| 1 | /* |
| 2 | * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This library is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
| 11 | * for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public License |
| 14 | * along with this library; if not, write to the Free Software Foundation, |
| 15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 16 | */ |
| 17 | |
| 18 | #ifndef LTTNG_TRIGGER_H |
| 19 | #define LTTNG_TRIGGER_H |
| 20 | |
| 21 | struct lttng_action; |
| 22 | struct lttng_condition; |
| 23 | struct lttng_trigger; |
| 24 | |
| 25 | #ifdef __cplusplus |
| 26 | extern "C" { |
| 27 | #endif |
| 28 | |
| 29 | enum lttng_register_trigger_status { |
| 30 | LTTNG_REGISTER_TRIGGER_STATUS_OK = 0, |
| 31 | LTTNG_REGISTER_TRIGGER_STATUS_INVALID = -1, |
| 32 | }; |
| 33 | |
| 34 | /* |
| 35 | * Create a trigger object associating a condition and an action. |
| 36 | * |
| 37 | * A trigger associates a condition and an action to take whenever the |
| 38 | * condition evaluates to true. Such actions can, for example, consist |
| 39 | * in the emission of a notification to clients listening through |
| 40 | * notification channels. |
| 41 | * |
| 42 | * The caller retains the ownership of both the condition and action |
| 43 | * and both must be kept alive for the lifetime of the trigger object. |
| 44 | * |
| 45 | * A trigger must be registered in order to become activate and can |
| 46 | * be destroyed after its registration. |
| 47 | * |
| 48 | * Returns a trigger object on success, NULL on error. |
| 49 | * Trigger objects must be destroyed using the lttng_trigger_destroy() |
| 50 | * function. |
| 51 | */ |
| 52 | extern struct lttng_trigger *lttng_trigger_create( |
| 53 | struct lttng_condition *condition, struct lttng_action *action); |
| 54 | |
| 55 | /* |
| 56 | * Get the condition of a trigger. |
| 57 | * |
| 58 | * The caller acquires no ownership of the returned condition. |
| 59 | * |
| 60 | * Returns a condition on success, NULL on error. |
| 61 | */ |
| 62 | extern struct lttng_condition *lttng_trigger_get_condition( |
| 63 | struct lttng_trigger *trigger); |
| 64 | |
| 65 | /* |
| 66 | * Get the action of a trigger. |
| 67 | * |
| 68 | * The caller acquires no ownership of the returned action. |
| 69 | * |
| 70 | * Returns an action on success, NULL on error. |
| 71 | */ |
| 72 | extern struct lttng_action *lttng_trigger_get_action( |
| 73 | struct lttng_trigger *trigger); |
| 74 | |
| 75 | /* |
| 76 | * Destroy (frees) a trigger object. |
| 77 | */ |
| 78 | extern void lttng_trigger_destroy(struct lttng_trigger *trigger); |
| 79 | |
| 80 | /* |
| 81 | * Register a trigger to the session daemon. |
| 82 | * |
| 83 | * The trigger can be destroyed after this call. |
| 84 | * |
| 85 | * Return 0 on success, a negative LTTng error code on error. |
| 86 | */ |
| 87 | extern int lttng_register_trigger(struct lttng_trigger *trigger); |
| 88 | |
| 89 | /* |
| 90 | * Unregister a trigger from the session daemon. |
| 91 | * |
| 92 | * The trigger can be destroyed after this call. |
| 93 | * |
| 94 | * Return 0 on success, a negative LTTng error code on error. |
| 95 | */ |
| 96 | extern int lttng_unregister_trigger(struct lttng_trigger *trigger); |
| 97 | |
| 98 | #ifdef __cplusplus |
| 99 | } |
| 100 | #endif |
| 101 | |
| 102 | #endif /* LTTNG_TRIGGER_H */ |