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