Docs: document trigger condition and action ownership in 2.13+

[lttng-tools.git] / include / lttng / trigger / trigger.h

diff --git a/include/lttng/trigger/trigger.h b/include/lttng/trigger/trigger.h
index b36ee13a286f0d1d785a83da0c1ec85031776c4f..3b1cedda1fb4709457537ded9df978e206d6d3ca 100644 (file)
--- a/include/lttng/trigger/trigger.h
+++ b/include/lttng/trigger/trigger.h
@@ -49,8 +49,14 @@ enum lttng_trigger_firing_policy {
  * in the emission of a notification to clients listening through
  * notification channels.
  *
- * The caller retains the ownership of both the condition and action
- * and both must be kept alive for the lifetime of the trigger object.
+ * Prior to 2.13, the caller had to retain the ownership of both the condition
+ * and action. Both objects had to be kept alive for the lifetime of the trigger
+ * object. This is no longer the case as the condition and action objects are
+ * internally reference counted. It is safe to destroy a condition and an action
+ * after using them to create a trigger. However, they should no longer be used.
+ *
+ * If the action is a notification action with capture descriptors,
+ * the condition must be an event rule condition.
  *
  * A trigger must be registered in order to become activate and can
  * be destroyed after its registration.
@@ -94,6 +100,9 @@ extern enum lttng_trigger_status lttng_trigger_get_owner_uid(
 extern struct lttng_condition *lttng_trigger_get_condition(
                struct lttng_trigger *trigger);
 
+const struct lttng_condition *lttng_trigger_get_const_condition(
+               const struct lttng_trigger *trigger);
+
 /*
  * Get the action of a trigger.
  *
@@ -104,6 +113,8 @@ extern struct lttng_condition *lttng_trigger_get_condition(
 extern struct lttng_action *lttng_trigger_get_action(
                struct lttng_trigger *trigger);
 
+const struct lttng_action *lttng_trigger_get_const_action(
+               const struct lttng_trigger *trigger);
 
 /*
  * Get the name of a trigger.
@@ -185,7 +196,7 @@ extern int lttng_register_trigger(struct lttng_trigger *trigger);
  *
  * Return 0 on success, a negative LTTng error code on error.
  */
-extern int lttng_unregister_trigger(struct lttng_trigger *trigger);
+extern int lttng_unregister_trigger(const struct lttng_trigger *trigger);
 
 /*
  * List triggers for the current user.