X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=include%2Flttng%2Ftrigger%2Ftrigger.h;h=b36ee13a286f0d1d785a83da0c1ec85031776c4f;hp=b2eab0e3da9fa10192b2f6a05da110c0178523c9;hb=fbc9f37df245d544a7705ba576297df791220b44;hpb=a58c490f0bff52a73717d31d04d1472629180de2 diff --git a/include/lttng/trigger/trigger.h b/include/lttng/trigger/trigger.h index b2eab0e3d..b36ee13a2 100644 --- a/include/lttng/trigger/trigger.h +++ b/include/lttng/trigger/trigger.h @@ -1,26 +1,21 @@ /* - * 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 #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" { @@ -31,22 +26,207 @@ 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, + 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. + * + * 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); +/* + * Set the user identity (uid) of a trigger. + * + * Only available for the root user (uid 0). + * + * Returns LTTNG_TRIGGER_STATUS_OK on success, + * LTTNG_TRIGGER_STATUS_EPERM if not authorized, + * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. + */ +extern enum lttng_trigger_status lttng_trigger_set_owner_uid( + struct lttng_trigger *trigger, uid_t uid); + +/* + * Get the user identity (uid) of a trigger. + * + * Returns LTTNG_TRIGGER_STATUS_OK on success, + * LTTNG_TRIGGER_STATUS_UNSET if unset, + * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed. + */ +extern enum lttng_trigger_status lttng_trigger_get_owner_uid( + const struct lttng_trigger *trigger, uid_t *uid); + +/* + * 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); +/* + * 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); + +/* + * 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 until 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 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. + */ 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); +/* + * 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(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 } #endif