message: Emit credit for two cycles instead of one
diff: @@ -98,12 +98,16 @@ void inbound_path::emit_ack_open(local_actor* self, actor_addr rebind_from) {
  void inbound_path::emit_ack_batch(local_actor* self, long queued_items,
  timespan cycle, timespan complexity) {
  + CAF_LOG_TRACE(CAF_ARG(queued_items) << CAF_ARG(cycle) << CAF_ARG(complexity));
  auto x = stats.calculate(cycle, complexity);
  - auto credit = std::max(x.max_throughput - (assigned_credit - queued_items),
  + // Hand out enough credit to fill our queue for 2 cycles.
  + auto credit = std::max((x.max_throughput * 2)
  + - (assigned_credit - queued_items),
  0l);
  auto batch_size = static_cast<int32_t>(x.items_per_batch);
  if (credit != 0)
  assigned_credit += credit;
  + CAF_LOG_DEBUG(CAF_ARG(credit) << CAF_ARG(batch_size));
  unsafe_send_as(self, hdl,
  make<upstream_msg::ack_batch>(slots.invert(), self->address(),
  static_cast<int32_t>(credit),
  