cpu-prof doesn't propagate to workers when env is set

[orinatic]

Version

20.8.1

Platform

Linux ushanka-housing 6.5.0-1020-oem #21-Ubuntu SMP PREEMPT_DYNAMIC Wed Apr 3 14:54:32 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

cpu-prof

What steps will reproduce the bug?

You can reproduce this by modifying one of the existent node tests.

If you edit tests/fixtures/workload/fibonacci-worker.js in this repo with

-new Worker(path.join(__dirname, 'fibonacci.js'));
+new Worker(path.join(__dirname, 'fibonacci.js'), {env: process.env});

and then run

node ./test/sequential/test-cpu-prof-dir-worker.js

the new test will fail

How often does it reproduce? Is there a required condition?

This should reproduce 100% of the time -- you don't need to do anything special

What is the expected behavior? Why is that the expected behavior?

According to https://nodejs.org/docs/latest-v20.x/api/worker_threads.html#new-workerfilename-options, the default value for a worker thread's env is process.env. Thus, not passing an environment and passing process.env as the environment should always produce the same behavior.

What do you see instead?

When running in its original form, the test produces two profile files, as intended. When passing {env: process.env} into the worker invocation, however, it only produces one profile file.

Additional information

If I print the environment in the worker thread, it appears to be identical in both cases. It doesn't seem like the problem is that part of the environment is getting lost, but rather there's some hidden variable that isn't getting propagated

[avivkeller]

I've been able to reproduce.

const worker_threads = require('worker_threads');

if (worker_threads.isMainThread) {
    new worker_threads.Worker(__filename, { env: process.env });
} else {
    console.log('Hello, world!');
}

node --cpu-prof index.js

[avivkeller]

The issue occurs when the env is set to any value. I'll look into it.

[avivkeller]

I've determined the issue is not on the JS side of things but on the C++ side instead. I'm no CPP expert, so I haven't looked into it much, but I'd assume it is has something to do with the node_worker.cc file: https://github.com/nodejs/node/blob/71a1fa3043d495dfaa2105d07cd090c51bcd8eed/src/node_worker.cc

(I determined this by fiddling around with the /lib/internal/worker.js file, and seeing that no matter the value set, the issue has to do with the WorkerImpl, implemented in CPP)

[avivkeller]

CC @nodejs/workers

[theanarkh]

I think the relevant code is here . I debug into the C++ code and found the cpu_prof in env->options_ is false.