rotation-api: introduce rotation schedule descriptors

[lttng-tools.git] / src / bin / lttng-sessiond / session.h

diff --git a/src/bin/lttng-sessiond/session.h b/src/bin/lttng-sessiond/session.h
index b8c7890810ab966d23860805cabfff5be62426e9..371b30d6be856444ac3afbcfaffe707d0a43a0cb 100644 (file)
--- a/src/bin/lttng-sessiond/session.h
+++ b/src/bin/lttng-sessiond/session.h
@@ -120,8 +120,20 @@ struct ltt_session {
         * Node in ltt_sessions_ht_by_id.
         */
        struct lttng_ht_node_u64 node;
-       /* Number of session rotation for this session. */
-       uint64_t rotate_count;
+       /*
+        * The current archive id corresponds to the number of session rotations
+        * that have occured for this session. The archive id
+        * is used to tag the "generation" of a stream. This tag allows the
+        * consumer and relay daemons to track when a given stream was created
+        * during the lifetime of a session.
+        *
+        * For instance, if a stream is created after a session rotation was
+        * launched, the consumer and relay daemons must not check its position
+        * to determine if that specific session rotation was completed. It is
+        * implicitly "completed" since the stream appeared _after_ the session
+        * rotation was initiated.
+        */
+       uint64_t current_archive_id;
        /*
         * Rotation is pending between the time it starts until the consumer has
         * finished extracting the data. If the session uses a relay, data related
@@ -177,8 +189,9 @@ struct ltt_session {
        /* Timer to periodically rotate a session. */
        bool rotate_timer_enabled;
        timer_t rotate_timer;
+       /* Value for periodic rotations, 0 if disabled. */
        uint64_t rotate_timer_period;
-       /* Value for size-based rotation, 0 if disabled. */
+       /* Value for size-based rotations, 0 if disabled. */
        uint64_t rotate_size;
        /*
         * Keep a state if this session was rotated after the last stop command.
@@ -200,6 +213,7 @@ int session_destroy(struct ltt_session *session);
 
 void session_lock(struct ltt_session *session);
 void session_lock_list(void);
+int session_trylock_list(void);
 void session_unlock(struct ltt_session *session);
 void session_unlock_list(void);