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 the registry.
  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;
  63         /* Length of bytes sent to the consumer. */
  64         size_t metadata_len_sent;
  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;
  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;
  78 };
  79
  80 struct ust_registry_channel {
  81         uint64_t key;
  82         /* Id set when replying to a register channel. */
  83         uint32_t chan_id;
  84         enum ustctl_channel_header header_type;
  85
  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
  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;
 109         struct lttng_ht_node_u64 node;
 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  */
 116 struct 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;
 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;
 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          */
 138         struct lttng_ht_node_u64 node;
 139 };
 140
 141 /*
 142  * Validate that the id has reached the maximum allowed or not.
 143  *
 144  * Return 0 if NOT else 1.
 145  */
 146 static 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  */
 160 static 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  */
 180 static 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  */
 194 static 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
 200 #ifdef HAVE_LIBLTTNG_UST_CTL
 201
 202 void ust_registry_channel_destroy(struct ust_registry_session *session,
 203                 struct ust_registry_channel *chan);
 204 struct ust_registry_channel *ust_registry_channel_find(
 205                 struct ust_registry_session *session, uint64_t key);
 206 int ust_registry_channel_add(struct ust_registry_session *session,
 207                 uint64_t key);
 208 void ust_registry_channel_del_free(struct ust_registry_session *session,
 209                 uint64_t key);
 210
 211 int ust_registry_session_init(struct ust_registry_session **sessionp,
 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,
 219                 int byte_order);
 220 void ust_registry_session_destroy(struct ust_registry_session *session);
 221
 222 int ust_registry_create_event(struct ust_registry_session *session,
 223                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 224                 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
 225                 char *model_emf_uri, int buffer_type, uint32_t *event_id_p);
 226 struct ust_registry_event *ust_registry_find_event(
 227                 struct ust_registry_channel *chan, char *name, char *sig);
 228 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 229                 struct ust_registry_event *event);
 230
 231 /* app can be NULL for registry shared across applications. */
 232 int ust_metadata_session_statedump(struct ust_registry_session *session,
 233                 struct ust_app *app);
 234 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 235                 struct ust_registry_channel *chan);
 236 int ust_metadata_event_statedump(struct ust_registry_session *session,
 237                 struct ust_registry_channel *chan,
 238                 struct ust_registry_event *event);
 239
 240 #else /* HAVE_LIBLTTNG_UST_CTL */
 241
 242 static inline
 243 void ust_registry_channel_destroy(struct ust_registry_session *session,
 244                 struct ust_registry_channel *chan)
 245 {}
 246 static inline
 247 struct ust_registry_channel *ust_registry_channel_find(
 248                 struct ust_registry_session *session, uint64_t key)
 249 {
 250         return NULL;
 251 }
 252 static inline
 253 int ust_registry_channel_add(struct ust_registry_session *session,
 254                 uint64_t key)
 255 {
 256         return 0;
 257 }
 258 static inline
 259 void ust_registry_channel_del_free(struct ust_registry_session *session,
 260                 uint64_t key)
 261 {}
 262 static inline
 263 int ust_registry_session_init(struct ust_registry_session **sessionp,
 264                 struct ust_app *app,
 265                 uint32_t bits_per_long,
 266                 uint32_t uint8_t_alignment,
 267                 uint32_t uint16_t_alignment,
 268                 uint32_t uint32_t_alignment,
 269                 uint32_t uint64_t_alignment,
 270                 uint32_t long_alignment,
 271                 int byte_order)
 272 {
 273         return 0;
 274 }
 275 static inline
 276 void ust_registry_session_destroy(struct ust_registry_session *session)
 277 {}
 278 static inline
 279 int ust_registry_create_event(struct ust_registry_session *session,
 280                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 281                 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
 282                 char *model_emf_uri, int buffer_type, uint32_t *event_id_p)
 283 {
 284         return 0;
 285 }
 286 static inline
 287 struct ust_registry_event *ust_registry_find_event(
 288                 struct ust_registry_channel *chan, char *name, char *sig)
 289 {
 290         return NULL;
 291 }
 292 static inline
 293 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 294                 struct ust_registry_event *event)
 295 {}
 296
 297 /* The app object can be NULL for registry shared across applications. */
 298 static inline
 299 int ust_metadata_session_statedump(struct ust_registry_session *session,
 300                 struct ust_app *app)
 301 {
 302         return 0;
 303 }
 304 static inline
 305 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 306                 struct ust_registry_channel *chan)
 307 {
 308         return 0;
 309 }
 310 static inline
 311 int ust_metadata_event_statedump(struct ust_registry_session *session,
 312                 struct ust_registry_channel *chan,
 313                 struct ust_registry_event *event)
 314 {
 315         return 0;
 316 }
 317
 318 #endif /* HAVE_LIBLTTNG_UST_CTL */
 319
 320 #endif /* LTTNG_UST_REGISTRY_H */