Apply policy on channel sampling
[lttng-tools.git] / include / lttng / trigger / trigger.h
CommitLineData
a58c490f 1/*
ab5be9fa 2 * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
a58c490f 3 *
ab5be9fa 4 * SPDX-License-Identifier: LGPL-2.1-only
a58c490f 5 *
a58c490f
JG
6 */
7
8#ifndef LTTNG_TRIGGER_H
9#define LTTNG_TRIGGER_H
10
64eafdf6 11#include <sys/types.h>
5c504c41 12#include <inttypes.h>
64eafdf6 13
a58c490f
JG
14struct lttng_action;
15struct lttng_condition;
16struct lttng_trigger;
a02903c0
JR
17/* A set of triggers. */
18struct lttng_triggers;
a58c490f
JG
19
20#ifdef __cplusplus
21extern "C" {
22#endif
23
24enum lttng_register_trigger_status {
25 LTTNG_REGISTER_TRIGGER_STATUS_OK = 0,
26 LTTNG_REGISTER_TRIGGER_STATUS_INVALID = -1,
27};
28
64eafdf6
JR
29enum lttng_trigger_status {
30 LTTNG_TRIGGER_STATUS_OK = 0,
31 LTTNG_TRIGGER_STATUS_ERROR = -1,
32 LTTNG_TRIGGER_STATUS_UNKNOWN = -2,
33 LTTNG_TRIGGER_STATUS_INVALID = -3,
34 LTTNG_TRIGGER_STATUS_UNSET = -4,
35 LTTNG_TRIGGER_STATUS_UNSUPPORTED = -5,
36 LTTNG_TRIGGER_STATUS_PERMISSION_DENIED = -6,
37};
38
5c504c41
JR
39enum lttng_trigger_firing_policy {
40 LTTNG_TRIGGER_FIRING_POLICY_EVERY_N = 0,
41 LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N = 1,
42};
43
75984389
JG
44/*
45 * Create a trigger object associating a condition and an action.
46 *
47 * A trigger associates a condition and an action to take whenever the
48 * condition evaluates to true. Such actions can, for example, consist
49 * in the emission of a notification to clients listening through
50 * notification channels.
51 *
52 * The caller retains the ownership of both the condition and action
53 * and both must be kept alive for the lifetime of the trigger object.
54 *
55 * A trigger must be registered in order to become activate and can
56 * be destroyed after its registration.
57 *
58 * Returns a trigger object on success, NULL on error.
59 * Trigger objects must be destroyed using the lttng_trigger_destroy()
60 * function.
61 */
a58c490f
JG
62extern struct lttng_trigger *lttng_trigger_create(
63 struct lttng_condition *condition, struct lttng_action *action);
64
64eafdf6
JR
65/*
66 * Set the user identity (uid) of a trigger.
67 *
68 * Only available for the root user (uid 0).
69 *
70 * Returns LTTNG_TRIGGER_STATUS_OK on success,
71 * LTTNG_TRIGGER_STATUS_EPERM if not authorized,
72 * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed.
73 */
74extern enum lttng_trigger_status lttng_trigger_set_owner_uid(
75 struct lttng_trigger *trigger, uid_t uid);
76
77/*
78 * Get the user identity (uid) of a trigger.
79 *
80 * Returns LTTNG_TRIGGER_STATUS_OK on success,
81 * LTTNG_TRIGGER_STATUS_UNSET if unset,
82 * LTTNG_TRIGGER_STATUS_INVALID if invalid parameters are passed.
83 */
84extern enum lttng_trigger_status lttng_trigger_get_owner_uid(
85 const struct lttng_trigger *trigger, uid_t *uid);
86
75984389
JG
87/*
88 * Get the condition of a trigger.
89 *
90 * The caller acquires no ownership of the returned condition.
91 *
92 * Returns a condition on success, NULL on error.
93 */
a58c490f
JG
94extern struct lttng_condition *lttng_trigger_get_condition(
95 struct lttng_trigger *trigger);
96
75984389
JG
97/*
98 * Get the action of a trigger.
99 *
100 * The caller acquires no ownership of the returned action.
101 *
102 * Returns an action on success, NULL on error.
103 */
a58c490f
JG
104extern struct lttng_action *lttng_trigger_get_action(
105 struct lttng_trigger *trigger);
106
242388e4
JR
107
108/*
109 * Get the name of a trigger.
110 *
111 * The caller does not assume the ownership of the returned name.
112 * The name shall only only be used for the duration of the trigger's
113 * lifetime, or until a different name is set.
114 *
115 * Returns LTTNG_TRIGGER_STATUS_OK and a pointer to the trigger's name on
116 * success, LTTNG_TRIGGER_STATUS_INVALID if an invalid parameter is passed,
117 * or LTTNG_TRIGGER_STATUS_UNSET if a name was not set prior to this call.
118 */
119extern enum lttng_trigger_status lttng_trigger_get_name(
120 const struct lttng_trigger *trigger, const char **name);
121
122/*
123 * Set the trigger name.
124 *
125 * A name is optional.
126 * A name will be assigned on trigger registration if no name is set.
127 *
128 * The name is copied.
129 *
130 * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID
131 * if invalid parameters are passed.
132 */
133extern enum lttng_trigger_status lttng_trigger_set_name(
134 struct lttng_trigger *trigger, const char *name);
135
5c504c41
JR
136/*
137 * Set the trigger firing policy.
138 *
139 * This is optional. By default a trigger is set to fire each time the
140 * associated condition occurs.
141 *
142 * Threshold is the number of times the condition must be hit before the policy
143 * is enacted.
144 *
145 * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID
146 * if invalid parameters are passed.
147 */
148extern enum lttng_trigger_status lttng_trigger_set_firing_policy(
149 struct lttng_trigger *trigger,
150 enum lttng_trigger_firing_policy policy_type,
151 uint64_t threshold);
152
153/*
154 * Get the trigger firing policy.
155 *
156 * Threshold is the number of time the condition must be hit before the policy is
157 * enacted.
158 *
159 * Return LTTNG_TRIGGER_STATUS_OK on success, LTTNG_TRIGGER_STATUS_INVALID
160 * if invalid parameters are passed.
161 */
162extern enum lttng_trigger_status lttng_trigger_get_firing_policy(
163 const struct lttng_trigger *trigger,
164 enum lttng_trigger_firing_policy *policy_type,
165 uint64_t *threshold);
166
75984389
JG
167/*
168 * Destroy (frees) a trigger object.
169 */
a58c490f
JG
170extern void lttng_trigger_destroy(struct lttng_trigger *trigger);
171
75984389
JG
172/*
173 * Register a trigger to the session daemon.
174 *
175 * The trigger can be destroyed after this call.
176 *
177 * Return 0 on success, a negative LTTng error code on error.
178 */
a58c490f
JG
179extern int lttng_register_trigger(struct lttng_trigger *trigger);
180
75984389
JG
181/*
182 * Unregister a trigger from the session daemon.
183 *
184 * The trigger can be destroyed after this call.
185 *
186 * Return 0 on success, a negative LTTng error code on error.
187 */
a58c490f
JG
188extern int lttng_unregister_trigger(struct lttng_trigger *trigger);
189
a02903c0
JR
190/*
191 * Get a trigger from the set at a given index.
192 *
193 * Note that the trigger set maintains the ownership of the returned trigger.
194 * It must not be destroyed by the user, nor should a reference to it be held
195 * beyond the lifetime of the trigger set.
196 *
197 * Returns a trigger, or NULL on error.
198 */
199extern const struct lttng_trigger *lttng_triggers_get_at_index(
200 const struct lttng_triggers *triggers, unsigned int index);
201
202/*
203 * Get the number of triggers in a trigger set.
204 *
205 * Return LTTNG_TRIGGER_STATUS_OK on success,
206 * LTTNG_TRIGGER_STATUS_INVALID when invalid parameters are passed.
207 */
208extern enum lttng_trigger_status lttng_triggers_get_count(
209 const struct lttng_triggers *triggers, unsigned int *count);
210
211/*
212 * Destroy a trigger set.
213 */
214extern void lttng_triggers_destroy(struct lttng_triggers *triggers);
215
216
a58c490f
JG
217#ifdef __cplusplus
218}
219#endif
220
221#endif /* LTTNG_TRIGGER_H */
This page took 0.065103 seconds and 4 git commands to generate.