DTD is sometimes not terminated correctly

[DanTup]

I've seen this a few times today after closing VS Code - the process isn't being shut down.

[DanTup]

This might be something in the daemon... I can repro this with the following code:

for (let i = 0; i < 10; i++) {
	const process = safeSpawn(undefined, "C:\\Dev\\Tools\\Dart\\Nightly\\bin\\dart.exe", [
		"tooling-daemon",
		"--machine",
	], {});

	console.log(`    Spawned PID: ${process.pid}`);

	process.stdout.on("data", (data: Buffer | string) => console.log(data));
	process.stderr.on("data", (data: Buffer | string) => console.error(data));
	process.on("exit", (code, signal) => console.warn(code, signal));
	process.on("error", (error) => console.error(error));

	await new Promise((resolve) => setTimeout(resolve, 500));

	process.kill();
	console.log(`    Killed PID: ${process.pid}`);
}

@CoderDake FYI - I'll try to repro from Dart to eliminate NodeJS weirdness.

[DanTup]

Of course it doesn't happen from the equivalent Dart code 😬 I'll keep looking! My money is going to be on shell we're using to spawn it not passing across the signal. This is why many of our tools advertise pids during startup... I think maybe we should do the same here.

[DanTup]

Yep, enabling the shell on Windows triggers it from Dart too:

import 'dart:convert';
import 'dart:io';

Future<void> main() async {
  final vmPath = Platform.resolvedExecutable;
  final args = [
    'tooling-daemon',
    '--machine',
  ];

  for (int i = 0; i < 30; i++) {
    final proc = await Process.start(vmPath, args, runInShell: true);
    print('Started ${proc.pid}');
    proc.stdout.transform(utf8.decoder).listen(print);
    proc.stderr.transform(utf8.decoder).listen(print);

    await Future.delayed(const Duration(milliseconds: 100));
    proc.kill();
    print('Killed ${proc.pid}');
  }
}

The PIDs being printed here are the shell, not the Dart process.

@CoderDake any objections to putting the real PID inside the initial json?

{"pid":12345,"tooling_daemon_details":{"uri":"ws://127.0.0.1:53841/","trusted_client_secret":"apGxfEl4bIDvrYxR"}}
 ^^^^^

We do similar in DevTools server and other tools:

• flutter/devtools@16ecf5c
• Include PID in --machine output flutter/devtools#402

[DanTup]

For now, I'm going to bypass the shell for DTD - we know we don't need it. I've opened #5018 to see if we can bypass shells in other places to reduce the chance of possible leaving orphaned processes.