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         /* Universal unique identifier used by the tracer. */
  49         unsigned char uuid[UUID_LEN];
  50
  51         /* session ABI description */
  52
  53         /* Size of long, in bits */
  54         unsigned int bits_per_long;
  55         /* Alignment, in bits */
  56         unsigned int uint8_t_alignment,
  57                 uint16_t_alignment,
  58                 uint32_t_alignment,
  59                 uint64_t_alignment,
  60                 long_alignment;
  61         /* endianness */
  62         int byte_order; /* BIG_ENDIAN or LITTLE_ENDIAN */
  63
  64         /* Generated metadata. */
  65         char *metadata;         /* NOT null-terminated ! Use memcpy. */
  66         size_t metadata_len, metadata_alloc_len;
  67         /* Length of bytes sent to the consumer. */
  68         size_t metadata_len_sent;
  69         /*
  70          * Hash table containing channels sent by the UST tracer. MUST
  71          * be accessed with a RCU read side lock acquired.
  72          */
  73         struct lttng_ht *channels;
  74         /*
  75          * Unique key to identify the metadata on the consumer side.
  76          */
  77         uint64_t metadata_key;
  78         /*
  79          * Indicates if the metadata is closed on the consumer side. This is to
  80          * avoid double close of metadata when an application unregisters AND
  81          * deletes its sessions.
  82          */
  83         unsigned int metadata_closed;
  84 };
  85
  86 struct ust_registry_channel {
  87         uint64_t key;
  88         /* Id set when replying to a register channel. */
  89         uint32_t chan_id;
  90         enum ustctl_channel_header header_type;
  91
  92         /*
  93          * Flag for this channel if the metadata was dumped once during
  94          * registration. 0 means no, 1 yes.
  95          */
  96         unsigned int metadata_dumped;
  97         /* Indicates if this channel registry has already been registered. */
  98         unsigned int register_done;
  99
 100         /*
 101          * Hash table containing events sent by the UST tracer. MUST be accessed
 102          * with a RCU read side lock acquired.
 103          */
 104         struct lttng_ht *ht;
 105         /* Next event ID available for a newly registered event. */
 106         uint32_t next_event_id;
 107         /* Once this value reaches UINT32_MAX, no more id can be allocated. */
 108         uint32_t used_event_id;
 109         /*
 110          * Context fields of the registry. Context are per channel. Allocated by a
 111          * register channel notification from the UST tracer.
 112          */
 113         size_t nr_ctx_fields;
 114         struct ustctl_field *ctx_fields;
 115         struct lttng_ht_node_u64 node;
 116         /* For delayed reclaim */
 117         struct rcu_head rcu_head;
 118 };
 119
 120 /*
 121  * Event registered from a UST tracer sent to the session daemon. This is
 122  * indexed and matched by <event_name/signature>.
 123  */
 124 struct ust_registry_event {
 125         int id;
 126         /* Both objd are set by the tracer. */
 127         int session_objd;
 128         int channel_objd;
 129         /* Name of the event returned by the tracer. */
 130         char name[LTTNG_UST_SYM_NAME_LEN];
 131         char *signature;
 132         int loglevel;
 133         size_t nr_fields;
 134         struct ustctl_field *fields;
 135         char *model_emf_uri;
 136         /*
 137          * Flag for this channel if the metadata was dumped once during
 138          * registration. 0 means no, 1 yes.
 139          */
 140         unsigned int metadata_dumped;
 141         /*
 142          * Node in the ust-registry hash table. The event name is used to
 143          * initialize the node and the event_name/signature for the match function.
 144          */
 145         struct lttng_ht_node_u64 node;
 146 };
 147
 148 /*
 149  * Validate that the id has reached the maximum allowed or not.
 150  *
 151  * Return 0 if NOT else 1.
 152  */
 153 static inline int ust_registry_is_max_id(uint32_t id)
 154 {
 155         return (id == UINT32_MAX) ? 1 : 0;
 156 }
 157
 158 /*
 159  * Return next available event id and increment the used counter. The
 160  * ust_registry_is_max_id function MUST be called before in order to validate
 161  * if the maximum number of IDs have been reached. If not, it is safe to call
 162  * this function.
 163  *
 164  * Return a unique channel ID. If max is reached, the used_event_id counter is
 165  * returned.
 166  */
 167 static inline uint32_t ust_registry_get_next_event_id(
 168                 struct ust_registry_channel *r)
 169 {
 170         if (ust_registry_is_max_id(r->used_event_id)) {
 171                 return r->used_event_id;
 172         }
 173
 174         r->used_event_id++;
 175         return r->next_event_id++;
 176 }
 177
 178 /*
 179  * Return next available channel id and increment the used counter. The
 180  * ust_registry_is_max_id function MUST be called before in order to validate
 181  * if the maximum number of IDs have been reached. If not, it is safe to call
 182  * this function.
 183  *
 184  * Return a unique channel ID. If max is reached, the used_channel_id counter
 185  * is returned.
 186  */
 187 static inline uint32_t ust_registry_get_next_chan_id(
 188                 struct ust_registry_session *r)
 189 {
 190         if (ust_registry_is_max_id(r->used_channel_id)) {
 191                 return r->used_channel_id;
 192         }
 193
 194         r->used_channel_id++;
 195         return r->next_channel_id++;
 196 }
 197
 198 /*
 199  * Return registry event count. This is read atomically.
 200  */
 201 static inline uint32_t ust_registry_get_event_count(
 202                 struct ust_registry_channel *r)
 203 {
 204         return (uint32_t) uatomic_read(&r->used_event_id);
 205 }
 206
 207 #ifdef HAVE_LIBLTTNG_UST_CTL
 208
 209 void ust_registry_channel_destroy(struct ust_registry_session *session,
 210                 struct ust_registry_channel *chan);
 211 struct ust_registry_channel *ust_registry_channel_find(
 212                 struct ust_registry_session *session, uint64_t key);
 213 int ust_registry_channel_add(struct ust_registry_session *session,
 214                 uint64_t key);
 215 void ust_registry_channel_del_free(struct ust_registry_session *session,
 216                 uint64_t key);
 217
 218 int ust_registry_session_init(struct ust_registry_session **sessionp,
 219                 struct ust_app *app,
 220                 uint32_t bits_per_long,
 221                 uint32_t uint8_t_alignment,
 222                 uint32_t uint16_t_alignment,
 223                 uint32_t uint32_t_alignment,
 224                 uint32_t uint64_t_alignment,
 225                 uint32_t long_alignment,
 226                 int byte_order,
 227                 uint32_t major,
 228                 uint32_t minor);
 229 void ust_registry_session_destroy(struct ust_registry_session *session);
 230
 231 int ust_registry_create_event(struct ust_registry_session *session,
 232                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 233                 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
 234                 char *model_emf_uri, int buffer_type, uint32_t *event_id_p,
 235                 struct ust_app *app);
 236 struct ust_registry_event *ust_registry_find_event(
 237                 struct ust_registry_channel *chan, char *name, char *sig);
 238 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 239                 struct ust_registry_event *event);
 240
 241 /* app can be NULL for registry shared across applications. */
 242 int ust_metadata_session_statedump(struct ust_registry_session *session,
 243                 struct ust_app *app, uint32_t major, uint32_t minor);
 244 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 245                 struct ust_registry_channel *chan);
 246 int ust_metadata_event_statedump(struct ust_registry_session *session,
 247                 struct ust_registry_channel *chan,
 248                 struct ust_registry_event *event);
 249
 250 #else /* HAVE_LIBLTTNG_UST_CTL */
 251
 252 static inline
 253 void ust_registry_channel_destroy(struct ust_registry_session *session,
 254                 struct ust_registry_channel *chan)
 255 {}
 256 static inline
 257 struct ust_registry_channel *ust_registry_channel_find(
 258                 struct ust_registry_session *session, uint64_t key)
 259 {
 260         return NULL;
 261 }
 262 static inline
 263 int ust_registry_channel_add(struct ust_registry_session *session,
 264                 uint64_t key)
 265 {
 266         return 0;
 267 }
 268 static inline
 269 void ust_registry_channel_del_free(struct ust_registry_session *session,
 270                 uint64_t key)
 271 {}
 272 static inline
 273 int ust_registry_session_init(struct ust_registry_session **sessionp,
 274                 struct ust_app *app,
 275                 uint32_t bits_per_long,
 276                 uint32_t uint8_t_alignment,
 277                 uint32_t uint16_t_alignment,
 278                 uint32_t uint32_t_alignment,
 279                 uint32_t uint64_t_alignment,
 280                 uint32_t long_alignment,
 281                 int byte_order)
 282 {
 283         return 0;
 284 }
 285 static inline
 286 void ust_registry_session_destroy(struct ust_registry_session *session)
 287 {}
 288 static inline
 289 int ust_registry_create_event(struct ust_registry_session *session,
 290                 uint64_t chan_key, int session_objd, int channel_objd, char *name,
 291                 char *sig, size_t nr_fields, struct ustctl_field *fields, int loglevel,
 292                 char *model_emf_uri, int buffer_type, uint32_t *event_id_p)
 293 {
 294         return 0;
 295 }
 296 static inline
 297 struct ust_registry_event *ust_registry_find_event(
 298                 struct ust_registry_channel *chan, char *name, char *sig)
 299 {
 300         return NULL;
 301 }
 302 static inline
 303 void ust_registry_destroy_event(struct ust_registry_channel *chan,
 304                 struct ust_registry_event *event)
 305 {}
 306
 307 /* The app object can be NULL for registry shared across applications. */
 308 static inline
 309 int ust_metadata_session_statedump(struct ust_registry_session *session,
 310                 struct ust_app *app)
 311 {
 312         return 0;
 313 }
 314 static inline
 315 int ust_metadata_channel_statedump(struct ust_registry_session *session,
 316                 struct ust_registry_channel *chan)
 317 {
 318         return 0;
 319 }
 320 static inline
 321 int ust_metadata_event_statedump(struct ust_registry_session *session,
 322                 struct ust_registry_channel *chan,
 323                 struct ust_registry_event *event)
 324 {
 325         return 0;
 326 }
 327
 328 #endif /* HAVE_LIBLTTNG_UST_CTL */
 329
 330 #endif /* LTTNG_UST_REGISTRY_H */