createReadStream seems to crash the program/make the file handles hang permanently

[robobun]

createReadStream (on its own or when given a specific file handle) seems to take permanent ownership of its file handle and not let it be closed naturally/manually

bun version: 1.0.20
operating system: debian on wsl 2 (5.10.102.1-microsoft-standard-WSL2)
ulimit size: 1024

code:

import { createReadStream, close } from "fs";
import { open, writeFile } from "fs/promises";

await writeFile("mlem", Buffer.alloc(2 ** 18));

const openAndReadFile = () => new Promise(async (resolve, reject) => {
    const fd = await open("mlem", 'r');
    if (typeof fd === "number")
        createReadStream("", { fd, autoClose: false, emitClose: false })
            .on("data", chunk => { })
            .on("end", () => {
                close(fd, error => void (error ? reject(error) : resolve()));
            })
            .on("error", reject);
    else
        fd.createReadStream({ autoClose: false, emitClose: false })
            .on("data", chunk => { })
            .on("end", () => {
                fd.close().then(resolve).catch(reject);
            })
            .on("error", reject);
});

for (let i = 0; i < 3000; ++i) {
    console.log("opened", i);
    await openAndReadFile();
    console.log("closed");
}

output when ran from node.js:

opened 0
closed
...
opened 2999
closed

output when ran from bun:

opened 0
closed
...
opened 2041
closed
1 | export default "native";
    ^
EMFILE: Too many open files
   errno: -24
 syscall: "dup"
      fd: 13

      at native:1:1
      at #internalConstruct (node:1:62)
      at _read (node:1:50)
      at #internalRead (node:1:465)
      at node:1:1993
      at maybeReadMore (native:1:1)
      at processTicksAndRejections (:61:39)

Originally reported on Discord: createReadStream seems to crash the program/make the file handles hang permanently

[lmachens]

I am facing the same issue with my express server.
Here is a test repository:
https://github.com/lmachens/bun-file-not-closed

Each time a file is opened on the server (e.g. to serve the index.html), the file handlers count increases.).

[sroussey]

I ran your test (bun 1.0.21) and did not see the error. I am running on a Mac, so not sure if it is the different platform or the different bun version.

[lmachens]

I ran your test (bun 1.0.21) and did not see the error. I am running on a Mac, so not sure if it is the different platform or the different bun version.

I have the same issues with 1.0.21, but on Ubuntu and with the official docker image.

[lmachens]

I tried out 1.0.22 (bun upgrade --canary && bun install) but it's still an issue

[ghost]

This still needs to be fixed, but in the meanwhile, you can use Bun.file().stream() instead:

const foo = await Bun.file("foo.txt").stream();

[lmachens]

This still needs to be fixed, but in the meanwhile, you can use Bun.file().stream() instead:

const foo = await Bun.file("foo.txt").stream();

Thx. Any advice how to apply this for Express?

[ghost]

This still needs to be fixed, but in the meanwhile, you can use Bun.file().stream() instead:

const foo = await Bun.file("foo.txt").stream();

Thx. Any advice how to apply this for Express?

I'm not sure about Express. There's more info about this in the docs though, if you want to look there.