include/lttng/ust-events.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * Holds LTTng per-session event registry.
   7  */
   8
   9 #ifndef _LTTNG_UST_EVENTS_H
  10 #define _LTTNG_UST_EVENTS_H
  11
  12 #include <urcu/list.h>
  13 #include <urcu/hlist.h>
  14 #include <stddef.h>
  15 #include <stdint.h>
  16 #include <lttng/ust-abi.h>
  17 #include <lttng/ust-tracer.h>
  18 #include <lttng/ust-endian.h>
  19 #include <float.h>
  20 #include <errno.h>
  21 #include <urcu/ref.h>
  22 #include <pthread.h>
  23
  24 #ifndef LTTNG_PACKED
  25 #error "LTTNG_PACKED should be defined"
  26 #endif
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif
  31
  32 #define LTTNG_UST_UUID_LEN              16
  33
  34 /*
  35  * Tracepoint provider version. Compatibility based on the major number.
  36  * Older tracepoint providers can always register to newer lttng-ust
  37  * library, but the opposite is rejected: a newer tracepoint provider is
  38  * rejected by an older lttng-ust library.
  39  */
  40 #define LTTNG_UST_PROVIDER_MAJOR        2
  41 #define LTTNG_UST_PROVIDER_MINOR        0
  42
  43 struct lttng_channel;
  44 struct lttng_session;
  45 struct lttng_ust_lib_ring_buffer_ctx;
  46 struct lttng_event_field;
  47 struct lttng_event_notifier;
  48 struct lttng_event_notifier_group;
  49
  50 /*
  51  * Data structures used by tracepoint event declarations, and by the
  52  * tracer. Those structures have padding for future extension.
  53  */
  54
  55 /* Type description */
  56
  57 /* Update the astract_types name table in lttng-types.c along with this enum */
  58 enum lttng_abstract_types {
  59         atype_integer,
  60         atype_enum,     /* legacy */
  61         atype_array,    /* legacy */
  62         atype_sequence, /* legacy */
  63         atype_string,
  64         atype_float,
  65         atype_dynamic,
  66         atype_struct,   /* legacy */
  67         atype_enum_nestable,
  68         atype_array_nestable,
  69         atype_sequence_nestable,
  70         atype_struct_nestable,
  71         NR_ABSTRACT_TYPES,
  72 };
  73
  74 /* Update the string_encodings name table in lttng-types.c along with this enum */
  75 enum lttng_string_encodings {
  76         lttng_encode_none = 0,
  77         lttng_encode_UTF8 = 1,
  78         lttng_encode_ASCII = 2,
  79         NR_STRING_ENCODINGS,
  80 };
  81
  82 struct lttng_enum_value {
  83         unsigned long long value;
  84         unsigned int signedness:1;
  85 };
  86
  87 enum lttng_enum_entry_options {
  88         LTTNG_ENUM_ENTRY_OPTION_IS_AUTO = 1U << 0,
  89 };
  90
  91 #define LTTNG_UST_ENUM_ENTRY_PADDING    16
  92 struct lttng_enum_entry {
  93         struct lttng_enum_value start, end; /* start and end are inclusive */
  94         const char *string;
  95         union {
  96                 struct {
  97                         unsigned int options;
  98                 } LTTNG_PACKED extra;
  99                 char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
 100         } u;
 101 };
 102
 103 #define __type_integer(_type, _byte_order, _base, _encoding)    \
 104         {                                                       \
 105           .atype = atype_integer,                               \
 106           .u =                                                  \
 107                 {                                               \
 108                   .integer =                                    \
 109                         {                                       \
 110                           .size = sizeof(_type) * CHAR_BIT,     \
 111                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 112                           .signedness = lttng_is_signed_type(_type), \
 113                           .reverse_byte_order = _byte_order != BYTE_ORDER, \
 114                           .base = _base,                        \
 115                           .encoding = lttng_encode_##_encoding, \
 116                         }                                       \
 117                 },                                              \
 118         }                                                       \
 119
 120 #define LTTNG_UST_INTEGER_TYPE_PADDING  24
 121 struct lttng_integer_type {
 122         unsigned int size;              /* in bits */
 123         unsigned short alignment;       /* in bits */
 124         unsigned int signedness:1;
 125         unsigned int reverse_byte_order:1;
 126         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 127         enum lttng_string_encodings encoding;
 128         char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 129 };
 130
 131 /*
 132  * Only float and double are supported. long double is not supported at
 133  * the moment.
 134  */
 135 #define _float_mant_dig(_type)                                          \
 136         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 137                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 138                 : 0))
 139
 140 #define __type_float(_type)                                     \
 141         {                                                       \
 142           .atype = atype_float,                                 \
 143           .u =                                                  \
 144                 {                                               \
 145                   ._float =                                     \
 146                         {                                       \
 147                           .exp_dig = sizeof(_type) * CHAR_BIT   \
 148                                           - _float_mant_dig(_type), \
 149                           .mant_dig = _float_mant_dig(_type),   \
 150                           .alignment = lttng_alignof(_type) * CHAR_BIT, \
 151                           .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
 152                         }                                       \
 153                 }                                               \
 154         }                                                       \
 155
 156 #define LTTNG_UST_FLOAT_TYPE_PADDING    24
 157 struct lttng_float_type {
 158         unsigned int exp_dig;           /* exponent digits, in bits */
 159         unsigned int mant_dig;          /* mantissa digits, in bits */
 160         unsigned short alignment;       /* in bits */
 161         unsigned int reverse_byte_order:1;
 162         char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 163 };
 164
 165 /* legacy */
 166 #define LTTNG_UST_BASIC_TYPE_PADDING    128
 167 union _lttng_basic_type {
 168         struct lttng_integer_type integer;      /* legacy */
 169         struct {
 170                 const struct lttng_enum_desc *desc;     /* Enumeration mapping */
 171                 struct lttng_integer_type container_type;
 172         } enumeration;                          /* legacy */
 173         struct {
 174                 enum lttng_string_encodings encoding;
 175         } string;                               /* legacy */
 176         struct lttng_float_type _float;         /* legacy */
 177         char padding[LTTNG_UST_BASIC_TYPE_PADDING];
 178 };
 179
 180 /* legacy */
 181 struct lttng_basic_type {
 182         enum lttng_abstract_types atype;
 183         union {
 184                 union _lttng_basic_type basic;
 185         } u;
 186 };
 187
 188 #define LTTNG_UST_TYPE_PADDING  128
 189 struct lttng_type {
 190         enum lttng_abstract_types atype;
 191         union {
 192                 /* provider ABI 2.0 */
 193                 struct lttng_integer_type integer;
 194                 struct lttng_float_type _float;
 195                 struct {
 196                         enum lttng_string_encodings encoding;
 197                 } string;
 198                 struct {
 199                         const struct lttng_enum_desc *desc;     /* Enumeration mapping */
 200                         struct lttng_type *container_type;
 201                 } enum_nestable;
 202                 struct {
 203                         const struct lttng_type *elem_type;
 204                         unsigned int length;                    /* Num. elems. */
 205                         unsigned int alignment;
 206                 } array_nestable;
 207                 struct {
 208                         const char *length_name;                /* Length field name. */
 209                         const struct lttng_type *elem_type;
 210                         unsigned int alignment;                 /* Alignment before elements. */
 211                 } sequence_nestable;
 212                 struct {
 213                         unsigned int nr_fields;
 214                         const struct lttng_event_field *fields; /* Array of fields. */
 215                         unsigned int alignment;
 216                 } struct_nestable;
 217
 218                 union {
 219                         /* legacy provider ABI 1.0 */
 220                         union _lttng_basic_type basic;  /* legacy */
 221                         struct {
 222                                 struct lttng_basic_type elem_type;
 223                                 unsigned int length;            /* Num. elems. */
 224                         } array;                        /* legacy */
 225                         struct {
 226                                 struct lttng_basic_type length_type;
 227                                 struct lttng_basic_type elem_type;
 228                         } sequence;                     /* legacy */
 229                         struct {
 230                                 unsigned int nr_fields;
 231                                 struct lttng_event_field *fields;       /* Array of fields. */
 232                         } _struct;                      /* legacy */
 233                 } legacy;
 234                 char padding[LTTNG_UST_TYPE_PADDING];
 235         } u;
 236 };
 237
 238 #define LTTNG_UST_ENUM_TYPE_PADDING     24
 239 struct lttng_enum_desc {
 240         const char *name;
 241         const struct lttng_enum_entry *entries;
 242         unsigned int nr_entries;
 243         char padding[LTTNG_UST_ENUM_TYPE_PADDING];
 244 };
 245
 246 /*
 247  * Event field description
 248  *
 249  * IMPORTANT: this structure is part of the ABI between the probe and
 250  * UST. Fields need to be only added at the end, never reordered, never
 251  * removed.
 252  */
 253
 254 #define LTTNG_UST_EVENT_FIELD_PADDING   28
 255 struct lttng_event_field {
 256         const char *name;
 257         struct lttng_type type;
 258         unsigned int nowrite;   /* do not write into trace */
 259         union {
 260                 struct {
 261                         unsigned int nofilter:1;        /* do not consider for filter */
 262                 } ext;
 263                 char padding[LTTNG_UST_EVENT_FIELD_PADDING];
 264         } u;
 265 };
 266
 267 enum lttng_ust_dynamic_type {
 268         LTTNG_UST_DYNAMIC_TYPE_NONE,
 269         LTTNG_UST_DYNAMIC_TYPE_S8,
 270         LTTNG_UST_DYNAMIC_TYPE_S16,
 271         LTTNG_UST_DYNAMIC_TYPE_S32,
 272         LTTNG_UST_DYNAMIC_TYPE_S64,
 273         LTTNG_UST_DYNAMIC_TYPE_U8,
 274         LTTNG_UST_DYNAMIC_TYPE_U16,
 275         LTTNG_UST_DYNAMIC_TYPE_U32,
 276         LTTNG_UST_DYNAMIC_TYPE_U64,
 277         LTTNG_UST_DYNAMIC_TYPE_FLOAT,
 278         LTTNG_UST_DYNAMIC_TYPE_DOUBLE,
 279         LTTNG_UST_DYNAMIC_TYPE_STRING,
 280         _NR_LTTNG_UST_DYNAMIC_TYPES,
 281 };
 282
 283 struct lttng_ctx_value {
 284         enum lttng_ust_dynamic_type sel;
 285         union {
 286                 int64_t s64;
 287                 uint64_t u64;
 288                 const char *str;
 289                 double d;
 290         } u;
 291 };
 292
 293 struct lttng_perf_counter_field;
 294
 295 #define LTTNG_UST_CTX_FIELD_PADDING     40
 296 struct lttng_ctx_field {
 297         struct lttng_event_field event_field;
 298         size_t (*get_size)(struct lttng_ctx_field *field, size_t offset);
 299         void (*record)(struct lttng_ctx_field *field,
 300                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 301                        struct lttng_channel *chan);
 302         void (*get_value)(struct lttng_ctx_field *field,
 303                          struct lttng_ctx_value *value);
 304         union {
 305                 struct lttng_perf_counter_field *perf_counter;
 306                 char padding[LTTNG_UST_CTX_FIELD_PADDING];
 307         } u;
 308         void (*destroy)(struct lttng_ctx_field *field);
 309         char *field_name;       /* Has ownership, dynamically allocated. */
 310 };
 311
 312 #define LTTNG_UST_CTX_PADDING   20
 313 struct lttng_ctx {
 314         struct lttng_ctx_field *fields;
 315         unsigned int nr_fields;
 316         unsigned int allocated_fields;
 317         unsigned int largest_align;
 318         char padding[LTTNG_UST_CTX_PADDING];
 319 };
 320
 321 #define LTTNG_UST_EVENT_DESC_PADDING    40
 322 struct lttng_event_desc {
 323         const char *name;
 324         void (*probe_callback)(void);
 325         const struct lttng_event_ctx *ctx;      /* context */
 326         const struct lttng_event_field *fields; /* event payload */
 327         unsigned int nr_fields;
 328         const int **loglevel;
 329         const char *signature;  /* Argument types/names received */
 330         union {
 331                 struct {
 332                         const char **model_emf_uri;
 333                         void (*event_notifier_callback)(void);
 334                 } ext;
 335                 char padding[LTTNG_UST_EVENT_DESC_PADDING];
 336         } u;
 337 };
 338
 339 #define LTTNG_UST_PROBE_DESC_PADDING    12
 340 struct lttng_probe_desc {
 341         const char *provider;
 342         const struct lttng_event_desc **event_desc;
 343         unsigned int nr_events;
 344         struct cds_list_head head;              /* chain registered probes */
 345         struct cds_list_head lazy_init_head;
 346         int lazy;                               /* lazy registration */
 347         uint32_t major;
 348         uint32_t minor;
 349         char padding[LTTNG_UST_PROBE_DESC_PADDING];
 350 };
 351
 352 /* Data structures used by the tracer. */
 353
 354 struct tp_list_entry {
 355         struct lttng_ust_tracepoint_iter tp;
 356         struct cds_list_head head;
 357 };
 358
 359 struct lttng_ust_tracepoint_list {
 360         struct tp_list_entry *iter;
 361         struct cds_list_head head;
 362 };
 363
 364 struct tp_field_list_entry {
 365         struct lttng_ust_field_iter field;
 366         struct cds_list_head head;
 367 };
 368
 369 struct lttng_ust_field_list {
 370         struct tp_field_list_entry *iter;
 371         struct cds_list_head head;
 372 };
 373
 374 struct ust_pending_probe;
 375 struct lttng_event;
 376
 377 /*
 378  * Bytecode interpreter return value masks.
 379  */
 380 enum lttng_bytecode_interpreter_ret {
 381         LTTNG_INTERPRETER_DISCARD = 0,
 382         LTTNG_INTERPRETER_RECORD_FLAG = (1ULL << 0),
 383         /* Other bits are kept for future use. */
 384 };
 385
 386 struct lttng_interpreter_output;
 387
 388 /*
 389  * This structure is used in the probes. More specifically, the `filter` and
 390  * `node` fields are explicity used in the probes. When modifying this
 391  * structure we must not change the layout of these two fields as it is
 392  * considered ABI.
 393  */
 394 struct lttng_bytecode_runtime {
 395         /* Associated bytecode */
 396         struct lttng_ust_bytecode_node *bc;
 397         union {
 398                 uint64_t (*filter)(void *interpreter_data,
 399                                 const char *interpreter_stack_data);
 400                 uint64_t (*capture)(void *interpreter_data,
 401                                 const char *interpreter_stack_data,
 402                                 struct lttng_interpreter_output *interpreter_output);
 403         } interpreter_funcs;
 404         int link_failed;
 405         struct cds_list_head node;      /* list of bytecode runtime in event */
 406         /*
 407          * Pointer to a URCU-protected pointer owned by an `struct
 408          * lttng_session`or `struct lttng_event_notifier_group`.
 409          */
 410         struct lttng_ctx **pctx;
 411 };
 412
 413 /*
 414  * Objects in a linked-list of enablers, owned by an event or event_notifier.
 415  * This is used because an event (or a event_notifier) can be enabled by more
 416  * than one enabler and we want a quick way to iterate over all enablers of an
 417  * object.
 418  *
 419  * For example, event rules "my_app:a*" and "my_app:ab*" will both match the
 420  * event with the name "my_app:abc".
 421  */
 422 struct lttng_enabler_ref {
 423         struct cds_list_head node;              /* enabler ref list */
 424         struct lttng_enabler *ref;              /* backward ref */
 425 };
 426
 427 /*
 428  * lttng_event structure is referred to by the tracing fast path. It
 429  * must be kept small.
 430  *
 431  * IMPORTANT: this structure is part of the ABI between the probe and
 432  * UST. Fields need to be only added at the end, never reordered, never
 433  * removed.
 434  */
 435 struct lttng_event {
 436         unsigned int id;
 437         struct lttng_channel *chan;
 438         int enabled;
 439         const struct lttng_event_desc *desc;
 440         struct lttng_ctx *ctx;
 441         enum lttng_ust_instrumentation instrumentation;
 442         struct cds_list_head node;              /* Event list in session */
 443
 444         /* list of struct lttng_bytecode_runtime, sorted by seqnum */
 445         struct cds_list_head filter_bytecode_runtime_head;
 446         int has_enablers_without_bytecode;
 447         /* Backward references: list of lttng_enabler_ref (ref to enablers) */
 448         struct cds_list_head enablers_ref_head;
 449         struct cds_hlist_node hlist;    /* session ht of events */
 450         int registered;                 /* has reg'd tracepoint probe */
 451 };
 452
 453 struct lttng_event_notifier {
 454         uint64_t user_token;
 455         uint64_t error_counter_index;
 456         int enabled;
 457         int registered;                 /* has reg'd tracepoint probe */
 458         size_t num_captures;            /* Needed to allocate the msgpack array. */
 459         void (*notification_send)(struct lttng_event_notifier *event_notifier,
 460                 const char *stack_data);
 461         struct cds_list_head filter_bytecode_runtime_head;
 462         struct cds_list_head capture_bytecode_runtime_head;
 463         int has_enablers_without_bytecode;
 464         struct cds_list_head enablers_ref_head;
 465         const struct lttng_event_desc *desc;
 466         struct cds_hlist_node hlist;    /* hashtable of event_notifiers */
 467         struct cds_list_head node;      /* event_notifier list in session */
 468         struct lttng_event_notifier_group *group; /* weak ref */
 469 };
 470
 471 struct lttng_enum {
 472         const struct lttng_enum_desc *desc;
 473         struct lttng_session *session;
 474         struct cds_list_head node;      /* Enum list in session */
 475         struct cds_hlist_node hlist;    /* Session ht of enums */
 476         uint64_t id;                    /* Enumeration ID in sessiond */
 477 };
 478
 479 struct channel;
 480 struct lttng_ust_shm_handle;
 481
 482 /*
 483  * IMPORTANT: this structure is part of the ABI between the probe and
 484  * UST. Fields need to be only added at the end, never reordered, never
 485  * removed.
 486  */
 487 struct lttng_channel_ops {
 488         struct lttng_channel *(*channel_create)(const char *name,
 489                         void *buf_addr,
 490                         size_t subbuf_size, size_t num_subbuf,
 491                         unsigned int switch_timer_interval,
 492                         unsigned int read_timer_interval,
 493                         unsigned char *uuid,
 494                         uint32_t chan_id,
 495                         const int *stream_fds, int nr_stream_fds,
 496                         int64_t blocking_timeout);
 497         void (*channel_destroy)(struct lttng_channel *chan);
 498         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 499                              uint32_t event_id);
 500         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 501         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 502                         const void *src, size_t len);
 503         /*
 504          * packet_avail_size returns the available size in the current
 505          * packet. Note that the size returned is only a hint, since it
 506          * may change due to concurrent writes.
 507          */
 508         size_t (*packet_avail_size)(struct channel *chan,
 509                                     struct lttng_ust_shm_handle *handle);
 510         int (*is_finalized)(struct channel *chan);
 511         int (*is_disabled)(struct channel *chan);
 512         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 513         void (*event_strcpy)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 514                         const char *src, size_t len);
 515 };
 516
 517 /*
 518  * IMPORTANT: this structure is part of the ABI between the probe and
 519  * UST. Fields need to be only added at the end, never reordered, never
 520  * removed.
 521  */
 522 struct lttng_channel {
 523         /*
 524          * The pointers located in this private data are NOT safe to be
 525          * dereferenced by the consumer. The only operations the
 526          * consumer process is designed to be allowed to do is to read
 527          * and perform subbuffer flush.
 528          */
 529         struct channel *chan;           /* Channel buffers */
 530         int enabled;
 531         struct lttng_ctx *ctx;
 532         /* Event ID management */
 533         struct lttng_session *session;
 534         int objd;                       /* Object associated to channel */
 535         struct cds_list_head node;      /* Channel list in session */
 536         const struct lttng_channel_ops *ops;
 537         int header_type;                /* 0: unset, 1: compact, 2: large */
 538         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 539
 540         /* Channel ID */
 541         unsigned int id;
 542         enum lttng_ust_chan_type type;
 543         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 544         int tstate:1;                   /* Transient enable state */
 545 };
 546
 547 #define LTTNG_COUNTER_DIMENSION_MAX     8
 548
 549 struct lttng_counter_dimension {
 550         uint64_t size;
 551         uint64_t underflow_index;
 552         uint64_t overflow_index;
 553         uint8_t has_underflow;
 554         uint8_t has_overflow;
 555 };
 556
 557 struct lttng_counter_ops {
 558         struct lib_counter *(*counter_create)(size_t nr_dimensions,
 559                         const struct lttng_counter_dimension *dimensions,
 560                         int64_t global_sum_step,
 561                         int global_counter_fd,
 562                         int nr_counter_cpu_fds,
 563                         const int *counter_cpu_fds,
 564                         bool is_daemon);
 565         void (*counter_destroy)(struct lib_counter *counter);
 566         int (*counter_add)(struct lib_counter *counter,
 567                         const size_t *dimension_indexes, int64_t v);
 568         int (*counter_read)(struct lib_counter *counter,
 569                         const size_t *dimension_indexes, int cpu,
 570                         int64_t *value, bool *overflow, bool *underflow);
 571         int (*counter_aggregate)(struct lib_counter *counter,
 572                         const size_t *dimension_indexes, int64_t *value,
 573                         bool *overflow, bool *underflow);
 574         int (*counter_clear)(struct lib_counter *counter, const size_t *dimension_indexes);
 575 };
 576
 577 #define LTTNG_UST_STACK_CTX_PADDING     32
 578 struct lttng_stack_ctx {
 579         struct lttng_event *event;
 580         struct lttng_ctx *chan_ctx;     /* RCU dereferenced. */
 581         struct lttng_ctx *event_ctx;    /* RCU dereferenced. */
 582         char padding[LTTNG_UST_STACK_CTX_PADDING];
 583 };
 584
 585 #define LTTNG_UST_EVENT_HT_BITS         12
 586 #define LTTNG_UST_EVENT_HT_SIZE         (1U << LTTNG_UST_EVENT_HT_BITS)
 587
 588 struct lttng_ust_event_ht {
 589         struct cds_hlist_head table[LTTNG_UST_EVENT_HT_SIZE];
 590 };
 591
 592 #define LTTNG_UST_EVENT_NOTIFIER_HT_BITS                12
 593 #define LTTNG_UST_EVENT_NOTIFIER_HT_SIZE                (1U << LTTNG_UST_EVENT_NOTIFIER_HT_BITS)
 594 struct lttng_ust_event_notifier_ht {
 595         struct cds_hlist_head table[LTTNG_UST_EVENT_NOTIFIER_HT_SIZE];
 596 };
 597
 598 #define LTTNG_UST_ENUM_HT_BITS          12
 599 #define LTTNG_UST_ENUM_HT_SIZE          (1U << LTTNG_UST_ENUM_HT_BITS)
 600
 601 struct lttng_ust_enum_ht {
 602         struct cds_hlist_head table[LTTNG_UST_ENUM_HT_SIZE];
 603 };
 604
 605 /*
 606  * IMPORTANT: this structure is part of the ABI between the probe and
 607  * UST. Fields need to be only added at the end, never reordered, never
 608  * removed.
 609  */
 610 struct lttng_session {
 611         int active;                             /* Is trace session active ? */
 612         int been_active;                        /* Been active ? */
 613         int objd;                               /* Object associated */
 614         struct cds_list_head chan_head;         /* Channel list head */
 615         struct cds_list_head events_head;       /* list of events */
 616         struct cds_list_head node;              /* Session list */
 617
 618         /* New UST 2.1 */
 619         /* List of enablers */
 620         struct cds_list_head enablers_head;
 621         struct lttng_ust_event_ht events_ht;    /* ht of events */
 622         void *owner;                            /* object owner */
 623         int tstate:1;                           /* Transient enable state */
 624
 625         /* New UST 2.4 */
 626         int statedump_pending:1;
 627
 628         /* New UST 2.8 */
 629         struct lttng_ust_enum_ht enums_ht;      /* ht of enumerations */
 630         struct cds_list_head enums_head;
 631         struct lttng_ctx *ctx;                  /* contexts for filters. */
 632 };
 633
 634 struct lttng_counter {
 635         int objd;
 636         struct lttng_event_notifier_group *event_notifier_group;    /* owner */
 637         struct lttng_counter_transport *transport;
 638         struct lib_counter *counter;
 639         struct lttng_counter_ops *ops;
 640 };
 641
 642 struct lttng_event_notifier_group {
 643         int objd;
 644         void *owner;
 645         int notification_fd;
 646         struct cds_list_head node;              /* Event notifier group handle list */
 647         struct cds_list_head enablers_head;
 648         struct cds_list_head event_notifiers_head;      /* list of event_notifiers */
 649         struct lttng_ust_event_notifier_ht event_notifiers_ht; /* hashtable of event_notifiers */
 650         struct lttng_ctx *ctx;                  /* contexts for filters. */
 651
 652         struct lttng_counter *error_counter;
 653         size_t error_counter_len;
 654 };
 655
 656 struct lttng_transport {
 657         char *name;
 658         struct cds_list_head node;
 659         struct lttng_channel_ops ops;
 660         const struct lttng_ust_lib_ring_buffer_config *client_config;
 661 };
 662
 663 struct lttng_counter_transport {
 664         char *name;
 665         struct cds_list_head node;
 666         struct lttng_counter_ops ops;
 667         const struct lib_counter_config *client_config;
 668 };
 669
 670 struct lttng_session *lttng_session_create(void);
 671 int lttng_session_enable(struct lttng_session *session);
 672 int lttng_session_disable(struct lttng_session *session);
 673 int lttng_session_statedump(struct lttng_session *session);
 674 void lttng_session_destroy(struct lttng_session *session);
 675
 676 struct lttng_channel *lttng_channel_create(struct lttng_session *session,
 677                                        const char *transport_name,
 678                                        void *buf_addr,
 679                                        size_t subbuf_size, size_t num_subbuf,
 680                                        unsigned int switch_timer_interval,
 681                                        unsigned int read_timer_interval,
 682                                        int **shm_fd, int **wait_fd,
 683                                        uint64_t **memory_map_size,
 684                                        struct lttng_channel *chan_priv_init);
 685
 686 int lttng_channel_enable(struct lttng_channel *channel);
 687 int lttng_channel_disable(struct lttng_channel *channel);
 688
 689 void lttng_transport_register(struct lttng_transport *transport);
 690 void lttng_transport_unregister(struct lttng_transport *transport);
 691
 692 int lttng_probe_register(struct lttng_probe_desc *desc);
 693 void lttng_probe_unregister(struct lttng_probe_desc *desc);
 694 void lttng_probe_provider_unregister_events(struct lttng_probe_desc *desc);
 695 int lttng_fix_pending_events(void);
 696 int lttng_probes_init(void);
 697 void lttng_probes_exit(void);
 698
 699 /*
 700  * Can be used by applications that change their procname to clear the ust cached value.
 701  */
 702 void lttng_context_procname_reset(void);
 703
 704 struct lttng_transport *lttng_transport_find(const char *name);
 705
 706 int lttng_probes_get_event_list(struct lttng_ust_tracepoint_list *list);
 707 void lttng_probes_prune_event_list(struct lttng_ust_tracepoint_list *list);
 708 struct lttng_ust_tracepoint_iter *
 709         lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list);
 710 int lttng_probes_get_field_list(struct lttng_ust_field_list *list);
 711 void lttng_probes_prune_field_list(struct lttng_ust_field_list *list);
 712 struct lttng_ust_field_iter *
 713         lttng_ust_field_list_get_iter_next(struct lttng_ust_field_list *list);
 714
 715 void lttng_free_event_filter_runtime(struct lttng_event *event);
 716
 717 struct cds_list_head *lttng_get_probe_list_head(void);
 718 int lttng_session_active(void);
 719
 720 typedef int (*t_statedump_func_ptr)(struct lttng_session *session);
 721 void lttng_handle_pending_statedump(void *owner);
 722 struct cds_list_head *_lttng_get_sessions(void);
 723
 724 struct lttng_enum *lttng_ust_enum_get_from_desc(struct lttng_session *session,
 725                 const struct lttng_enum_desc *enum_desc);
 726
 727 void lttng_ust_dl_update(void *ip);
 728
 729 #ifdef __cplusplus
 730 }
 731 #endif
 732
 733 #endif /* _LTTNG_UST_EVENTS_H */