AsyncEventBus subscribing two callbacks for the same event results in only one being called twice

[dbrignoli]

• Nim Compiler Version 1.6.4
• chronos-3.0.11 (installed via nimble)

import chronos

type
  Payload = object
    test: int

let eventBus = newAsyncEventBus()

proc eventEV1(bus: AsyncEventBus, payload: EventPayload[Payload]) {.async.} =
  echo "eventEV1"

proc eventEV2(bus: AsyncEventBus, payload: EventPayload[Payload]) {.async.} =
  echo "eventEV2"

proc main() {.async.} =
  var payload: Payload
  discard eventBus.subscribe("EV", eventEV1)
  discard eventBus.subscribe("EV", eventEV2)
  eventBus.emit("EV", payload)
  await sleepAsync(1000)

waitFor main()

Expected output:

eventEV1
eventEV2

Actual output:

eventEV2
eventEV2

[dbrignoli]

using capture from sugar in proc emit[T]() like so:

      capture subscriber_copy:
        callSoon(proc (udata: pointer) = subscriber_copy.cb(bus, event, subscriber_copy, payload))

makes the test code from my previous comment output the expected text.

[Menduist]

Hi, with which GC & nim version are you hitting this? EDIT: Just saw the version 1.6.4

[Menduist]

Thanks for reporting! I have opened an PR integrating your fix, #271

[dbrignoli]

Great, thank you @Menduist! I also tried to capture subscriber directly but found it didn't work. It's probably caused by an issue with the for loop macro implementation.