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,      /* Backward compat. */
 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         LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER  = 13,
 148         LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER = 14,
 149 };
 150
 151 enum lttng_calibrate_type {
 152         LTTNG_CALIBRATE_FUNCTION              = 0,
 153 };
 154
 155 /* Health component for the health check function. */
 156 enum lttng_health_component {
 157         LTTNG_HEALTH_CMD,
 158         LTTNG_HEALTH_APP_MANAGE,
 159         LTTNG_HEALTH_APP_REG,
 160         LTTNG_HEALTH_KERNEL,
 161         LTTNG_HEALTH_CONSUMER,
 162         LTTNG_HEALTH_HT_CLEANUP,
 163         LTTNG_HEALTH_APP_MANAGE_NOTIFY,
 164         LTTNG_HEALTH_APP_REG_DISPATCH,
 165         LTTNG_HEALTH_ALL,
 166 };
 167
 168 /* Buffer type for a specific domain. */
 169 enum lttng_buffer_type {
 170         LTTNG_BUFFER_PER_PID,   /* Only supported by UST being the default. */
 171         LTTNG_BUFFER_PER_UID,   /* Only supported by UST. */
 172         LTTNG_BUFFER_GLOBAL,    /* Only supported by the Kernel. */
 173 };
 174
 175 /*
 176  * The structures should be initialized to zero before use.
 177  */
 178 #define LTTNG_DOMAIN_PADDING1              12
 179 #define LTTNG_DOMAIN_PADDING2              LTTNG_SYMBOL_NAME_LEN + 32
 180 struct lttng_domain {
 181         enum lttng_domain_type type;
 182         enum lttng_buffer_type buf_type;
 183         char padding[LTTNG_DOMAIN_PADDING1];
 184
 185         union {
 186                 pid_t pid;
 187                 char exec_name[NAME_MAX];
 188                 char padding[LTTNG_DOMAIN_PADDING2];
 189         } attr;
 190 };
 191
 192 /*
 193  * Perf counter attributes
 194  *
 195  * The structures should be initialized to zero before use.
 196  */
 197 #define LTTNG_PERF_EVENT_PADDING1          16
 198 struct lttng_event_perf_counter_ctx {
 199         uint32_t type;
 200         uint64_t config;
 201         char name[LTTNG_SYMBOL_NAME_LEN];
 202
 203         char padding[LTTNG_PERF_EVENT_PADDING1];
 204 };
 205
 206 /*
 207  * Event/channel context
 208  *
 209  * The structures should be initialized to zero before use.
 210  */
 211 #define LTTNG_EVENT_CONTEXT_PADDING1       16
 212 #define LTTNG_EVENT_CONTEXT_PADDING2       LTTNG_SYMBOL_NAME_LEN + 32
 213 struct lttng_event_context {
 214         enum lttng_event_context_type ctx;
 215         char padding[LTTNG_EVENT_CONTEXT_PADDING1];
 216
 217         union {
 218                 struct lttng_event_perf_counter_ctx perf_counter;
 219                 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
 220         } u;
 221 };
 222
 223 /*
 224  * Event probe.
 225  *
 226  * Either addr is used or symbol_name and offset.
 227  *
 228  * The structures should be initialized to zero before use.
 229  */
 230 #define LTTNG_EVENT_PROBE_PADDING1         16
 231 struct lttng_event_probe_attr {
 232         uint64_t addr;
 233
 234         uint64_t offset;
 235         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 236
 237         char padding[LTTNG_EVENT_PROBE_PADDING1];
 238 };
 239
 240 /*
 241  * Function tracer
 242  *
 243  * The structures should be initialized to zero before use.
 244  */
 245 #define LTTNG_EVENT_FUNCTION_PADDING1      16
 246 struct lttng_event_function_attr {
 247         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 248
 249         char padding[LTTNG_EVENT_FUNCTION_PADDING1];
 250 };
 251
 252 /*
 253  * Generic lttng event
 254  *
 255  * The structures should be initialized to zero before use.
 256  */
 257 #define LTTNG_EVENT_PADDING1               14
 258 #define LTTNG_EVENT_PADDING2               LTTNG_SYMBOL_NAME_LEN + 32
 259 struct lttng_event {
 260         enum lttng_event_type type;
 261         char name[LTTNG_SYMBOL_NAME_LEN];
 262
 263         enum lttng_loglevel_type loglevel_type;
 264         int loglevel;
 265
 266         int32_t enabled;        /* Does not apply: -1 */
 267         pid_t pid;
 268         unsigned char filter;   /* filter enabled ? */
 269         unsigned char exclusion; /* exclusions added ? */
 270
 271         char padding[LTTNG_EVENT_PADDING1];
 272
 273         /* Per event type configuration */
 274         union {
 275                 struct lttng_event_probe_attr probe;
 276                 struct lttng_event_function_attr ftrace;
 277
 278                 char padding[LTTNG_EVENT_PADDING2];
 279         } attr;
 280 };
 281
 282 enum lttng_event_field_type {
 283         LTTNG_EVENT_FIELD_OTHER                 = 0,
 284         LTTNG_EVENT_FIELD_INTEGER               = 1,
 285         LTTNG_EVENT_FIELD_ENUM                  = 2,
 286         LTTNG_EVENT_FIELD_FLOAT                 = 3,
 287         LTTNG_EVENT_FIELD_STRING                = 4,
 288 };
 289
 290 #define LTTNG_EVENT_FIELD_PADDING       LTTNG_SYMBOL_NAME_LEN + 32
 291 struct lttng_event_field {
 292         char field_name[LTTNG_SYMBOL_NAME_LEN];
 293         enum lttng_event_field_type type;
 294         char padding[LTTNG_EVENT_FIELD_PADDING];
 295         struct lttng_event event;
 296         int nowrite;
 297 };
 298
 299 /*
 300  * Tracer channel attributes. For both kernel and user-space.
 301  *
 302  * The structures should be initialized to zero before use.
 303  */
 304 #define LTTNG_CHANNEL_ATTR_PADDING1        LTTNG_SYMBOL_NAME_LEN + 12
 305 struct lttng_channel_attr {
 306         int overwrite;                      /* 1: overwrite, 0: discard */
 307         uint64_t subbuf_size;               /* bytes */
 308         uint64_t num_subbuf;                /* power of 2 */
 309         unsigned int switch_timer_interval; /* usec */
 310         unsigned int read_timer_interval;   /* usec */
 311         enum lttng_event_output output;     /* splice, mmap */
 312         /* LTTng 2.1 padding limit */
 313         uint64_t tracefile_size;            /* bytes */
 314         uint64_t tracefile_count;           /* number of tracefiles */
 315         /* LTTng 2.3 padding limit */
 316         unsigned int live_timer_interval;   /* usec */
 317
 318         char padding[LTTNG_CHANNEL_ATTR_PADDING1];
 319 };
 320
 321 /*
 322  * Channel information structure. For both kernel and user-space.
 323  *
 324  * The structures should be initialized to zero before use.
 325  */
 326 #define LTTNG_CHANNEL_PADDING1             16
 327 struct lttng_channel {
 328         char name[LTTNG_SYMBOL_NAME_LEN];
 329         uint32_t enabled;
 330         struct lttng_channel_attr attr;
 331
 332         char padding[LTTNG_CHANNEL_PADDING1];
 333 };
 334
 335 #define LTTNG_CALIBRATE_PADDING1           16
 336 struct lttng_calibrate {
 337         enum lttng_calibrate_type type;
 338
 339         char padding[LTTNG_CALIBRATE_PADDING1];
 340 };
 341
 342 /*
 343  * Basic session information.
 344  *
 345  * This is an 'output data' meaning that it only comes *from* the session
 346  * daemon *to* the lttng client. It's basically a 'human' representation of
 347  * tracing entities (here a session).
 348  *
 349  * The structures should be initialized to zero before use.
 350  */
 351 #define LTTNG_SESSION_PADDING1             12
 352 struct lttng_session {
 353         char name[NAME_MAX];
 354         /* The path where traces are written */
 355         char path[PATH_MAX];
 356         uint32_t enabled;       /* enabled/started: 1, disabled/stopped: 0 */
 357         uint32_t snapshot_mode;
 358         unsigned int live_timer_interval;       /* usec */
 359
 360         char padding[LTTNG_SESSION_PADDING1];
 361 };
 362
 363 /*
 364  * Handle used as a context for commands.
 365  *
 366  * The structures should be initialized to zero before use.
 367  */
 368 #define LTTNG_HANDLE_PADDING1              16
 369 struct lttng_handle {
 370         char session_name[NAME_MAX];
 371         struct lttng_domain domain;
 372
 373         char padding[LTTNG_HANDLE_PADDING1];
 374 };
 375
 376 /*
 377  * Public LTTng control API
 378  */
 379
 380 /*
 381  * Create a tracing session using a name and an optional URL.
 382  *
 383  * If _url_ is NULL, no consumer is created for the session. The name can't be
 384  * NULL here.
 385  *
 386  * Return 0 on success else a negative LTTng error code.
 387  */
 388 extern int lttng_create_session(const char *name, const char *url);
 389
 390 /*
 391  * Create a tracing session that will exclusively be used for snapshot meaning
 392  * the session will be in no output mode and every channel enabled for that
 393  * session will be set in overwrite mode and in mmap output since splice is not
 394  * supported.
 395  *
 396  * Name can't be NULL. If an url is given, it will be used to create a default
 397  * snapshot output using it as a destination. If NULL, no output will be
 398  * defined and an add-output call will be needed.
 399  *
 400  * Return 0 on success else a negative LTTng error code.
 401  */
 402 extern int lttng_create_session_snapshot(const char *name,
 403                 const char *snapshot_url);
 404
 405 /*
 406  * Create a session exclusively used for live reading.
 407  *
 408  * In this mode, the switch-timer parameter is forced for each UST channel, a
 409  * live-switch-timer is enabled for kernel channels, manually setting
 410  * switch-timer is forbidden. Synchronization beacons are sent to the relayd,
 411  * indexes are sent and metadata is checked for each packet.
 412  *
 413  * Name can't be NULL. If no URL is given, the default is to send the data to
 414  * net://127.0.0.1. The timer_interval is in usec and by default set to 1000000
 415  * (1 second).
 416  *
 417  * Return 0 on success else a negative LTTng error code.
 418  */
 419 extern int lttng_create_session_live(const char *name, const char *url,
 420                 unsigned int timer_interval);
 421
 422 /*
 423  * Create an handle used as a context for every request made to the library.
 424  *
 425  * This handle contains the session name and domain on which the command will
 426  * be executed. A domain is basically a tracer like the kernel or user space.
 427  *
 428  * Return an newly allocated handle that should be freed using
 429  * lttng_destroy_handle. On error, NULL is returned.
 430  */
 431 extern struct lttng_handle *lttng_create_handle(const char *session_name,
 432                 struct lttng_domain *domain);
 433
 434 /*
 435  * Destroy an handle that has been previously created with lttng_create_handle.
 436  *
 437  * It free the given pointer making it unusable.
 438  */
 439 extern void lttng_destroy_handle(struct lttng_handle *handle);
 440
 441 /*
 442  * Destroy a tracing session.
 443  *
 444  * The session will not be usable, tracing will be stopped thus buffers will be
 445  * flushed.
 446  *
 447  * The name can't be NULL here.
 448  *
 449  * Return 0 on success else a negative LTTng error code.
 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 sessions. On error, a negative LTTng error code is returned.
 458  */
 459 extern int lttng_list_sessions(struct lttng_session **sessions);
 460
 461 /*
 462  * List the registered domain(s) of a session.
 463  *
 464  * Session name CAN NOT be NULL.
 465  *
 466  * Return the size (number of entries) of the "lttng_domain" array. Caller
 467  * must free domains. On error, a negative LTTng error code is returned.
 468  */
 469 extern int lttng_list_domains(const char *session_name,
 470                 struct lttng_domain **domains);
 471
 472 /*
 473  * List the channel(s) of a session.
 474  *
 475  * The handle CAN NOT be NULL.
 476  *
 477  * Return the size (number of entries) of the "lttng_channel" array. Caller
 478  * must free channels. On error, a negative LTTng error code is returned.
 479  */
 480 extern int lttng_list_channels(struct lttng_handle *handle,
 481                 struct lttng_channel **channels);
 482
 483 /*
 484  * List the event(s) of a session channel.
 485  *
 486  * Both handle and channel_name CAN NOT be NULL.
 487  *
 488  * Return the size (number of entries) of the "lttng_event" array. Caller must
 489  * free events. On error a negative LTTng error code is returned.
 490  */
 491 extern int lttng_list_events(struct lttng_handle *handle,
 492                 const char *channel_name, struct lttng_event **events);
 493
 494 /*
 495  * List the available tracepoints of a specific lttng domain.
 496  *
 497  * The handle CAN NOT be NULL.
 498  *
 499  * Return the size (number of entries) of the "lttng_event" array.  Caller must
 500  * free events. On error a negative LTTng error code is returned.
 501  */
 502 extern int lttng_list_tracepoints(struct lttng_handle *handle,
 503                 struct lttng_event **events);
 504
 505 /*
 506  * List the available tracepoints fields of a specific lttng domain.
 507  *
 508  * The handle CAN NOT be NULL.
 509  *
 510  * Return the size (number of entries) of the "lttng_event_field" array.
 511  * Caller must free fields. On error a negative LTTng error code is
 512  * returned.
 513  */
 514 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
 515                 struct lttng_event_field **fields);
 516
 517 /*
 518  * Check if a session daemon is alive.
 519  *
 520  * Return 1 if alive or 0 if not. On error, returns a negative negative LTTng
 521  * error code.
 522  */
 523 extern int lttng_session_daemon_alive(void);
 524
 525 /*
 526  * Set the tracing group for the *current* flow of execution.
 527  *
 528  * On success, returns 0 else a negative LTTng error code.
 529  */
 530 extern int lttng_set_tracing_group(const char *name);
 531
 532 /*
 533  * Return a human-readable error message for a LTTng error code.
 534  *
 535  * Parameter MUST be a negative value or else you'll get a generic message.
 536  */
 537 extern const char *lttng_strerror(int code);
 538
 539 /*
 540  * This call registers an "outside consumer" for a session and an lttng domain.
 541  * No consumer will be spawned and all fds/commands will go through the socket
 542  * path given (socket_path).
 543  *
 544  * NOTE that this is not recommended unless you absolutely know what you are
 545  * doing.
 546  *
 547  * Return 0 on success else a negative LTTng error code.
 548  */
 549 extern int lttng_register_consumer(struct lttng_handle *handle,
 550                 const char *socket_path);
 551
 552 /*
 553  * Start tracing for *all* domain(s) in the session.
 554  *
 555  * Return 0 on success else a negative LTTng error code.
 556  */
 557 extern int lttng_start_tracing(const char *session_name);
 558
 559 /*
 560  * Stop tracing for *all* domain(s) in the session.
 561  *
 562  * This call will wait for data availability for each domain of the session so
 563  * this can take an abritrary amount of time. However, when returning you have
 564  * the guarantee that the data is ready to be read and analyze. Use the
 565  * _no_wait call below to avoid this behavior.
 566  *
 567  * The session_name can't be NULL.
 568  *
 569  * Return 0 on success else a negative LTTng error code.
 570  */
 571 extern int lttng_stop_tracing(const char *session_name);
 572
 573 /*
 574  * Behave exactly like lttng_stop_tracing but does not wait for data
 575  * availability.
 576  */
 577 extern int lttng_stop_tracing_no_wait(const char *session_name);
 578
 579 /*
 580  * Add context to event(s) for a specific channel (or for all).
 581  *
 582  * If the channel_name is NULL and they are no channel for the domain, the
 583  * default channel is created (channel0). The context is then added on ALL
 584  * channels since no name was specified.
 585  *
 586  * The event_name is ignored since adding a context to an event is not possible
 587  * for now.
 588  *
 589  * Return 0 on success else a negative LTTng error code.
 590  */
 591 extern int lttng_add_context(struct lttng_handle *handle,
 592                 struct lttng_event_context *ctx, const char *event_name,
 593                 const char *channel_name);
 594
 595 /*
 596  * Create or enable an event (or events) for a channel.
 597  *
 598  * If the event you are trying to enable does not exist, it will be created,
 599  * else it is enabled. If channel_name is NULL, the default channel is used
 600  * (channel0).
 601  *
 602  * The handle and ev params can not be NULL.
 603  *
 604  * Return 0 on success else a negative LTTng error code.
 605  */
 606 extern int lttng_enable_event(struct lttng_handle *handle,
 607                 struct lttng_event *ev, const char *channel_name);
 608
 609 /*
 610  * Create or enable an event with a specific filter.
 611  *
 612  * If the event you are trying to enable does not exist, it will be created,
 613  * else it is enabled.
 614  * If ev is NULL, all events are enabled with that filter.
 615  * If channel_name is NULL, the default channel is used (channel0) and created
 616  * if not found.
 617  * If filter_expression is NULL, an event without associated filter is
 618  * created.
 619  *
 620  * Return 0 on success else a negative LTTng error code.
 621  */
 622 extern int lttng_enable_event_with_filter(struct lttng_handle *handle,
 623                 struct lttng_event *event, const char *channel_name,
 624                 const char *filter_expression);
 625
 626 /*
 627  * Create or enable an event with a filter and/or exclusions.
 628  *
 629  * If the event you are trying to enable does not exist, it will be created,
 630  * else it is enabled.
 631  * If ev is NULL, all events are enabled with the filter and exclusion options.
 632  * If channel_name is NULL, the default channel is used (channel0) and created
 633  * if not found.
 634  * If filter_expression is NULL, an event without associated filter is
 635  * created.
 636  * If exclusion count is zero, the event will be created without exclusions.
 637  *
 638  * Return 0 on success else a negative LTTng error code.
 639  */
 640 extern int lttng_enable_event_with_exclusions(struct lttng_handle *handle,
 641                 struct lttng_event *event, const char *channel_name,
 642                 const char *filter_expression,
 643                 int exclusion_count, char **exclusion_names);
 644
 645 /*
 646  * Create or enable a channel.
 647  *
 648  * The chan and handle params can not be NULL.
 649  *
 650  * Return 0 on success else a negative LTTng error code.
 651  */
 652 extern int lttng_enable_channel(struct lttng_handle *handle,
 653                 struct lttng_channel *chan);
 654
 655 /*
 656  * Disable event(s) of a channel and domain.
 657  *
 658  * If name is NULL, all events are disabled.
 659  * If channel_name is NULL, the default channel is used (channel0).
 660  *
 661  * Return 0 on success else a negative LTTng error code.
 662  */
 663 extern int lttng_disable_event(struct lttng_handle *handle,
 664                 const char *name, const char *channel_name);
 665
 666 /*
 667  * Disable channel.
 668  *
 669  * Name and handle CAN NOT be NULL.
 670  *
 671  * Return 0 on success else a negative LTTng error code.
 672  */
 673 extern int lttng_disable_channel(struct lttng_handle *handle,
 674                 const char *name);
 675
 676 /*
 677  * Calibrate LTTng overhead.
 678  *
 679  * The chan and handle params can not be NULL.
 680  *
 681  * Return 0 on success else a negative LTTng error code.
 682  */
 683 extern int lttng_calibrate(struct lttng_handle *handle,
 684                 struct lttng_calibrate *calibrate);
 685
 686 /*
 687  * Set the default channel attributes for a specific domain and an allocated
 688  * lttng_channel_attr pointer.
 689  *
 690  * If one or both arguments are NULL, nothing happens.
 691  */
 692 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
 693                 struct lttng_channel_attr *attr);
 694
 695 /*
 696  * Set URL for a consumer for a session and domain.
 697  *
 698  * Both data and control URL must be defined. If both URLs are the same, only
 699  * the control URL is used even for network streaming.
 700  *
 701  * Default port are 5342 and 5343 respectively for control and data which uses
 702  * the TCP protocol.
 703  *
 704  * URL format: proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
 705  *
 706  * Possible protocols are:
 707  * > file://...
 708  *   Local filesystem full path.
 709  *
 710  * > net[6]://...
 711  *   This will use the default network transport layer which is TCP for both
 712  *   control (PORT1) and data port (PORT2).
 713  *
 714  * > tcp[6]://...
 715  *   TCP only streaming. For this one, both data and control URL must be given.
 716  *
 717  * Return 0 on success else a negative LTTng error code.
 718  */
 719 extern int lttng_set_consumer_url(struct lttng_handle *handle,
 720                 const char *control_url, const char *data_url);
 721
 722 /*
 723  * Enable the consumer for a session and domain.
 724  */
 725 extern LTTNG_DEPRECATED("This call is now obsolete.")
 726 int lttng_enable_consumer(struct lttng_handle *handle);
 727
 728 /*
 729  * Disable consumer for a session and domain.
 730  */
 731 extern LTTNG_DEPRECATED("This call is now obsolete.")
 732 int lttng_disable_consumer(struct lttng_handle *handle);
 733
 734 /*
 735  * Check session daemon health for a specific component.
 736  *
 737  * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
 738  * the control library was not able to connect to the session daemon health
 739  * socket.
 740  *
 741  * Any other positive value is an lttcomm error which can be translate with
 742  * lttng_strerror().
 743  *
 744  * Please see lttng-health-check(3) man page for more information.
 745  */
 746 extern LTTNG_DEPRECATED("This call is now obsolete.")
 747 int lttng_health_check(enum lttng_health_component c);
 748
 749 /*
 750  * For a given session name, this call checks if the data is ready to be read
 751  * or is still being extracted by the consumer(s) (pending) hence not ready to
 752  * be used by any readers.
 753  *
 754  * Return 0 if there is _no_ data pending in the buffers thus having a
 755  * guarantee that the data can be read safely. Else, return 1 if there is still
 756  * traced data is pending. On error, a negative value is returned and readable
 757  * by lttng_strerror().
 758  */
 759 extern int lttng_data_pending(const char *session_name);
 760
 761 #ifdef __cplusplus
 762 }
 763 #endif
 764
 765 #endif /* LTTNG_H */