include/lttng/lttng.h

   1 /*
   2  * lttng.h
   3  *
   4  * Linux Trace Toolkit Control Library Header File
   5  *
   6  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   7  *
   8  * This library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License, version 2.1 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This library is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  15  * for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this library; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef LTTNG_H
  23 #define LTTNG_H
  24
  25 #include <limits.h>
  26 /*
  27  * Necessary to include the fixed width type limits on glibc versions older
  28  * than 2.18 when building with a C++ compiler.
  29  */
  30 #ifndef __STDC_LIMIT_MACROS
  31 #define __STDC_LIMIT_MACROS
  32 #include <stdint.h>
  33 #undef __STDC_LIMIT_MACROS
  34 #else /* #ifndef __STDC_LIMIT_MACROS */
  35 #include <stdint.h>
  36 #endif /* #else #ifndef __STDC_LIMIT_MACROS */
  37 #include <sys/types.h>
  38
  39 /* Error codes that can be returned by API calls */
  40 #include <lttng/lttng-error.h>
  41
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46 /*
  47  * Event symbol length. Copied from LTTng kernel ABI.
  48  */
  49 #define LTTNG_SYMBOL_NAME_LEN             256
  50
  51 /*
  52  * Every lttng_event_* structure both apply to kernel event and user-space
  53  * event.
  54  */
  55
  56 /*
  57  * Domain types: the different possible tracers.
  58  */
  59 enum lttng_domain_type {
  60         LTTNG_DOMAIN_KERNEL                   = 1,      /* Linux Kernel tracer. */
  61         LTTNG_DOMAIN_UST                      = 2,      /* Global Userspace tracer. */
  62         LTTNG_DOMAIN_JUL                      = 3,      /* Java Util Logging. */
  63 };
  64
  65 /*
  66  * Instrumentation type of tracing event.
  67  */
  68 enum lttng_event_type {
  69         LTTNG_EVENT_ALL                       = -1,
  70         LTTNG_EVENT_TRACEPOINT                = 0,
  71         LTTNG_EVENT_PROBE                     = 1,
  72         LTTNG_EVENT_FUNCTION                  = 2,
  73         LTTNG_EVENT_FUNCTION_ENTRY            = 3,
  74         LTTNG_EVENT_NOOP                      = 4,
  75         LTTNG_EVENT_SYSCALL                   = 5,
  76 };
  77
  78 /*
  79  * Loglevel information.
  80  */
  81 enum lttng_loglevel_type {
  82         LTTNG_EVENT_LOGLEVEL_ALL              = 0,
  83         LTTNG_EVENT_LOGLEVEL_RANGE            = 1,
  84         LTTNG_EVENT_LOGLEVEL_SINGLE           = 2,
  85 };
  86
  87 /*
  88  * Available loglevels.
  89  */
  90 enum lttng_loglevel {
  91         LTTNG_LOGLEVEL_EMERG                  = 0,
  92         LTTNG_LOGLEVEL_ALERT                  = 1,
  93         LTTNG_LOGLEVEL_CRIT                   = 2,
  94         LTTNG_LOGLEVEL_ERR                    = 3,
  95         LTTNG_LOGLEVEL_WARNING                = 4,
  96         LTTNG_LOGLEVEL_NOTICE                 = 5,
  97         LTTNG_LOGLEVEL_INFO                   = 6,
  98         LTTNG_LOGLEVEL_DEBUG_SYSTEM           = 7,
  99         LTTNG_LOGLEVEL_DEBUG_PROGRAM          = 8,
 100         LTTNG_LOGLEVEL_DEBUG_PROCESS          = 9,
 101         LTTNG_LOGLEVEL_DEBUG_MODULE           = 10,
 102         LTTNG_LOGLEVEL_DEBUG_UNIT             = 11,
 103         LTTNG_LOGLEVEL_DEBUG_FUNCTION         = 12,
 104         LTTNG_LOGLEVEL_DEBUG_LINE             = 13,
 105         LTTNG_LOGLEVEL_DEBUG                  = 14,
 106 };
 107
 108 /*
 109  * Available loglevels for the JUL domain. Those are an exact map from the
 110  * class java.util.logging.Level.
 111  */
 112 enum lttng_loglevel_jul {
 113         LTTNG_LOGLEVEL_JUL_OFF                = INT32_MAX,
 114         LTTNG_LOGLEVEL_JUL_SEVERE             = 1000,
 115         LTTNG_LOGLEVEL_JUL_WARNING            = 900,
 116         LTTNG_LOGLEVEL_JUL_INFO               = 800,
 117         LTTNG_LOGLEVEL_JUL_CONFIG             = 700,
 118         LTTNG_LOGLEVEL_JUL_FINE               = 500,
 119         LTTNG_LOGLEVEL_JUL_FINER              = 400,
 120         LTTNG_LOGLEVEL_JUL_FINEST             = 300,
 121         LTTNG_LOGLEVEL_JUL_ALL                = INT32_MIN,
 122 };
 123
 124 /*
 125  * LTTng consumer mode
 126  */
 127 enum lttng_event_output {
 128         LTTNG_EVENT_SPLICE                    = 0,
 129         LTTNG_EVENT_MMAP                      = 1,
 130 };
 131
 132 /* Event context possible type */
 133 enum lttng_event_context_type {
 134         LTTNG_EVENT_CONTEXT_PID               = 0,
 135         LTTNG_EVENT_CONTEXT_PERF_COUNTER      = 1,
 136         LTTNG_EVENT_CONTEXT_PROCNAME          = 2,
 137         LTTNG_EVENT_CONTEXT_PRIO              = 3,
 138         LTTNG_EVENT_CONTEXT_NICE              = 4,
 139         LTTNG_EVENT_CONTEXT_VPID              = 5,
 140         LTTNG_EVENT_CONTEXT_TID               = 6,
 141         LTTNG_EVENT_CONTEXT_VTID              = 7,
 142         LTTNG_EVENT_CONTEXT_PPID              = 8,
 143         LTTNG_EVENT_CONTEXT_VPPID             = 9,
 144         LTTNG_EVENT_CONTEXT_PTHREAD_ID        = 10,
 145         LTTNG_EVENT_CONTEXT_HOSTNAME          = 11,
 146         LTTNG_EVENT_CONTEXT_IP                = 12,
 147 };
 148
 149 enum lttng_calibrate_type {
 150         LTTNG_CALIBRATE_FUNCTION              = 0,
 151 };
 152
 153 /* Health component for the health check function. */
 154 enum lttng_health_component {
 155         LTTNG_HEALTH_CMD,
 156         LTTNG_HEALTH_APP_MANAGE,
 157         LTTNG_HEALTH_APP_REG,
 158         LTTNG_HEALTH_KERNEL,
 159         LTTNG_HEALTH_CONSUMER,
 160         LTTNG_HEALTH_HT_CLEANUP,
 161         LTTNG_HEALTH_APP_MANAGE_NOTIFY,
 162         LTTNG_HEALTH_APP_REG_DISPATCH,
 163         LTTNG_HEALTH_ALL,
 164 };
 165
 166 /* Buffer type for a specific domain. */
 167 enum lttng_buffer_type {
 168         LTTNG_BUFFER_PER_PID,   /* Only supported by UST being the default. */
 169         LTTNG_BUFFER_PER_UID,   /* Only supported by UST. */
 170         LTTNG_BUFFER_GLOBAL,    /* Only supported by the Kernel. */
 171 };
 172
 173 /*
 174  * The structures should be initialized to zero before use.
 175  */
 176 #define LTTNG_DOMAIN_PADDING1              12
 177 #define LTTNG_DOMAIN_PADDING2              LTTNG_SYMBOL_NAME_LEN + 32
 178 struct lttng_domain {
 179         enum lttng_domain_type type;
 180         enum lttng_buffer_type buf_type;
 181         char padding[LTTNG_DOMAIN_PADDING1];
 182
 183         union {
 184                 pid_t pid;
 185                 char exec_name[NAME_MAX];
 186                 char padding[LTTNG_DOMAIN_PADDING2];
 187         } attr;
 188 };
 189
 190 /*
 191  * Perf counter attributes
 192  *
 193  * The structures should be initialized to zero before use.
 194  */
 195 #define LTTNG_PERF_EVENT_PADDING1          16
 196 struct lttng_event_perf_counter_ctx {
 197         uint32_t type;
 198         uint64_t config;
 199         char name[LTTNG_SYMBOL_NAME_LEN];
 200
 201         char padding[LTTNG_PERF_EVENT_PADDING1];
 202 };
 203
 204 /*
 205  * Event/channel context
 206  *
 207  * The structures should be initialized to zero before use.
 208  */
 209 #define LTTNG_EVENT_CONTEXT_PADDING1       16
 210 #define LTTNG_EVENT_CONTEXT_PADDING2       LTTNG_SYMBOL_NAME_LEN + 32
 211 struct lttng_event_context {
 212         enum lttng_event_context_type ctx;
 213         char padding[LTTNG_EVENT_CONTEXT_PADDING1];
 214
 215         union {
 216                 struct lttng_event_perf_counter_ctx perf_counter;
 217                 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
 218         } u;
 219 };
 220
 221 /*
 222  * Event probe.
 223  *
 224  * Either addr is used or symbol_name and offset.
 225  *
 226  * The structures should be initialized to zero before use.
 227  */
 228 #define LTTNG_EVENT_PROBE_PADDING1         16
 229 struct lttng_event_probe_attr {
 230         uint64_t addr;
 231
 232         uint64_t offset;
 233         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 234
 235         char padding[LTTNG_EVENT_PROBE_PADDING1];
 236 };
 237
 238 /*
 239  * Function tracer
 240  *
 241  * The structures should be initialized to zero before use.
 242  */
 243 #define LTTNG_EVENT_FUNCTION_PADDING1      16
 244 struct lttng_event_function_attr {
 245         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 246
 247         char padding[LTTNG_EVENT_FUNCTION_PADDING1];
 248 };
 249
 250 /*
 251  * Generic lttng event
 252  *
 253  * The structures should be initialized to zero before use.
 254  */
 255 #define LTTNG_EVENT_PADDING1               14
 256 #define LTTNG_EVENT_PADDING2               LTTNG_SYMBOL_NAME_LEN + 32
 257 struct lttng_event {
 258         enum lttng_event_type type;
 259         char name[LTTNG_SYMBOL_NAME_LEN];
 260
 261         enum lttng_loglevel_type loglevel_type;
 262         int loglevel;
 263
 264         int32_t enabled;        /* Does not apply: -1 */
 265         pid_t pid;
 266         unsigned char filter;   /* filter enabled ? */
 267         unsigned char exclusion; /* exclusions added ? */
 268
 269         char padding[LTTNG_EVENT_PADDING1];
 270
 271         /* Per event type configuration */
 272         union {
 273                 struct lttng_event_probe_attr probe;
 274                 struct lttng_event_function_attr ftrace;
 275
 276                 char padding[LTTNG_EVENT_PADDING2];
 277         } attr;
 278 };
 279
 280 enum lttng_event_field_type {
 281         LTTNG_EVENT_FIELD_OTHER                 = 0,
 282         LTTNG_EVENT_FIELD_INTEGER               = 1,
 283         LTTNG_EVENT_FIELD_ENUM                  = 2,
 284         LTTNG_EVENT_FIELD_FLOAT                 = 3,
 285         LTTNG_EVENT_FIELD_STRING                = 4,
 286 };
 287
 288 #define LTTNG_EVENT_FIELD_PADDING       LTTNG_SYMBOL_NAME_LEN + 32
 289 struct lttng_event_field {
 290         char field_name[LTTNG_SYMBOL_NAME_LEN];
 291         enum lttng_event_field_type type;
 292         char padding[LTTNG_EVENT_FIELD_PADDING];
 293         struct lttng_event event;
 294         int nowrite;
 295 };
 296
 297 /*
 298  * Tracer channel attributes. For both kernel and user-space.
 299  *
 300  * The structures should be initialized to zero before use.
 301  */
 302 #define LTTNG_CHANNEL_ATTR_PADDING1        LTTNG_SYMBOL_NAME_LEN + 12
 303 struct lttng_channel_attr {
 304         int overwrite;                      /* 1: overwrite, 0: discard */
 305         uint64_t subbuf_size;               /* bytes */
 306         uint64_t num_subbuf;                /* power of 2 */
 307         unsigned int switch_timer_interval; /* usec */
 308         unsigned int read_timer_interval;   /* usec */
 309         enum lttng_event_output output;     /* splice, mmap */
 310         /* LTTng 2.1 padding limit */
 311         uint64_t tracefile_size;            /* bytes */
 312         uint64_t tracefile_count;           /* number of tracefiles */
 313         /* LTTng 2.3 padding limit */
 314         unsigned int live_timer_interval;   /* usec */
 315
 316         char padding[LTTNG_CHANNEL_ATTR_PADDING1];
 317 };
 318
 319 /*
 320  * Channel information structure. For both kernel and user-space.
 321  *
 322  * The structures should be initialized to zero before use.
 323  */
 324 #define LTTNG_CHANNEL_PADDING1             16
 325 struct lttng_channel {
 326         char name[LTTNG_SYMBOL_NAME_LEN];
 327         uint32_t enabled;
 328         struct lttng_channel_attr attr;
 329
 330         char padding[LTTNG_CHANNEL_PADDING1];
 331 };
 332
 333 #define LTTNG_CALIBRATE_PADDING1           16
 334 struct lttng_calibrate {
 335         enum lttng_calibrate_type type;
 336
 337         char padding[LTTNG_CALIBRATE_PADDING1];
 338 };
 339
 340 /*
 341  * Basic session information.
 342  *
 343  * This is an 'output data' meaning that it only comes *from* the session
 344  * daemon *to* the lttng client. It's basically a 'human' representation of
 345  * tracing entities (here a session).
 346  *
 347  * The structures should be initialized to zero before use.
 348  */
 349 #define LTTNG_SESSION_PADDING1             12
 350 struct lttng_session {
 351         char name[NAME_MAX];
 352         /* The path where traces are written */
 353         char path[PATH_MAX];
 354         uint32_t enabled;       /* enabled/started: 1, disabled/stopped: 0 */
 355         uint32_t snapshot_mode;
 356         unsigned int live_timer_interval;       /* usec */
 357
 358         char padding[LTTNG_SESSION_PADDING1];
 359 };
 360
 361 /*
 362  * Handle used as a context for commands.
 363  *
 364  * The structures should be initialized to zero before use.
 365  */
 366 #define LTTNG_HANDLE_PADDING1              16
 367 struct lttng_handle {
 368         char session_name[NAME_MAX];
 369         struct lttng_domain domain;
 370
 371         char padding[LTTNG_HANDLE_PADDING1];
 372 };
 373
 374 /*
 375  * Public LTTng control API
 376  *
 377  * For functions having an lttng domain type as parameter, if a bad value is
 378  * given, NO default is applied and an error is returned.
 379  *
 380  * On success, all functions of the API return 0 or the size of the allocated
 381  * array (in bytes).
 382  *
 383  * On error, a negative value is returned being a specific lttng-tools error
 384  * code which can be humanly interpreted with lttng_strerror(err).
 385  *
 386  * Exceptions to this are noted below.
 387  */
 388
 389 /*
 390  * Create a handle used as a context for every request made to the library.
 391  *
 392  * This handle contains the session name and lttng domain on which the command
 393  * will be executed.
 394  * The returned pointer will be NULL in case of malloc() error.
 395  */
 396 extern struct lttng_handle *lttng_create_handle(const char *session_name,
 397                 struct lttng_domain *domain);
 398
 399 /*
 400  * Destroy an handle.
 401  *
 402  * It free(3) the data pointer returned by lttng_create_handle(), rendering it
 403  * unusable.
 404  */
 405 extern void lttng_destroy_handle(struct lttng_handle *handle);
 406
 407 /*
 408  * Create a tracing session using a name and an optional URL.
 409  *
 410  * If _url_ is NULL, no consumer is created for the session. The name can't be
 411  * NULL here.
 412  */
 413 extern int lttng_create_session(const char *name, const char *url);
 414
 415 /*
 416  * Create a tracing session that will exclusively be used for snapshot meaning
 417  * the session will be in no output mode and every channel enabled for that
 418  * session will be set in overwrite mode and in mmap output since splice is not
 419  * supported.
 420  *
 421  * If an url is given, it will be used to create a default snapshot output
 422  * using it as a destination. If NULL, no output will be defined and an
 423  * add-output call will be needed.
 424  *
 425  * Name can't be NULL.
 426  */
 427 extern int lttng_create_session_snapshot(const char *name,
 428                 const char *snapshot_url);
 429
 430 /*
 431  * Create a session exclusively used for live reading.
 432  *
 433  * In this mode, the switch-timer parameter is forced for each UST channel, a
 434  * live-switch-timer is enabled for kernel channels, manually setting
 435  * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
 436  * indexes are sent and metadata is checked for each packet.
 437  *
 438  * Returns LTTNG_OK on success or a negative error code.
 439  */
 440 extern int lttng_create_session_live(const char *name, const char *url,
 441                 unsigned int timer_interval);
 442
 443 /*
 444  * Destroy a tracing session.
 445  *
 446  * The session will not be usable anymore, tracing will be stopped for all
 447  * registered traces, and the tracing buffers will be flushed.
 448  *
 449  * The name can't be NULL here.
 450  */
 451 extern int lttng_destroy_session(const char *name);
 452
 453 /*
 454  * List all the tracing sessions.
 455  *
 456  * Return the size (number of entries) of the "lttng_session" array. Caller
 457  * must free(3).
 458  */
 459 extern int lttng_list_sessions(struct lttng_session **sessions);
 460
 461 /*
 462  * List the registered domain(s) of a session.
 463  *
 464  * Return the size (number of entries) of the "lttng_domain" array. Caller
 465  * must free(3).
 466  */
 467 extern int lttng_list_domains(const char *session_name,
 468                 struct lttng_domain **domains);
 469
 470 /*
 471  * List the channel(s) of a session.
 472  *
 473  * Return the size (number of entries) of the "lttng_channel" array. Caller
 474  * must free(3).
 475  */
 476 extern int lttng_list_channels(struct lttng_handle *handle,
 477                 struct lttng_channel **channels);
 478
 479 /*
 480  * List the event(s) of a session channel.
 481  *
 482  * Return the size (number of entries) of the "lttng_event" array.
 483  * Caller must free(3).
 484  */
 485 extern int lttng_list_events(struct lttng_handle *handle,
 486                 const char *channel_name, struct lttng_event **events);
 487
 488 /*
 489  * List the available tracepoints of a specific lttng domain.
 490  *
 491  * Return the size (number of entries) of the "lttng_event" array.
 492  * Caller must free(3).
 493  */
 494 extern int lttng_list_tracepoints(struct lttng_handle *handle,
 495                 struct lttng_event **events);
 496
 497 /*
 498  * List the available tracepoints fields of a specific lttng domain.
 499  *
 500  * Return the size (number of entries) of the "lttng_event_field" array.
 501  * Caller must free(3).
 502  */
 503 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
 504                 struct lttng_event_field **fields);
 505
 506 /*
 507  * Check if a session daemon is alive.
 508  *
 509  * Return 1 if alive or 0 if not. On error returns a negative value.
 510  */
 511 extern int lttng_session_daemon_alive(void);
 512
 513 /*
 514  * Set the tracing group for the *current* flow of execution.
 515  *
 516  * On success, returns 0 else a negative value on error being a lttng error
 517  * code found in lttng-error.h
 518  */
 519 extern int lttng_set_tracing_group(const char *name);
 520
 521 /*
 522  * Return a human-readable error message for an lttng-tools error code.
 523  *
 524  * Parameter MUST be a negative value or else you'll get a generic message.
 525  */
 526 extern const char *lttng_strerror(int code);
 527
 528 /*
 529  * This call registers an "outside consumer" for a session and an lttng domain.
 530  * No consumer will be spawned and all fds/commands will go through the socket
 531  * path given (socket_path).
 532  *
 533  * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
 534  * command socket. The error socket is not supported yet for roaming consumers.
 535  */
 536 extern int lttng_register_consumer(struct lttng_handle *handle,
 537                 const char *socket_path);
 538
 539 /*
 540  * Start tracing for *all* registered traces (kernel and user-space).
 541  */
 542 extern int lttng_start_tracing(const char *session_name);
 543
 544 /*
 545  * Stop tracing for *all* registered traces (kernel and user-space).
 546  *
 547  * This call will wait for data availability for each domain of the session so
 548  * this can take an abritrary amount of time. However, when returning you have
 549  * the guarantee that the data is ready to be read and analyse. Use the
 550  * _no_wait call below to avoid this behavior.
 551  *
 552  * The session_name can't be NULL.
 553  */
 554 extern int lttng_stop_tracing(const char *session_name);
 555
 556 /*
 557  * Behave exactly like lttng_stop_tracing but does not wait for data
 558  * availability.
 559  */
 560 extern int lttng_stop_tracing_no_wait(const char *session_name);
 561
 562 /*
 563  * Add context to event(s) for a specific channel (or for all).
 564  *
 565  * If channel_name is NULL, a lookup of the event's channel is done. If both
 566  * are NULL, the context is applied to all events of all channels.
 567  *
 568  * Note that whatever event_name value is, a context can not be added to an
 569  * event, so we just ignore it for now.
 570  */
 571 extern int lttng_add_context(struct lttng_handle *handle,
 572                 struct lttng_event_context *ctx, const char *event_name,
 573                 const char *channel_name);
 574
 575 /*
 576  * Create or enable an event (or events) for a channel.
 577  *
 578  * If the event you are trying to enable does not exist, it will be created,
 579  * else it is enabled.
 580  * If channel_name is NULL, the default channel is used (channel0).
 581  *
 582  * The handle and ev params can not be NULL.
 583  */
 584 extern int lttng_enable_event(struct lttng_handle *handle,
 585                 struct lttng_event *ev, const char *channel_name);
 586
 587 /*
 588  * Create or enable an event with a specific filter.
 589  *
 590  * If the event you are trying to enable does not exist, it will be created,
 591  * else it is enabled.
 592  * If ev is NULL, all events are enabled with that filter.
 593  * If channel_name is NULL, the default channel is used (channel0) and created
 594  * if not found.
 595  * If filter_expression is NULL, an event without associated filter is
 596  * created.
 597  */
 598 extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
 599                 struct lttng_event *event, const char *channel_name,
 600                 const char *filter_expression);
 601
 602 /*
 603  * Create or enable an event with a filter and/or exclusions.
 604  *
 605  * If the event you are trying to enable does not exist, it will be created,
 606  * else it is enabled.
 607  * If ev is NULL, all events are enabled with the filter and exclusion options.
 608  * If channel_name is NULL, the default channel is used (channel0) and created
 609  * if not found.
 610  * If filter_expression is NULL, an event without associated filter is
 611  * created.
 612  * If exclusion count is zero, the event will be created without exclusions.
 613  */
 614 extern int lttng_enable_event_with_exclusions(struct lttng_handle *handle,
 615                 struct lttng_event *event, const char *channel_name,
 616                 const char *filter_expression,
 617                 int exclusion_count, char **exclusion_names);
 618
 619 /*
 620  * Create or enable a channel.
 621  *
 622  * The chan and handle params can not be NULL.
 623  */
 624 extern int lttng_enable_channel(struct lttng_handle *handle,
 625                 struct lttng_channel *chan);
 626
 627 /*
 628  * Disable event(s) of a channel and domain.
 629  *
 630  * If name is NULL, all events are disabled.
 631  * If channel_name is NULL, the default channel is used (channel0).
 632  */
 633 extern int lttng_disable_event(struct lttng_handle *handle,
 634                 const char *name, const char *channel_name);
 635
 636 /*
 637  * Disable channel.
 638  *
 639  */
 640 extern int lttng_disable_channel(struct lttng_handle *handle,
 641                 const char *name);
 642
 643 /*
 644  * Calibrate LTTng overhead.
 645  *
 646  * The chan and handle params can not be NULL.
 647  */
 648 extern int lttng_calibrate(struct lttng_handle *handle,
 649                 struct lttng_calibrate *calibrate);
 650
 651 /*
 652  * Set the default channel attributes for a specific domain and an allocated
 653  * lttng_channel_attr pointer.
 654  *
 655  * If one or both arguments are NULL, nothing happens.
 656  */
 657 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
 658                 struct lttng_channel_attr *attr);
 659
 660 /*
 661  * Set URL for a consumer for a session and domain.
 662  *
 663  * Both data and control URL must be defined. If both URLs are the same, only
 664  * the control URL is used even for network streaming.
 665  *
 666  * Default port are 5342 and 5343 respectively for control and data which uses
 667  * the TCP protocol.
 668  */
 669 extern int lttng_set_consumer_url(struct lttng_handle *handle,
 670                 const char *control_url, const char *data_url);
 671
 672 /*
 673  * Enable the consumer for a session and domain.
 674  */
 675 extern LTTNG_DEPRECATED("This call is now obsolete.")
 676 int lttng_enable_consumer(struct lttng_handle *handle);
 677
 678 /*
 679  * Disable consumer for a session and domain.
 680  */
 681 extern LTTNG_DEPRECATED("This call is now obsolete.")
 682 int lttng_disable_consumer(struct lttng_handle *handle);
 683
 684 /*
 685  * Check session daemon health for a specific component.
 686  *
 687  * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
 688  * the control library was not able to connect to the session daemon health
 689  * socket.
 690  *
 691  * Any other positive value is an lttcomm error which can be translate with
 692  * lttng_strerror().
 693  *
 694  * Please see lttng-health-check(3) man page for more information.
 695  */
 696 extern LTTNG_DEPRECATED("This call is now obsolete.")
 697 int lttng_health_check(enum lttng_health_component c);
 698
 699 /*
 700  * For a given session name, this call checks if the data is ready to be read
 701  * or is still being extracted by the consumer(s) (pending) hence not ready to
 702  * be used by any readers.
 703  *
 704  * Return 0 if there is _no_ data pending in the buffers thus having a
 705  * guarantee that the data can be read safely. Else, return 1 if there is still
 706  * traced data is pending. On error, a negative value is returned and readable
 707  * by lttng_strerror().
 708  */
 709 extern int lttng_data_pending(const char *session_name);
 710
 711 #ifdef __cplusplus
 712 }
 713 #endif
 714
 715 #endif /* LTTNG_H */