What’s new in barectf 3.1?

Thanks to a contribution from Jon Lamb, the CTF packets which a barectf-generated tracer writes can contain an automatically-incremented sequence number in their context field. This is useful for a trace reader/analyzer to detect packets lost at transport time, for example. Babeltrace 2 supports such a packet context field out of the box.

To enable this new packet feature, set the sequence-number-field-type property of the packet features object, for example:

Example 1. Data stream type object with an enabled packet sequence number field type feature.

$features:
  packet:
    sequence-number-field-type: true
event-record-types:
  # ...

This feature is disabled (false) by default to avoid breaking changes.

The packet closing function automatically increments the current packet sequence number of the barectf context. Within platform code, you can get the current value with barectf_packet_sequence_number().