grpc-node: Does not support multiple threads

Problem description

If I try to use the grpc library in multiple threads, I get Error: Module did not self-register. exception.

Reproduction steps

Run with node --experimental-worker:

import { isMainThread, Worker } from 'worker_threads';

if (isMainThread) {
  require('grpc');
  new Worker(__filename);
} else {
  require('grpc'); // throws: `Error: Module did not self-register.` 
}

Environment

• OS name, version and architecture: Windows or Linux
• Node version: 10.12.0
• Node installation method: nvm
• Package name and version: grpc@1.13.1

Additional context

Related issue in node repo with more info: https://github.com/nodejs/node/issues/21783

Proposed fix: https://github.com/nodejs/node/issues/21783#issuecomment-429637117 (The module has to be context-aware.)

This has been already fixed at least in these projects:

• node-lzo#10
• iltorb#78

Full stack trace:

Error: Module did not self-register.
    at Object.Module._extensions..node (internal/modules/cjs/loader.js:717:18)
    at Module.load (internal/modules/cjs/loader.js:598:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:537:12)
    at Function.Module._load (internal/modules/cjs/loader.js:529:3)
    at Module.require (internal/modules/cjs/loader.js:636:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (...\node_modules\grpc\src\grpc_extension.js:32:13)
    at Module._compile (internal/modules/cjs/loader.js:688:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:699:10)
    at Module.load (internal/modules/cjs/loader.js:598:32)