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
  22 #include <urcu/list.h>
  23 #include <urcu/hlist.h>
  24 #include <stdint.h>
  25 #include <lttng/ust-abi.h>
  26 #include <lttng/ust-tracer.h>
  27 #include <lttng/ust-endian.h>
  28 #include <float.h>
  29
  30 #define LTTNG_UST_UUID_LEN              16
  31
  32 struct ltt_channel;
  33 struct ltt_session;
  34 struct lttng_ust_lib_ring_buffer_ctx;
  35
  36 /*
  37  * Data structures used by tracepoint event declarations, and by the
  38  * tracer. Those structures have padding for future extension.
  39  */
  40
  41 /*
  42  * LTTng client type enumeration. Used by the consumer to map the
  43  * callbacks from its own address space.
  44  */
  45 enum lttng_client_types {
  46         LTTNG_CLIENT_METADATA = 0,
  47         LTTNG_CLIENT_DISCARD = 1,
  48         LTTNG_CLIENT_OVERWRITE = 2,
  49         LTTNG_NR_CLIENT_TYPES,
  50 };
  51
  52 /* Type description */
  53
  54 /* Update the astract_types name table in lttng-types.c along with this enum */
  55 enum abstract_types {
  56         atype_integer,
  57         atype_enum,
  58         atype_array,
  59         atype_sequence,
  60         atype_string,
  61         atype_float,
  62         NR_ABSTRACT_TYPES,
  63 };
  64
  65 /* Update the string_encodings name table in lttng-types.c along with this enum */
  66 enum lttng_string_encodings {
  67         lttng_encode_none = 0,
  68         lttng_encode_UTF8 = 1,
  69         lttng_encode_ASCII = 2,
  70         NR_STRING_ENCODINGS,
  71 };
  72
  73 #define LTTNG_UST_ENUM_ENTRY_PADDING    16
  74 struct lttng_enum_entry {
  75         unsigned long long start, end;  /* start and end are inclusive */
  76         const char *string;
  77         char padding[LTTNG_UST_ENUM_ENTRY_PADDING];
  78 };
  79
  80 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  81         {                                                       \
  82             .atype = atype_integer,                             \
  83             .u.basic.integer =                                  \
  84                 {                                               \
  85                   .size = sizeof(_type) * CHAR_BIT,             \
  86                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
  87                   .signedness = lttng_is_signed_type(_type),    \
  88                   .reverse_byte_order = _byte_order != BYTE_ORDER,      \
  89                   .base = _base,                                \
  90                   .encoding = lttng_encode_##_encoding,         \
  91                 },                                              \
  92         }                                                       \
  93
  94 #define LTTNG_UST_INTEGER_TYPE_PADDING  24
  95 struct lttng_integer_type {
  96         unsigned int size;              /* in bits */
  97         unsigned short alignment;       /* in bits */
  98         unsigned int signedness:1;
  99         unsigned int reverse_byte_order:1;
 100         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
 101         enum lttng_string_encodings encoding;
 102         char padding[LTTNG_UST_INTEGER_TYPE_PADDING];
 103 };
 104
 105 /*
 106  * Only float and double are supported. long double is not supported at
 107  * the moment.
 108  */
 109 #define _float_mant_dig(_type)                                          \
 110         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 111                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 112                 : 0))
 113
 114 #define __type_float(_type)                                     \
 115         {                                                       \
 116             .atype = atype_float,                               \
 117             .u.basic._float =                                   \
 118                 {                                               \
 119                   .exp_dig = sizeof(_type) * CHAR_BIT           \
 120                                 - _float_mant_dig(_type),       \
 121                   .mant_dig = _float_mant_dig(_type),           \
 122                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
 123                   .reverse_byte_order = BYTE_ORDER != FLOAT_WORD_ORDER, \
 124                 },                                              \
 125         }                                                       \
 126
 127 #define LTTNG_UST_FLOAT_TYPE_PADDING    24
 128 struct lttng_float_type {
 129         unsigned int exp_dig;           /* exponent digits, in bits */
 130         unsigned int mant_dig;          /* mantissa digits, in bits */
 131         unsigned short alignment;       /* in bits */
 132         unsigned int reverse_byte_order:1;
 133         char padding[LTTNG_UST_FLOAT_TYPE_PADDING];
 134 };
 135
 136 #define LTTNG_UST_BASIC_TYPE_PADDING    128
 137 union _lttng_basic_type {
 138         struct lttng_integer_type integer;
 139         struct {
 140                 const char *name;
 141         } enumeration;
 142         struct {
 143                 enum lttng_string_encodings encoding;
 144         } string;
 145         struct lttng_float_type _float;
 146         char padding[LTTNG_UST_BASIC_TYPE_PADDING];
 147 };
 148
 149 struct lttng_basic_type {
 150         enum abstract_types atype;
 151         union {
 152                 union _lttng_basic_type basic;
 153         } u;
 154 };
 155
 156 #define LTTNG_UST_TYPE_PADDING  128
 157 struct lttng_type {
 158         enum abstract_types atype;
 159         union {
 160                 union _lttng_basic_type basic;
 161                 struct {
 162                         struct lttng_basic_type elem_type;
 163                         unsigned int length;            /* num. elems. */
 164                 } array;
 165                 struct {
 166                         struct lttng_basic_type length_type;
 167                         struct lttng_basic_type elem_type;
 168                 } sequence;
 169                 char padding[LTTNG_UST_TYPE_PADDING];
 170         } u;
 171 };
 172
 173 #define LTTNG_UST_ENUM_TYPE_PADDING     24
 174 struct lttng_enum {
 175         const char *name;
 176         struct lttng_type container_type;
 177         const struct lttng_enum_entry *entries;
 178         unsigned int len;
 179         char padding[LTTNG_UST_ENUM_TYPE_PADDING];
 180 };
 181
 182 /* Event field description */
 183
 184 #define LTTNG_UST_EVENT_FIELD_PADDING   32
 185 struct lttng_event_field {
 186         const char *name;
 187         struct lttng_type type;
 188         char padding[LTTNG_UST_EVENT_FIELD_PADDING];
 189 };
 190
 191 #define LTTNG_UST_CTX_FIELD_PADDING     40
 192 struct lttng_ctx_field {
 193         struct lttng_event_field event_field;
 194         size_t (*get_size)(size_t offset);
 195         void (*record)(struct lttng_ctx_field *field,
 196                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 197                        struct ltt_channel *chan);
 198         union {
 199                 char padding[LTTNG_UST_CTX_FIELD_PADDING];
 200         } u;
 201         void (*destroy)(struct lttng_ctx_field *field);
 202 };
 203
 204 #define LTTNG_UST_CTX_PADDING   24
 205 struct lttng_ctx {
 206         struct lttng_ctx_field *fields;
 207         unsigned int nr_fields;
 208         unsigned int allocated_fields;
 209         char padding[LTTNG_UST_CTX_PADDING];
 210 };
 211
 212 #define LTTNG_UST_EVENT_DESC_PADDING    40
 213 struct lttng_event_desc {
 214         const char *name;
 215         void (*probe_callback)(void);
 216         const struct lttng_event_ctx *ctx;      /* context */
 217         const struct lttng_event_field *fields; /* event payload */
 218         unsigned int nr_fields;
 219         const int **loglevel;
 220         const char *signature;  /* Argument types/names received */
 221         char padding[LTTNG_UST_EVENT_DESC_PADDING];
 222 };
 223
 224 #define LTTNG_UST_PROBE_DESC_PADDING    40
 225 struct lttng_probe_desc {
 226         const char *provider;
 227         const struct lttng_event_desc **event_desc;
 228         unsigned int nr_events;
 229         struct cds_list_head head;              /* chain registered probes */
 230         char padding[LTTNG_UST_PROBE_DESC_PADDING];
 231 };
 232
 233 /* Data structures used by the tracer. */
 234
 235 /*
 236  * Entry describing a per-session active wildcard, along with the event
 237  * attribute and channel information configuring the events that need to
 238  * be enabled.
 239  */
 240 struct session_wildcard {
 241         struct ltt_channel *chan;
 242         struct lttng_ctx *ctx;  /* TODO */
 243         struct lttng_ust_event event_param;
 244         struct cds_list_head events;    /* list of events enabled */
 245         struct cds_list_head list;      /* per-session list of wildcards */
 246         struct cds_list_head session_list; /* node of session wildcard list */
 247         struct wildcard_entry *entry;
 248         unsigned int enabled:1;
 249 };
 250
 251 /*
 252  * Entry describing an active wildcard (per name) for all sessions.
 253  */
 254 struct wildcard_entry {
 255         /* node of global wildcards list */
 256         struct cds_list_head list;
 257         /* head of session list to which this wildcard apply */
 258         struct cds_list_head session_list;
 259         enum lttng_ust_loglevel_type loglevel_type;
 260         int loglevel;
 261         char name[0];
 262 };
 263
 264 struct tp_list_entry {
 265         struct lttng_ust_tracepoint_iter tp;
 266         struct cds_list_head head;
 267 };
 268
 269 struct lttng_ust_tracepoint_list {
 270         struct tp_list_entry *iter;
 271         struct cds_list_head head;
 272 };
 273
 274 struct ust_pending_probe;
 275 struct ltt_event;
 276
 277 /*
 278  * ltt_event structure is referred to by the tracing fast path. It must be
 279  * kept small.
 280  */
 281 struct ltt_event {
 282         unsigned int id;
 283         struct ltt_channel *chan;
 284         int enabled;
 285         const struct lttng_event_desc *desc;
 286         void (*filter)(struct ltt_event *event);
 287         struct lttng_ctx *ctx;
 288         enum lttng_ust_instrumentation instrumentation;
 289         union {
 290         } u;
 291         struct cds_list_head list;              /* Event list */
 292         struct cds_list_head wildcard_list;     /* Event list for wildcard */
 293         struct ust_pending_probe *pending_probe;
 294         unsigned int metadata_dumped:1;
 295 };
 296
 297 struct channel;
 298 struct lttng_ust_shm_handle;
 299
 300 struct ltt_channel_ops {
 301         struct ltt_channel *(*channel_create)(const char *name,
 302                                 void *buf_addr,
 303                                 size_t subbuf_size, size_t num_subbuf,
 304                                 unsigned int switch_timer_interval,
 305                                 unsigned int read_timer_interval,
 306                                 int **shm_fd, char **shm_path,
 307                                 int **wait_fd, char **wait_pipe_path,
 308                                 uint64_t **memory_map_size,
 309                                 struct ltt_channel *chan_priv_init);
 310         void (*channel_destroy)(struct ltt_channel *ltt_chan);
 311         struct lttng_ust_lib_ring_buffer *(*buffer_read_open)(struct channel *chan,
 312                                 struct lttng_ust_shm_handle *handle,
 313                                 int **shm_fd, char **shm_path,
 314                                 int **wait_fd, char **wait_pipe_path,
 315                                 uint64_t **memory_map_size);
 316         void (*buffer_read_close)(struct lttng_ust_lib_ring_buffer *buf,
 317                                 struct lttng_ust_shm_handle *handle);
 318         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 319                              uint32_t event_id);
 320         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 321         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 322                             size_t len);
 323         /*
 324          * packet_avail_size returns the available size in the current
 325          * packet. Note that the size returned is only a hint, since it
 326          * may change due to concurrent writes.
 327          */
 328         size_t (*packet_avail_size)(struct channel *chan,
 329                                     struct lttng_ust_shm_handle *handle);
 330         //wait_queue_head_t *(*get_reader_wait_queue)(struct channel *chan);
 331         //wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 332         int (*is_finalized)(struct channel *chan);
 333         int (*is_disabled)(struct channel *chan);
 334         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 335 };
 336
 337 struct ltt_channel {
 338         /*
 339          * The pointers located in this private data are NOT safe to be
 340          * dereferenced by the consumer. The only operations the
 341          * consumer process is designed to be allowed to do is to read
 342          * and perform subbuffer flush.
 343          */
 344         struct channel *chan;           /* Channel buffers */
 345         int enabled;
 346         struct lttng_ctx *ctx;
 347         /* Event ID management */
 348         struct ltt_session *session;
 349         int objd;                       /* Object associated to channel */
 350         unsigned int free_event_id;     /* Next event ID to allocate */
 351         unsigned int used_event_id;     /* Max allocated event IDs */
 352         struct cds_list_head list;      /* Channel list */
 353         struct ltt_channel_ops *ops;
 354         int header_type;                /* 0: unset, 1: compact, 2: large */
 355         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 356         unsigned int metadata_dumped:1;
 357
 358         /* Channel ID, available for consumer too */
 359         unsigned int id;
 360         /* Copy of session UUID for consumer (availability through shm) */
 361         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 362 };
 363
 364 struct ltt_session {
 365         int active;                     /* Is trace session active ? */
 366         int been_active;                /* Has trace session been active ? */
 367         int objd;                       /* Object associated to session */
 368         struct ltt_channel *metadata;   /* Metadata channel */
 369         struct cds_list_head chan;      /* Channel list head */
 370         struct cds_list_head events;    /* Event list head */
 371         struct cds_list_head wildcards; /* Wildcard list head */
 372         struct cds_list_head list;      /* Session list */
 373         unsigned int free_chan_id;      /* Next chan ID to allocate */
 374         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
 375         unsigned int metadata_dumped:1;
 376 };
 377
 378 struct ltt_transport {
 379         char *name;
 380         struct cds_list_head node;
 381         struct ltt_channel_ops ops;
 382 };
 383
 384 struct ltt_session *ltt_session_create(void);
 385 int ltt_session_enable(struct ltt_session *session);
 386 int ltt_session_disable(struct ltt_session *session);
 387 void ltt_session_destroy(struct ltt_session *session);
 388
 389 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 390                                        const char *transport_name,
 391                                        void *buf_addr,
 392                                        size_t subbuf_size, size_t num_subbuf,
 393                                        unsigned int switch_timer_interval,
 394                                        unsigned int read_timer_interval,
 395                                        int **shm_fd, char **shm_path,
 396                                        int **wait_fd, char **wait_pipe_path,
 397                                        uint64_t **memory_map_size,
 398                                        struct ltt_channel *chan_priv_init);
 399 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 400                                        int overwrite, void *buf_addr,
 401                                        size_t subbuf_size, size_t num_subbuf,
 402                                        unsigned int switch_timer_interval,
 403                                        unsigned int read_timer_interval,
 404                                        int **shm_fd, char **shm_path,
 405                                        int **wait_fd, char **wait_pipe_path,
 406                                        uint64_t **memory_map_size);
 407
 408 int ltt_event_create(struct ltt_channel *chan,
 409                 struct lttng_ust_event *event_param,
 410                 void (*filter)(struct ltt_event *event),
 411                 struct ltt_event **event);
 412
 413 int ltt_channel_enable(struct ltt_channel *channel);
 414 int ltt_channel_disable(struct ltt_channel *channel);
 415 int ltt_event_enable(struct ltt_event *event);
 416 int ltt_event_disable(struct ltt_event *event);
 417
 418 void ltt_transport_register(struct ltt_transport *transport);
 419 void ltt_transport_unregister(struct ltt_transport *transport);
 420
 421 void synchronize_trace(void);
 422
 423 int ltt_probe_register(struct lttng_probe_desc *desc);
 424 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 425 int pending_probe_fix_events(const struct lttng_event_desc *desc);
 426 const struct lttng_event_desc *ltt_event_get(const char *name);
 427 void ltt_event_put(const struct lttng_event_desc *desc);
 428 int ltt_probes_init(void);
 429 void ltt_probes_exit(void);
 430 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 431 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p);
 432 void lttng_remove_context_field(struct lttng_ctx **ctx_p,
 433                                 struct lttng_ctx_field *field);
 434 void lttng_destroy_context(struct lttng_ctx *ctx);
 435 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 436 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 437 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx);
 438 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 439 void lttng_context_vtid_reset(void);
 440 void lttng_context_vpid_reset(void);
 441
 442 extern const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_metadata;
 443 extern const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_discard;
 444 extern const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_overwrite;
 445
 446 struct ltt_transport *ltt_transport_find(const char *name);
 447
 448 int ltt_probes_get_event_list(struct lttng_ust_tracepoint_list *list);
 449 void ltt_probes_prune_event_list(struct lttng_ust_tracepoint_list *list);
 450 struct lttng_ust_tracepoint_iter *
 451         lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list);
 452
 453 int ltt_wildcard_enable(struct session_wildcard *wildcard);
 454 int ltt_wildcard_disable(struct session_wildcard *wildcard);
 455 int ltt_wildcard_create(struct ltt_channel *chan,
 456         struct lttng_ust_event *event_param,
 457         struct session_wildcard **sl);
 458 int ltt_loglevel_match(const struct lttng_event_desc *desc,
 459                 enum lttng_ust_loglevel_type req_type,
 460                 int req_loglevel);
 461 void ltt_probes_create_wildcard_events(struct wildcard_entry *entry,
 462                                 struct session_wildcard *wildcard);
 463
 464 #endif /* _LTTNG_UST_EVENTS_H */