X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fust-metadata.cpp;h=3a2eb5ca2446b5042884d5917c468df281cb3bf5;hb=f149493493fbd8a3efa4748832c03278c96c38ca;hp=7e6b1aba0810933f725a32b64986d8c29e9f1e82;hpb=a13748e9cfc3a9544d7195bcb2037e212dcec829;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/ust-metadata.cpp b/src/bin/lttng-sessiond/ust-metadata.cpp
index 7e6b1aba0..3a2eb5ca2 100644
--- a/src/bin/lttng-sessiond/ust-metadata.cpp
+++ b/src/bin/lttng-sessiond/ust-metadata.cpp
@@ -13,23 +13,24 @@
 #include <limits.h>
 #include <unistd.h>
 #include <inttypes.h>
-#include <common/common.h>
-#include <common/time.h>
+#include <common/common.hpp>
+#include <common/time.hpp>
+#include <vector>
 
-#include "ust-registry.h"
-#include "ust-clock.h"
-#include "ust-app.h"
-
-#ifndef max_t
-#define max_t(type, a, b)	((type) ((a) > (b) ? (a) : (b)))
-#endif
+#include "ust-registry.hpp"
+#include "ust-clock.hpp"
+#include "ust-app.hpp"
 
 #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,
@@ -69,7 +70,7 @@ ssize_t metadata_reserve(struct ust_registry_session *session, size_t len)
 		char *newptr;
 
 		new_alloc_len =
-			max_t(size_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
+			std::max<size_t>(1U << get_count_order(new_alloc_len), old_alloc_len << 1);
 		newptr = (char *) realloc(session->metadata, new_alloc_len);
 		if (!newptr)
 			return -ENOMEM;
@@ -845,6 +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"
@@ -899,11 +910,15 @@ 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 = 0;
+	int ret;
+
+	ASSERT_RCU_READ_LOCKED();
 
 	/* Don't dump metadata events */
 	if (chan->chan_id == -1U)
@@ -922,37 +937,65 @@ int ust_metadata_channel_statedump(struct ust_registry_session *session,
 			"struct event_header_compact" :
 			"struct event_header_large");
 	if (ret) {
-		goto end;
+		return ret;
 	}
 
 	if (chan->ctx_fields) {
 		ret = lttng_metadata_printf(session,
 			"	event.context := struct {\n");
 		if (ret) {
-			goto end;
+			return ret;
 		}
 	}
 	ret = _lttng_context_metadata_statedump(session,
 		chan->nr_ctx_fields,
 		chan->ctx_fields);
 	if (ret) {
-		goto end;
+		return ret;
 	}
 	if (chan->ctx_fields) {
 		ret = lttng_metadata_printf(session,
 			"	};\n");
 		if (ret) {
-			goto end;
+			return ret;
 		}
 	}
 
 	ret = lttng_metadata_printf(session,
 		"};\n\n");
+	if (ret) {
+		return ret;
+	}
+
 	/* Flag success of metadata dump. */
 	chan->metadata_dumped = 1;
 
-end:
-	return ret;
+	/*
+	 * 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;
 }
 
 static