Crashing with assertion/segmentation fault/bus error

Issuing new (require('midi')).input().getPortCount(); in a node repl gives me one of the following:

Assertion failed: (0), function uv_close, file ../deps/uv/src/unix/core.c, line 165. Abort trap: 6

Segmentation fault: 11

Bus error 10

But only after using the repl for a while. Easiest way for me to reproduce is by repeatedly pressing enter some 30 times.

Can reproduce on Mac running OS X 10.11.2, node v5.4.0 and on a Raspberry Pi running Linux 4.1.13, node v4.2.1.

[ryanlaws]

@grav Here’s an example, hacked down a bit so it only depends on node-midi, child_process, and segfault-handler.

midispawn.js

const cp = require('child_process');
const exitEvents = ['close', 'disconnect', 'error', 'exit'];

let inPortNumber = 1, outPortNumber = 1;
let outProcess = mountOutput(outPortNumber);
let inProcess = mountInput(inPortNumber, outProcess);

function mountInput(portNumber, outProcess) {
  let inProcess = cp.fork('./midiinchild.js', [portNumber]);

  inProcess.on('message', (m) => {
    m.thing = 'inProcess';
    outProcess.send(m);
  });

  exitEvents.forEach((eventType) => {
    inProcess.on(eventType, () => {
      console.log("inProcess sent (" + eventType + ")");
      outProcess.send({ method: 'crash', thing: 'inProcess' });
      mountInput(portNumber, outProcess);
    });
  });

  return inProcess;
}

function mountOutput(portNumber) {
  let outProcess = cp.fork('./midioutchild.js', [portNumber]);

  exitEvents.forEach((eventType) => {
    outProcess.on(eventType, () => {
      console.log("outProcess sent (" + eventType + ")");
      process.exit();
    });
  });

  return outProcess;
}

midiinchild.js

const midi = require('midi'), midiInput = new midi.input();
const SegfaultHandler = require('segfault-handler');

midiInput.on('message', (dt, msg) => {
  process.send({ method: 'midi', bytes: msg });
});

midiInput.openPort(Number.parseInt(process.argv[2], 10));

process.send({ method: 'ready' });

SegfaultHandler.registerHandler('incrash.log', (signal, address, stack) => {
  console.log({ signal, address, stack });
});

midioutchild.js

const midi = require('midi'), midiOutput = new midi.output();
const SegfaultHandler = require('segfault-handler');

let crashedThing = null;

midiOutput.openPort(Number.parseInt(process.argv[2], 10));

process.on('message', (m) => {
  if (m.method === 'crash' && !crashedThing) {
    crashedThing = m.thing;
    console.log(crashedThing + " crashed!");
    return;
  }

  if (m.method === 'ready' && m.thing === crashedThing) {
    console.log(crashedThing + "is back online!");
    crashedThing = null;
    return;
  }

  if (m.method === 'midi') {
    console.log("Received MIDI from input. Data: " + m.bytes.join(','));
    midiOutput.sendMessage(m.bytes);
  }
});

SegfaultHandler.registerHandler('outcrash.log', function(signal, address, stack) {
  console.log({signal, address, stack});
});

[justinlatimer]

Happy days. Reopen if it comes back!