[Bug] Alarms execute before @Persist properties are hydrated on cold start #121

Describe the bug

When an Actor wakes up from hibernation/eviction (triggered by an alarm scheduled far enough in the future), the alarm callback executes before the @Persist properties have been hydrated from storage.

If the alarm callback relies on any @Persist property, it reads null/undefined, leading to silent failures on tasks like longer interval cron jobs.

While debugging this, I noticed it might be related to the initialization order of blockConcurrencyWhile locks on cold start. It seems like this.alarms = new Alarms(...) runs and schedules the alarms before the Actor constructor queues the lock to _initializePersistedProperties().

To Reproduce

Steps to reproduce the behavior:

1. Create a basic Hono worker and Actor that schedules a task far enough in the future to force a Durable Object eviction (for example, 2 min):

• Commands used:

pnpm create hono@latest my-actor --template cloudflare-workers
cd my-actor
pnpm add @cloudflare/actors

• Add this to wrangler.jsonc:

{
  "migrations": [
    {
      "new_sqlite_classes": ["MyActor"],
      "tag": "v1"
    }
  ],
  "durable_objects": {
    "bindings": [
      {
        "class_name": "MyActor",
        "name": "MyActor"
      }
    ]
  }
}

import { Actor, Persist } from "@cloudflare/actors";
import { Hono } from "hono";
import { logger } from "hono/logger";

export class MyActor extends Actor<CloudflareBindings> {
  @Persist
  myConfig: string | null = null;

  async scheduleTask() {
    this.myConfig = "hydrated_value";
    // Schedule an alarm 2 minutes in the future (long enough to force DO eviction)
    await this.alarms.schedule(120, "myAlarmCallback");
    console.log("Scheduled!");
  }
  async myAlarmCallback() {
    // BUG: When the DO wakes up, this logs "null" instead of "hydrated_value"
    console.log("Alarm fired. Config is:", this.myConfig);
  }
}

const app = new Hono<{ Bindings: CloudflareBindings }>();
app.use(logger());

app.get("/", async (c) => {
  const exampleActor = MyActor.get("example");

  const date = new Date();
  console.log(`Current time: ${date.toLocaleTimeString()}`);

  await exampleActor.scheduleTask();

  date.setMinutes(date.getMinutes() + 2);

  console.log(`Check back at: ${date.toLocaleTimeString()}`);
  return c.text(`Schedule started`);
});

export default app;

2. Trigger the / route using wrangler dev.
3. Wait 2 minutes for the alarm to trigger (ensure the DO goes idle and gets evicted).
4. Check logs: The logs will print Alarm fired. Config is: null instead of hydrated_value.

Expected behavior
When the alarm triggers a callback on a sleeping Actor, the @Persist properties should be fully hydrated from the SQLite table before the user's callback function is invoked. In the example hydrated_value should have been printed.

Screenshots: N/A

Information:

• Actor Version: 0.0.1-beta.6
• Wrangler: 4.4.0 (I've tried deleting the .wrangler folder and updating wrangler to latest version(4.86.0) but faced the same issue)
• Node.js: v24.15.0
• Typescript: 6.0.3

Additional context
Currently, my only workaround is to manually query this.sql for the _actor_persist table inside the alarm handler to get the data I need.