src,worker: runtime error on loop creation failure

[HarshithaKP]

Instead of hard asserting throw a runtime error,
that is more consumable.
Fixes: #31614

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[HarshithaKP]

When I run the test case mentioned in the issue with this change, getting the following error.

node: ../deps/uv/src/unix/core.c:556: uv__close_nocheckstdio: Assertion `fd > -1' failed.

[HarshithaKP]

With this change in place, test parallel/test-worker-resource-limits is failing with this stack:

bash-4.2$ ./node test/parallel/test-worker-resource-limits
Mismatched <anonymous> function calls. Expected exactly 1, actual 0.
    at mustCall (/home/harshitha/node/test/common/index.js:325:10)
    at Object.expectsError (/home/harshitha/node/test/common/index.js:531:10)
    at Object.<anonymous> (/home/harshitha/node/test/parallel/test-worker-resource-limits.js:26:24)
    at Module._compile (internal/modules/cjs/loader.js:1208:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1228:10)
    at Module.load (internal/modules/cjs/loader.js:1057:32)
    at Function.Module._load (internal/modules/cjs/loader.js:952:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
    at internal/main/run_main_module.js:17:47

I believe it is not because of the mismatch in the error code, but because the error callback is not invoked. I am able to recreate with the test in the referenced issue: missing error callback. My original intent with this PR was to covert C++ assertion into an error callback, which is missing! any guidance here?

[HarshithaKP]

Getting this currently, I will debug further.

bash-4.2$ ./node bar.js 10000
internal/worker.js:191
      this.emit('error', new errorCodes[customErr]());
                         ^
TypeError: errorCodes[customErr] is not a constructor
    at Worker.[kOnExit] (internal/worker.js:191:26)
    at Worker.<computed>.onexit (internal/worker.js:139:62)

[addaleax]

@HarshithaKP Hi! Let me/us know if you need anything to make this PR work :)

[HarshithaKP]

@addaleax, Thanks.
When I check the constructor with a string value, it works as follows.

bash-4.2$ ./node --expose-internals
Welcome to Node.js v14.0.0-pre.
Type ".help" for more information.
> const errorCodes = require('internal/errors').codes
undefined
> const obj = new errorCodes['ERR_WORKER_INIT_FAILED']('foo')
undefined
> obj
Error [ERR_WORKER_INIT_FAILED]: Worker initialization failed: foo
    at repl:1:13
    at Script.runInThisContext (vm.js:120:20)
    at REPLServer.defaultEval (repl.js:436:29)
    at bound (domain.js:429:14)
    at REPLServer.runBound [as eval] (domain.js:442:12)
    at REPLServer.onLine (repl.js:763:10)
    at REPLServer.emit (events.js:333:22)
    at REPLServer.EventEmitter.emit (domain.js:485:12)
    at REPLServer.Interface._onLine (readline.js:329:10)
    at REPLServer.Interface._line (readline.js:658:8) {
  code: 'ERR_WORKER_INIT_FAILED'
}

But when I run the test it is failing.

bash-4.2$ ./node bar 10000
internal/worker.js:192
      this.emit('error', new errorCodes[customErr]());
                         ^

TypeError: errorCodes[customErr] is not a constructor
    at Worker.[kOnExit] (internal/worker.js:192:26)
    at Worker.<computed>.onexit (internal/worker.js:140:62)

Right now I am stuck here.

[HarshithaKP]

@addaleax, thanks again for following up and offer to help!
In the above test case, bar contains creation of a number of workers that will fail eventually due to lack of resource. I would expect an error stack similar to above, but passed to the worker’s error callback, not thrown uncaught the way it did.

$ cat bar.js

const { Worker } = require('worker_threads');

var er = 0
var ex = 0
for (let i = 0; i < +process.argv[2]; ++i) {
  const worker = new Worker(
    'require(\'worker_threads\').parentPort.postMessage(2 + 2)',
    { eval: true });
  worker.on('error', (a, b, c) => {
    console.log(`${er++} err'd!`)
    console.log(a)
    console.log(b)
    console.log(c)
  })
  worker.on('exit', () => {
    console.log(`${ex++} exited.`)
  })
}

[HarshithaKP]

The changes were resulting in node_worker_assertion.js test failure. Fixed it in one more commit.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/29229/

[addaleax]

Landed in 2d3717a 🎉

@HarshithaKP Thanks for persisting and bringing this over the finish line!