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