When use vm2 in worker_threads, is it possible to share a NodeVM instance between workers?

问题

I am using worker_threads and vm2 to implement a serverless-like thing, but I cannot get a NodeVM instance in the main thread and then pass through workData(because of worker_threads's limitation), so I can only new NodeVM in a worker thread per request, inside which I cannot reuse a vm instance and the cost hurts.

The new NodeVM() takes 200 ~ 450 ms to finish, so I wish to pre-init a reusable instance.

const w = new Worker(`
    (async () => {
      const { workerData, parentPort } = require('worker_threads');
      const { NodeVM } = require('vm2');
      const t = Date.now();
      const vm = new NodeVM({ // cost 200 ~ 450 ms
        console: 'inherit',
        require: {
          external: [ 'request-promise', 'lodash' ],
          builtin: [],
          import: [ 'request-promise', 'lodash' ], // faster if added
        },
      });
      console.log('time cost on new NodeVM:', Date.now() - t);
      const fnn = vm.run(workerData.code, workerData.filename);
      console.log('time cost by initializing vm:', Date.now() - t);
      try {
        const ret = await fnn(workerData.params);

        parentPort.postMessage({
          data: typeof ret === 'string' ? ret : JSON.stringify(ret),
        });
      } catch (e) {
        parentPort.postMessage({
          err: e.toString(),
        });
      }
      console.log('----worker donex');
    })();
  `,
  {
    workerData: {
      params,
      code,
      dirname: __dirname,
      filename: `${__dirname}/faasVirtual/${fn}.js`,
    },
    eval: true,
  });

Can anybody give me some advice?

Thanks a lot.

回答1:

I've decided to prohibit external module import. Because require is internally readFileSync, which costs most of the time, and the http module within node itself can be used to replace request-promise.

After comment out external option, the average time cost for init is roughly 10+ms, which is acceptable for now.

But if worker_threads can clone function object through workerData, it would be more efficient.

来源：https://stackoverflow.com/questions/54229230/when-use-vm2-in-worker-threads-is-it-possible-to-share-a-nodevm-instance-betwee