tdl: Napi::Error

In version 5.1.0 I added pause() and resume() functions. You can use multiple clients, but not at the same time. Example:

const client1 = new Client(...)
const client2 = new Client(...)

;(async () => {
  await client1.connect()
  await client1.login(...)

  console.log('Client 1', await client1.invoke({ _: 'getMe' }))
  client1.pause()

  await client2.connect()
  await client2.login(...)

  console.log('Client 2', await client2.invoke({ _: 'getMe' }))
  client2.pause()

  client1.resume()
  console.log('Client 1 again', await client1.invoke({ _: 'getMe' }))
})()

@denisakov You need tdl v6 (npm install tdl@6.0.0-rc.2). tdl-tdlib-addon is mostly just a proof-of-concept, and it most likely won’t work from npm. You can copy it from the repository into your app.

Also there is no big profit in using it, as it limited to libuv threadpool (better implementation could create a thread per client without using libuv threadpool). You can just create a process for each client instance (described above in the issue). Otherwise someone need to write tdlib-client-actor<->node.js binding.

It turned out that shouldn't be called simultaneously from two different threads is applicable only for a fixed client:

Different instances are completely Independent. You shouldn’t run receive simultameously only for a fixed client.

You should consume result of td_json_client_receive and copy it somewhere or parse before next call to td_json_client_receive in the same thread. There are no other restrictions.

So you can use multiple clients with node addon (addon example), but not with ffi, as it requires modification of node-ffi (or node-ffi-napi) library code. But there is a limitation, every td_receive call consumes a thread in libuv threadpool, you can’t use more than UV_THREADPOOL_SIZE+1 clients in parallel (by default UV_THREADPOOL_SIZE is 4, maximum is 128). Ideally ClientActor should be used instead of td_json_client somehow.

I’ll update my code to use tdl v.5 and extract the multi process client as a reusable library.

I added a wrapper around tdl that forks and transfers updates/event/input requests via process messages and it all started to work reliably. 5 clients start simultaneously without problems. I can’t share it as I built it application specific rather than reusable (shame on me) but it was pretty straightforward.

@Bannerets Honestly I believe that it should go into the library itself (or, the ff-napi should be replaced with something else), or at the very least it should be documented in README that you will need to fork in order to maintain several telegram connections.

I am having this too. If I start 3 clients at once it always crashes. If I start them one after another it works but then eventually it will crash anyway (the more clients the faster it fails).

ffi-napi documentation says: “It is recommended to avoid any multi-threading usage of this library if possible.” so chances are it’s not really possible to avoid other than going multi-process.