memery leak for deno_bindgen

[usrtax]

deno 1.26.0 (release, x86_64-unknown-linux-gnu) v8 10.7.193.3 typescript 4.8.3

code is there https://github.com/usrtax/deno_bindgen_test

use deno_bindgen::deno_bindgen;

#[deno_bindgen]
fn add3() -> &'static [u8] {
    &[
        1, 2, 3, 4, 5, 6, 7, 9, 0, 1, 2, 3, 4, 5, 6, 7, 9, 0, 1, 2, 3, 4, 5, 6, 7, 9, 0, 1, 2, 3,
    ]
}

test code https://github.com/usrtax/deno_bindgen_test/blob/main/lib/test.js

#!/usr/bin/env -S node --es-module-specifier-resolution=node --trace-uncaught --expose-gc --unhandled-rejections=strict
var main, n, sleep;

import {
  add3
} from '../bindings/bindings.ts';

sleep = () => {
  return new Promise((resolve) => {
    return setTimeout(resolve, 10);
  });
};

n = 0;

while (true) {
  main();
  if (n++ % 10000 === 0) {
    gc();
    await sleep();
    console.log(n, Deno.memoryUsage());
  }
}

run as begin

run 3mintues RES 1040M

run 10minutes RES 2177M

run 1hour RES 14.9G

Deno.memoryUsage doesn't seem to be very accurate, pay more attention to the memory usage in top

[ar37-rs]

You are doing 'static stuff, any 'static stuff including &'static [u8] won't be dropped or freed until the application successfully exited.

[usrtax]

I change code into

#[deno_bindgen]
fn add3(a: u64, b: u64) -> u64 {
    a + b
}

memery still leak

1 mintues

2 mintues

[littledivy]

Thanks for the report. This is a known issue, deno_bindgen leaks the buffer to JS land. The JS bindings should register a finalization callback to free the buffer.