Implement consumer ring buffer position sampling
[lttng-tools.git] / src / bin / lttng-sessiond / ust-registry.h
1 /*
2 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program 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 General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #ifndef LTTNG_UST_REGISTRY_H
19 #define LTTNG_UST_REGISTRY_H
20
21 #include <pthread.h>
22 #include <stdint.h>
23
24 #include <common/hashtable/hashtable.h>
25 #include <common/compat/uuid.h>
26
27 #include "ust-ctl.h"
28
29 #define CTF_SPEC_MAJOR 1
30 #define CTF_SPEC_MINOR 8
31
32 struct ust_app;
33
34 struct ust_registry_session {
35 /*
36 * With multiple writers and readers, use this lock to access
37 * the registry. Can nest within the ust app session lock.
38 * Also acts as a registry serialization lock. Used by registry
39 * readers to serialize the registry information sent from the
40 * sessiond to the consumerd.
41 * The consumer socket lock nests within this lock.
42 */
43 pthread_mutex_t lock;
44 /* Next channel ID available for a newly registered channel. */
45 uint32_t next_channel_id;
46 /* Once this value reaches UINT32_MAX, no more id can be allocated. */
47 uint32_t used_channel_id;
48 /* Next enumeration ID available. */
49 uint64_t next_enum_id;
50 /* Universal unique identifier used by the tracer. */
51 unsigned char uuid[UUID_LEN];
52
53 /* session ABI description */
54
55 /* Size of long, in bits */
56 unsigned int bits_per_long;
57 /* Alignment, in bits */
58 unsigned int uint8_t_alignment,
59 uint16_t_alignment,
60 uint32_t_alignment,
61 uint64_t_alignment,
62 long_alignment;
63 /* endianness */
64 int byte_order; /* BIG_ENDIAN or LITTLE_ENDIAN */
65
66 /* Generated metadata. */
67 char *metadata; /* NOT null-terminated ! Use memcpy. */
68 size_t metadata_len, metadata_alloc_len;
69 /* Length of bytes sent to the consumer. */
70 size_t metadata_len_sent;
71 /* Current version of the metadata. */
72 uint64_t metadata_version;
73
74 char root_shm_path[PATH_MAX];
75 char shm_path[PATH_MAX];
76 char metadata_path[PATH_MAX];
77 int metadata_fd; /* file-backed metadata FD */
78
79 /*
80 * Hash table containing channels sent by the UST tracer. MUST
81 * be accessed with a RCU read side lock acquired.
82 */
83 struct lttng_ht *channels;
84 /*
85 * Unique key to identify the metadata on the consumer side.
86 */
87 uint64_t metadata_key;
88 /*
89 * Indicates if the metadata is closed on the consumer side. This is to
90 * avoid double close of metadata when an application unregisters AND
91 * deletes its sessions.
92 */
93 unsigned int metadata_closed;
94
95 /* User and group owning the session. */
96 uid_t uid;
97 gid_t gid;
98
99 /* Enumerations table. */
100 struct lttng_ht *enums;
101
102 /*
103 * Copy of the tracer version when the first app is registered.
104 * It is used if we need to regenerate the metadata.
105 */
106 uint32_t major;
107 uint32_t minor;
108 };
109
110 struct ust_registry_channel {
111 uint64_t key;
112 uint64_t consumer_key;
113 /* Id set when replying to a register channel. */
114 uint32_t chan_id;
115 enum ustctl_channel_header header_type;
116
117 /*
118 * Flag for this channel if the metadata was dumped once during
119 * registration. 0 means no, 1 yes.
120 */
121 unsigned int metadata_dumped;
122 /* Indicates if this channel registry has already been registered. */
123 unsigned int register_done;
124
125 /*
126 * Hash table containing events sent by the UST tracer. MUST be accessed
127 * with a RCU read side lock acquired.
128 */
129 struct lttng_ht *ht;
130 /* Next event ID available for a newly registered event. */
131 uint32_t next_event_id;
132 /* Once this value reaches UINT32_MAX, no more id can be allocated. */
133 uint32_t used_event_id;
134 /*
135 * Context fields of the registry. Context are per channel. Allocated by a
136 * register channel notification from the UST tracer.
137 */
138 size_t nr_ctx_fields;
139 struct ustctl_field *ctx_fields;
140 struct lttng_ht_node_u64 node;
141 /* For delayed reclaim */
142 struct rcu_head rcu_head;
143 };
144
145 /*
146 * Event registered from a UST tracer sent to the session daemon. This is
147 * indexed and matched by <event_name/signature>.
148 */
149 struct ust_registry_event {
150 int id;
151 /* Both objd are set by the tracer. */
152 int session_objd;
153 int channel_objd;
154 /* Name of the event returned by the tracer. */
155 char name[LTTNG_UST_SYM_NAME_LEN];
156 char *signature;
157 int loglevel_value;
158 size_t nr_fields;
159 struct ustctl_field *fields;
160 char *model_emf_uri;
161 /*
162 * Flag for this channel if the metadata was dumped once during
163 * registration. 0 means no, 1 yes.
164 */
165 unsigned int metadata_dumped;
166 /*
167 * Node in the ust-registry hash table. The event name is used to
168 * initialize the node and the event_name/signature for the match function.
169 */
170 struct lttng_ht_node_u64 node;
171 };
172
173 struct ust_registry_enum {
174 char name[LTTNG_UST_SYM_NAME_LEN];
175 struct ustctl_enum_entry *entries;
176 size_t nr_entries;
177 uint64_t id; /* enum id in session */
178 /* Enumeration node in session hash table. */
179 struct lttng_ht_node_str node;
180 /* For delayed reclaim. */
181 struct rcu_head rcu_head;
182 };
183
184 /*
185 * Validate that the id has reached the maximum allowed or not.
186 *
187 * Return 0 if NOT else 1.
188 */
189 static inline int ust_registry_is_max_id(uint32_t id)
190 {
191 return (id == UINT32_MAX) ? 1 : 0;
192 }
193
194 /*
195 * Return next available event id and increment the used counter. The
196 * ust_registry_is_max_id function MUST be called before in order to validate
197 * if the maximum number of IDs have been reached. If not, it is safe to call
198 * this function.
199 *
200 * Return a unique channel ID. If max is reached, the used_event_id counter is
201 * returned.
202 */
203 static inline uint32_t ust_registry_get_next_event_id(
204 struct ust_registry_channel *r)
205 {
206 if (ust_registry_is_max_id(r->used_event_id)) {
207 return r->used_event_id;
208 }
209
210 r->used_event_id++;
211 return r->next_event_id++;
212 }
213
214 /*
215 * Return next available channel id and increment the used counter. The
216 * ust_registry_is_max_id function MUST be called before in order to validate
217 * if the maximum number of IDs have been reached. If not, it is safe to call
218 * this function.
219 *
220 * Return a unique channel ID. If max is reached, the used_channel_id counter
221 * is returned.
222 */
223 static inline uint32_t ust_registry_get_next_chan_id(
224 struct ust_registry_session *r)
225 {
226 if (ust_registry_is_max_id(r->used_channel_id)) {
227 return r->used_channel_id;
228 }
229
230 r->used_channel_id++;
231 return r->next_channel_id++;
232 }
233
234 /*
235 * Return registry event count. This is read atomically.
236 */
237 static inline uint32_t ust_registry_get_event_count(
238 struct ust_registry_channel *r)
239 {
240 return (uint32_t) uatomic_read(&r->used_event_id);
241 }
242
243 #ifdef HAVE_LIBLTTNG_UST_CTL
244
245 void ust_registry_channel_destroy(struct ust_registry_session *session,
246 struct ust_registry_channel *chan);
247 struct ust_registry_channel *ust_registry_channel_find(
248 struct ust_registry_session *session, uint64_t key);
249 int ust_registry_channel_add(struct ust_registry_session *session,
250 uint64_t key);
251 void ust_registry_channel_del_free(struct ust_registry_session *session,
252 uint64_t key, bool notif);
253
254 int ust_registry_session_init(struct ust_registry_session **sessionp,
255 struct ust_app *app,
256 uint32_t bits_per_long,
257 uint32_t uint8_t_alignment,
258 uint32_t uint16_t_alignment,
259 uint32_t uint32_t_alignment,
260 uint32_t uint64_t_alignment,
261 uint32_t long_alignment,
262 int byte_order,
263 uint32_t major,
264 uint32_t minor,
265 const char *root_shm_path,
266 const char *shm_path,
267 uid_t euid,
268 gid_t egid);
269 void ust_registry_session_destroy(struct ust_registry_session *session);
270
271 int ust_registry_create_event(struct ust_registry_session *session,
272 uint64_t chan_key, int session_objd, int channel_objd, char *name,
273 char *sig, size_t nr_fields, struct ustctl_field *fields,
274 int loglevel_value, char *model_emf_uri, int buffer_type,
275 uint32_t *event_id_p, struct ust_app *app);
276 struct ust_registry_event *ust_registry_find_event(
277 struct ust_registry_channel *chan, char *name, char *sig);
278 void ust_registry_destroy_event(struct ust_registry_channel *chan,
279 struct ust_registry_event *event);
280
281 /* app can be NULL for registry shared across applications. */
282 int ust_metadata_session_statedump(struct ust_registry_session *session,
283 struct ust_app *app, uint32_t major, uint32_t minor);
284 int ust_metadata_channel_statedump(struct ust_registry_session *session,
285 struct ust_registry_channel *chan);
286 int ust_metadata_event_statedump(struct ust_registry_session *session,
287 struct ust_registry_channel *chan,
288 struct ust_registry_event *event);
289 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
290 int session_objd, char *name,
291 struct ustctl_enum_entry *entries, size_t nr_entries,
292 uint64_t *enum_id);
293 struct ust_registry_enum *
294 ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
295 const char *name, uint64_t id);
296
297 #else /* HAVE_LIBLTTNG_UST_CTL */
298
299 static inline
300 void ust_registry_channel_destroy(struct ust_registry_session *session,
301 struct ust_registry_channel *chan)
302 {}
303 static inline
304 struct ust_registry_channel *ust_registry_channel_find(
305 struct ust_registry_session *session, uint64_t key)
306 {
307 return NULL;
308 }
309 static inline
310 int ust_registry_channel_add(struct ust_registry_session *session,
311 uint64_t key)
312 {
313 return 0;
314 }
315 static inline
316 void ust_registry_channel_del_free(struct ust_registry_session *session,
317 uint64_t key, bool notif)
318 {}
319 static inline
320 int ust_registry_session_init(struct ust_registry_session **sessionp,
321 struct ust_app *app,
322 uint32_t bits_per_long,
323 uint32_t uint8_t_alignment,
324 uint32_t uint16_t_alignment,
325 uint32_t uint32_t_alignment,
326 uint32_t uint64_t_alignment,
327 uint32_t long_alignment,
328 int byte_order)
329 {
330 return 0;
331 }
332 static inline
333 void ust_registry_session_destroy(struct ust_registry_session *session)
334 {}
335 static inline
336 int ust_registry_create_event(struct ust_registry_session *session,
337 uint64_t chan_key, int session_objd, int channel_objd, char *name,
338 char *sig, size_t nr_fields, struct ustctl_field *fields,
339 int loglevel_value, char *model_emf_uri, int buffer_type,
340 uint32_t *event_id_p)
341 {
342 return 0;
343 }
344 static inline
345 struct ust_registry_event *ust_registry_find_event(
346 struct ust_registry_channel *chan, char *name, char *sig)
347 {
348 return NULL;
349 }
350 static inline
351 void ust_registry_destroy_event(struct ust_registry_channel *chan,
352 struct ust_registry_event *event)
353 {}
354
355 /* The app object can be NULL for registry shared across applications. */
356 static inline
357 int ust_metadata_session_statedump(struct ust_registry_session *session,
358 struct ust_app *app, uint32_t major, uint32_t minor)
359 {
360 return 0;
361 }
362 static inline
363 int ust_metadata_channel_statedump(struct ust_registry_session *session,
364 struct ust_registry_channel *chan)
365 {
366 return 0;
367 }
368 static inline
369 int ust_metadata_event_statedump(struct ust_registry_session *session,
370 struct ust_registry_channel *chan,
371 struct ust_registry_event *event)
372 {
373 return 0;
374 }
375 static inline
376 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
377 int session_objd, char *name,
378 struct ustctl_enum_entry *entries, size_t nr_entries,
379 uint64_t *enum_id)
380 {
381 return 0;
382 }
383 static inline
384 struct ust_registry_enum *
385 ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
386 const char *name, uint64_t id)
387 {
388 return NULL;
389 }
390
391 #endif /* HAVE_LIBLTTNG_UST_CTL */
392
393 #endif /* LTTNG_UST_REGISTRY_H */
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