Multi-workers serve - with same port

[cooffeeRequired]

How can we reproduce the crash?

Asynchronmic serve...

import { serve } from "bun";
import { Worker, isMainThread, parentPort } from "worker_threads";

const defaultInstances = 3;

if (isMainThread) {
    console.log("Main thread: Starting server and spawning workers...");

    // Hlavní vlákno spouští server
    const server = serve({
        port: 3000,
        fetch: async (req) => {
            const workerIndex = Math.floor(Math.random() * defaultInstances);
            return await sendToWorker(workerIndex, req);
        },
    });

    console.log("Server running on port 3000");

    // Spuštění workerů
    const workers = [];
    for (let i = 0; i < defaultInstances; i++) {
        workers.push(new Worker(new URL(import.meta.url)));
    }

    const workerChannels = new Map(
        workers.map((worker, index) => [
            index,
            {
                worker,
                port: new MessageChannel().port1,
            },
        ])
    );

    async function sendToWorker(workerIndex: number, req: Request): Promise<Response> {
        const { worker, port } = workerChannels.get(workerIndex);
        return new Promise((resolve, reject) => {
            port.postMessage({ req: req.url });
            port.on("message", (response) => resolve(new Response(response)));
            port.on("error", (err) => reject(err));
        });
    }
} else {
    // Worker logika: zpracování požadavků
    console.log(`Worker started (Thread: ${process.pid})`);

    parentPort?.on("message", ({ req }) => {
        console.log(`Worker ${process.pid} handling request: ${req}`);
        parentPort?.postMessage(`Handled by worker ${process.pid}`);
    });
}

Relevant log output

C:\projects\bun-appiest git:[master]
bun run test.ts
Main thread: Starting server and spawning workers...
Server running on port 3000
Worker started (Thread: 32520)
Worker started (Thread: 32520)
Worker started (Thread: 32520)
============================================================
Bun v1.1.34 (5e5e7c60) Windows x64
Windows v.win10_fe
CPU: sse42 avx avx2
Args: "C:\Users\nexti\.bun\bin\bun.exe" "run" "test.ts"
Features: http_server jsc tsconfig workers_spawned(3) 
Builtins: "bun:main" "node:worker_threads" 
Elapsed: 263ms | User: 62ms | Sys: 46ms
RSS: 0.19GB | Peak: 0.19GB | Commit: 0.25GB | Faults: 47845

panic(main thread): Segmentation fault at address 0x18
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

 https://bun.report/1.1.34/wr15e5e7c6EggglggCgw2muC0m44yBigv1zB40q1zB__s3tnkCA2AwB

Stack Trace (bun.report)

Bun v1.1.34 (5e5e7c6) on windows x86_64 [RunCommand]

Segmentation fault at address 0x00000018

• ScriptExecutionContext.h:64: WebCore::ScriptExecutionContext::jsGlobalObject
• MessagePort.cpp:209: WebCore::MessagePort::postMessage
• optional:388: std::optional<WebCore::Exception>::operator bool
• JSMessagePort.cpp:290: WebCore::jsMessagePortPrototypeFunction_postMessageOverloadDispatcher
• 2 unknown/js code
• llint_entry

Features: workers_spawned, http_server, jsc, tsconfig

_{Sentry Issue: BUN-9H3}

[github-actions]

@cooffeeRequired, the latest version of Bun is v1.1.38, but this crash was reported on Bun v1.1.34.

Are you able to reproduce this crash on the latest version of Bun?

bun upgrade

[cooffeeRequired]

Ofcourse i can, let me check it, after updates.

[cooffeeRequired]

new crash with latest version

Bun v1.1.38 ([`bf2f153`](<https://github.com/oven-sh/bun/tree/bf2f153f5ca45876bc88369273743cd6fa04881c>)) on windows x86_64 [RunCommand]

Segmentation fault at address 0x00000018

- [`ScriptExecutionContext.h:64`](<https://github.com/oven-sh/bun/blob/bf2f153f5ca45876bc88369273743cd6fa04881c/src/bun.js/bindings/ScriptExecutionContext.h#L64>): `WebCore::ScriptExecutionContext::jsGlobalObject`
- [`MessagePort.cpp:209`](<https://github.com/oven-sh/bun/blob/bf2f153f5ca45876bc88369273743cd6fa04881c/src/bun.js/bindings/webcore/MessagePort.cpp#L209>): `WebCore::MessagePort::postMessage`
- [`optional:388`](<https://github.com/oven-sh/bun/blob/bf2f153f5ca45876bc88369273743cd6fa04881c/C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.39.33519/include/optional#L388>): `std::optional<WebCore::Exception>::operator bool`
- [`JSMessagePort.cpp:290`](<https://github.com/oven-sh/bun/blob/bf2f153f5ca45876bc88369273743cd6fa04881c/src/bun.js/bindings/webcore/JSMessagePort.cpp#L290>): `WebCore::jsMessagePortPrototypeFunction_postMessageOverloadDispatcher`
- *2 unknown/js code*
- `llint_entry`

Features: workers\_spawned, http\_server, jsc, tsconfig

<!-- from bun.report: 1KljbdDJrc3HU_3k8Ap8 -->

<!-- sentry_id: 86385cdc4c1c6d084ea6037266fb7e20 -->

Totaly same script, let me try it on linux

[Jarred-Sumner]

Tracking this in #15964