Create task to send batched messages and handle confirmations with he…

…lper.

docs/source/rabbitmq-tutorial/7-publisher-confirms.rst

@@ -101,6 +101,19 @@ One drawback is that we do not know exactly what went wrong in case of failure,
 to log something meaningful or to re-publish the messages.
 And this solution is still synchronous, so it blocks the publishing of messages.
 
+.. note::
+
+   To initiate message sending asynchronously, a task is created with :code:`asyncio.create_task`, so the execution of our function
+   is handled by the event-loop.
+   The :code:`await asyncio.sleep(0)` is required to make the event loop switch to our coroutine.
+   Any :code:`await` would have sufficed, though.
+   Using :code:`async for` with an :code:`async` generator also requires the generator to yield control flow with :code:`await` for message
+   sending to be initiated.
+
+   Without the task and the :code:`await` the message sending would only be initiated with the :code:`asyncio.gather` call.
+   For some applications this behaivior might be acceptable.
+
+
 Strategy #3: Handling Publisher Confirms Asynchronously
 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 

docs/source/rabbitmq-tutorial/examples/7-publisher-confirms/publish_batches.py

@@ -25,12 +25,17 @@ async def main() -> None:
         # Sending the messages
         for msg in get_messages_to_publish():
             outstanding_messages.append(
-                channel.default_exchange.publish(
-                    Message(msg),
-                    routing_key=queue.name,
-                    timeout=5.0,
+                asyncio.create_task(
+                    channel.default_exchange.publish(
+                        Message(msg),
+                        routing_key=queue.name,
+                        timeout=5.0,
+                    )
                 )
             )
+            # Yield control flow to event loop, so message sending is initiated:
+            await asyncio.sleep(0)
+
             if len(outstanding_messages) == batchsize:
                 await asyncio.gather(*outstanding_messages)
                 outstanding_messages.clear()