2nd/10_Wiki/Topics/Programming & Language/bitECS와 SharedArrayBuffer를 결합한 멀티스레드 고성능 아키텍처.md

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id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-bitecs와-sharedarraybuffer를-결합한-멀	bitECS와 SharedArrayBuffer를 결합한 멀티스레드 고성능 아키텍처	10_Wiki/Topics	verified	self	bitECS multithreaded SAB ECS ECS parallel bitECS SharedArrayBuffer	none	A	0.9	applied	ecs bitecs sharedarraybuffer parallel gamedev browser		2026-05-10	pending	language framework TypeScript 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

// 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

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

// 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

// 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

// 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

// 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

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)

// 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)

// 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