child_process: add fast path for spawn

[ronag]

No description provided.

[ronag]

https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1661/

[ronag]

Unrelated CI benchmark failure...

10:42:39 ../src/node_config_file.h:35:32: error: ‘simdjson’ has not been declared
10:42:39    35 |   ParseResult ParseNodeOptions(simdjson::ondemand::object* node_options_object);
10:42:39       |                                ^~~~~~~~
10:42:39 ../src/node_config_file.h:35:58: error: expected ‘,’ or ‘...’ before ‘*’ token
10:42:39    35 |   ParseResult ParseNodeOptions(simdjson::ondemand::object* node_options_object);
10:42:39       |                                                          ^
10:42:39 make[1]: *** [libnode.target.mk:510: /w/bnch-comp/node/out/Release/obj.target/libnode/src/node.o] Error 1

Who's a good ping on that? @nodejs/benchmarking

[atlowChemi]

ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1661

https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/1662/

                                   confidence improvement accuracy (*)   (**)  (***)
child_process/spawn-echo.js n=1000        ***     16.87 %       ±1.27% ±1.69% ±2.21%

Be aware that when doing many comparisons the risk of a false-positive
result increases. In this case, there are 1 comparisons, you can thus
expect the following amount of false-positive results:
  0.05 false positives, when considering a   5% risk acceptance (*, **, ***),
  0.01 false positives, when considering a   1% risk acceptance (**, ***),
  0.00 false positives, when considering a 0.1% risk acceptance (***)

[aduh95]

nit: I find the commit message a bit confusing, our guidelines asks for the first word to be an imperative verb, which "spawn" is, but is not used as such here. My suggestion would be child_process: add fast path for `spawn`

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/65426/

[ronag]

I have to admit I don't actually understand what normalizeSpawnArguments does in terms of the env variables... seems a bit suspect.

[ronag]

In particular what does this do? Seems to always process process.env. Which seems rather wasteful?

  const env = options.env || process.env;
  const envPairs = [];

  // process.env.NODE_V8_COVERAGE always propagates, making it possible to
  // collect coverage for programs that spawn with white-listed environment.
  copyProcessEnvToEnv(env, 'NODE_V8_COVERAGE', options.env);

  if (isZOS) {
    // The following environment variables must always propagate if set.
    copyProcessEnvToEnv(env, '_BPXK_AUTOCVT', options.env);
    copyProcessEnvToEnv(env, '_CEE_RUNOPTS', options.env);
    copyProcessEnvToEnv(env, '_TAG_REDIR_ERR', options.env);
    copyProcessEnvToEnv(env, '_TAG_REDIR_IN', options.env);
    copyProcessEnvToEnv(env, '_TAG_REDIR_OUT', options.env);
    copyProcessEnvToEnv(env, 'STEPLIB', options.env);
    copyProcessEnvToEnv(env, 'LIBPATH', options.env);
    copyProcessEnvToEnv(env, '_EDC_SIG_DFLT', options.env);
    copyProcessEnvToEnv(env, '_EDC_SUSV3', options.env);
  }

  let envKeys = [];
  // Prototype values are intentionally included.
  for (const key in env) {
    ArrayPrototypePush(envKeys, key);
  }

  if (process.platform === 'win32') {
    // On Windows env keys are case insensitive. Filter out duplicates,
    // keeping only the first one (in lexicographic order)
    const sawKey = new SafeSet();
    envKeys = ArrayPrototypeFilter(
      ArrayPrototypeSort(envKeys),
      (key) => {
        const uppercaseKey = StringPrototypeToUpperCase(key);
        if (sawKey.has(uppercaseKey)) {
          return false;
        }
        sawKey.add(uppercaseKey);
        return true;
      },
    );
  }

  for (const key of envKeys) {
    const value = env[key];
    if (value !== undefined) {
      validateArgumentNullCheck(key, `options.env['${key}']`);
      validateArgumentNullCheck(value, `options.env['${key}']`);
      ArrayPrototypePush(envPairs, `${key}=${value}`);
    }
  }