include/lttng/ust-events.h

   1 #ifndef _LTTNG_UST_EVENTS_H
   2 #define _LTTNG_UST_EVENTS_H
   3
   4 /*
   5  * lttng/ust-events.h
   6  *
   7  * Copyright 2010-2012 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Holds LTTng per-session event registry.
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  */
  29
  30 #include <urcu/list.h>
  31 #include <urcu/hlist.h>
  32 #include <stdint.h>
  33 #include <lttng/ust-config.h>
  34 #include <lttng/ust-abi.h>
  35 #include <lttng/ust-tracer.h>
  36 #include <lttng/ust-endian.h>
  37 #include <float.h>
  38 #include <errno.h>
  39 #include <urcu/ref.h>
  40 #include <pthread.h>
  41
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46 #define LTTNG_UST_UUID_LEN              16
  47
  48 /*
  49  * Tracepoint provider version. Compatibility based on the major number.
  50  * Older tracepoint providers can always register to newer lttng-ust
  51  * library, but the opposite is rejected: a newer tracepoint provider is
  52  * rejected by an older lttng-ust library.
  53  */
  54 #define LTTNG_UST_PROVIDER_MAJOR        1
  55 #define LTTNG_UST_PROVIDER_MINOR        0
  56
  57 struct lttng_channel;
  58 struct lttng_session;
  59 struct lttng_ust_lib_ring_buffer_ctx;
  60
  61 /*
  62  * Data structures used by tracepoint event declarations, and by the
  63  * tracer. Those structures have padding for future extension.
  64  */
  65
  66 /*
  67  * LTTng client type enumeration. Used by the consumer to map the
  68  * callbacks from its own address space.
  69  */
  70 enum lttng_client_types {
  71         LTTNG_CLIENT_METADATA = 0,
  72         LTTNG_CLIENT_DISCARD = 1,
  73         LTTNG_CLIENT_OVERWRITE = 2,
  74         LTTNG_CLIENT_DISCARD_RT = 3,
  75         LTTNG_CLIENT_OVERWRITE_RT = 4,
  76         LTTNG_NR_CLIENT_TYPES,
  77 };
  78
  79 /* Type description */
  80
  81 /* Update the astract_types name table in lttng-types.c along with this enum */
  82 enum lttng_abstract_types {
  83         atype_integer,
  84         atype_enum,
  85         atype_array,
  86         atype_sequence,
  87         atype_string,
  88         atype_float,
  89         NR_ABSTRACT_TYPES,
  90 };
  91
  92 /* Update the string_encodings name table in lttng-types.c along with this enum */
  93 enum lttng_string_encodings {
  94         lttng_encode_none = 0,
  95         lttng_encode_UTF8 = 1,
  96         lttng_encode_ASCII = 2,
  97         NR_STRING_ENCODINGS,
  98 };
  99
 100 #define LTTNG_UST_ENUM_ENTRY_PADDING    16
 101 struct lttng_enum_entry {
 102         unsigned long long start, end;  /* start and end are inclusive */
 103         const char *string;
 104         char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
 105 };
 106
 107 #define __type_integer(_type, _byte_order, _base, _encoding)    \
 108         {                                                       \
 109           .atype = atype_integer,                               \
 110           .u =                                                  \
 111                 {                                               \
 112                   .basic =                                      \
 113                         {                                       \
 114                           .integer =                            \
 115                                 {                               \
 116                                   .size = sizeof(_type) * CHAR_BIT,             \
 117                                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
 118                                   .signedness = lttng_is_signed_type(_type),    \
 119                                   .reverse_byte_order = _byte_order != BYTE_ORDER, \
 120                                   .base = _base,                                \
 121                                   .encoding = lttng_encode_##_encoding,         \
 122                                 }                               \
 123                         }                                       \
 124                 },                                              \
 125         }                                                       \
 126
 127 #define LTTNG_UST_INTEGER_TYPE_PADDING  24
 128 struct lttng_integer_type {
 129         unsigned int size;              /* in bits */
 130         unsigned short alignment;       /* in bits */
 131         unsigned int signedness:1;
 132         unsigned int reverse_byte_order:1;
 133         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 134         enum lttng_string_encodings encoding;
 135         char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 136 };
 137
 138 /*
 139  * Only float and double are supported. long double is not supported at
 140  * the moment.
 141  */
 142 #define _float_mant_dig(_type)                                          \
 143         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 144                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 145                 : 0))
 146
 147 #define __type_float(_type)                                     \
 148         {                                                       \
 149           .atype = atype_float,                                 \
 150           .u =                                                  \
 151                 {                                               \
 152                   .basic =                                      \
 153                         {                                       \
 154                           ._float =                             \
 155                                 {                               \
 156                                   .exp_dig = sizeof(_type) * CHAR_BIT           \
 157                                                   - _float_mant_dig(_type),     \
 158                                   .mant_dig = _float_mant_dig(_type),           \
 159                                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
 160                                   .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
 161                                 }                               \
 162                         }                                       \
 163                 },                                              \
 164         }                                                       \
 165
 166 #define LTTNG_UST_FLOAT_TYPE_PADDING    24
 167 struct lttng_float_type {
 168         unsigned int exp_dig;           /* exponent digits, in bits */
 169         unsigned int mant_dig;          /* mantissa digits, in bits */
 170         unsigned short alignment;       /* in bits */
 171         unsigned int reverse_byte_order:1;
 172         char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 173 };
 174
 175 #define LTTNG_UST_BASIC_TYPE_PADDING    128
 176 union _lttng_basic_type {
 177         struct lttng_integer_type integer;
 178         struct {
 179                 const char *name;
 180         } enumeration;
 181         struct {
 182                 enum lttng_string_encodings encoding;
 183         } string;
 184         struct lttng_float_type _float;
 185         char padding[LTTNG_UST_BASIC_TYPE_PADDING];
 186 };
 187
 188 struct lttng_basic_type {
 189         enum lttng_abstract_types atype;
 190         union {
 191                 union _lttng_basic_type basic;
 192         } u;
 193 };
 194
 195 #define LTTNG_UST_TYPE_PADDING  128
 196 struct lttng_type {
 197         enum lttng_abstract_types atype;
 198         union {
 199                 union _lttng_basic_type basic;
 200                 struct {
 201                         struct lttng_basic_type elem_type;
 202                         unsigned int length;            /* num. elems. */
 203                 } array;
 204                 struct {
 205                         struct lttng_basic_type length_type;
 206                         struct lttng_basic_type elem_type;
 207                 } sequence;
 208                 char padding[LTTNG_UST_TYPE_PADDING];
 209         } u;
 210 };
 211
 212 #define LTTNG_UST_ENUM_TYPE_PADDING     24
 213 struct lttng_enum {
 214         const char *name;
 215         struct lttng_type container_type;
 216         const struct lttng_enum_entry *entries;
 217         unsigned int len;
 218         char padding[LTTNG_UST_ENUM_TYPE_PADDING];
 219 };
 220
 221 /*
 222  * Event field description
 223  *
 224  * IMPORTANT: this structure is part of the ABI between the probe and
 225  * UST. Fields need to be only added at the end, never reordered, never
 226  * removed.
 227  */
 228
 229 #define LTTNG_UST_EVENT_FIELD_PADDING   28
 230 struct lttng_event_field {
 231         const char *name;
 232         struct lttng_type type;
 233         unsigned int nowrite;   /* do not write into trace */
 234         char padding[LTTNG_UST_EVENT_FIELD_PADDING];
 235 };
 236
 237 union lttng_ctx_value {
 238         int64_t s64;
 239         const char *str;
 240         double d;
 241 };
 242
 243 struct lttng_perf_counter_field;
 244
 245 #define LTTNG_UST_CTX_FIELD_PADDING     40
 246 struct lttng_ctx_field {
 247         struct lttng_event_field event_field;
 248         size_t (*get_size)(size_t offset);
 249         void (*record)(struct lttng_ctx_field *field,
 250                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 251                        struct lttng_channel *chan);
 252         void (*get_value)(struct lttng_ctx_field *field,
 253                          union lttng_ctx_value *value);
 254         union {
 255                 struct lttng_perf_counter_field *perf_counter;
 256                 char padding[LTTNG_UST_CTX_FIELD_PADDING];
 257         } u;
 258         void (*destroy)(struct lttng_ctx_field *field);
 259 };
 260
 261 #define LTTNG_UST_CTX_PADDING   20
 262 struct lttng_ctx {
 263         struct lttng_ctx_field *fields;
 264         unsigned int nr_fields;
 265         unsigned int allocated_fields;
 266         unsigned int largest_align;
 267         char padding[LTTNG_UST_CTX_PADDING];
 268 };
 269
 270 #define LTTNG_UST_EVENT_DESC_PADDING    40
 271 struct lttng_event_desc {
 272         const char *name;
 273         void (*probe_callback)(void);
 274         const struct lttng_event_ctx *ctx;      /* context */
 275         const struct lttng_event_field *fields; /* event payload */
 276         unsigned int nr_fields;
 277         const int **loglevel;
 278         const char *signature;  /* Argument types/names received */
 279         union {
 280                 struct {
 281                         const char **model_emf_uri;
 282                 } ext;
 283                 char padding[LTTNG_UST_EVENT_DESC_PADDING];
 284         } u;
 285 };
 286
 287 #define LTTNG_UST_PROBE_DESC_PADDING    12
 288 struct lttng_probe_desc {
 289         const char *provider;
 290         const struct lttng_event_desc **event_desc;
 291         unsigned int nr_events;
 292         struct cds_list_head head;              /* chain registered probes */
 293         struct cds_list_head lazy_init_head;
 294         int lazy;                               /* lazy registration */
 295         uint32_t major;
 296         uint32_t minor;
 297         char padding[LTTNG_UST_PROBE_DESC_PADDING];
 298 };
 299
 300 /* Data structures used by the tracer. */
 301
 302 enum lttng_enabler_type {
 303         LTTNG_ENABLER_WILDCARD,
 304         LTTNG_ENABLER_EVENT,
 305 };
 306
 307 /*
 308  * Enabler field, within whatever object is enabling an event. Target of
 309  * backward reference.
 310  */
 311 struct lttng_enabler {
 312         enum lttng_enabler_type type;
 313
 314         /* head list of struct lttng_ust_filter_bytecode_node */
 315         struct cds_list_head filter_bytecode_head;
 316         /* head list of struct lttng_ust_excluder_node */
 317         struct cds_list_head excluder_head;
 318         struct cds_list_head node;      /* per-session list of enablers */
 319
 320         struct lttng_ust_event event_param;
 321         struct lttng_channel *chan;
 322         struct lttng_ctx *ctx;
 323         unsigned int enabled:1;
 324 };
 325
 326 struct tp_list_entry {
 327         struct lttng_ust_tracepoint_iter tp;
 328         struct cds_list_head head;
 329 };
 330
 331 struct lttng_ust_tracepoint_list {
 332         struct tp_list_entry *iter;
 333         struct cds_list_head head;
 334 };
 335
 336 struct tp_field_list_entry {
 337         struct lttng_ust_field_iter field;
 338         struct cds_list_head head;
 339 };
 340
 341 struct lttng_ust_field_list {
 342         struct tp_field_list_entry *iter;
 343         struct cds_list_head head;
 344 };
 345
 346 struct ust_pending_probe;
 347 struct lttng_event;
 348
 349 struct lttng_ust_filter_bytecode_node {
 350         struct cds_list_head node;
 351         struct lttng_enabler *enabler;
 352         /*
 353          * struct lttng_ust_filter_bytecode has var. sized array, must
 354          * be last field.
 355          */
 356         struct lttng_ust_filter_bytecode bc;
 357 };
 358
 359 struct lttng_ust_excluder_node {
 360         struct cds_list_head node;
 361         struct lttng_enabler *enabler;
 362         /*
 363          * struct lttng_ust_event_exclusion had variable sized array,
 364          * must be last field.
 365          */
 366         struct lttng_ust_event_exclusion excluder;
 367 };
 368 /*
 369  * Filter return value masks.
 370  */
 371 enum lttng_filter_ret {
 372         LTTNG_FILTER_DISCARD = 0,
 373         LTTNG_FILTER_RECORD_FLAG = (1ULL << 0),
 374         /* Other bits are kept for future use. */
 375 };
 376
 377 struct lttng_bytecode_runtime {
 378         /* Associated bytecode */
 379         struct lttng_ust_filter_bytecode_node *bc;
 380         uint64_t (*filter)(void *filter_data, const char *filter_stack_data);
 381         int link_failed;
 382         struct cds_list_head node;      /* list of bytecode runtime in event */
 383 };
 384
 385 /*
 386  * Objects in a linked-list of enablers, owned by an event.
 387  */
 388 struct lttng_enabler_ref {
 389         struct cds_list_head node;              /* enabler ref list */
 390         struct lttng_enabler *ref;              /* backward ref */
 391 };
 392
 393 /*
 394  * lttng_event structure is referred to by the tracing fast path. It
 395  * must be kept small.
 396  *
 397  * IMPORTANT: this structure is part of the ABI between the probe and
 398  * UST. Fields need to be only added at the end, never reordered, never
 399  * removed.
 400  */
 401 struct lttng_event {
 402         /* LTTng-UST 2.0 starts here */
 403         unsigned int id;
 404         struct lttng_channel *chan;
 405         int enabled;
 406         const struct lttng_event_desc *desc;
 407         void *_deprecated1;
 408         struct lttng_ctx *ctx;
 409         enum lttng_ust_instrumentation instrumentation;
 410         struct cds_list_head node;              /* Event list in session */
 411         struct cds_list_head _deprecated2;
 412         void *_deprecated3;
 413         unsigned int _deprecated4:1;
 414
 415         /* LTTng-UST 2.1 starts here */
 416         /* list of struct lttng_bytecode_runtime, sorted by seqnum */
 417         struct cds_list_head bytecode_runtime_head;
 418         int has_enablers_without_bytecode;
 419         /* Backward references: list of lttng_enabler_ref (ref to enablers) */
 420         struct cds_list_head enablers_ref_head;
 421         struct cds_hlist_node hlist;    /* session ht of events */
 422         int registered;                 /* has reg'd tracepoint probe */
 423 };
 424
 425 struct channel;
 426 struct lttng_ust_shm_handle;
 427
 428 /*
 429  * IMPORTANT: this structure is part of the ABI between the probe and
 430  * UST. Fields need to be only added at the end, never reordered, never
 431  * removed.
 432  */
 433 struct lttng_channel_ops {
 434         struct lttng_channel *(*channel_create)(const char *name,
 435                         void *buf_addr,
 436                         size_t subbuf_size, size_t num_subbuf,
 437                         unsigned int switch_timer_interval,
 438                         unsigned int read_timer_interval,
 439                         unsigned char *uuid,
 440                         uint32_t chan_id);
 441         void (*channel_destroy)(struct lttng_channel *chan);
 442         union {
 443                 void *_deprecated1;
 444                 unsigned long has_strcpy:1;             /* ABI has strcpy */
 445         } u;
 446         void *_deprecated2;
 447         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 448                              uint32_t event_id);
 449         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 450         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 451                         const void *src, size_t len);
 452         /*
 453          * packet_avail_size returns the available size in the current
 454          * packet. Note that the size returned is only a hint, since it
 455          * may change due to concurrent writes.
 456          */
 457         size_t (*packet_avail_size)(struct channel *chan,
 458                                     struct lttng_ust_shm_handle *handle);
 459         //wait_queue_head_t *(*get_reader_wait_queue)(struct channel *chan);
 460         //wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 461         int (*is_finalized)(struct channel *chan);
 462         int (*is_disabled)(struct channel *chan);
 463         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 464         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 465                         const char *src, size_t len);
 466 };
 467
 468 /*
 469  * IMPORTANT: this structure is part of the ABI between the probe and
 470  * UST. Fields need to be only added at the end, never reordered, never
 471  * removed.
 472  */
 473 struct lttng_channel {
 474         /*
 475          * The pointers located in this private data are NOT safe to be
 476          * dereferenced by the consumer. The only operations the
 477          * consumer process is designed to be allowed to do is to read
 478          * and perform subbuffer flush.
 479          */
 480         struct channel *chan;           /* Channel buffers */
 481         int enabled;
 482         struct lttng_ctx *ctx;
 483         /* Event ID management */
 484         struct lttng_session *session;
 485         int objd;                       /* Object associated to channel */
 486         unsigned int _deprecated1;
 487         unsigned int _deprecated2;
 488         struct cds_list_head node;      /* Channel list in session */
 489         const struct lttng_channel_ops *ops;
 490         int header_type;                /* 0: unset, 1: compact, 2: large */
 491         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 492         unsigned int _deprecated3:1;
 493
 494         /* Channel ID */
 495         unsigned int id;
 496         enum lttng_ust_chan_type type;
 497         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 498         int tstate:1;                   /* Transient enable state */
 499 };
 500
 501 #define LTTNG_UST_EVENT_HT_BITS         12
 502 #define LTTNG_UST_EVENT_HT_SIZE         (1U << LTTNG_UST_EVENT_HT_BITS)
 503
 504 struct lttng_ust_event_ht {
 505         struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
 506 };
 507
 508 /*
 509  * IMPORTANT: this structure is part of the ABI between the probe and
 510  * UST. Fields need to be only added at the end, never reordered, never
 511  * removed.
 512  */
 513 struct lttng_session {
 514         int active;                             /* Is trace session active ? */
 515         int been_active;                        /* Been active ? */
 516         int objd;                               /* Object associated */
 517         void *_deprecated1;
 518         struct cds_list_head chan_head;         /* Channel list head */
 519         struct cds_list_head events_head;       /* list of events */
 520         struct cds_list_head _deprecated2;
 521         struct cds_list_head node;              /* Session list */
 522         int _deprecated3;
 523         unsigned int _deprecated4:1;
 524
 525         /* New UST 2.1 */
 526         /* List of enablers */
 527         struct cds_list_head enablers_head;
 528         struct lttng_ust_event_ht events_ht;    /* ht of events */
 529         void *owner;                            /* object owner */
 530         int tstate:1;                           /* Transient enable state */
 531
 532         /* New UST 2.4 */
 533         int statedump_pending:1;
 534 };
 535
 536 struct lttng_transport {
 537         char *name;
 538         struct cds_list_head node;
 539         struct lttng_channel_ops ops;
 540         const struct lttng_ust_lib_ring_buffer_config *client_config;
 541 };
 542
 543 struct lttng_session *lttng_session_create(void);
 544 int lttng_session_enable(struct lttng_session *session);
 545 int lttng_session_disable(struct lttng_session *session);
 546 void lttng_session_destroy(struct lttng_session *session);
 547
 548 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 549                                        const char *transport_name,
 550                                        void *buf_addr,
 551                                        size_t subbuf_size, size_t num_subbuf,
 552                                        unsigned int switch_timer_interval,
 553                                        unsigned int read_timer_interval,
 554                                        int **shm_fd, int **wait_fd,
 555                                        uint64_t **memory_map_size,
 556                                        struct lttng_channel *chan_priv_init);
 557
 558 int lttng_channel_enable(struct lttng_channel *channel);
 559 int lttng_channel_disable(struct lttng_channel *channel);
 560
 561 struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
 562                 struct lttng_ust_event *event_param,
 563                 struct lttng_channel *chan);
 564 int lttng_enabler_enable(struct lttng_enabler *enabler);
 565 int lttng_enabler_disable(struct lttng_enabler *enabler);
 566 int lttng_enabler_attach_bytecode(struct lttng_enabler *enabler,
 567                 struct lttng_ust_filter_bytecode_node *bytecode);
 568 int lttng_enabler_attach_context(struct lttng_enabler *enabler,
 569                 struct lttng_ust_context *ctx);
 570 int lttng_enabler_attach_exclusion(struct lttng_enabler *enabler,
 571                 struct lttng_ust_excluder_node *excluder);
 572
 573 int lttng_attach_context(struct lttng_ust_context *context_param,
 574                 struct lttng_ctx **ctx, struct lttng_session *session);
 575 void lttng_context_init(void);
 576 void lttng_context_exit(void);
 577 extern struct lttng_ctx *lttng_static_ctx;      /* Used by filtering */
 578
 579 void lttng_transport_register(struct lttng_transport *transport);
 580 void lttng_transport_unregister(struct lttng_transport *transport);
 581
 582 void synchronize_trace(void);
 583
 584 int lttng_probe_register(struct lttng_probe_desc *desc);
 585 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 586 int lttng_fix_pending_events(void);
 587 int lttng_probes_init(void);
 588 void lttng_probes_exit(void);
 589 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 590 int lttng_get_context_index(struct lttng_ctx *ctx, const char *name);
 591 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p);
 592 void lttng_context_update(struct lttng_ctx *ctx);
 593 void lttng_remove_context_field(struct lttng_ctx **ctx_p,
 594                                 struct lttng_ctx_field *field);
 595 void lttng_destroy_context(struct lttng_ctx *ctx);
 596 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 597 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 598 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx);
 599 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 600 int lttng_add_ip_to_ctx(struct lttng_ctx **ctx);
 601 void lttng_context_vtid_reset(void);
 602 void lttng_context_vpid_reset(void);
 603
 604 #ifdef LTTNG_UST_HAVE_PERF_EVENT
 605 int lttng_add_perf_counter_to_ctx(uint32_t type,
 606                                   uint64_t config,
 607                                   const char *name,
 608                                   struct lttng_ctx **ctx);
 609 int lttng_perf_counter_init(void);
 610 void lttng_perf_counter_exit(void);
 611 #else /* #ifdef LTTNG_UST_HAVE_PERF_EVENT */
 612 static inline
 613 int lttng_add_perf_counter_to_ctx(uint32_t type,
 614                                   uint64_t config,
 615                                   const char *name,
 616                                   struct lttng_ctx **ctx)
 617 {
 618         return -ENOSYS;
 619 }
 620 static inline
 621 int lttng_perf_counter_init(void)
 622 {
 623         return 0;
 624 }
 625 static inline
 626 void lttng_perf_counter_exit(void)
 627 {
 628 }
 629 #endif /* #else #ifdef LTTNG_UST_HAVE_PERF_EVENT */
 630
 631 extern const struct lttng_ust_client_lib_ring_buffer_client_cb *lttng_client_callbacks_metadata;
 632 extern const struct lttng_ust_client_lib_ring_buffer_client_cb *lttng_client_callbacks_discard;
 633 extern const struct lttng_ust_client_lib_ring_buffer_client_cb *lttng_client_callbacks_overwrite;
 634
 635 struct lttng_transport *lttng_transport_find(const char *name);
 636
 637 int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list);
 638 void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list);
 639 struct lttng_ust_tracepoint_iter *
 640         lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list);
 641 int lttng_probes_get_field_list(struct lttng_ust_field_list *list);
 642 void lttng_probes_prune_field_list(struct lttng_ust_field_list *list);
 643 struct lttng_ust_field_iter *
 644         lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list);
 645
 646 void lttng_filter_event_link_bytecode(struct lttng_event *event);
 647 void lttng_enabler_event_link_bytecode(struct lttng_event *event,
 648                 struct lttng_enabler *enabler);
 649 void lttng_free_event_filter_runtime(struct lttng_event *event);
 650 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime);
 651
 652 struct cds_list_head *lttng_get_probe_list_head(void);
 653 int lttng_session_active(void);
 654
 655 typedef int (*t_statedump_func_ptr)(struct lttng_session *session);
 656 void lttng_handle_pending_statedump(void *owner);
 657 struct cds_list_head *_lttng_get_sessions(void);
 658
 659 #ifdef __cplusplus
 660 }
 661 #endif
 662
 663 #endif /* _LTTNG_UST_EVENTS_H */