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