sharp: Windows, SVG, possible font rendering deadlock under load

Possible bug

Is this a possible bug in a feature of sharp, unrelated to installation?

• Running npm install sharp completes without error.
• Running node -e "require('sharp')" completes without error.

If you cannot confirm both of these, please open an installation issue instead.

Are you using the latest version of sharp?

• I am using the latest version of sharp as reported by npm view sharp dist-tags.latest.

If you cannot confirm this, please upgrade to the latest version and try again before opening an issue.

If you are using another package which depends on a version of sharp that is not the latest, please open an issue against that package instead.

What is the output of running npx envinfo --binaries --system --npmPackages=sharp --npmGlobalPackages=sharp?

  System:
    OS: Windows 10 10.0.22621
    CPU: (24) x64 AMD Ryzen 9 3900X 12-Core Processor
    Memory: 31.84 GB / 63.93 GB
  Binaries:
    Node: 19.0.0 - C:\Program Files\nodejs\node.EXE
    npm: 8.19.2 - C:\Program Files\nodejs\npm.CMD
  npmPackages:
    sharp: ^0.31.3 => 0.31.3

What are the steps to reproduce?

Sometimes our express server stops responding to requests. I traced it down to our usage of sharp. Sometimes, sharp returns a Promise that neither resolves nor rejects. I’ve isolated the problem into the code below that exhibits the bug. It appears to have something to do with SVG. I force the bug to happen quicker by running many operations in parallel.

What is the expected behaviour?

The program should print Generation 0..99 and then exit.

Instead, the program hangs, usually at the first or after just a few generations. The CPU usage of the process drops to 0.

Please provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem

import sharp = require("sharp")

const svg = `<?xml version="1.0" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg" xml:lang="en"
    height="846"
    width="540">
    <text
        text-anchor="middle"
        x="50%" y="209"
        font-size="28"
    >
    ${"ABCDEFG ".repeat(20)}
    ${"ABCDEFG ".repeat(20)}
    </text>
    <text
        text-anchor="middle"
        x="50%" y="237"
        font-size="28"
    >
    </text>
</svg>`


main()
    .then(() => console.log("OK"))
    .catch(err => console.log(`Error: ${err}`))

async function main() {
    for (let i = 0; i < 100; i++) {
        console.log(`Generation ${i}`)
        await Promise.all(Array(100).fill(1).map(_ => createImg()))
    }
}

async function createImg() {
    return await sharp({
        create: {
            width: 540,
            height: 846,
            background: { r: 255, g: 255, b: 255 },
            channels: 3,
        }
    })
    .composite([{ input: Buffer.from(svg) }])
    .toBuffer()
}

Please provide sample image(s) that help explain this problem