LTTng » LTTng-tools

Currently:

• lttng_enable_event() calls lttng_enable_event_with_exclusions(), passing no filter expression and no event name exclusion patterns.
• lttng_enable_event_with_filter() calls lttng_enable_event_with_exclusions(), passing no event name exclusion patterns.

This means that if you want to enable a recording event rule described with a filter expression and event name exclusion patterns, you need to:

1. Get the filter expression from its descriptor with lttng_event_get_filter_expression().
2. Build an array of event name exclusion patterns, getting them from its descriptor with lttng_event_get_exclusion_name_count() and lttng_event_get_exclusion_name().
3. Call lttng_enable_event_with_exclusions().

This is what you would need to do to blindly enable a disabled recording event rule of which the descriptor comes from lttng_list_events().

lttng_enable_event() and lttng_enable_event_with_filter() could do the steps above for you, if this doesn't break any backward compatibility.