Not working with Worker thread.

[alexey11231]

If "onMessage" listener is called inside worker thread "Segmentation fault (core dumped) " occurs upon received can msg.

[sebi2k1]

You have a code snippet demonstrating the issue?

[alexey11231]

main:

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

if (isMainThread) {

  new Worker("./worker.js");

}  

worker.js:

 console.log("inThread")

var can = require('socketcan');

var channel = can.createRawChannel("can0", true);

channel.addListener("onMessage", function(msg) { console.log(msg); } );

channel.addListener("onMessage", channel.send, channel);

channel.start();`

errormsg:

FATAL ERROR: HandleScope::HandleScope Entering the V8 API without proper locking in place Aborted

Today on first run it gave that msg. Before and after it was throwing segmentation fault.

[juleq]

Seems one would need to litter the cpp code with multithreading protection to support workers.

Could you share why you want to use a worker? The whole node idea is to eleminate multithreading complexity by offering an event driven infrastructure and non-blocking async io. The thread pools node uses for that are hidden under the hood.

[alexey11231]

Nothing specific. I wanted to put can logic in separate worker, no good reason, just force of habit I guess. I was just playing around and noticed this, so I decided to inform you about it.

Btw great job with this(node-can), its quite useful. Ty !

[juleq]

These flowers go straight to @sebi2k1 💐.

I have a direct comparison implementing stuff with node in one instance and C# and its TPL in another. I really appreciate the simplicity that the event driven approach provides for IO heavy use cases.

Your feedback regarding workers is definitely a limitation to keep in mind. If someone is interested in making himself familiar with thread safety mechanisms of V8, it could be a nice little project to implement support. But I have used node-can quite extensively in a busy embedded system and I never felt lonely without the thread safety 😃.