From: Julien Desfossez <jdesfossez@efficios.com>
Date: Fri, 3 Jul 2015 21:48:27 +0000 (-0400)
Subject: Display discarded and lost events at destroy and stop
X-Git-Tag: v2.8.0-rc1~91
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=20fb9e0220fe6ca9d6fd52e4e3e41b898452a8f1

Display discarded and lost events at destroy and stop

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng/commands/destroy.c b/src/bin/lttng/commands/destroy.c
index 87231858f..ad181d7c4 100644
--- a/src/bin/lttng/commands/destroy.c
+++ b/src/bin/lttng/commands/destroy.c
@@ -23,6 +23,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <stdbool.h>
 
 #include "../command.h"
 
@@ -79,11 +80,13 @@ static int destroy_session(struct lttng_session *session)
 {
 	int ret;
 	char *session_name = NULL;
+	bool session_was_stopped;
 
 	ret = lttng_stop_tracing_no_wait(session->name);
 	if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) {
 		ERR("%s", lttng_strerror(ret));
 	}
+	session_was_stopped = ret == -LTTNG_ERR_TRACE_ALREADY_STOPPED;
 	if (!opt_no_wait) {
 		_MSG("Waiting for data availability");
 		fflush(stdout);
@@ -106,6 +109,13 @@ static int destroy_session(struct lttng_session *session)
 		} while (ret != 0);
 		MSG("");
 	}
+	if (!session_was_stopped) {
+		/*
+		 * Don't print the event and packet loss warnings since the user
+		 * already saw them when stopping the trace.
+		 */
+		print_session_stats(session->name);
+	}
 
 	ret = lttng_destroy_session_no_wait(session->name);
 	if (ret < 0) {
diff --git a/src/bin/lttng/commands/stop.c b/src/bin/lttng/commands/stop.c
index affc3985b..b3fff0753 100644
--- a/src/bin/lttng/commands/stop.c
+++ b/src/bin/lttng/commands/stop.c
@@ -155,6 +155,7 @@ static int stop_tracing(void)
 
 	ret = CMD_SUCCESS;
 
+	print_session_stats(session_name);
 	MSG("Tracing stopped for session %s", session_name);
 	if (lttng_opt_mi) {
 		ret = mi_print_session(session_name, 0);
diff --git a/src/bin/lttng/utils.c b/src/bin/lttng/utils.c
index ea9108fba..802e0971b 100644
--- a/src/bin/lttng/utils.c
+++ b/src/bin/lttng/utils.c
@@ -25,6 +25,7 @@
 #include <signal.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#include <inttypes.h>
 
 #include <common/error.h>
 #include <common/utils.h>
@@ -415,3 +416,66 @@ int print_missing_or_multiple_domains(unsigned int sum)
 
 	return ret;
 }
+
+/*
+ * Get the discarded events and lost packet counts.
+ */
+void print_session_stats(const char *session_name)
+{
+	int count, nb_domains, domain_idx, channel_idx;
+	struct lttng_domain *domains;
+	struct lttng_channel *channels;
+	uint64_t discarded_total = 0, lost_total = 0;
+
+	nb_domains = lttng_list_domains(session_name, &domains);
+	if (nb_domains < 0) {
+		goto end;
+	}
+	for (domain_idx = 0; domain_idx < nb_domains; domain_idx++) {
+		struct lttng_handle *handle = lttng_create_handle(session_name,
+				&domains[domain_idx]);
+
+		if (!handle) {
+			ERR("Failed to create session handle while printing session stats.");
+			goto end;
+		}
+
+		count = lttng_list_channels(handle, &channels);
+		for (channel_idx = 0; channel_idx < count; channel_idx++) {
+			int ret;
+			uint64_t discarded = 0, lost = 0;
+			struct lttng_channel *channel = &channels[channel_idx];
+
+			ret = lttng_channel_get_discarded_event_count(channel,
+					&discarded);
+			if (ret) {
+				ERR("Failed to retrieve discarded event count from channel %s",
+						channel->name);
+			}
+
+			ret = lttng_channel_get_lost_packet_count(channel,
+					&lost);
+			if (ret) {
+				ERR("Failed to retrieve lost packet count from channel %s",
+						channel->name);
+			}
+
+			discarded_total += discarded;
+			lost_total += lost;
+		}
+		lttng_destroy_handle(handle);
+	}
+	if (discarded_total > 0) {
+		MSG("[warning] %" PRIu64 " events discarded, please refer to "
+				"the documentation on channel configuration.",
+				discarded_total);
+	}
+	if (lost_total > 0) {
+		MSG("[warning] %" PRIu64 " packets lost, please refer to "
+				"the documentation on channel configuration.",
+				lost_total);
+	}
+
+end:
+	return;
+}
diff --git a/src/bin/lttng/utils.h b/src/bin/lttng/utils.h
index 662975a76..0d70cf751 100644
--- a/src/bin/lttng/utils.h
+++ b/src/bin/lttng/utils.h
@@ -59,5 +59,6 @@ int print_missing_or_multiple_domains(unsigned int sum);
 
 int spawn_relayd(const char *pathname, int port);
 int check_relayd(void);
+void print_session_stats(const char *session_name);
 
 #endif /* _LTTNG_UTILS_H */