From fcf1c6efa2936be0065867fbfb86f4c8c182c35f Mon Sep 17 00:00:00 2001
From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Wed, 24 Apr 2019 11:22:23 -0400
Subject: [PATCH] Metadata: add vpid_datetime field to metadta env

This information can be used by viewer and previously contain in the
path hierarchy of a trace.

Add the registration_time field to ust_app to access it when printing
metadata. Reuse this field to generate the trace path.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
---
 src/bin/lttng-sessiond/ust-app.c      |  7 ++--
 src/bin/lttng-sessiond/ust-app.h      |  5 +++
 src/bin/lttng-sessiond/ust-metadata.c | 49 ++++++++++++++++++++-------
 3 files changed, 45 insertions(+), 16 deletions(-)

diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c
index faa51c759..8b3028c57 100644
--- a/src/bin/lttng-sessiond/ust-app.c
+++ b/src/bin/lttng-sessiond/ust-app.c
@@ -1831,15 +1831,12 @@ static void shadow_copy_channel(struct ust_app_channel *ua_chan,
 static void shadow_copy_session(struct ust_app_session *ua_sess,
 		struct ltt_ust_session *usess, struct ust_app *app)
 {
-	time_t rawtime;
 	struct tm *timeinfo;
 	char datetime[16];
 	int ret;
 	char tmp_shm_path[PATH_MAX];
 
-	/* Get date and time for unique app path */
-	time(&rawtime);
-	timeinfo = localtime(&rawtime);
+	timeinfo = localtime(&app->registration_time);
 	strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
 
 	DBG2("Shadow copy of session handle %d", ua_sess->handle);
@@ -3377,6 +3374,8 @@ void ust_app_add(struct ust_app *app)
 	assert(app);
 	assert(app->notify_sock >= 0);
 
+	app->registration_time = time(NULL);
+
 	rcu_read_lock();
 
 	/*
diff --git a/src/bin/lttng-sessiond/ust-app.h b/src/bin/lttng-sessiond/ust-app.h
index b90ff4bce..d9279f0e4 100644
--- a/src/bin/lttng-sessiond/ust-app.h
+++ b/src/bin/lttng-sessiond/ust-app.h
@@ -298,6 +298,11 @@ struct ust_app {
 	 * to a negative value indicating that the agent application is gone.
 	 */
 	int agent_app_sock;
+	/*
+	 * Time at which the app is registred.
+	 * Used for path creation
+	 */
+	time_t registration_time;
 };
 
 #ifdef HAVE_LIBLTTNG_UST_CTL
diff --git a/src/bin/lttng-sessiond/ust-metadata.c b/src/bin/lttng-sessiond/ust-metadata.c
index 324169559..48db2cc56 100644
--- a/src/bin/lttng-sessiond/ust-metadata.c
+++ b/src/bin/lttng-sessiond/ust-metadata.c
@@ -969,6 +969,39 @@ error:
 	return ret;
 }
 
+static
+int print_metadata_app_information(struct ust_registry_session *registry,
+		struct ust_app *app)
+{
+	int ret;
+	char datetime[ISO8601_LEN];
+
+	if (!app) {
+		ret = 0;
+		goto end;
+	}
+
+	ret = time_t_to_ISO8601(datetime, sizeof(datetime),
+			app->registration_time);
+	if (ret) {
+		goto end;
+	}
+
+	ret = lttng_metadata_printf(registry,
+			"	tracer_patchlevel = %u;\n"
+			"	vpid = %d;\n"
+			"	procname = \"%s\";\n"
+			"	vpid_datetime = \"%s\";\n" ,
+			app->version.patchlevel,
+			(int) app->pid,
+			app->name,
+			datetime
+	);
+
+end:
+	return ret;
+}
+
 /*
  * Should be called with session registry mutex held.
  */
@@ -1055,18 +1088,10 @@ int ust_metadata_session_statedump(struct ust_registry_session *session,
 	 * If per-application registry, we can output extra information
 	 * about the application.
 	 */
-	if (app) {
-		ret = lttng_metadata_printf(session,
-			"	tracer_patchlevel = %u;\n"
-			"	vpid = %d;\n"
-			"	procname = \"%s\";\n",
-			app->version.patchlevel,
-			(int) app->pid,
-			app->name
-			);
-		if (ret)
-			goto end;
-	}
+	ret = print_metadata_app_information(session, app);
+	if (ret)
+		goto end;
+
 
 	ret = lttng_metadata_printf(session,
 		"};\n\n"
-- 
2.34.1