ckdb - track the number of db connections

src/ckdb.c

@@ -453,6 +453,11 @@ char *by_default = "code";
 char *inet_default = "127.0.0.1";
 char *id_default = "42";
 
+// Emulate a list for lock checking
+K_LIST *pgdb_free;
+// Count of db connections
+int pgdb_count;
+
 // NULL or poolinstance must match
 const char *sys_poolinstance = NULL;
 // lock for accessing all mismatch variables
@@ -2281,6 +2286,9 @@ static void alloc_storage()
 	userinfo_store = k_new_store(userinfo_free);
 	userinfo_root = new_ktree(NULL, cmp_userinfo, userinfo_free);
 
+	// Emulate a list for lock checking
+	pgdb_free = k_lock_only_list("PGDB");
+
 #if LOCK_CHECK
 	DLPRIO(seqset, 91);
 
@@ -2343,6 +2351,7 @@ static void alloc_storage()
 	DLPRIO(workers, PRIO_TERMINAL);
 	DLPRIO(ips, PRIO_TERMINAL);
 	DLPRIO(replies, PRIO_TERMINAL);
+	DLPRIO(pgdb, PRIO_TERMINAL);
 
 	DLPCHECK();
 

src/ckdb.h

@@ -58,7 +58,7 @@
 
 #define DB_VLOCK "1"
 #define DB_VERSION "1.0.7"
-#define CKDB_VERSION DB_VERSION"-2.714"
+#define CKDB_VERSION DB_VERSION"-2.715"
 
 #define WHERE_FFL " - from %s %s() line %d"
 #define WHERE_FFL_HERE __FILE__, __func__, __LINE__
@@ -445,6 +445,10 @@ extern char *by_default;
 extern char *inet_default;
 extern char *id_default;
 
+// Emulate a list for lock checking
+extern K_LIST *pgdb_free;
+extern int pgdb_count;
+
 // Number of seconds per poolinstance message for run
 #define POOLINSTANCE_MSG_EVERY 30
 

src/ckdb_cmd.c

@@ -7728,6 +7728,15 @@ static char *cmd_query(__maybe_unused PGconn *conn, char *cmd, char *id,
 			 "ESM", FLDSEP, "", FLDSEP);
 		APPEND_REALLOC(buf, off, len, tmp);
 
+		ok = true;
+	} else if (strcasecmp(request, "pg") == 0) {
+		K_RLOCK(pgdb_free);
+		snprintf(tmp, sizeof(tmp), "connections=%d%c",
+			 pgdb_count, FLDSEP);
+		APPEND_REALLOC(buf, off, len, tmp);
+		K_RUNLOCK(pgdb_free);
+		rows++;
+
 		ok = true;
 #if 0
 	} else if (strcasecmp(request, "transfer") == 0) {

src/ckdb_dbio.c

@@ -434,6 +434,9 @@ bool _CKPQConn(PGconn **conn, WHERE_FFL_ARGS)
 	if (*conn == NULL) {
 		LOGDEBUG("%s(): connecting", __func__);
 		*conn = dbconnect();
+		K_WLOCK(pgdb_free);
+		pgdb_count++;
+		K_WUNLOCK(pgdb_free);
 		return true;
 	}
 	return false;
@@ -445,6 +448,9 @@ bool _CKPQDisco(PGconn **conn, bool conned, WHERE_FFL_ARGS)
 		LOGDEBUG("%s(): disco", __func__);
 		PQfinish(*conn);
 		*conn = NULL;
+		K_WLOCK(pgdb_free);
+		pgdb_count--;
+		K_WUNLOCK(pgdb_free);
 	}
 	return false;
 }