X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=include%2Flttng%2Ftrigger%2Ftrigger.h;h=823a026518ecfc7d42a7462415576a3190667df9;hp=b2eab0e3da9fa10192b2f6a05da110c0178523c9;hb=refs%2Fheads%2Fsow-2019-0002-rev1;hpb=a58c490f0bff52a73717d31d04d1472629180de2 diff --git a/include/lttng/trigger/trigger.h b/include/lttng/trigger/trigger.h index b2eab0e3d..823a02651 100644 --- a/include/lttng/trigger/trigger.h +++ b/include/lttng/trigger/trigger.h @@ -1,18 +1,8 @@ /* - * Copyright (C) 2017 - Jérémie Galarneau + * Copyright (C) 2017 Jérémie Galarneau * - * This library is free software; you can redistribute it and/or modify it - * under the terms of the GNU Lesser General Public License, version 2.1 only, - * as published by the Free Software Foundation. + * SPDX-License-Identifier: LGPL-2.1-only * - * This library is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License - * for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this library; if not, write to the Free Software Foundation, - * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef LTTNG_TRIGGER_H @@ -21,6 +11,8 @@ struct lttng_action; struct lttng_condition; struct lttng_trigger; +/* A collection of trigger */ +struct lttng_triggers; #ifdef __cplusplus extern "C" { @@ -31,21 +23,175 @@ enum lttng_register_trigger_status { LTTNG_REGISTER_TRIGGER_STATUS_INVALID = -1, }; -/* The caller retains the ownership of both condition and action. */ +enum lttng_trigger_status { + LTTNG_TRIGGER_STATUS_OK = 0, + LTTNG_TRIGGER_STATUS_ERROR = -1, + LTTNG_TRIGGER_STATUS_UNKNOWN = -2, + LTTNG_TRIGGER_STATUS_INVALID = -3, + LTTNG_TRIGGER_STATUS_UNSET = -4, + LTTNG_TRIGGER_STATUS_UNSUPPORTED = -5, +}; + +enum lttng_trigger_firing_policy_type { + LTTNG_TRIGGER_FIRE_EVERY_N = 0, + LTTNG_TRIGGER_FIRE_ONCE_AFTER_N = 1, +}; + +/* + * Create a trigger object associating a condition and an action. + * + * A trigger associates a condition and an action to take whenever the + * condition evaluates to true. Such actions can, for example, consist + * 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. + * + * A trigger must be registered in order to become activate and can + * be destroyed after its registration. + * + * Returns a trigger object on success, NULL on error. + * Trigger objects must be destroyed using the lttng_trigger_destroy() + * function. + */ extern struct lttng_trigger *lttng_trigger_create( struct lttng_condition *condition, struct lttng_action *action); +/* + * Get the condition of a trigger. + * + * The caller acquires no ownership of the returned condition. + * + * Returns a condition on success, NULL on error. + */ 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. + * + * The caller acquires no ownership of the returned action. + * + * Returns an action on success, NULL on error. + */ 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. + * + * The caller does not assume the ownership of the returned name. + * The name shall only only be used for the duration of the trigger's + * lifetime, or before a different name is set. + * + * Returns LTTNG_TRIGGER_STATUS_OK and a pointer to the trigger's name on + * success, LTTNG_TRIGGER_STATUS_INVALID if an invalid parameter is passed, + * or LTTNG_TRIGGER_STATUS_UNSET if a name was not set prior to this call. + */ +extern enum lttng_trigger_status lttng_trigger_get_name( + const struct lttng_trigger *trigger, const char **name); + +/* + * Set the trigger name. + * + * A name is optional. + * A name will be assigned on trigger registration if no name is set. + * + * The name is copied. + * + * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID + * if invalid parameters are passed. + */ +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 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_set_firing_policy( + struct lttng_trigger *trigger, + enum lttng_trigger_firing_policy_type policy_type, + unsigned long long threshold); +extern enum lttng_trigger_status lttng_trigger_get_firing_policy( + const struct lttng_trigger *trigger, + enum lttng_trigger_firing_policy_type *policy_type, + unsigned long long *threshold); + +/* + * Destroy (frees) a trigger object. + */ extern void lttng_trigger_destroy(struct lttng_trigger *trigger); +/* + * Register a trigger to the session daemon. + * + * The trigger can be destroyed after this call. + * + * Return 0 on success, a negative LTTng error code on error. + */ extern int lttng_register_trigger(struct lttng_trigger *trigger); -extern int lttng_unregister_trigger(struct lttng_trigger *trigger); +/* + * Unregister a trigger from the session daemon. + * + * The trigger can be destroyed after this call. + * + * Return 0 on success, a negative LTTng error code on error. + */ +extern int lttng_unregister_trigger(const struct lttng_trigger *trigger); + +/* + * List current triggers. + * + * On success, triggers is allocated. + * The trigger collection must be free by the caller with lttng_destroy_triggers + * + * Returns 0 on success, else a negative LTTng error code. + */ +extern int lttng_list_triggers(struct lttng_triggers **triggers); + +/* + * Get a trigger from the collection at a given index. + * + * Note that the collection maintains the ownership of the returned trigger. + * It must not be destroyed by the user, nor should it be held beyond the + * lifetime of the trigger collection. + * + * 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 trigger in a tracker id list. + * + * Return LTTNG_TRIGGER_STATUS_OK on success, + * LTTNG_TRIGGER_STATUS_INVALID when passed invalid parameters. + */ +extern enum lttng_trigger_status lttng_triggers_get_count( + const struct lttng_triggers *triggers, unsigned int *count); + +/* + * Destroy a trigger collection. + */ +extern void lttng_triggers_destroy(struct lttng_triggers *ids); + #ifdef __cplusplus }