fix: worker-pool ID collision + query-do init race condition

- worker-pool: Date.now() in fan-out worker IDs can collide when multiple
  fan-outs execute within the same millisecond — use crypto.randomUUID()
- query-do: ensureInitialized() set initialized=true before async work
  completed, allowing concurrent callers to proceed before WASM was ready —
  now uses promise-based serialization so all callers await the same init

Author: teamchong

src/query-do.ts

@@ -409,7 +409,7 @@ export class QueryDO extends DurableObject<Env> {
   private resultCache = new VipCache<string, QueryResult>(RESULT_CACHE_MAX, RESULT_VIP_THRESHOLD);
   private wasmEngine!: WasmEngine;
   private activeFragmentSlots = new Set<number>(); // slots currently scanning
-  private initialized = false;
+  private initPromise: Promise<void> | null = null;
   private registeredWithMaster = false;
 
   constructor(ctx: DurableObjectState, env: Env) {
@@ -524,10 +524,14 @@ export class QueryDO extends DurableObject<Env> {
     }
   }
 
-  private async ensureInitialized(): Promise<void> {
-    if (this.initialized) return;
-    this.initialized = true;
+  private ensureInitialized(): Promise<void> {
+    if (!this.initPromise) {
+      this.initPromise = this.doInit();
+    }
+    return this.initPromise;
+  }
 
+  private async doInit(): Promise<void> {
     const stored = await this.ctx.storage.list<TableMeta>({ prefix: "table:" });
     for (const [key, meta] of stored) this.footerCache.set(key.replace("table:", ""), meta);
 

src/worker-pool.ts

@@ -159,7 +159,7 @@ export class WorkerPool {
   ): Promise<R2Partition[]> {
     const results = await Promise.all(
       partitions.map(async (partition, i) => {
-        const workerId = `worker-${taskName}-${i}-${Date.now()}`;
+        const workerId = `worker-${taskName}-${i}-${crypto.randomUUID()}`;
         const id = this.doNamespace.idFromName(workerId);
         const handle = this.doNamespace.get(id) as unknown as WorkerDORpc;
         return handle.executeTask({
@@ -187,7 +187,7 @@ export class WorkerPool {
 
     const results = await Promise.all(
       chunks.map(async (chunk, ci) => {
-        const coordId = `coord-${taskName}-${ci}-${Date.now()}`;
+        const coordId = `coord-${taskName}-${ci}-${crypto.randomUUID()}`;
         const id = this.doNamespace.idFromName(coordId);
         const handle = this.doNamespace.get(id) as unknown as WorkerDORpc;
         return handle.executeCoordinator({
@@ -222,7 +222,7 @@ export class WorkerPool {
 
     const results = await Promise.all(
       superChunks.map(async (superChunk, sci) => {
-        const superCoordId = `supercoord-${taskName}-${sci}-${Date.now()}`;
+        const superCoordId = `supercoord-${taskName}-${sci}-${crypto.randomUUID()}`;
         const id = this.doNamespace.idFromName(superCoordId);
         const handle = this.doNamespace.get(id) as unknown as WorkerDORpc;
         return handle.executeSuperCoordinator({