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 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Holds LTTng per-session event registry.
  10  *
  11  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
  12  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
  13  *
  14  * Permission is hereby granted to use or copy this program
  15  * for any purpose,  provided the above notices are retained on all copies.
  16  * Permission to modify the code and to distribute modified code is granted,
  17  * provided the above notices are retained, and a notice that the code was
  18  * modified is included with the above copyright notice.
  19  */
  20
  21 #include <urcu/list.h>
  22 #include <urcu/hlist.h>
  23 #include <uuid/uuid.h>
  24 #include <stdint.h>
  25 #include <lttng/ust-abi.h>
  26 #include <lttng/ust-tracer.h>
  27 #include <endian.h>
  28 #include <float.h>
  29
  30 struct ltt_channel;
  31 struct ltt_session;
  32 struct lttng_ust_lib_ring_buffer_ctx;
  33
  34 /*
  35  * LTTng client type enumeration. Used by the consumer to map the
  36  * callbacks from its own address space.
  37  */
  38 enum lttng_client_types {
  39         LTTNG_CLIENT_METADATA = 0,
  40         LTTNG_CLIENT_DISCARD = 1,
  41         LTTNG_CLIENT_OVERWRITE = 2,
  42         LTTNG_NR_CLIENT_TYPES,
  43 };
  44
  45 /* Type description */
  46
  47 /* Update the astract_types name table in lttng-types.c along with this enum */
  48 enum abstract_types {
  49         atype_integer,
  50         atype_enum,
  51         atype_array,
  52         atype_sequence,
  53         atype_string,
  54         atype_float,
  55         NR_ABSTRACT_TYPES,
  56 };
  57
  58 /* Update the string_encodings name table in lttng-types.c along with this enum */
  59 enum lttng_string_encodings {
  60         lttng_encode_none = 0,
  61         lttng_encode_UTF8 = 1,
  62         lttng_encode_ASCII = 2,
  63         NR_STRING_ENCODINGS,
  64 };
  65
  66 struct lttng_enum_entry {
  67         unsigned long long start, end;  /* start and end are inclusive */
  68         const char *string;
  69 };
  70
  71 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  72         {                                                       \
  73             .atype = atype_integer,                             \
  74             .u.basic.integer =                                  \
  75                 {                                               \
  76                   .size = sizeof(_type) * CHAR_BIT,             \
  77                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
  78                   .signedness = lttng_is_signed_type(_type),    \
  79                   .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
  80                   .base = _base,                                \
  81                   .encoding = lttng_encode_##_encoding,         \
  82                 },                                              \
  83         }                                                       \
  84
  85 struct lttng_integer_type {
  86         unsigned int size;              /* in bits */
  87         unsigned short alignment;       /* in bits */
  88         unsigned int signedness:1;
  89         unsigned int reverse_byte_order:1;
  90         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
  91         enum lttng_string_encodings encoding;
  92 };
  93
  94 /*
  95  * Only float and double are supported. long double is not supported at
  96  * the moment.
  97  */
  98 #define _float_mant_dig(_type)                                          \
  99         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
 100                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
 101                 : 0))
 102
 103 #define __type_float(_type)                                     \
 104         {                                                       \
 105             .atype = atype_float,                               \
 106             .u.basic._float =                                   \
 107                 {                                               \
 108                   .exp_dig = sizeof(_type) * CHAR_BIT           \
 109                                 - _float_mant_dig(_type),       \
 110                   .mant_dig = _float_mant_dig(_type),           \
 111                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
 112                   .reverse_byte_order = __BYTE_ORDER != __FLOAT_WORD_ORDER, \
 113                 },                                              \
 114         }                                                       \
 115
 116 struct lttng_float_type {
 117         unsigned int exp_dig;           /* exponent digits, in bits */
 118         unsigned int mant_dig;          /* mantissa digits, in bits */
 119         unsigned short alignment;       /* in bits */
 120         unsigned int reverse_byte_order:1;
 121 };
 122
 123 union _lttng_basic_type {
 124         struct lttng_integer_type integer;
 125         struct {
 126                 const char *name;
 127         } enumeration;
 128         struct {
 129                 enum lttng_string_encodings encoding;
 130         } string;
 131         struct lttng_float_type _float;
 132 };
 133
 134 struct lttng_basic_type {
 135         enum abstract_types atype;
 136         union {
 137                 union _lttng_basic_type basic;
 138         } u;
 139 };
 140
 141 struct lttng_type {
 142         enum abstract_types atype;
 143         union {
 144                 union _lttng_basic_type basic;
 145                 struct {
 146                         struct lttng_basic_type elem_type;
 147                         unsigned int length;            /* num. elems. */
 148                 } array;
 149                 struct {
 150                         struct lttng_basic_type length_type;
 151                         struct lttng_basic_type elem_type;
 152                 } sequence;
 153         } u;
 154 };
 155
 156 struct lttng_enum {
 157         const char *name;
 158         struct lttng_type container_type;
 159         const struct lttng_enum_entry *entries;
 160         unsigned int len;
 161 };
 162
 163 /* Event field description */
 164
 165 struct lttng_event_field {
 166         const char *name;
 167         struct lttng_type type;
 168 };
 169
 170 struct lttng_ctx_field {
 171         struct lttng_event_field event_field;
 172         size_t (*get_size)(size_t offset);
 173         void (*record)(struct lttng_ctx_field *field,
 174                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 175                        struct ltt_channel *chan);
 176         union {
 177         } u;
 178         void (*destroy)(struct lttng_ctx_field *field);
 179 };
 180
 181 struct lttng_ctx {
 182         struct lttng_ctx_field *fields;
 183         unsigned int nr_fields;
 184         unsigned int allocated_fields;
 185 };
 186
 187 struct tracepoint_loglevel_entry  {
 188         const char *identifier;
 189         long value;
 190 };
 191
 192 struct loglevel_entry;
 193
 194 /*
 195  * Entry describing a per-session active loglevel, along with the event
 196  * attribute and channel information configuring the events that need to
 197  * be enabled.
 198  */
 199 struct session_loglevel {
 200         struct ltt_channel *chan;
 201         struct lttng_ctx *ctx;  /* TODO */
 202         struct lttng_ust_event event_param;
 203         struct cds_list_head events;    /* list of events enabled */
 204         struct cds_list_head list;      /* per-session list of loglevels */
 205         struct cds_list_head session_list;
 206         struct loglevel_entry *entry;
 207         unsigned int enabled:1;
 208 };
 209
 210 /*
 211  * Entry describing an active loglevel (per name) for all sessions.
 212  */
 213 struct loglevel_entry {
 214         struct cds_hlist_node hlist;
 215         struct cds_list_head session_list;
 216         char name[0];
 217 };
 218
 219 struct lttng_event_desc {
 220         const char *name;
 221         void *probe_callback;
 222         const struct lttng_event_ctx *ctx;      /* context */
 223         const struct lttng_event_field *fields; /* event payload */
 224         unsigned int nr_fields;
 225         const struct tracepoint_loglevel_entry **loglevel;
 226 };
 227
 228 struct lttng_probe_desc {
 229         const char *provider;
 230         const struct lttng_event_desc **event_desc;
 231         unsigned int nr_events;
 232         const struct tracepoint_loglevel_entry **loglevels;
 233         unsigned int nr_loglevels;
 234         struct cds_list_head head;              /* chain registered probes */
 235 };
 236
 237 struct tp_list_entry {
 238         struct lttng_ust_tracepoint_iter tp;
 239         struct cds_list_head head;
 240 };
 241
 242 struct lttng_ust_tracepoint_list {
 243         struct tp_list_entry *iter;
 244         struct cds_list_head head;
 245 };
 246
 247 struct ust_pending_probe;
 248
 249 /*
 250  * ltt_event structure is referred to by the tracing fast path. It must be
 251  * kept small.
 252  * Note about loglevel_list: this list is only used to enable/disable
 253  * events on a per-loglevel basis. The events created internally by the
 254  * loglevel are only freed when the session is destroyed.
 255  */
 256 struct ltt_event {
 257         unsigned int id;
 258         struct ltt_channel *chan;
 259         int enabled;
 260         const struct lttng_event_desc *desc;
 261         void *filter;
 262         struct lttng_ctx *ctx;
 263         enum lttng_ust_instrumentation instrumentation;
 264         union {
 265         } u;
 266         struct cds_list_head list;              /* Event list */
 267         struct cds_list_head loglevel_list;     /* Event list for loglevel */
 268         struct ust_pending_probe *pending_probe;
 269         unsigned int metadata_dumped:1;
 270 };
 271
 272 struct channel;
 273 struct lttng_ust_shm_handle;
 274
 275 struct ltt_channel_ops {
 276         struct ltt_channel *(*channel_create)(const char *name,
 277                                 void *buf_addr,
 278                                 size_t subbuf_size, size_t num_subbuf,
 279                                 unsigned int switch_timer_interval,
 280                                 unsigned int read_timer_interval,
 281                                 int *shm_fd, int *wait_fd,
 282                                 uint64_t *memory_map_size,
 283                                 struct ltt_channel *chan_priv_init);
 284         void (*channel_destroy)(struct ltt_channel *ltt_chan);
 285         struct lttng_ust_lib_ring_buffer *(*buffer_read_open)(struct channel *chan,
 286                                 struct lttng_ust_shm_handle *handle,
 287                                 int *shm_fd, int *wait_fd,
 288                                 uint64_t *memory_map_size);
 289         void (*buffer_read_close)(struct lttng_ust_lib_ring_buffer *buf,
 290                                 struct lttng_ust_shm_handle *handle);
 291         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 292                              uint32_t event_id);
 293         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 294         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 295                             size_t len);
 296         /*
 297          * packet_avail_size returns the available size in the current
 298          * packet. Note that the size returned is only a hint, since it
 299          * may change due to concurrent writes.
 300          */
 301         size_t (*packet_avail_size)(struct channel *chan,
 302                                     struct lttng_ust_shm_handle *handle);
 303         //wait_queue_head_t *(*get_reader_wait_queue)(struct channel *chan);
 304         //wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 305         int (*is_finalized)(struct channel *chan);
 306         int (*is_disabled)(struct channel *chan);
 307         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 308 };
 309
 310 struct ltt_channel {
 311         /*
 312          * The pointers located in this private data are NOT safe to be
 313          * dereferenced by the consumer. The only operations the
 314          * consumer process is designed to be allowed to do is to read
 315          * and perform subbuffer flush.
 316          */
 317         struct channel *chan;           /* Channel buffers */
 318         int enabled;
 319         struct lttng_ctx *ctx;
 320         /* Event ID management */
 321         struct ltt_session *session;
 322         int objd;                       /* Object associated to channel */
 323         unsigned int free_event_id;     /* Next event ID to allocate */
 324         unsigned int used_event_id;     /* Max allocated event IDs */
 325         struct cds_list_head list;      /* Channel list */
 326         struct ltt_channel_ops *ops;
 327         int header_type;                /* 0: unset, 1: compact, 2: large */
 328         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 329         unsigned int metadata_dumped:1;
 330
 331         /* Channel ID, available for consumer too */
 332         unsigned int id;
 333         /* Copy of session UUID for consumer (availability through shm) */
 334         uuid_t uuid;                    /* Trace session unique ID */
 335 };
 336
 337 struct ltt_session {
 338         int active;                     /* Is trace session active ? */
 339         int been_active;                /* Has trace session been active ? */
 340         int objd;                       /* Object associated to session */
 341         struct ltt_channel *metadata;   /* Metadata channel */
 342         struct cds_list_head chan;      /* Channel list head */
 343         struct cds_list_head events;    /* Event list head */
 344         struct cds_list_head loglevels; /* Loglevel list head */
 345         struct cds_list_head list;      /* Session list */
 346         unsigned int free_chan_id;      /* Next chan ID to allocate */
 347         uuid_t uuid;                    /* Trace session unique ID */
 348         unsigned int metadata_dumped:1;
 349 };
 350
 351 struct ltt_transport {
 352         char *name;
 353         struct cds_list_head node;
 354         struct ltt_channel_ops ops;
 355 };
 356
 357 struct ltt_session *ltt_session_create(void);
 358 int ltt_session_enable(struct ltt_session *session);
 359 int ltt_session_disable(struct ltt_session *session);
 360 void ltt_session_destroy(struct ltt_session *session);
 361
 362 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 363                                        const char *transport_name,
 364                                        void *buf_addr,
 365                                        size_t subbuf_size, size_t num_subbuf,
 366                                        unsigned int switch_timer_interval,
 367                                        unsigned int read_timer_interval,
 368                                        int *shm_fd, int *wait_fd,
 369                                        uint64_t *memory_map_size,
 370                                        struct ltt_channel *chan_priv_init);
 371 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 372                                        int overwrite, void *buf_addr,
 373                                        size_t subbuf_size, size_t num_subbuf,
 374                                        unsigned int switch_timer_interval,
 375                                        unsigned int read_timer_interval,
 376                                        int *shm_fd, int *wait_fd,
 377                                        uint64_t *memory_map_size);
 378
 379 int ltt_event_create(struct ltt_channel *chan,
 380                 struct lttng_ust_event *event_param,
 381                 void *filter,
 382                 struct ltt_event **event);
 383
 384 int ltt_channel_enable(struct ltt_channel *channel);
 385 int ltt_channel_disable(struct ltt_channel *channel);
 386 int ltt_event_enable(struct ltt_event *event);
 387 int ltt_event_disable(struct ltt_event *event);
 388
 389 void ltt_transport_register(struct ltt_transport *transport);
 390 void ltt_transport_unregister(struct ltt_transport *transport);
 391
 392 void synchronize_trace(void);
 393
 394 int ltt_probe_register(struct lttng_probe_desc *desc);
 395 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 396 int pending_probe_fix_events(const struct lttng_event_desc *desc);
 397 const struct lttng_event_desc *ltt_event_get(const char *name);
 398 void ltt_event_put(const struct lttng_event_desc *desc);
 399 int ltt_probes_init(void);
 400 void ltt_probes_exit(void);
 401 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 402 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p);
 403 void lttng_remove_context_field(struct lttng_ctx **ctx_p,
 404                                 struct lttng_ctx_field *field);
 405 void lttng_destroy_context(struct lttng_ctx *ctx);
 406 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 407 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 408 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx);
 409 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 410 void lttng_context_vtid_reset(void);
 411 void lttng_context_vpid_reset(void);
 412
 413 const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_metadata;
 414 const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_discard;
 415 const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_overwrite;
 416
 417 struct ltt_transport *ltt_transport_find(const char *name);
 418
 419 int ltt_probes_get_event_list(struct lttng_ust_tracepoint_list *list);
 420 void ltt_probes_prune_event_list(struct lttng_ust_tracepoint_list *list);
 421 struct lttng_ust_tracepoint_iter *
 422         lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list);
 423
 424 struct loglevel_entry *get_loglevel(const char *name);
 425 struct session_loglevel *add_loglevel(const char *name,
 426         struct ltt_channel *chan,
 427         struct lttng_ust_event *event_param);
 428 void _remove_loglevel(struct session_loglevel *loglevel);
 429 int ltt_loglevel_enable(struct session_loglevel *loglevel);
 430 int ltt_loglevel_disable(struct session_loglevel *loglevel);
 431 int ltt_loglevel_create(struct ltt_channel *chan,
 432         struct lttng_ust_event *event_param,
 433         struct session_loglevel **sl);
 434
 435 #endif /* _LTTNG_UST_EVENTS_H */