rculfhash: check for callers from RCU read-side C.S.
[lttng-tools.git] / src / bin / lttng-sessiond / ust-registry.h
CommitLineData
d0b96690
DG
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>
d0b96690
DG
23
24#include <common/hashtable/hashtable.h>
25#include <common/compat/uuid.h>
26
7972aab2
DG
27#include "ust-ctl.h"
28
d0b96690
DG
29#define CTF_SPEC_MAJOR 1
30#define CTF_SPEC_MINOR 8
31
32struct ust_app;
33
34struct ust_registry_session {
35 /*
7972aab2 36 * With multiple writers and readers, use this lock to access the registry.
d0b96690
DG
37 * Can nest within the ust app session lock.
38 */
39 pthread_mutex_t lock;
40 /* Next channel ID available for a newly registered channel. */
41 uint32_t next_channel_id;
42 /* Once this value reaches UINT32_MAX, no more id can be allocated. */
43 uint32_t used_channel_id;
44 /* Universal unique identifier used by the tracer. */
45 unsigned char uuid[UUID_LEN];
46
47 /* session ABI description */
48
49 /* Size of long, in bits */
50 unsigned int bits_per_long;
51 /* Alignment, in bits */
52 unsigned int uint8_t_alignment,
53 uint16_t_alignment,
54 uint32_t_alignment,
55 uint64_t_alignment,
56 long_alignment;
57 /* endianness */
58 int byte_order; /* BIG_ENDIAN or LITTLE_ENDIAN */
59
60 /* Generated metadata. */
61 char *metadata; /* NOT null-terminated ! Use memcpy. */
62 size_t metadata_len, metadata_alloc_len;
d88aee68
DG
63 /* Length of bytes sent to the consumer. */
64 size_t metadata_len_sent;
45893984
DG
65 /*
66 * Hash table containing channels sent by the UST tracer. MUST be accessed
67 * with a RCU read side lock acquired.
68 */
69 struct lttng_ht *channels;
7972aab2
DG
70 /* Unique key to identify the metadata on the consumer side. */
71 uint64_t metadata_key;
72 /*
73 * Indicates if the metadata is closed on the consumer side. This is to
74 * avoid double close of metadata when an application unregisters AND
75 * deletes its sessions.
76 */
77 unsigned int metadata_closed;
d0b96690
DG
78};
79
80struct ust_registry_channel {
45893984 81 uint64_t key;
d0b96690
DG
82 /* Id set when replying to a register channel. */
83 uint32_t chan_id;
84 enum ustctl_channel_header header_type;
85
7972aab2
DG
86 /*
87 * Flag for this channel if the metadata was dumped once during
88 * registration. 0 means no, 1 yes.
89 */
90 unsigned int metadata_dumped;
91 /* Indicates if this channel registry has already been registered. */
92 unsigned int register_done;
93
d0b96690
DG
94 /*
95 * Hash table containing events sent by the UST tracer. MUST be accessed
96 * with a RCU read side lock acquired.
97 */
98 struct lttng_ht *ht;
99 /* Next event ID available for a newly registered event. */
100 uint32_t next_event_id;
101 /* Once this value reaches UINT32_MAX, no more id can be allocated. */
102 uint32_t used_event_id;
103 /*
104 * Context fields of the registry. Context are per channel. Allocated by a
105 * register channel notification from the UST tracer.
106 */
107 size_t nr_ctx_fields;
108 struct ustctl_field *ctx_fields;
45893984 109 struct lttng_ht_node_u64 node;
d0b96690
DG
110};
111
112/*
113 * Event registered from a UST tracer sent to the session daemon. This is
114 * indexed and matched by <event_name/signature>.
115 */
116struct ust_registry_event {
117 int id;
118 /* Both objd are set by the tracer. */
119 int session_objd;
120 int channel_objd;
121 /* Name of the event returned by the tracer. */
122 char name[LTTNG_UST_SYM_NAME_LEN];
123 char *signature;
124 int loglevel;
125 size_t nr_fields;
126 struct ustctl_field *fields;
127 char *model_emf_uri;
7972aab2
DG
128 struct lttng_ust_object_data *obj;
129 /*
130 * Flag for this channel if the metadata was dumped once during
131 * registration. 0 means no, 1 yes.
132 */
133 unsigned int metadata_dumped;
d0b96690
DG
134 /*
135 * Node in the ust-registry hash table. The event name is used to
136 * initialize the node and the event_name/signature for the match function.
137 */
7972aab2 138 struct lttng_ht_node_u64 node;
d0b96690
DG
139};
140
141/*
142 * Validate that the id has reached the maximum allowed or not.
143 *
144 * Return 0 if NOT else 1.
145 */
146static inline int ust_registry_is_max_id(uint32_t id)
147{
148 return (id == UINT32_MAX) ? 1 : 0;
149}
150
151/*
152 * Return next available event id and increment the used counter. The
153 * ust_registry_is_max_id function MUST be called before in order to validate
154 * if the maximum number of IDs have been reached. If not, it is safe to call
155 * this function.
156 *
157 * Return a unique channel ID. If max is reached, the used_event_id counter is
158 * returned.
159 */
160static inline uint32_t ust_registry_get_next_event_id(
161 struct ust_registry_channel *r)
162{
163 if (ust_registry_is_max_id(r->used_event_id)) {
164 return r->used_event_id;
165 }
166
167 r->used_event_id++;
168 return r->next_event_id++;
169}
170
171/*
172 * Return next available channel id and increment the used counter. The
173 * ust_registry_is_max_id function MUST be called before in order to validate
174 * if the maximum number of IDs have been reached. If not, it is safe to call
175 * this function.
176 *
177 * Return a unique channel ID. If max is reached, the used_channel_id counter
178 * is returned.
179 */
180static inline uint32_t ust_registry_get_next_chan_id(
181 struct ust_registry_session *r)
182{
183 if (ust_registry_is_max_id(r->used_channel_id)) {
184 return r->used_channel_id;
185 }
186
187 r->used_channel_id++;
188 return r->next_channel_id++;
189}
190
191/*
192 * Return registry event count. This is read atomically.
193 */
194static inline uint32_t ust_registry_get_event_count(
195 struct ust_registry_channel *r)
196{
197 return (uint32_t) uatomic_read(&r->used_event_id);
198}
199
7972aab2
DG
200#ifdef HAVE_LIBLTTNG_UST_CTL
201
d0b96690
DG
202void ust_registry_channel_destroy(struct ust_registry_session *session,
203 struct ust_registry_channel *chan);
45893984
DG
204struct ust_registry_channel *ust_registry_channel_find(
205 struct ust_registry_session *session, uint64_t key);
206int ust_registry_channel_add(struct ust_registry_session *session,
207 uint64_t key);
208void ust_registry_channel_del_free(struct ust_registry_session *session,
209 uint64_t key);
210
211int ust_registry_session_init(struct ust_registry_session **sessionp,
d0b96690
DG
212 struct ust_app *app,
213 uint32_t bits_per_long,
214 uint32_t uint8_t_alignment,
215 uint32_t uint16_t_alignment,
216 uint32_t uint32_t_alignment,
217 uint32_t uint64_t_alignment,
218 uint32_t long_alignment,
af6142cf
MD
219 int byte_order,
220 uint32_t major,
221 uint32_t minor);
d0b96690
DG
222void ust_registry_session_destroy(struct ust_registry_session *session);
223
224int ust_registry_create_event(struct ust_registry_session *session,
45893984
DG
225 uint64_t chan_key, int session_objd, int channel_objd, char *name,
226 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
7972aab2 227 char *model_emf_uri, int buffer_type, uint32_t *event_id_p);
d0b96690
DG
228struct ust_registry_event *ust_registry_find_event(
229 struct ust_registry_channel *chan, char *name, char *sig);
230void ust_registry_destroy_event(struct ust_registry_channel *chan,
231 struct ust_registry_event *event);
232
233/* app can be NULL for registry shared across applications. */
234int ust_metadata_session_statedump(struct ust_registry_session *session,
af6142cf 235 struct ust_app *app, uint32_t major, uint32_t minor);
d0b96690
DG
236int ust_metadata_channel_statedump(struct ust_registry_session *session,
237 struct ust_registry_channel *chan);
238int ust_metadata_event_statedump(struct ust_registry_session *session,
239 struct ust_registry_channel *chan,
240 struct ust_registry_event *event);
241
7972aab2
DG
242#else /* HAVE_LIBLTTNG_UST_CTL */
243
244static inline
245void ust_registry_channel_destroy(struct ust_registry_session *session,
246 struct ust_registry_channel *chan)
247{}
248static inline
249struct ust_registry_channel *ust_registry_channel_find(
250 struct ust_registry_session *session, uint64_t key)
251{
252 return NULL;
253}
254static inline
255int ust_registry_channel_add(struct ust_registry_session *session,
256 uint64_t key)
257{
258 return 0;
259}
260static inline
261void ust_registry_channel_del_free(struct ust_registry_session *session,
262 uint64_t key)
263{}
264static inline
265int ust_registry_session_init(struct ust_registry_session **sessionp,
266 struct ust_app *app,
267 uint32_t bits_per_long,
268 uint32_t uint8_t_alignment,
269 uint32_t uint16_t_alignment,
270 uint32_t uint32_t_alignment,
271 uint32_t uint64_t_alignment,
272 uint32_t long_alignment,
273 int byte_order)
274{
275 return 0;
276}
277static inline
278void ust_registry_session_destroy(struct ust_registry_session *session)
279{}
280static inline
281int ust_registry_create_event(struct ust_registry_session *session,
282 uint64_t chan_key, int session_objd, int channel_objd, char *name,
283 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
284 char *model_emf_uri, int buffer_type, uint32_t *event_id_p)
285{
286 return 0;
287}
288static inline
289struct ust_registry_event *ust_registry_find_event(
290 struct ust_registry_channel *chan, char *name, char *sig)
291{
292 return NULL;
293}
294static inline
295void ust_registry_destroy_event(struct ust_registry_channel *chan,
296 struct ust_registry_event *event)
297{}
298
299/* The app object can be NULL for registry shared across applications. */
300static inline
301int ust_metadata_session_statedump(struct ust_registry_session *session,
302 struct ust_app *app)
303{
304 return 0;
305}
306static inline
307int ust_metadata_channel_statedump(struct ust_registry_session *session,
308 struct ust_registry_channel *chan)
309{
310 return 0;
311}
312static inline
313int ust_metadata_event_statedump(struct ust_registry_session *session,
314 struct ust_registry_channel *chan,
315 struct ust_registry_event *event)
316{
317 return 0;
318}
319
320#endif /* HAVE_LIBLTTNG_UST_CTL */
321
d0b96690 322#endif /* LTTNG_UST_REGISTRY_H */
This page took 0.034612 seconds and 4 git commands to generate.