Will block for at most \p timeout_ms milliseconds.
@remark An application should make sure to call consumer_poll() at regular
intervals, even if no messages are expected, to serve any
queued callbacks waiting to be called. This is especially
important when a rebalance_cb has been registered as it needs
to be called and handled properly to synchronize internal
consumer state.
@returns A message object which is a proper message if \p ->err is
RD_KAFKA_RESP_ERR_NO_ERROR, or an event or error for any other
value.
@brief Poll the consumer for messages or events.
Will block for at most \p timeout_ms milliseconds.
@remark An application should make sure to call consumer_poll() at regular intervals, even if no messages are expected, to serve any queued callbacks waiting to be called. This is especially important when a rebalance_cb has been registered as it needs to be called and handled properly to synchronize internal consumer state.
@returns A message object which is a proper message if \p ->err is RD_KAFKA_RESP_ERR_NO_ERROR, or an event or error for any other value.
@sa rd_kafka_message_t