X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=include%2Flttng%2Ftrigger%2Ftrigger.h;h=3b1cedda1fb4709457537ded9df978e206d6d3ca;hp=96e018f248d536eecc6c08e3c0d06f2f5a212dbc;hb=2c30250238cbd1c1976aca903cacc4abbb4f59ce;hpb=242388e491e4219f967ee424d7bf02035a313e6f diff --git a/include/lttng/trigger/trigger.h b/include/lttng/trigger/trigger.h index 96e018f24..3b1cedda1 100644 --- a/include/lttng/trigger/trigger.h +++ b/include/lttng/trigger/trigger.h @@ -9,10 +9,13 @@ #define LTTNG_TRIGGER_H #include +#include struct lttng_action; struct lttng_condition; struct lttng_trigger; +/* A set of triggers. */ +struct lttng_triggers; #ifdef __cplusplus extern "C" { @@ -33,6 +36,11 @@ enum lttng_trigger_status { LTTNG_TRIGGER_STATUS_PERMISSION_DENIED = -6, }; +enum lttng_trigger_firing_policy { + LTTNG_TRIGGER_FIRING_POLICY_EVERY_N = 0, + LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N = 1, +}; + /* * Create a trigger object associating a condition and an action. * @@ -41,8 +49,14 @@ enum lttng_trigger_status { * 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. @@ -86,6 +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. * @@ -96,6 +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. @@ -125,6 +144,37 @@ extern enum lttng_trigger_status lttng_trigger_get_name( extern enum lttng_trigger_status lttng_trigger_set_name( struct lttng_trigger *trigger, const char *name); +/* + * Set the trigger firing policy. + * + * This is optional. By default a trigger is set to fire each time the + * associated condition occurs. + * + * Threshold is the number of times the condition must be hit before the policy + * is enacted. + * + * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID + * if invalid parameters are passed. + */ +extern enum lttng_trigger_status lttng_trigger_set_firing_policy( + struct lttng_trigger *trigger, + enum lttng_trigger_firing_policy policy_type, + uint64_t threshold); + +/* + * Get the trigger firing policy. + * + * Threshold is the number of time the condition must be hit before the policy is + * enacted. + * + * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID + * if invalid parameters are passed. + */ +extern enum lttng_trigger_status lttng_trigger_get_firing_policy( + const struct lttng_trigger *trigger, + enum lttng_trigger_firing_policy *policy_type, + uint64_t *threshold); + /* * Destroy (frees) a trigger object. */ @@ -146,7 +196,47 @@ 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. + * + * On success, a newly-allocated trigger set is returned. + * + * The trigger set must be destroyed by the caller (see + * lttng_triggers_destroy()). + * + * Returns LTTNG_OK on success, else a suitable LTTng error code. + */ +extern enum lttng_error_code lttng_list_triggers( + struct lttng_triggers **triggers); + +/* + * Get a trigger from the set at a given index. + * + * Note that the trigger set maintains the ownership of the returned trigger. + * It must not be destroyed by the user, nor should a reference to it be held + * beyond the lifetime of the trigger set. + * + * Returns a trigger, or NULL on error. + */ +extern const struct lttng_trigger *lttng_triggers_get_at_index( + const struct lttng_triggers *triggers, unsigned int index); + +/* + * Get the number of triggers in a trigger set. + * + * Return LTTNG_TRIGGER_STATUS_OK on success, + * LTTNG_TRIGGER_STATUS_INVALID when invalid parameters are passed. + */ +extern enum lttng_trigger_status lttng_triggers_get_count( + const struct lttng_triggers *triggers, unsigned int *count); + +/* + * Destroy a trigger set. + */ +extern void lttng_triggers_destroy(struct lttng_triggers *triggers); + #ifdef __cplusplus }