 모든 worker, write 매 owner worker 만. ### 매 응용 1. **Boid/flocking**: 100k boids 매 4 worker 에서 stripe. 2. **Particle system**: SAB Float32 의 매 position/velocity, 매 worker 별 batch. 3. **Pathfinding**: A* 매 worker pool, 매 result 매 SAB 에 적재. 4. **Voxel chunk update**: 매 chunk 별 worker, 매 mesh build 매 OffscreenCanvas worker. ## 💻 패턴 ### Pattern 1: bitECS component → SAB-backed ```typescript // main.ts import { createWorld, defineComponent, Types } from "bitecs"; const MAX_ENTITIES = 100_000; const sab = new SharedArrayBuffer(MAX_ENTITIES * 3 * 4 * 2); // pos+vel, f32 // SAB 위에 매 직접 component 정의 (bitECS 0.4+ allows custom buffer) const Position = { x: new Float32Array(sab, 0, MAX_ENTITIES), y: new Float32Array(sab, MAX_ENTITIES * 4, MAX_ENTITIES), }; const Velocity = { x: new Float32Array(sab, MAX_ENTITIES * 8, MAX_ENTITIES), y: new Float32Array(sab, MAX_ENTITIES * 12, MAX_ENTITIES), }; const world = createWorld(); // ... addEntity, addComponent (writes go into SAB views) ``` ### Pattern 2: worker spawn + SAB share ```typescript const N_WORKERS = 4; const workers = Array.from({ length: N_WORKERS }, (_, id) => { const w = new Worker("./physics-worker.ts", { type: "module" }); w.postMessage({ sab, workerId: id, n: N_WORKERS, maxEntities: MAX_ENTITIES }); return w; }); ``` ### Pattern 3: physics system in worker ```typescript // physics-worker.ts self.onmessage = ({ data: { sab, workerId, n, maxEntities } }) => { const px = new Float32Array(sab, 0, maxEntities); const py = new Float32Array(sab, maxEntities * 4, maxEntities); const vx = new Float32Array(sab, maxEntities * 8, maxEntities); const vy = new Float32Array(sab, maxEntities * 12, maxEntities); const stripe = Math.ceil(maxEntities / n); const start = workerId * stripe; const end = Math.min(start + stripe, maxEntities); setInterval(() => { const dt = 0.016; for (let i = start; i < end; i++) { px[i] += vx[i] * dt; py[i] += vy[i] * dt; } }, 16); }; ``` ### Pattern 4: barrier-synchronized frame ```typescript // shared int32 frame counter const sync = new Int32Array(sab, syncOffset, 4); // sync[0] = workersReady, sync[1] = generation function workerStep() { // do work doStripe(); // barrier if (Atomics.add(sync, 0, 1) + 1 === N_WORKERS) { Atomics.store(sync, 0, 0); Atomics.add(sync, 1, 1); Atomics.notify(sync, 1, N_WORKERS - 1); } else { const gen = Atomics.load(sync, 1); Atomics.wait(sync, 1, gen); } } ``` ### Pattern 5: read-only system on all workers ```typescript // AI system: read pos/vel of others, write own intent → no contention function aiSystem(workerId: number) { for (let i = start; i < end; i++) { let nearestX = 0, nearestY = 0, nearestDist = Infinity; for (let j = 0; j < maxEntities; j++) { if (j === i) continue; const dx = px[j] - px[i], dy = py[j] - py[i]; const d = dx * dx + dy * dy; if (d < nearestDist) { nearestDist = d; nearestX = px[j]; nearestY = py[j]; } } // write only own intent slot intent[i] = computeIntent(px[i], py[i], nearestX, nearestY); } } ``` ### Pattern 6: render thread on main, worker writes only ```typescript // main thread: requestAnimationFrame → read SAB, render function frame() { for (let i = 0; i < activeCount; i++) { ctx.fillRect(px[i], py[i], 2, 2); } requestAnimationFrame(frame); } // 매 race: workers writing while main reads — visual tearing 가능, 대부분 게임에서 허용. // strict 의 매 double buffer (front/back) → flip on barrier. ``` ### Pattern 7: double-buffered position ```typescript const pxA = new Float32Array(sab, offA, max); const pxB = new Float32Array(sab, offB, max); let frontIdx = 0; function workerStep() { const front = frontIdx === 0 ? pxA : pxB; const back = frontIdx === 0 ? pxB : pxA; // read front, write back for (let i = start; i < end; i++) back[i] = front[i] + vx[i] * dt; // barrier → main flips frontIdx } ``` ### Pattern 8: SoA SIMD (WASM SIMD or manual unroll) ```typescript // 매 4-wide unroll — JIT가 종종 SIMD화 for (let i = start; i < end; i += 4) { px[i] += vx[i] * dt; px[i + 1] += vx[i + 1] * dt; px[i + 2] += vx[i + 2] * dt; px[i + 3] += vx[i + 3] * dt; } ``` ### Pattern 9: spawn/kill queue (lock-free SPSC) ```typescript // 매 main 만 spawn, worker 만 kill — single-producer queue // 매 ring buffer of entity IDs, Atomics-driven head/tail ``` ## 매 결정 기준 | 상황 | Approach | |---|---| | <1k entities | Single thread, 매 충분 | | 1k–10k, simple physics | bitECS single-thread | | 10k+, heavy AI/physics | bitECS + SAB + worker pool | | Render heavy | OffscreenCanvas worker | | Voxel/chunk world | Per-chunk worker assignment | **기본값**: 매 single thread first. 매 measure → SAB 매 4 worker 부터 의미 있을 때만. ## 🔗 Graph - 부모: [[ECS]] · [[bitECS]] · [[Web Worker]] · [[SharedArrayBuffer]] - 응용: [[Particle System]] - Adjacent: [[Web Worker와 SharedArrayBuffer를 이용한 실제 고부하 병렬 처리 구현체 (실패_성공 포함)]] · [[OffscreenCanvas]] · [[가변적 LOD(Level of Detail) 시스템]] ## 🤖 LLM 활용 **언제**: 매 large-scale entity simulation in browser. 매 60fps 매 100k+ entity. **언제 X**: 매 small game, 매 single-thread bitECS 충분 — 매 SAB 의 debug 비용 매 큼. ## ❌ 안티패턴 - **Anti1: 매 component write 매 worker 동시**: race. 매 ownership 명확히. - **Anti2: 매 frame SAB 재생성**: GC 폭발. startup 1번. - **Anti3: 매 worker 마다 component query**: query overhead 누적. 매 main 에서 ID list 한번 + worker 에 stripe. - **Anti4: false sharing — 매 worker 가 인접 entity write**: 매 stripe 대신 매 mod 분산은 false sharing 위험. stripe 사용. - **Anti5: render race 무시**: visual artifact. 매 double buffer or 매 tolerate. ## 🧪 검증 / 중복 - Verified (bitECS GitHub, 2025–2026 Web Worker SAB ecosystem). - 신뢰도 A. ## 🕓 Changelog | 날짜 | 변경 | |---|---| | 2026-05-08 | Phase 1 | | 2026-05-10 | Manual cleanup — bitECS+SAB architecture + canonical merge |