Introduce stats msc.ran_peers.{total,active}

osmo_stats_init() was already being called despite no stats were being
used.

Change-Id: Ib01576036f34ac7f21c5bce0155b50932eb9b72a

include/osmocom/smlc/smlc_data.h

@@ -37,6 +37,7 @@ enum smlc_ctrl_node {
 	_LAST_CTRL_NODE_SMLC
 };
 
+/* rate_ctr */
 enum {
 	SMLC_CTR_BSSMAP_LE_RX_UDT_RESET,
 	SMLC_CTR_BSSMAP_LE_RX_UDT_RESET_ACK,
@@ -58,3 +59,9 @@ enum {
 	SMLC_CTR_BSSMAP_LE_TX_DT1_PERFORM_LOCATION_RESPONSE,
 	SMLC_CTR_BSSMAP_LE_TX_DT1_BSSLAP_TA_REQUEST,
 };
+
+/* osmo_stat */
+enum {
+	SMLC_STAT_LB_PEERS_TOTAL,
+	SMLC_STAT_LB_PEERS_ACTIVE,
+};

src/osmo-smlc/lb_peer.c

@@ -23,6 +23,7 @@
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/logging.h>
 #include <osmocom/core/fsm.h>
+#include <osmocom/core/stat_item.h>
 #include <osmocom/gsm/bssmap_le.h>
 #include <osmocom/sigtran/sccp_helpers.h>
 
@@ -57,6 +58,7 @@ static struct lb_peer *lb_peer_alloc(struct sccp_lb_inst *sli, const struct osmo
 	fi->priv = lbp;
 
 	llist_add(&lbp->entry, &sli->lb_peers);
+	osmo_stat_item_inc(osmo_stat_item_group_get_item(g_smlc->statg, SMLC_STAT_LB_PEERS_TOTAL), 1);
 
 	return lbp;
 }
@@ -303,6 +305,12 @@ static void lb_peer_st_wait_rx_reset_ack(struct osmo_fsm_inst *fi, uint32_t even
 	}
 }
 
+static void lb_peer_st_ready_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	if (prev_state != LB_PEER_ST_READY)
+		osmo_stat_item_inc(osmo_stat_item_group_get_item(g_smlc->statg, SMLC_STAT_LB_PEERS_ACTIVE), 1);
+}
+
 static void lb_peer_st_ready(struct osmo_fsm_inst *fi, uint32_t event, void *data)
 {
 	struct lb_peer *lbp = fi->priv;
@@ -377,6 +385,12 @@ static void lb_peer_st_ready(struct osmo_fsm_inst *fi, uint32_t event, void *dat
 	}
 }
 
+static void lb_peer_st_ready_onleave(struct osmo_fsm_inst *fi, uint32_t next_state)
+{
+	if (next_state != LB_PEER_ST_READY)
+		osmo_stat_item_dec(osmo_stat_item_group_get_item(g_smlc->statg, SMLC_STAT_LB_PEERS_ACTIVE), 1);
+}
+
 static int lb_peer_fsm_timer_cb(struct osmo_fsm_inst *fi)
 {
 	struct lb_peer *lbp = fi->priv;
@@ -384,10 +398,17 @@ static int lb_peer_fsm_timer_cb(struct osmo_fsm_inst *fi)
 	return 0;
 }
 
+/* struct lb_peer destructor: */
 static void lb_peer_fsm_cleanup(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause)
 {
 	struct lb_peer *lbp = fi->priv;
+
 	lb_peer_discard_all_conns(lbp);
+
+	if (lbp->fi->state == LB_PEER_ST_READY)
+		osmo_stat_item_dec(osmo_stat_item_group_get_item(g_smlc->statg, SMLC_STAT_LB_PEERS_ACTIVE), 1);
+	osmo_stat_item_dec(osmo_stat_item_group_get_item(g_smlc->statg, SMLC_STAT_LB_PEERS_TOTAL), 1);
+
 	llist_del(&lbp->entry);
 }
 
@@ -446,6 +467,8 @@ static const struct osmo_fsm_state lb_peer_fsm_states[] = {
 	[LB_PEER_ST_READY] = {
 		.name = "READY",
 		.action = lb_peer_st_ready,
+		.onenter = lb_peer_st_ready_onenter,
+		.onleave = lb_peer_st_ready_onleave,
 		.in_event_mask = 0
 			| S(LB_PEER_EV_RX_RESET)
 			| S(LB_PEER_EV_MSG_UP_CO_INITIAL)

src/osmo-smlc/smlc_data.c

@@ -54,6 +54,19 @@ static const struct rate_ctr_group_desc smlc_ctrg_desc = {
 	smlc_ctr_description,
 };
 
+static const struct osmo_stat_item_desc smlc_stat_item_description[] = {
+	[SMLC_STAT_LB_PEERS_TOTAL]	= { "lb_peers.total", "Total Lb peers seen since startup", OSMO_STAT_ITEM_NO_UNIT, 4, 0},
+	[SMLC_STAT_LB_PEERS_ACTIVE]	= { "lb_peers.active", "Currently active Lb peers", OSMO_STAT_ITEM_NO_UNIT, 4, 0},
+};
+
+static const struct osmo_stat_item_group_desc smlc_statg_desc = {
+	"smlc",
+	"serving mobile location center",
+	OSMO_STATS_CLASS_GLOBAL,
+	ARRAY_SIZE(smlc_stat_item_description),
+	smlc_stat_item_description,
+};
+
 struct smlc_state *smlc_state_alloc(void *ctx)
 {
 	struct smlc_state *smlc = talloc_zero(ctx, struct smlc_state);
@@ -61,5 +74,14 @@ struct smlc_state *smlc_state_alloc(void *ctx)
 	INIT_LLIST_HEAD(&smlc->subscribers);
 	INIT_LLIST_HEAD(&smlc->cell_locations);
 	smlc->ctrs = rate_ctr_group_alloc(smlc, &smlc_ctrg_desc, 0);
+
+	smlc->statg = osmo_stat_item_group_alloc(smlc, &smlc_statg_desc, 0);
+	if (!smlc->statg)
+		goto ret_free;
 	return smlc;
+
+ret_free:
+	rate_ctr_group_free(smlc->ctrs);
+	talloc_free(smlc);
+	return NULL;
 }

src/osmo-smlc/smlc_vty.c

@@ -23,6 +23,8 @@
 #include <osmocom/ctrl/control_vty.h>
 #include <osmocom/vty/logging.h>
 #include <osmocom/vty/misc.h>
+#include <osmocom/vty/stats.h>
+#include <osmocom/vty/vty.h>
 
 #include <osmocom/sigtran/osmo_ss7.h>
 #include <osmocom/sigtran/sccp_sap.h>
@@ -37,6 +39,7 @@ void smlc_vty_init(struct vty_app_info *vty_app_info)
 	osmo_talloc_vty_add_cmds();
 	ctrl_vty_init(vty_app_info->tall_ctx);
 	osmo_fsm_vty_add_cmds();
+	osmo_stats_vty_add_cmds();
 
 	osmo_ss7_vty_init_asp(vty_app_info->tall_ctx);
 	osmo_sccp_vty_init();