SourceTextModule leaks memory when context is used #50113
Description
Version
21.0.0-nightly20231008fce8fbadcd
Platform
Microsoft Windows NT 10.0.22621.0 x64
Subsystem
No response
What steps will reproduce the bug?
Create two or more SourceTextModules and a SyntheticModule and link them together using a shared context (vm.createContext())
https://github.com/Havunen/nodejs-memory-leak
import {SourceTextModule, SyntheticModule, createContext} from 'vm';
async function link() {
// Having a shared context leaks nodejs memory
let context = createContext()
const module = new SourceTextModule(`
import foo from 'foo';
export default {a: new Array(100000).fill('-')};
`, {
context,
identifier: ''
});
const subModule = new SourceTextModule(`
import asd from 'asd.json';
export default asd;
`, {
context,
identifier: 'foo'
})
const jsonModule = new SyntheticModule(
['default'],
function () {
// mimic some large file
this.setExport('default', {a: new Array(100000).fill('-')});
},
{
context,
identifier: 'asd.json'
}
)
await subModule.link(() => jsonModule)
await module.link(() => subModule)
await module.evaluate();
// UN-COMMENT THIS LINE TO FIX THE LEAK?? wtf...
context = null
return module;
}
for (let i = 0; i < 100000; i++) {
if (i % 100 === 0) {
console.log("iterations" + i)
}
await link();
}How often does it reproduce? Is there a required condition?
100%
What is the expected behavior? Why is that the expected behavior?
NodeJs should not leak memory because the context object goes out of scope and should get garbage collected and all the modules associated with it.
What do you see instead?
The memory grows and grows depending on a number of modules and size of their data until nodejs fails to OOM.
Additional information
Note: Manually setting the context object null in JS side fixes the leak, but that should not be required