77b9a866657c940dde26ab19dc3a9ed748e714eb
[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
72 char root_shm_path[PATH_MAX];
73 char shm_path[PATH_MAX];
74 char metadata_path[PATH_MAX];
75 int metadata_fd; /* file-backed metadata FD */
76
77 /*
78 * Hash table containing channels sent by the UST tracer. MUST
79 * be accessed with a RCU read side lock acquired.
80 */
81 struct lttng_ht *channels;
82 /*
83 * Unique key to identify the metadata on the consumer side.
84 */
85 uint64_t metadata_key;
86 /*
87 * Indicates if the metadata is closed on the consumer side. This is to
88 * avoid double close of metadata when an application unregisters AND
89 * deletes its sessions.
90 */
91 unsigned int metadata_closed;
92
93 /* User and group owning the session. */
94 uid_t uid;
95 gid_t gid;
96
97 /* Enumerations table. */
98 struct lttng_ht *enums;
99
100 /*
101 * Copy of the tracer version when the first app is registered.
102 * It is used if we need to regenerate the metadata.
103 */
104 uint32_t major;
105 uint32_t minor;
106 };
107
108 struct ust_registry_channel {
109 uint64_t key;
110 /* Id set when replying to a register channel. */
111 uint32_t chan_id;
112 enum ustctl_channel_header header_type;
113
114 /*
115 * Flag for this channel if the metadata was dumped once during
116 * registration. 0 means no, 1 yes.
117 */
118 unsigned int metadata_dumped;
119 /* Indicates if this channel registry has already been registered. */
120 unsigned int register_done;
121
122 /*
123 * Hash table containing events sent by the UST tracer. MUST be accessed
124 * with a RCU read side lock acquired.
125 */
126 struct lttng_ht *ht;
127 /* Next event ID available for a newly registered event. */
128 uint32_t next_event_id;
129 /* Once this value reaches UINT32_MAX, no more id can be allocated. */
130 uint32_t used_event_id;
131 /*
132 * Context fields of the registry. Context are per channel. Allocated by a
133 * register channel notification from the UST tracer.
134 */
135 size_t nr_ctx_fields;
136 struct ustctl_field *ctx_fields;
137 struct lttng_ht_node_u64 node;
138 /* For delayed reclaim */
139 struct rcu_head rcu_head;
140 };
141
142 /*
143 * Event registered from a UST tracer sent to the session daemon. This is
144 * indexed and matched by <event_name/signature>.
145 */
146 struct ust_registry_event {
147 int id;
148 /* Both objd are set by the tracer. */
149 int session_objd;
150 int channel_objd;
151 /* Name of the event returned by the tracer. */
152 char name[LTTNG_UST_SYM_NAME_LEN];
153 char *signature;
154 int loglevel_value;
155 size_t nr_fields;
156 struct ustctl_field *fields;
157 char *model_emf_uri;
158 /*
159 * Flag for this channel if the metadata was dumped once during
160 * registration. 0 means no, 1 yes.
161 */
162 unsigned int metadata_dumped;
163 /*
164 * Node in the ust-registry hash table. The event name is used to
165 * initialize the node and the event_name/signature for the match function.
166 */
167 struct lttng_ht_node_u64 node;
168 };
169
170 struct ust_registry_enum {
171 char name[LTTNG_UST_SYM_NAME_LEN];
172 struct ustctl_enum_entry *entries;
173 size_t nr_entries;
174 uint64_t id; /* enum id in session */
175 /* Enumeration node in session hash table. */
176 struct lttng_ht_node_str node;
177 /* For delayed reclaim. */
178 struct rcu_head rcu_head;
179 };
180
181 /*
182 * Validate that the id has reached the maximum allowed or not.
183 *
184 * Return 0 if NOT else 1.
185 */
186 static inline int ust_registry_is_max_id(uint32_t id)
187 {
188 return (id == UINT32_MAX) ? 1 : 0;
189 }
190
191 /*
192 * Return next available event id and increment the used counter. The
193 * ust_registry_is_max_id function MUST be called before in order to validate
194 * if the maximum number of IDs have been reached. If not, it is safe to call
195 * this function.
196 *
197 * Return a unique channel ID. If max is reached, the used_event_id counter is
198 * returned.
199 */
200 static inline uint32_t ust_registry_get_next_event_id(
201 struct ust_registry_channel *r)
202 {
203 if (ust_registry_is_max_id(r->used_event_id)) {
204 return r->used_event_id;
205 }
206
207 r->used_event_id++;
208 return r->next_event_id++;
209 }
210
211 /*
212 * Return next available channel id and increment the used counter. The
213 * ust_registry_is_max_id function MUST be called before in order to validate
214 * if the maximum number of IDs have been reached. If not, it is safe to call
215 * this function.
216 *
217 * Return a unique channel ID. If max is reached, the used_channel_id counter
218 * is returned.
219 */
220 static inline uint32_t ust_registry_get_next_chan_id(
221 struct ust_registry_session *r)
222 {
223 if (ust_registry_is_max_id(r->used_channel_id)) {
224 return r->used_channel_id;
225 }
226
227 r->used_channel_id++;
228 return r->next_channel_id++;
229 }
230
231 /*
232 * Return registry event count. This is read atomically.
233 */
234 static inline uint32_t ust_registry_get_event_count(
235 struct ust_registry_channel *r)
236 {
237 return (uint32_t) uatomic_read(&r->used_event_id);
238 }
239
240 #ifdef HAVE_LIBLTTNG_UST_CTL
241
242 void ust_registry_channel_destroy(struct ust_registry_session *session,
243 struct ust_registry_channel *chan);
244 struct ust_registry_channel *ust_registry_channel_find(
245 struct ust_registry_session *session, uint64_t key);
246 int ust_registry_channel_add(struct ust_registry_session *session,
247 uint64_t key);
248 void ust_registry_channel_del_free(struct ust_registry_session *session,
249 uint64_t key);
250
251 int ust_registry_session_init(struct ust_registry_session **sessionp,
252 struct ust_app *app,
253 uint32_t bits_per_long,
254 uint32_t uint8_t_alignment,
255 uint32_t uint16_t_alignment,
256 uint32_t uint32_t_alignment,
257 uint32_t uint64_t_alignment,
258 uint32_t long_alignment,
259 int byte_order,
260 uint32_t major,
261 uint32_t minor,
262 const char *root_shm_path,
263 const char *shm_path,
264 uid_t euid,
265 gid_t egid);
266 void ust_registry_session_destroy(struct ust_registry_session *session);
267
268 int ust_registry_create_event(struct ust_registry_session *session,
269 uint64_t chan_key, int session_objd, int channel_objd, char *name,
270 char *sig, size_t nr_fields, struct ustctl_field *fields,
271 int loglevel_value, char *model_emf_uri, int buffer_type,
272 uint32_t *event_id_p, struct ust_app *app);
273 struct ust_registry_event *ust_registry_find_event(
274 struct ust_registry_channel *chan, char *name, char *sig);
275 void ust_registry_destroy_event(struct ust_registry_channel *chan,
276 struct ust_registry_event *event);
277
278 /* app can be NULL for registry shared across applications. */
279 int ust_metadata_session_statedump(struct ust_registry_session *session,
280 struct ust_app *app, uint32_t major, uint32_t minor);
281 int ust_metadata_channel_statedump(struct ust_registry_session *session,
282 struct ust_registry_channel *chan);
283 int ust_metadata_event_statedump(struct ust_registry_session *session,
284 struct ust_registry_channel *chan,
285 struct ust_registry_event *event);
286 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
287 int session_objd, char *name,
288 struct ustctl_enum_entry *entries, size_t nr_entries,
289 uint64_t *enum_id);
290 struct ust_registry_enum *
291 ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
292 const char *name, uint64_t id);
293
294 #else /* HAVE_LIBLTTNG_UST_CTL */
295
296 static inline
297 void ust_registry_channel_destroy(struct ust_registry_session *session,
298 struct ust_registry_channel *chan)
299 {}
300 static inline
301 struct ust_registry_channel *ust_registry_channel_find(
302 struct ust_registry_session *session, uint64_t key)
303 {
304 return NULL;
305 }
306 static inline
307 int ust_registry_channel_add(struct ust_registry_session *session,
308 uint64_t key)
309 {
310 return 0;
311 }
312 static inline
313 void ust_registry_channel_del_free(struct ust_registry_session *session,
314 uint64_t key)
315 {}
316 static inline
317 int ust_registry_session_init(struct ust_registry_session **sessionp,
318 struct ust_app *app,
319 uint32_t bits_per_long,
320 uint32_t uint8_t_alignment,
321 uint32_t uint16_t_alignment,
322 uint32_t uint32_t_alignment,
323 uint32_t uint64_t_alignment,
324 uint32_t long_alignment,
325 int byte_order)
326 {
327 return 0;
328 }
329 static inline
330 void ust_registry_session_destroy(struct ust_registry_session *session)
331 {}
332 static inline
333 int ust_registry_create_event(struct ust_registry_session *session,
334 uint64_t chan_key, int session_objd, int channel_objd, char *name,
335 char *sig, size_t nr_fields, struct ustctl_field *fields,
336 int loglevel_value, char *model_emf_uri, int buffer_type,
337 uint32_t *event_id_p)
338 {
339 return 0;
340 }
341 static inline
342 struct ust_registry_event *ust_registry_find_event(
343 struct ust_registry_channel *chan, char *name, char *sig)
344 {
345 return NULL;
346 }
347 static inline
348 void ust_registry_destroy_event(struct ust_registry_channel *chan,
349 struct ust_registry_event *event)
350 {}
351
352 /* The app object can be NULL for registry shared across applications. */
353 static inline
354 int ust_metadata_session_statedump(struct ust_registry_session *session,
355 struct ust_app *app)
356 {
357 return 0;
358 }
359 static inline
360 int ust_metadata_channel_statedump(struct ust_registry_session *session,
361 struct ust_registry_channel *chan)
362 {
363 return 0;
364 }
365 static inline
366 int ust_metadata_event_statedump(struct ust_registry_session *session,
367 struct ust_registry_channel *chan,
368 struct ust_registry_event *event)
369 {
370 return 0;
371 }
372 static inline
373 int ust_registry_create_or_find_enum(struct ust_registry_session *session,
374 int session_objd, char *name,
375 struct ustctl_enum_entry *entries, size_t nr_entries,
376 uint64_t *enum_id)
377 {
378 return 0;
379 }
380 static inline
381 struct ust_registry_enum *
382 ust_registry_lookup_enum_by_id(struct ust_registry_session *session,
383 const char *name, uint64_t id)
384 {
385 return NULL;
386 }
387
388 #endif /* HAVE_LIBLTTNG_UST_CTL */
389
390 #endif /* LTTNG_UST_REGISTRY_H */
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