#include <lttng/lttng.h>
#include <urcu/list.h>
-/* Global session list */
+/*
+ * Tracing session list
+ *
+ * Statically declared in session.c and can be accessed by using
+ * get_session_list() function that returns the pointer to the list.
+ */
struct ltt_session_list {
+ /*
+ * This lock protects any read/write access to the list and count (which is
+ * basically the list size). All public functions in session.c acquire this
+ * lock and release it before returning. If none of those functions are
+ * used, the lock MUST be acquired in order to iterate or/and do any
+ * actions on that list.
+ */
+ pthread_mutex_t lock;
+ /*
+ * Number of element in the list.
+ */
+ unsigned int count;
struct cds_list_head head;
};
-extern struct ltt_session_list ltt_session_list;
-
-/* ltt-session - This data structure contains information needed
- * to identify a tracing session for both LTTng and UST.
+/*
+ * This data structure contains information needed to identify a tracing
+ * session for both LTTng and UST.
*/
struct ltt_session {
- struct cds_list_head list;
char *name;
char *path;
- struct cds_list_head ust_traces;
struct ltt_kernel_session *kernel_session;
+ struct cds_list_head ust_traces;
unsigned int ust_trace_count;
- pid_t ust_consumer;
+ /*
+ * Protect any read/write on this session data structure. This lock must be
+ * acquired *before* using any public functions declared below. Use
+ * lock_session() and unlock_session() for that.
+ */
+ pthread_mutex_t lock;
+ struct cds_list_head list;
};
/* Prototypes */
int create_session(char *name, char *path);
int destroy_session(char *name);
void get_lttng_session(struct lttng_session *sessions);
+void lock_session(struct ltt_session *session);
+void unlock_session(struct ltt_session *session);
struct ltt_session *find_session_by_name(char *name);
unsigned int get_session_count(void);
struct ltt_session_list *get_session_list(void);