include/lttng/ust-events.h

   1 #ifndef _UST_LTTNG_EVENTS_H
   2 #define _UST_LTTNG_EVENTS_H
   3
   4 /*
   5  * ust/lttng-events.h
   6  *
   7  * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * Holds LTTng per-session event registry.
  10  *
  11  * Dual LGPL v2.1/GPL v2 license.
  12  */
  13
  14 #include <urcu/list.h>
  15 #include <uuid/uuid.h>
  16 #include <stdint.h>
  17 #include <lttng/ust-abi.h>
  18 #include <lttng/ust-tracer.h>
  19 #include <endian.h>
  20 #include <float.h>
  21
  22 struct ltt_channel;
  23 struct ltt_session;
  24 struct lttng_ust_lib_ring_buffer_ctx;
  25
  26 /*
  27  * LTTng client type enumeration. Used by the consumer to map the
  28  * callbacks from its own address space.
  29  */
  30 enum lttng_client_types {
  31         LTTNG_CLIENT_METADATA = 0,
  32         LTTNG_CLIENT_DISCARD = 1,
  33         LTTNG_CLIENT_OVERWRITE = 2,
  34         LTTNG_NR_CLIENT_TYPES,
  35 };
  36
  37 /* Type description */
  38
  39 /* Update the astract_types name table in lttng-types.c along with this enum */
  40 enum abstract_types {
  41         atype_integer,
  42         atype_enum,
  43         atype_array,
  44         atype_sequence,
  45         atype_string,
  46         atype_float,
  47         NR_ABSTRACT_TYPES,
  48 };
  49
  50 /* Update the string_encodings name table in lttng-types.c along with this enum */
  51 enum lttng_string_encodings {
  52         lttng_encode_none = 0,
  53         lttng_encode_UTF8 = 1,
  54         lttng_encode_ASCII = 2,
  55         NR_STRING_ENCODINGS,
  56 };
  57
  58 struct lttng_enum_entry {
  59         unsigned long long start, end;  /* start and end are inclusive */
  60         const char *string;
  61 };
  62
  63 #define __type_integer(_type, _byte_order, _base, _encoding)    \
  64         {                                                       \
  65             .atype = atype_integer,                             \
  66             .u.basic.integer =                                  \
  67                 {                                               \
  68                   .size = sizeof(_type) * CHAR_BIT,             \
  69                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
  70                   .signedness = lttng_is_signed_type(_type),    \
  71                   .reverse_byte_order = _byte_order != __BYTE_ORDER,    \
  72                   .base = _base,                                \
  73                   .encoding = lttng_encode_##_encoding,         \
  74                 },                                              \
  75         }                                                       \
  76
  77 struct lttng_integer_type {
  78         unsigned int size;              /* in bits */
  79         unsigned short alignment;       /* in bits */
  80         unsigned int signedness:1;
  81         unsigned int reverse_byte_order:1;
  82         unsigned int base;              /* 2, 8, 10, 16, for pretty print */
  83         enum lttng_string_encodings encoding;
  84 };
  85
  86 /*
  87  * Only float and double are supported. long double is not supported at
  88  * the moment.
  89  */
  90 #define _float_mant_dig(_type)                                          \
  91         (sizeof(_type) == sizeof(float) ? FLT_MANT_DIG                  \
  92                 : (sizeof(_type) == sizeof(double) ? DBL_MANT_DIG       \
  93                 : 0))
  94
  95 #define __type_float(_type)                                     \
  96         {                                                       \
  97             .atype = atype_float,                               \
  98             .u.basic._float =                                   \
  99                 {                                               \
 100                   .exp_dig = sizeof(_type) * CHAR_BIT           \
 101                                 - _float_mant_dig(_type),       \
 102                   .mant_dig = _float_mant_dig(_type),           \
 103                   .alignment = lttng_alignof(_type) * CHAR_BIT, \
 104                   .reverse_byte_order = __BYTE_ORDER != __FLOAT_WORD_ORDER, \
 105                 },                                              \
 106         }                                                       \
 107
 108 struct lttng_float_type {
 109         unsigned int exp_dig;           /* exponent digits, in bits */
 110         unsigned int mant_dig;          /* mantissa digits, in bits */
 111         unsigned short alignment;       /* in bits */
 112         unsigned int reverse_byte_order:1;
 113 };
 114
 115 union _lttng_basic_type {
 116         struct lttng_integer_type integer;
 117         struct {
 118                 const char *name;
 119         } enumeration;
 120         struct {
 121                 enum lttng_string_encodings encoding;
 122         } string;
 123         struct lttng_float_type _float;
 124 };
 125
 126 struct lttng_basic_type {
 127         enum abstract_types atype;
 128         union {
 129                 union _lttng_basic_type basic;
 130         } u;
 131 };
 132
 133 struct lttng_type {
 134         enum abstract_types atype;
 135         union {
 136                 union _lttng_basic_type basic;
 137                 struct {
 138                         struct lttng_basic_type elem_type;
 139                         unsigned int length;            /* num. elems. */
 140                 } array;
 141                 struct {
 142                         struct lttng_basic_type length_type;
 143                         struct lttng_basic_type elem_type;
 144                 } sequence;
 145         } u;
 146 };
 147
 148 struct lttng_enum {
 149         const char *name;
 150         struct lttng_type container_type;
 151         const struct lttng_enum_entry *entries;
 152         unsigned int len;
 153 };
 154
 155 /* Event field description */
 156
 157 struct lttng_event_field {
 158         const char *name;
 159         struct lttng_type type;
 160 };
 161
 162 struct lttng_ctx_field {
 163         struct lttng_event_field event_field;
 164         size_t (*get_size)(size_t offset);
 165         void (*record)(struct lttng_ctx_field *field,
 166                        struct lttng_ust_lib_ring_buffer_ctx *ctx,
 167                        struct ltt_channel *chan);
 168         union {
 169         } u;
 170         void (*destroy)(struct lttng_ctx_field *field);
 171 };
 172
 173 struct lttng_ctx {
 174         struct lttng_ctx_field *fields;
 175         unsigned int nr_fields;
 176         unsigned int allocated_fields;
 177 };
 178
 179 struct lttng_event_desc {
 180         const char *name;
 181         void *probe_callback;
 182         const struct lttng_event_ctx *ctx;      /* context */
 183         const struct lttng_event_field *fields; /* event payload */
 184         unsigned int nr_fields;
 185 };
 186
 187 struct lttng_probe_desc {
 188         const struct lttng_event_desc *event_desc;
 189         unsigned int nr_events;
 190         struct cds_list_head head;              /* chain registered probes */
 191 };
 192
 193 struct ust_pending_probe;
 194
 195 /*
 196  * ltt_event structure is referred to by the tracing fast path. It must be
 197  * kept small.
 198  */
 199 struct ltt_event {
 200         unsigned int id;
 201         struct ltt_channel *chan;
 202         int enabled;
 203         const struct lttng_event_desc *desc;
 204         void *filter;
 205         struct lttng_ctx *ctx;
 206         enum lttng_ust_instrumentation instrumentation;
 207         union {
 208         } u;
 209         struct cds_list_head list;              /* Event list */
 210         struct ust_pending_probe *pending_probe;
 211         int metadata_dumped:1;
 212 };
 213
 214 struct channel;
 215 struct lttng_ust_shm_handle;
 216
 217 struct ltt_channel_ops {
 218         struct ltt_channel *(*channel_create)(const char *name,
 219                                 void *buf_addr,
 220                                 size_t subbuf_size, size_t num_subbuf,
 221                                 unsigned int switch_timer_interval,
 222                                 unsigned int read_timer_interval,
 223                                 int *shm_fd, int *wait_fd,
 224                                 uint64_t *memory_map_size);
 225         void (*channel_destroy)(struct ltt_channel *ltt_chan);
 226         struct lttng_ust_lib_ring_buffer *(*buffer_read_open)(struct channel *chan,
 227                                 struct lttng_ust_shm_handle *handle,
 228                                 int *shm_fd, int *wait_fd,
 229                                 uint64_t *memory_map_size);
 230         void (*buffer_read_close)(struct lttng_ust_lib_ring_buffer *buf,
 231                                 struct lttng_ust_shm_handle *handle);
 232         int (*event_reserve)(struct lttng_ust_lib_ring_buffer_ctx *ctx,
 233                              uint32_t event_id);
 234         void (*event_commit)(struct lttng_ust_lib_ring_buffer_ctx *ctx);
 235         void (*event_write)(struct lttng_ust_lib_ring_buffer_ctx *ctx, const void *src,
 236                             size_t len);
 237         /*
 238          * packet_avail_size returns the available size in the current
 239          * packet. Note that the size returned is only a hint, since it
 240          * may change due to concurrent writes.
 241          */
 242         size_t (*packet_avail_size)(struct channel *chan,
 243                                     struct lttng_ust_shm_handle *handle);
 244         //wait_queue_head_t *(*get_reader_wait_queue)(struct channel *chan);
 245         //wait_queue_head_t *(*get_hp_wait_queue)(struct channel *chan);
 246         int (*is_finalized)(struct channel *chan);
 247         int (*is_disabled)(struct channel *chan);
 248         int (*flush_buffer)(struct channel *chan, struct lttng_ust_shm_handle *handle);
 249 };
 250
 251 struct ltt_channel {
 252         /*
 253          * The pointers located in this private data are NOT safe to be
 254          * dereferenced by the consumer. The only operations the
 255          * consumer process is designed to be allowed to do is to read
 256          * and perform subbuffer flush.
 257          */
 258         struct channel *chan;           /* Channel buffers */
 259         int enabled;
 260         struct lttng_ctx *ctx;
 261         /* Event ID management */
 262         struct ltt_session *session;
 263         int objd;                       /* Object associated to channel */
 264         unsigned int free_event_id;     /* Next event ID to allocate */
 265         unsigned int used_event_id;     /* Max allocated event IDs */
 266         struct cds_list_head list;      /* Channel list */
 267         struct ltt_channel_ops *ops;
 268         int header_type;                /* 0: unset, 1: compact, 2: large */
 269         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
 270         int metadata_dumped:1;
 271
 272         /* Channel ID, available for consumer too */
 273         unsigned int id;
 274         /* Copy of session UUID for consumer (availability through shm) */
 275         uuid_t uuid;                    /* Trace session unique ID */
 276 };
 277
 278 struct ltt_session {
 279         int active;                     /* Is trace session active ? */
 280         int been_active;                /* Has trace session been active ? */
 281         int objd;                       /* Object associated to session */
 282         struct ltt_channel *metadata;   /* Metadata channel */
 283         struct cds_list_head chan;      /* Channel list head */
 284         struct cds_list_head events;    /* Event list head */
 285         struct cds_list_head list;      /* Session list */
 286         unsigned int free_chan_id;      /* Next chan ID to allocate */
 287         uuid_t uuid;                    /* Trace session unique ID */
 288         int metadata_dumped:1;
 289 };
 290
 291 struct ltt_transport {
 292         char *name;
 293         struct cds_list_head node;
 294         struct ltt_channel_ops ops;
 295 };
 296
 297 struct ltt_session *ltt_session_create(void);
 298 int ltt_session_enable(struct ltt_session *session);
 299 int ltt_session_disable(struct ltt_session *session);
 300 void ltt_session_destroy(struct ltt_session *session);
 301
 302 struct ltt_channel *ltt_channel_create(struct ltt_session *session,
 303                                        const char *transport_name,
 304                                        void *buf_addr,
 305                                        size_t subbuf_size, size_t num_subbuf,
 306                                        unsigned int switch_timer_interval,
 307                                        unsigned int read_timer_interval,
 308                                        int *shm_fd, int *wait_fd,
 309                                        uint64_t *memory_map_size);
 310 struct ltt_channel *ltt_global_channel_create(struct ltt_session *session,
 311                                        int overwrite, void *buf_addr,
 312                                        size_t subbuf_size, size_t num_subbuf,
 313                                        unsigned int switch_timer_interval,
 314                                        unsigned int read_timer_interval,
 315                                        int *shm_fd, int *wait_fd,
 316                                        uint64_t *memory_map_size);
 317
 318 struct ltt_event *ltt_event_create(struct ltt_channel *chan,
 319                                    struct lttng_ust_event *event_param,
 320                                    void *filter);
 321
 322 int ltt_channel_enable(struct ltt_channel *channel);
 323 int ltt_channel_disable(struct ltt_channel *channel);
 324 int ltt_event_enable(struct ltt_event *event);
 325 int ltt_event_disable(struct ltt_event *event);
 326
 327 void ltt_transport_register(struct ltt_transport *transport);
 328 void ltt_transport_unregister(struct ltt_transport *transport);
 329
 330 void synchronize_trace(void);
 331
 332 int ltt_probe_register(struct lttng_probe_desc *desc);
 333 void ltt_probe_unregister(struct lttng_probe_desc *desc);
 334 int pending_probe_fix_events(const struct lttng_event_desc *desc);
 335 const struct lttng_event_desc *ltt_event_get(const char *name);
 336 void ltt_event_put(const struct lttng_event_desc *desc);
 337 int ltt_probes_init(void);
 338 void ltt_probes_exit(void);
 339 int lttng_find_context(struct lttng_ctx *ctx, const char *name);
 340 struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p);
 341 void lttng_remove_context_field(struct lttng_ctx **ctx_p,
 342                                 struct lttng_ctx_field *field);
 343 void lttng_destroy_context(struct lttng_ctx *ctx);
 344 int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx);
 345 int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx);
 346 int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx);
 347 int lttng_add_procname_to_ctx(struct lttng_ctx **ctx);
 348 void lttng_context_vtid_reset(void);
 349 void lttng_context_vpid_reset(void);
 350
 351 const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_metadata;
 352 const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_discard;
 353 const struct lttng_ust_lib_ring_buffer_client_cb *lttng_client_callbacks_overwrite;
 354
 355 struct cds_list_head ltt_transport_list;
 356 struct ltt_transport *ltt_transport_find(const char *name);
 357
 358 #endif /* _UST_LTTNG_EVENTS_H */