| 1 | /* |
| 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #ifndef LTTNG_TRIGGER_H |
| 9 | #define LTTNG_TRIGGER_H |
| 10 | |
| 11 | struct lttng_action; |
| 12 | struct lttng_condition; |
| 13 | struct lttng_trigger; |
| 14 | /* A collection of trigger */ |
| 15 | struct lttng_triggers; |
| 16 | |
| 17 | #ifdef __cplusplus |
| 18 | extern "C" { |
| 19 | #endif |
| 20 | |
| 21 | enum lttng_register_trigger_status { |
| 22 | LTTNG_REGISTER_TRIGGER_STATUS_OK = 0, |
| 23 | LTTNG_REGISTER_TRIGGER_STATUS_INVALID = -1, |
| 24 | }; |
| 25 | |
| 26 | enum lttng_trigger_status { |
| 27 | LTTNG_TRIGGER_STATUS_OK = 0, |
| 28 | LTTNG_TRIGGER_STATUS_ERROR = -1, |
| 29 | LTTNG_TRIGGER_STATUS_UNKNOWN = -2, |
| 30 | LTTNG_TRIGGER_STATUS_INVALID = -3, |
| 31 | LTTNG_TRIGGER_STATUS_UNSET = -4, |
| 32 | LTTNG_TRIGGER_STATUS_UNSUPPORTED = -5, |
| 33 | }; |
| 34 | |
| 35 | enum lttng_trigger_firing_policy_type { |
| 36 | LTTNG_TRIGGER_FIRE_EVERY_N = 0, |
| 37 | LTTNG_TRIGGER_FIRE_ONCE_AFTER_N = 1, |
| 38 | }; |
| 39 | |
| 40 | /* |
| 41 | * Create a trigger object associating a condition and an action. |
| 42 | * |
| 43 | * A trigger associates a condition and an action to take whenever the |
| 44 | * condition evaluates to true. Such actions can, for example, consist |
| 45 | * in the emission of a notification to clients listening through |
| 46 | * notification channels. |
| 47 | * |
| 48 | * The caller retains the ownership of both the condition and action |
| 49 | * and both must be kept alive for the lifetime of the trigger object. |
| 50 | * |
| 51 | * A trigger must be registered in order to become activate and can |
| 52 | * be destroyed after its registration. |
| 53 | * |
| 54 | * Returns a trigger object on success, NULL on error. |
| 55 | * Trigger objects must be destroyed using the lttng_trigger_destroy() |
| 56 | * function. |
| 57 | */ |
| 58 | extern struct lttng_trigger *lttng_trigger_create( |
| 59 | struct lttng_condition *condition, struct lttng_action *action); |
| 60 | |
| 61 | /* |
| 62 | * Get the condition of a trigger. |
| 63 | * |
| 64 | * The caller acquires no ownership of the returned condition. |
| 65 | * |
| 66 | * Returns a condition on success, NULL on error. |
| 67 | */ |
| 68 | extern struct lttng_condition *lttng_trigger_get_condition( |
| 69 | struct lttng_trigger *trigger); |
| 70 | |
| 71 | const struct lttng_condition *lttng_trigger_get_const_condition( |
| 72 | const struct lttng_trigger *trigger); |
| 73 | |
| 74 | /* |
| 75 | * Get the action of a trigger. |
| 76 | * |
| 77 | * The caller acquires no ownership of the returned action. |
| 78 | * |
| 79 | * Returns an action on success, NULL on error. |
| 80 | */ |
| 81 | extern struct lttng_action *lttng_trigger_get_action( |
| 82 | struct lttng_trigger *trigger); |
| 83 | |
| 84 | const struct lttng_action *lttng_trigger_get_const_action( |
| 85 | const struct lttng_trigger *trigger); |
| 86 | |
| 87 | /* |
| 88 | * Get the name of a trigger. |
| 89 | * |
| 90 | * The caller does not assume the ownership of the returned name. |
| 91 | * The name shall only only be used for the duration of the trigger's |
| 92 | * lifetime, or before a different name is set. |
| 93 | * |
| 94 | * Returns LTTNG_TRIGGER_STATUS_OK and a pointer to the trigger's name on |
| 95 | * success, LTTNG_TRIGGER_STATUS_INVALID if an invalid parameter is passed, |
| 96 | * or LTTNG_TRIGGER_STATUS_UNSET if a name was not set prior to this call. |
| 97 | */ |
| 98 | extern enum lttng_trigger_status lttng_trigger_get_name( |
| 99 | const struct lttng_trigger *trigger, const char **name); |
| 100 | |
| 101 | /* |
| 102 | * Set the trigger name. |
| 103 | * |
| 104 | * A name is optional. |
| 105 | * A name will be assigned on trigger registration if no name is set. |
| 106 | * |
| 107 | * The name is copied. |
| 108 | * |
| 109 | * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID |
| 110 | * if invalid parameters are passed. |
| 111 | */ |
| 112 | extern enum lttng_trigger_status lttng_trigger_set_name( |
| 113 | struct lttng_trigger *trigger, const char *name); |
| 114 | |
| 115 | /* |
| 116 | * Set the trigger firing policy. |
| 117 | * |
| 118 | * This is optional. By default a trigger is set to fire each time the |
| 119 | * associated condition occurs. |
| 120 | * |
| 121 | * Threshold is the number of time the condition must be hit before the policy is |
| 122 | * enacted. |
| 123 | * |
| 124 | * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID |
| 125 | * if invalid parameters are passed. |
| 126 | */ |
| 127 | extern enum lttng_trigger_status lttng_trigger_set_firing_policy( |
| 128 | struct lttng_trigger *trigger, |
| 129 | enum lttng_trigger_firing_policy_type policy_type, |
| 130 | unsigned long long threshold); |
| 131 | extern enum lttng_trigger_status lttng_trigger_get_firing_policy( |
| 132 | const struct lttng_trigger *trigger, |
| 133 | enum lttng_trigger_firing_policy_type *policy_type, |
| 134 | unsigned long long *threshold); |
| 135 | |
| 136 | /* |
| 137 | * Destroy (frees) a trigger object. |
| 138 | */ |
| 139 | extern void lttng_trigger_destroy(struct lttng_trigger *trigger); |
| 140 | |
| 141 | /* |
| 142 | * Register a trigger to the session daemon. |
| 143 | * |
| 144 | * The trigger can be destroyed after this call. |
| 145 | * |
| 146 | * Return 0 on success, a negative LTTng error code on error. |
| 147 | */ |
| 148 | extern int lttng_register_trigger(struct lttng_trigger *trigger); |
| 149 | |
| 150 | /* |
| 151 | * Unregister a trigger from the session daemon. |
| 152 | * |
| 153 | * The trigger can be destroyed after this call. |
| 154 | * |
| 155 | * Return 0 on success, a negative LTTng error code on error. |
| 156 | */ |
| 157 | extern int lttng_unregister_trigger(const struct lttng_trigger *trigger); |
| 158 | |
| 159 | /* |
| 160 | * List current triggers. |
| 161 | * |
| 162 | * On success, triggers is allocated. |
| 163 | * The trigger collection must be free by the caller with lttng_destroy_triggers |
| 164 | * |
| 165 | * Returns 0 on success, else a negative LTTng error code. |
| 166 | */ |
| 167 | extern int lttng_list_triggers(struct lttng_triggers **triggers); |
| 168 | |
| 169 | /* |
| 170 | * Get a trigger from the collection at a given index. |
| 171 | * |
| 172 | * Note that the collection maintains the ownership of the returned trigger. |
| 173 | * It must not be destroyed by the user, nor should it be held beyond the |
| 174 | * lifetime of the trigger collection. |
| 175 | * |
| 176 | * Returns a trigger, or NULL on error. |
| 177 | */ |
| 178 | extern const struct lttng_trigger *lttng_triggers_get_at_index( |
| 179 | const struct lttng_triggers *triggers, unsigned int index); |
| 180 | |
| 181 | /* |
| 182 | * Get the number of trigger in a tracker id list. |
| 183 | * |
| 184 | * Return LTTNG_TRIGGER_STATUS_OK on success, |
| 185 | * LTTNG_TRIGGER_STATUS_INVALID when passed invalid parameters. |
| 186 | */ |
| 187 | extern enum lttng_trigger_status lttng_triggers_get_count( |
| 188 | const struct lttng_triggers *triggers, unsigned int *count); |
| 189 | |
| 190 | /* |
| 191 | * Destroy a trigger collection. |
| 192 | */ |
| 193 | extern void lttng_triggers_destroy(struct lttng_triggers *ids); |
| 194 | |
| 195 | |
| 196 | #ifdef __cplusplus |
| 197 | } |
| 198 | #endif |
| 199 | |
| 200 | #endif /* LTTNG_TRIGGER_H */ |