sessiond: document effect of rotated_after_last_stop on clear

[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 20a7fcbc86ed0d4ab2057b5364515734325e8546..883a265545e6965e2a82286cbcb6592d9781168c 100644 (file)
--- a/src/bin/lttng-sessiond/session.h
+++ b/src/bin/lttng-sessiond/session.h
@@ -36,6 +36,8 @@ struct ltt_ust_session;
 
 typedef void (*ltt_session_destroy_notifier)(const struct ltt_session *session,
                void *user_data);
+typedef void (*ltt_session_clear_notifier)(const struct ltt_session *session,
+               void *user_data);
 
 /*
  * Tracing session list
@@ -170,9 +172,20 @@ struct ltt_session {
         * Keep a state if this session was rotated after the last stop command.
         * We only allow one rotation after a stop. At destroy, we also need to
         * know if a rotation occurred since the last stop to rename the current
-        * chunk.
+        * chunk. After a stop followed by rotate, all subsequent clear
+        * (without prior start) will succeed, but will be effect-less.
         */
        bool rotated_after_last_stop;
+       /*
+        * Track whether the session was cleared after last stop. All subsequent
+        * clear (without prior start) will succeed, but will be effect-less. A
+        * subsequent rotate (without prior start) will return an error.
+        */
+       bool cleared_after_last_stop;
+       /*
+        * True if the session has had an explicit non-quiet rotation.
+        */
+       bool rotated;
        /*
         * Condition and trigger for size-based rotations.
         */
@@ -187,6 +200,7 @@ struct ltt_session {
        char *last_archived_chunk_name;
        LTTNG_OPTIONAL(uint64_t) last_archived_chunk_id;
        struct lttng_dynamic_array destroy_notifiers;
+       struct lttng_dynamic_array clear_notifiers;
        /* Session base path override. Set non-null. */
        char *base_path;
 };
@@ -204,6 +218,10 @@ void session_destroy(struct ltt_session *session);
 int session_add_destroy_notifier(struct ltt_session *session,
                ltt_session_destroy_notifier notifier, void *user_data);
 
+int session_add_clear_notifier(struct ltt_session *session,
+               ltt_session_clear_notifier notifier, void *user_data);
+void session_notify_clear(struct ltt_session *session);
+
 bool session_get(struct ltt_session *session);
 void session_put(struct ltt_session *session);
 
@@ -251,9 +269,9 @@ int session_set_trace_chunk(struct ltt_session *session,
  * Close a chunk on the remote peers of a session. Has no effect on the
  * ltt_session itself.
  */
-int session_close_trace_chunk(const struct ltt_session *session,
+int session_close_trace_chunk(struct ltt_session *session,
                struct lttng_trace_chunk *trace_chunk,
-               const enum lttng_trace_chunk_command_type *close_command,
+               enum lttng_trace_chunk_command_type close_command,
                char *path);
 
 bool session_output_supports_trace_chunks(const struct ltt_session *session);