From e8be5f4f7541ab84521ab4e1722708d2234218c6 Mon Sep 17 00:00:00 2001
From: David Goulet <david.goulet@polymtl.ca>
Date: Wed, 27 Apr 2011 11:18:25 -0400
Subject: [PATCH] Add --session feature

This allows any user to select a session and any
tracing command will affect that particular session.

Signed-off-by: David Goulet <david.goulet@polymtl.ca>
---
 include/lttng/liblttngctl.h |  1 +
 liblttngctl/liblttngctl.c   | 11 ++++++++++-
 lttng/lttng.c               |  4 ++++
 lttng/lttng.h               |  2 +-
 lttng/options.c             | 13 +++++++++----
 5 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/include/lttng/liblttngctl.h b/include/lttng/liblttngctl.h
index b729f2b5b..df9731342 100644
--- a/include/lttng/liblttngctl.h
+++ b/include/lttng/liblttngctl.h
@@ -50,5 +50,6 @@ extern int lttng_check_session_daemon(void);
 extern const char *lttng_get_readable_code(int code);
 extern int lttng_ust_list_apps(pid_t **pids);
 extern int lttng_list_sessions(struct lttng_session **sessions);
+extern void lttng_set_current_session_uuid(char *uuid);
 
 #endif /* _LIBLTTNGCTL_H */
diff --git a/liblttngctl/liblttngctl.c b/liblttngctl/liblttngctl.c
index 9afd6fda3..a15a26dff 100644
--- a/liblttngctl/liblttngctl.c
+++ b/liblttngctl/liblttngctl.c
@@ -197,7 +197,6 @@ int lttng_ust_list_apps(pid_t **pids)
 int lttng_create_session(char *name, uuid_t *session_id)
 {
 	int ret;
-	char *uuid;
 
 	strncpy(lsm.session_name, name, sizeof(lsm.session_name));
 	lsm.session_name[sizeof(lsm.session_name) - 1] = '\0';
@@ -281,6 +280,16 @@ int lttng_connect_sessiond(void)
 	return 0;
 }
 
+/*
+ *  lttng_set_current_session_uuid
+ *
+ *  Set the session uuid for current lsm.
+ */
+void lttng_set_current_session_uuid(char *uuid)
+{
+	uuid_parse(uuid, lsm.session_id);
+}
+
 /*
  *  lttng_set_tracing_group
  *
diff --git a/lttng/lttng.c b/lttng/lttng.c
index 169e70eb0..9ef92a7d4 100644
--- a/lttng/lttng.c
+++ b/lttng/lttng.c
@@ -93,6 +93,10 @@ static int process_client_opt(void)
 		}
 	}
 
+	if (opt_session_uuid != NULL) {
+		lttng_set_current_session_uuid(opt_session_uuid);
+	}
+
 	return 0;
 
 end:
diff --git a/lttng/lttng.h b/lttng/lttng.h
index f9e75538c..804ccf694 100644
--- a/lttng/lttng.h
+++ b/lttng/lttng.h
@@ -27,7 +27,7 @@ extern int opt_trace_kernel;
 extern int opt_verbose;
 extern int opt_quiet;
 extern char *opt_tracing_group;
-extern char *opt_session_name;
+extern char *opt_session_uuid;
 extern char *opt_create_session;
 extern char *opt_sessiond_path;
 extern char *opt_destroy_session;
diff --git a/lttng/options.c b/lttng/options.c
index befeab54a..11b82fba7 100644
--- a/lttng/options.c
+++ b/lttng/options.c
@@ -23,7 +23,7 @@
 
 /* Option variables */
 char *opt_tracing_group;
-char *opt_session_name;
+char *opt_session_uuid;
 char *opt_create_session;
 char *opt_sessiond_path;
 char *opt_destroy_session;
@@ -44,7 +44,8 @@ static struct poptOption long_options[] = {
 	{"group",			0,		POPT_ARG_STRING,	&opt_tracing_group, 0, 0},
 	{"kernel",			0,		POPT_ARG_VAL,		&opt_trace_kernel, 1, 0, 0},
 	{"no-kernel",		0,		POPT_ARG_VAL,		&opt_trace_kernel, 0, 0, 0},
-	{"session",			0,		POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_session_name, 0, 0},
+	//{"session",			0,		POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_session_name, 0, 0},
+	{"session",			's',	POPT_ARG_STRING,	&opt_session_uuid, 0, 0},
 	{"create-session",  'c',	POPT_ARG_STRING,	&opt_create_session, 0, 0},
 	{"quiet",			'q',	POPT_ARG_VAL,		&opt_quiet, 1, 0},
 	{"verbose",			'v',	POPT_ARG_VAL,		&opt_verbose, 1, 0},
@@ -76,8 +77,7 @@ static void usage(FILE *ofp)
 	fprintf(ofp, "Session options:\n");
 	fprintf(ofp, "  -c, --create-session NAME    Create a new session\n");
 	fprintf(ofp, "      --list-session           List all available sessions\n");
-	fprintf(ofp, "      --session [NAME]         Specify tracing session. If no NAME is given\n");
-	fprintf(ofp, "                               or option is ommited, a session will be created\n");
+	fprintf(ofp, "  -s, --session UUID           Specify tracing session using UUID.\n");
 	fprintf(ofp, "  -d, --destroy-session=NAME   Destroy the session specified by NAME\n");
 	fprintf(ofp, "\n");
 	fprintf(ofp, "Tracing options:\n");
@@ -97,6 +97,11 @@ int parse_args(int argc, const char **argv)
 	static poptContext pc;
 	int opt;
 
+	/* If no options, fail */
+	if (argc < 2) {
+		return -1;
+	}
+
 	pc = poptGetContext("lttng", argc, argv, long_options, 0);
 	poptReadDefaultConfig(pc, 0);
 
-- 
2.34.1