From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 21 Nov 2011 15:55:25 +0000 (+0100)
Subject: Allocate session UID with count increment
X-Git-Tag: v2.0-pre15~91
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=44e96653751b3d75c823abc6275d8e732738c789

Allocate session UID with count increment

Otherwise, the UST session UID gets assigned only when the first UST
channel is created for a session, causing IDs to be used for many
sessions (the count of the number of sessions allocated so far) if the
session creation / channel creation is not performed in a usual
sequence.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/lttng-sessiond/main.c b/lttng-sessiond/main.c
index d5b4c8db2..7fe0f9a4b 100644
--- a/lttng-sessiond/main.c
+++ b/lttng-sessiond/main.c
@@ -1780,10 +1780,7 @@ static int create_ust_session(struct ltt_session *session,
 
 	DBG("Creating UST session");
 
-	session_lock_list();
-	uid = session_list_ptr->count;
-	session_unlock_list();
-
+	uid = session->uid;
 	lus = trace_ust_create_session(session->path, uid, domain);
 	if (lus == NULL) {
 		ret = LTTCOMM_UST_SESS_FAIL;
diff --git a/lttng-sessiond/session.c b/lttng-sessiond/session.c
index 2ab49485f..bf16f76cb 100644
--- a/lttng-sessiond/session.c
+++ b/lttng-sessiond/session.c
@@ -55,11 +55,12 @@ static struct ltt_session_list ltt_session_list = {
  * Add a ltt_session structure to the global list.
  *
  * The caller MUST acquire the session list lock before.
+ * Returns the unique identifier for the session.
  */
-static void add_session_list(struct ltt_session *ls)
+static int add_session_list(struct ltt_session *ls)
 {
 	cds_list_add(&ls->list, &ltt_session_list.head);
-	ltt_session_list.count++;
+	return ++ltt_session_list.count;
 }
 
 /*
@@ -215,10 +216,10 @@ int session_create(char *name, char *path)
 
 	/* Add new session to the session list */
 	session_lock_list();
-	add_session_list(new_session);
+	new_session->uid = add_session_list(new_session);
 	session_unlock_list();
 
-	DBG("Tracing session %s created in %s", name, path);
+	DBG("Tracing session %s created in %s with UID %d", name, path, new_session->uid);
 
 	return LTTCOMM_OK;
 
diff --git a/lttng-sessiond/session.h b/lttng-sessiond/session.h
index 2d077a4bc..9d8bd32aa 100644
--- a/lttng-sessiond/session.h
+++ b/lttng-sessiond/session.h
@@ -68,6 +68,7 @@ struct ltt_session {
 	pthread_mutex_t lock;
 	struct cds_list_head list;
 	int enabled;	/* enabled/started flag */
+	int uid;
 };
 
 /* Prototypes */