Osmocom Libraries » libosmocore

src/stat_item.c:osmo_stat_item_get_next() is supposed to return the amount of skipped values (see comment describing the function). But this is broken if there is more than one osmo_stat_item involved.

• stats are tracked for a list of osmo_stat_item_group, of which each has a list of osmo_stat_item, of which each has an array of values.
• The logic to find skipped entries is based on the global current_stat_item_index in stats.c and global_value_id in stats_item.c. Both are shared for all values, items, groups.
• Whenever a new value is added to any of the osmo_stat_item's values, global_value_id gets increased by one and the id gets assigned to that value.
• current_stat_item_index stores the last ID that was reported to all attached reporters (e.g. the log reporter, or a statsd instance).
• In osmo_stat_item_get_next, the diff from current_stat_item_index to the IDs of the first value that is lower than current_stat_item_index, is assumed to be the number of skipped stat values. But if there is more than one osmo_stat_item, the ID may increase by more than one between the values.

I'm working on a fix.