+/*
+ * To enable detailed tracing of barrier usage, including call stacks and
+ * timings, define BARRIER_TRACING here or in relevant TAGS. If also used
+ * with CLIB_DEBUG, timing will _not_ be representative of normal code
+ * execution.
+ *
+ */
+
+// #define BARRIER_TRACING 1
+
+/*
+ * Two options for barrier tracing output: syslog & elog.
+ */
+
+// #define BARRIER_TRACING_ELOG 1
+