stat_item: make value ids item specific
Fix counting of values missed because of FIFO overflow in
osmo_stat_item_get_next(), by assigning a new item value id effectively
as item->value[n + 1].id = item->value[n].id + 1, instead of increasing
a global_value_id that is shared between all items and groups. With
global_value_id, the count of values missed was wrong for one item, as
soon as a new value was added to another item.
This partially reverts b27b352e ("stats: Use a global index for stat
item values") from 2015, right after stats was added to libosmocore. It
was supposed to make multiple readers (reporters) possible, which could
read independently from stat_item (and later added comments explain it
like that). But this remained unused, stats has implemented multiple
reporters by reading all stat_items once and sending the same data to
all enabled reporters. The patch caused last_value_index in struct
osmo_stat_item to always remain at -1.
Replace this unused last_value_index with stats_next_id, so stats can
store the item-specific next_id in the struct again. It appears that
stats is the only direct user of osmo_stat_item, but if there are
others, they can bring their own item-specific next_id: functions in
stat_item.c still accept a next_id argument.
Related: OS#5088
Change-Id: Ie65dcdf52c8fc3d916e20d7f0455f6223be6b64f
diff --git a/src/stats.c b/src/stats.c
index 88b733f..91cf839 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -107,7 +107,6 @@
static LLIST_HEAD(osmo_stats_reporter_list);
static void *osmo_stats_ctx = NULL;
static int is_initialised = 0;
-static int32_t current_stat_item_next_id = 0;
static struct osmo_stats_config s_stats_config = {
.interval = STATS_DEFAULT_INTERVAL,
@@ -236,12 +235,27 @@
talloc_free(srep);
}
+static int osmo_stats_discard_item(struct osmo_stat_item_group *statg, struct osmo_stat_item *item, void *sctx_)
+{
+ return osmo_stat_item_discard(item, &item->stats_next_id);
+}
+
+static int osmo_stats_discard_group(struct osmo_stat_item_group *statg, void *sctx_)
+{
+ return osmo_stat_item_for_each_item(statg, &osmo_stats_discard_item, NULL);
+}
+
+static int osmo_stats_discard_all()
+{
+ return osmo_stat_item_for_each_group(&osmo_stats_discard_group, NULL);
+}
+
/*! Initilize the stats reporting module; call this once in your program
* \param[in] ctx Talloc context from which stats related memory is allocated */
void osmo_stats_init(void *ctx)
{
osmo_stats_ctx = ctx;
- osmo_stat_item_discard_all(¤t_stat_item_next_id);
+ osmo_stats_discard_all();
is_initialised = 1;
start_timer();
@@ -694,18 +708,17 @@
struct osmo_stat_item_group *statg, struct osmo_stat_item *item, void *sctx_)
{
struct osmo_stats_reporter *srep;
- int32_t next_id = current_stat_item_next_id;
int32_t value;
int have_value;
- have_value = osmo_stat_item_get_next(item, &next_id, &value) > 0;
+ have_value = osmo_stat_item_get_next(item, &item->stats_next_id, &value) > 0;
if (!have_value) {
/* Send the last value in case a flush is requested */
value = osmo_stat_item_get_last(item);
} else {
int32_t next_val;
/* If we have multiple values only send the max */
- while (osmo_stat_item_get_next(item, &next_id, &next_val) > 0)
+ while (osmo_stat_item_get_next(item, &item->stats_next_id, &next_val) > 0)
value = OSMO_MAX(value, next_val);
}
@@ -798,7 +811,7 @@
osmo_stat_item_for_each_group(osmo_stat_item_group_handler, NULL);
/* global actions */
- osmo_stat_item_discard_all(¤t_stat_item_next_id);
+ osmo_stats_discard_all();
flush_all_reporters();
TRACE(LIBOSMOCORE_STATS_DONE());