X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-metadata.cpp;h=3a2eb5ca2446b5042884d5917c468df281cb3bf5;hb=f149493493fbd8a3efa4748832c03278c96c38ca;hp=d08cb40ae7f10ade8a8add223997a2e7aa884bed;hpb=e4589ae2396a53ed0b17251616694afeefba2986;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/ust-metadata.cpp b/src/bin/lttng-sessiond/ust-metadata.cpp
index d08cb40ae..3a2eb5ca2 100644
--- a/src/bin/lttng-sessiond/ust-metadata.cpp
+++ b/src/bin/lttng-sessiond/ust-metadata.cpp
@@ -15,6 +15,7 @@
 #include <inttypes.h>
 #include <common/common.hpp>
 #include <common/time.hpp>
+#include <vector>
 
 #include "ust-registry.hpp"
 #include "ust-clock.hpp"
@@ -22,10 +23,14 @@
 
 #define NR_CLOCK_OFFSET_SAMPLES		10
 
+namespace {
 struct offset_sample {
-	int64_t offset;			/* correlation offset */
-	uint64_t measure_delta;		/* lower is better */
+	/* correlation offset */
+	int64_t offset;
+	/* lower is better */
+	uint64_t measure_delta;
 };
+} /* namespace */
 
 static
 int _lttng_field_statedump(struct ust_registry_session *session,
@@ -841,6 +846,16 @@ int ust_metadata_event_statedump(struct ust_registry_session *session,
 	if (chan->chan_id == -1U)
 		return 0;
 
+	/*
+	 * We don't want to output an event's metadata before its parent
+	 * stream's metadata.  If the stream's metadata hasn't been output yet,
+	 * skip this event.  Its metadata will be output when we output the
+	 * stream's metadata.
+	 */
+	if (!chan->metadata_dumped || event->metadata_dumped) {
+		return 0;
+	}
+
 	ret = lttng_metadata_printf(session,
 		"event {\n"
 		"	name = \"%s\";\n"
@@ -895,12 +910,16 @@ end:
 
 /*
  * Should be called with session registry mutex held.
+ *
+ * RCU read lock must be held by the caller.
  */
 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 		struct ust_registry_channel *chan)
 {
 	int ret;
 
+	ASSERT_RCU_READ_LOCKED();
+
 	/* Don't dump metadata events */
 	if (chan->chan_id == -1U)
 		return 0;
@@ -951,6 +970,31 @@ int ust_metadata_channel_statedump(struct ust_registry_session *session,
 	/* Flag success of metadata dump. */
 	chan->metadata_dumped = 1;
 
+	/*
+	 * Output the metadata of any existing event.
+	 *
+	 * Sort the events by id.  This is not necessary, but it's nice to have
+	 * a more predictable order in the metadata file.
+	 */
+	std::vector<ust_registry_event *> events;
+	{
+		cds_lfht_iter event_iter;
+		ust_registry_event *event;
+		cds_lfht_for_each_entry(chan->events->ht, &event_iter, event,
+				node.node) {
+			events.push_back(event);
+		}
+	}
+
+	std::sort(events.begin(), events.end(),
+		[] (ust_registry_event *a, ust_registry_event *b) {
+			return a->id < b->id;
+		});
+
+	for (ust_registry_event *event : events) {
+		ust_metadata_event_statedump(session, chan, event);
+	}
+
 	return 0;
 }