src/common/mi-lttng.h

   1 /*
   2  * Copyright (C) 2014 - Jonathan Rajotte <jonathan.r.julien@gmail.com>
   3  *                    - Olivier Cotte <olivier.cotte@polymtl.ca>
   4  * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #ifndef _MI_LTTNG_H
  21 #define _MI_LTTNG_H
  22
  23 #include <stdint.h>
  24
  25 #include <common/error.h>
  26 #include <common/macros.h>
  27 #include <common/config/session-config.h>
  28 #include <lttng/lttng.h>
  29
  30 /* Don't want to reference snapshot-internal.h here */
  31 struct lttng_snapshot_output;
  32
  33 /* Instance of a machine interface writer. */
  34 struct mi_writer {
  35         struct config_writer *writer;
  36         enum lttng_mi_output_type type;
  37 };
  38
  39 /*
  40  * Version information for the machine interface.
  41  */
  42 struct mi_lttng_version {
  43         char version[LTTNG_NAME_MAX]; /* Version number of package */
  44         uint32_t version_major; /* LTTng-Tools major version number */
  45         uint32_t version_minor; /* LTTng-Tools minor version number */
  46         uint32_t version_patchlevel; /* LTTng-Tools patchlevel version number */
  47         char version_commit[LTTNG_NAME_MAX]; /* Commit hash of the current version */
  48         char version_name[LTTNG_NAME_MAX];
  49         char package_url[LTTNG_NAME_MAX]; /* Define to the home page for this package. */
  50 };
  51
  52 /* Strings related to command */
  53 extern const char * const mi_lttng_element_command;
  54 extern const char * const mi_lttng_element_command_action;
  55 extern const char * const mi_lttng_element_command_add_context;
  56 extern const char * const mi_lttng_element_command_create;
  57 extern const char * const mi_lttng_element_command_destroy;
  58 extern const char * const mi_lttng_element_command_disable_channel;
  59 extern const char * const mi_lttng_element_command_disable_event;
  60 extern const char * const mi_lttng_element_command_enable_channels;
  61 extern const char * const mi_lttng_element_command_enable_event;
  62 extern const char * const mi_lttng_element_command_list;
  63 extern const char * const mi_lttng_element_command_load;
  64 extern const char * const mi_lttng_element_command_metadata;
  65 extern const char * const mi_lttng_element_command_metadata_action;
  66 extern const char * const mi_lttng_element_command_regenerate;
  67 extern const char * const mi_lttng_element_command_regenerate_action;
  68 extern const char * const mi_lttng_element_command_name;
  69 extern const char * const mi_lttng_element_command_output;
  70 extern const char * const mi_lttng_element_command_save;
  71 extern const char * const mi_lttng_element_command_set_session;
  72 extern const char * const mi_lttng_element_command_snapshot;
  73 extern const char * const mi_lttng_element_command_snapshot_add;
  74 extern const char * const mi_lttng_element_command_snapshot_del;
  75 extern const char * const mi_lttng_element_command_snapshot_list;
  76 extern const char * const mi_lttng_element_command_snapshot_record;
  77 extern const char * const mi_lttng_element_command_start;
  78 extern const char * const mi_lttng_element_command_stop;
  79 extern const char * const mi_lttng_element_command_success;
  80 extern const char * const mi_lttng_element_command_track;
  81 extern const char * const mi_lttng_element_command_untrack;
  82 extern const char * const mi_lttng_element_command_version;
  83 extern const char * const mi_lttng_element_command_rotate;
  84 extern const char * const mi_lttng_element_command_enable_rotation;
  85 extern const char * const mi_lttng_element_command_disable_rotation;
  86
  87 /* Strings related to version command */
  88 extern const char * const mi_lttng_element_version;
  89 extern const char * const mi_lttng_element_version_commit;
  90 extern const char * const mi_lttng_element_version_description;
  91 extern const char * const mi_lttng_element_version_license;
  92 extern const char * const mi_lttng_element_version_major;
  93 extern const char * const mi_lttng_element_version_minor;
  94 extern const char * const mi_lttng_element_version_patch_level;
  95 extern const char * const mi_lttng_element_version_str;
  96 extern const char * const mi_lttng_element_version_web;
  97
  98 /* String related to a lttng_event_field */
  99 extern const char * const mi_lttng_element_event_field;
 100 extern const char * const mi_lttng_element_event_fields;
 101
 102 /* String related to lttng_event_perf_counter_ctx */
 103 extern const char * const mi_lttng_element_perf_counter_context;
 104
 105 /* Strings related to pid */
 106 extern const char * const mi_lttng_element_pid_id;
 107
 108 /* Strings related to save command */
 109 extern const char * const mi_lttng_element_save;
 110
 111 /* Strings related to load command */
 112 extern const char * const mi_lttng_element_load;
 113 LTTNG_HIDDEN const char * const mi_lttng_element_load_overrides;
 114 LTTNG_HIDDEN const char * const mi_lttng_element_load_override_url;
 115
 116 /* General element of mi_lttng */
 117 extern const char * const mi_lttng_element_empty;
 118 extern const char * const mi_lttng_element_id;
 119 extern const char * const mi_lttng_element_nowrite;
 120 extern const char * const mi_lttng_element_success;
 121 extern const char * const mi_lttng_element_type_enum;
 122 extern const char * const mi_lttng_element_type_float;
 123 extern const char * const mi_lttng_element_type_integer;
 124 extern const char * const mi_lttng_element_type_other;
 125 extern const char * const mi_lttng_element_type_string;
 126
 127 /* String related to loglevel */
 128 extern const char * const mi_lttng_loglevel_str_alert;
 129 extern const char * const mi_lttng_loglevel_str_crit;
 130 extern const char * const mi_lttng_loglevel_str_debug;
 131 extern const char * const mi_lttng_loglevel_str_debug_function;
 132 extern const char * const mi_lttng_loglevel_str_debug_line;
 133 extern const char * const mi_lttng_loglevel_str_debug_module;
 134 extern const char * const mi_lttng_loglevel_str_debug_process;
 135 extern const char * const mi_lttng_loglevel_str_debug_program;
 136 extern const char * const mi_lttng_loglevel_str_debug_system;
 137 extern const char * const mi_lttng_loglevel_str_debug_unit;
 138 extern const char * const mi_lttng_loglevel_str_emerg;
 139 extern const char * const mi_lttng_loglevel_str_err;
 140 extern const char * const mi_lttng_loglevel_str_info;
 141 extern const char * const mi_lttng_loglevel_str_notice;
 142 extern const char * const mi_lttng_loglevel_str_unknown;
 143 extern const char * const mi_lttng_loglevel_str_warning;
 144
 145 /* String related to loglevel JUL */
 146 extern const char * const mi_lttng_loglevel_str_jul_all;
 147 extern const char * const mi_lttng_loglevel_str_jul_config;
 148 extern const char * const mi_lttng_loglevel_str_jul_fine;
 149 extern const char * const mi_lttng_loglevel_str_jul_finer;
 150 extern const char * const mi_lttng_loglevel_str_jul_finest;
 151 extern const char * const mi_lttng_loglevel_str_jul_info;
 152 extern const char * const mi_lttng_loglevel_str_jul_off;
 153 extern const char * const mi_lttng_loglevel_str_jul_severe;
 154 extern const char * const mi_lttng_loglevel_str_jul_warning;
 155
 156 /* String related to loglevel Log4j */
 157 extern const char * const mi_lttng_loglevel_str_log4j_off;
 158 extern const char * const mi_lttng_loglevel_str_log4j_fatal;
 159 extern const char * const mi_lttng_loglevel_str_log4j_error;
 160 extern const char * const mi_lttng_loglevel_str_log4j_warn;
 161 extern const char * const mi_lttng_loglevel_str_log4j_info;
 162 extern const char * const mi_lttng_loglevel_str_log4j_debug;
 163 extern const char * const mi_lttng_loglevel_str_log4j_trace;
 164 extern const char * const mi_lttng_loglevel_str_log4j_all;
 165
 166 /* String related to loglevel Python */
 167 extern const char * const mi_lttng_loglevel_str_python_critical;
 168 extern const char * const mi_lttng_loglevel_str_python_error;
 169 extern const char * const mi_lttng_loglevel_str_python_warning;
 170 extern const char * const mi_lttng_loglevel_str_python_info;
 171 extern const char * const mi_lttng_loglevel_str_python_debug;
 172 extern const char * const mi_lttng_loglevel_str_python_notset;
 173
 174 /* String related to loglevel type */
 175 extern const char * const mi_lttng_loglevel_type_all;
 176 extern const char * const mi_lttng_loglevel_type_range;
 177 extern const char * const mi_lttng_loglevel_type_single;
 178 extern const char * const mi_lttng_loglevel_type_unknown;
 179
 180 /* String related to a lttng_snapshot */
 181 extern const char * const mi_lttng_element_snapshot_ctrl_url;
 182 extern const char * const mi_lttng_element_snapshot_data_url;
 183 extern const char * const mi_lttng_element_snapshot_max_size;
 184 extern const char * const mi_lttng_element_snapshot_n_ptr;
 185 extern const char * const mi_lttng_element_snapshot_session_name;
 186 extern const char * const mi_lttng_element_snapshots;
 187
 188 /* String related to track/untrack command */
 189 const char * const mi_lttng_element_track_untrack_all_wildcard;
 190
 191 LTTNG_HIDDEN const char * const mi_lttng_element_session_name;
 192
 193 /* String related to rotate command */
 194 LTTNG_HIDDEN const char * const mi_lttng_element_rotation;
 195 LTTNG_HIDDEN const char * const mi_lttng_element_rotations;
 196 LTTNG_HIDDEN const char * const mi_lttng_element_rotate_status;
 197 LTTNG_HIDDEN const char * const mi_lttng_element_rotation_schedule;
 198
 199 /* String related to add-context command */
 200 LTTNG_HIDDEN extern const char * const mi_lttng_element_context_symbol;
 201
 202 /* Utility string function  */
 203 const char *mi_lttng_loglevel_string(int value, enum lttng_domain_type domain);
 204 const char *mi_lttng_logleveltype_string(enum lttng_loglevel_type value);
 205 const char *mi_lttng_eventfieldtype_string(enum lttng_event_field_type value);
 206 const char *mi_lttng_domaintype_string(enum lttng_domain_type value);
 207 const char *mi_lttng_buffertype_string(enum lttng_buffer_type value);
 208
 209 /*
 210  * Create an instance of a machine interface writer.
 211  *
 212  * fd_output File to which the XML content must be written. The file will be
 213  * closed once the mi_writer has been destroyed.
 214  *
 215  * Returns an instance of a machine interface writer on success, NULL on
 216  * error.
 217  */
 218 struct mi_writer *mi_lttng_writer_create(int fd_output, int mi_output_type);
 219
 220 /*
 221  * Destroy an instance of a machine interface writer.
 222  *
 223  * writer An instance of a machine interface writer.
 224  *
 225  * Returns zero if the XML document could be closed cleanly. Negative values
 226  * indicate an error.
 227  */
 228 int mi_lttng_writer_destroy(struct mi_writer *writer);
 229
 230 /*
 231  * Open a command tag and add it's name node.
 232  *
 233  * writer An instance of a machine interface writer.
 234  * command The command name.
 235  *
 236  * Returns zero if the XML document could be closed cleanly.
 237  * Negative values indicate an error.
 238  */
 239 int mi_lttng_writer_command_open(struct mi_writer *writer, const char *command);
 240
 241 /*
 242  * Close a command tag.
 243  *
 244  * writer An instance of a machine interface writer.
 245  *
 246  * Returns zero if the XML document could be closed cleanly.
 247  * Negative values indicate an error.
 248  */
 249 int mi_lttng_writer_command_close(struct mi_writer *writer);
 250
 251 /*
 252  * Open an element tag.
 253  *
 254  * writer An instance of a machine interface writer.
 255  * element_name Element tag name.
 256  *
 257  * Returns zero if the XML document could be closed cleanly.
 258  * Negative values indicate an error.
 259  */
 260 int mi_lttng_writer_open_element(struct mi_writer *writer,
 261                 const char *element_name);
 262
 263 /*
 264  * Close the current element tag.
 265  *
 266  * writer An instance of a machine interface writer.
 267  *
 268  * Returns zero if the XML document could be closed cleanly.
 269  * Negative values indicate an error.
 270  */
 271 int mi_lttng_writer_close_element(struct mi_writer *writer);
 272
 273 /*
 274  * Close multiple element.
 275  *
 276  * writer An instance of a machine interface writer.
 277  * nb_element Number of elements.
 278  *
 279  * Returns zero if the XML document could be closed cleanly.
 280  * Negative values indicate an error.
 281  */
 282 int mi_lttng_close_multi_element(struct mi_writer *writer,
 283                 unsigned int nb_element);
 284
 285 /*
 286  * Write an element of type unsigned int.
 287  *
 288  * writer An instance of a machine interface writer.
 289  * element_name Element name.
 290  * value Unsigned int value of the element
 291  *
 292  * Returns zero if the element's value could be written.
 293  * Negative values indicate an error.
 294  */
 295 int mi_lttng_writer_write_element_unsigned_int(struct mi_writer *writer,
 296                 const char *element_name, uint64_t value);
 297
 298 /*
 299  * Write an element of type signed int.
 300  *
 301  * writer An instance of a machine interface writer.
 302  * element_name Element name.
 303  * value Signed int value of the element.
 304  *
 305  * Returns zero if the element's value could be written.
 306  * Negative values indicate an error.
 307  */
 308 int mi_lttng_writer_write_element_signed_int(struct mi_writer *writer,
 309                 const char *element_name, int64_t value);
 310
 311 /*
 312  * Write an element of type boolean.
 313  *
 314  * writer An instance of a machine interface writer.
 315  * element_name Element name.
 316  * value Boolean value of the element.
 317  *
 318  * Returns zero if the element's value could be written.
 319  * Negative values indicate an error.
 320  */
 321 int mi_lttng_writer_write_element_bool(struct mi_writer *writer,
 322                 const char *element_name, int value);
 323
 324 /*
 325  * Write an element of type string.
 326  *
 327  * writer An instance of a machine interface writer.
 328  * element_name Element name.
 329  * value String value of the element.
 330  *
 331  * Returns zero if the element's value could be written.
 332  * Negative values indicate an error.
 333  */
 334 int mi_lttng_writer_write_element_string(struct mi_writer *writer,
 335                 const char *element_name, const char *value);
 336
 337 /*
 338  * Machine interface of struct version.
 339  *
 340  * writer An instance of a machine interface writer.
 341  * version Version struct.
 342  * lttng_description String value of the version description.
 343  * lttng_license String value of the version license.
 344  *
 345  * Returns zero if the element's value could be written.
 346  * Negative values indicate an error.
 347  */
 348 int mi_lttng_version(struct mi_writer *writer, struct mi_lttng_version *version,
 349                 const char *lttng_description, const char *lttng_license);
 350
 351 /*
 352  * Machine interface: open a sessions element.
 353  *
 354  * writer An instance of a machine interface writer.
 355  *
 356  * Returns zero if the element's value could be written.
 357  * Negative values indicate an error.
 358  */
 359 int mi_lttng_sessions_open(struct mi_writer *writer);
 360
 361 /*
 362  * Machine interface of struct session.
 363  *
 364  * writer An instance of a machine interface writer.
 365  * session An instance of a session.
 366  * is_open Defines whether or not the session element shall be closed.
 367  *         This should be used carefully and the client
 368  *         must close the session element.
 369  *         Use case: nested additional information on a session
 370  *                  ex: domain,channel event.
 371  *
 372  * Returns zero if the element's value could be written.
 373  * Negative values indicate an error.
 374  */
 375 int mi_lttng_session(struct mi_writer *writer,
 376                 struct lttng_session *session, int is_open);
 377
 378 /*
 379  * Machine interface: open a domains element.
 380  *
 381  * writer An instance of a machine interface writer.
 382  *
 383  * Returns zero if the element's value could be written.
 384  * Negative values indicate an error.
 385  */
 386 int mi_lttng_domains_open(struct mi_writer *writer);
 387
 388 /*
 389  * Machine interface of struct domain.
 390  *
 391  * writer An instance of a machine interface writer.
 392  * domain An instance of a domain.
 393  *
 394  * is_open Defines whether or not the session element shall be closed.
 395  *         This should be used carefully and the client
 396  *         must close the domain element.
 397  *         Use case: nested addition information on a domain
 398  *                  ex: channel event.
 399  *
 400  * Returns zero if the element's value could be written.
 401  * Negative values indicate an error.
 402  */
 403 int mi_lttng_domain(struct mi_writer *writer,
 404                 struct lttng_domain *domain, int is_open);
 405
 406 /*
 407  * Machine interface: open a channels element.
 408  *
 409  * writer An instance of a machine interface writer.
 410  *
 411  * Returns zero if the element's value could be written.
 412  * Negative values indicate an error.
 413  */
 414 int mi_lttng_channels_open(struct mi_writer *writer);
 415
 416 /*
 417  * Machine interface of struct channel.
 418  *
 419  * writer An instance of a machine interface writer.
 420  * channel An instance of a channel.
 421  *
 422  * is_open Defines whether or not the session element shall be closed.
 423  *         This should be used carefully and the client
 424  *         must close the channel element.
 425  *         Use case: nested addition information on a channel.
 426  *                  ex: channel event.
 427  *
 428  * Returns zero if the element's value could be written.
 429  * Negative values indicate an error.
 430  */
 431 int mi_lttng_channel(struct mi_writer *writer,
 432                 struct lttng_channel *channel, int is_open);
 433
 434 /*
 435  * Machine interface of struct channel_attr.
 436  *
 437  * writer An instance of a machine interface writer.
 438  * attr An instance of a channel_attr struct.
 439  *
 440  * Returns zero if the element's value could be written.
 441  * Negative values indicate an error.
 442  */
 443 int mi_lttng_channel_attr(struct mi_writer *writer,
 444                 struct lttng_channel_attr *attr);
 445
 446 /*
 447 * Machine interface for event common attributes.
 448 *
 449 * writer An instance of a mi writer.
 450 * event single trace event.
 451 *
 452 * The common attribute are:
 453 * - mi event element
 454 * - event name
 455 * - event type
 456 * - enabled tag
 457 * - event filter
 458 *
 459 * Returns zero if the element's value could be written.
 460 * Negative values indicate an error.
 461 */
 462 int mi_lttng_event_common_attributes(struct mi_writer *writer,
 463                 struct lttng_event *event);
 464
 465 /*
 466  * Machine interface for kernel tracepoint event with a loglevel.
 467  *
 468  * writer An instance of a mi writer.
 469  * event single trace event.
 470  * domain Event's domain
 471  *
 472  * Returns zero if the element's value could be written.
 473  * Negative values indicate an error.
 474  */
 475 int mi_lttng_event_tracepoint_loglevel(struct mi_writer *writer,
 476                 struct lttng_event *event, enum lttng_domain_type domain);
 477
 478 /*
 479  * Machine interface for kernel tracepoint event with no loglevel.
 480  *
 481  * writer An instance of a mi writer.
 482  * event single trace event.
 483  *
 484  * Returns zero if the element's value could be written.
 485  * Negative values indicate an error.
 486  */
 487 int mi_lttng_event_tracepoint_no_loglevel(struct mi_writer *writer,
 488                 struct lttng_event *event);
 489
 490 /*
 491  * Machine interface for kernel function and probe event.
 492  *
 493  * writer An instance of a mi writer.
 494  * event single trace event.
 495  *
 496  * Returns zero if the element's value could be written.
 497  * Negative values indicate an error.
 498  */
 499 int mi_lttng_event_function_probe(struct mi_writer *writer,
 500                 struct lttng_event *event);
 501
 502 /*
 503  * Machine interface for kernel function entry event.
 504  *
 505  * writer An instance of a mi writer.
 506  * event single trace event.
 507  *
 508  * Returns zero if the element's value could be written.
 509  * Negative values indicate an error.
 510  */
 511 int mi_lttng_event_function_entry(struct mi_writer *writer,
 512                 struct lttng_event *event);
 513
 514 /*
 515  * Machine interface: open an events element.
 516  *
 517  * writer An instance of a machine interface writer.
 518  *
 519  * Returns zero if the element's value could be written.
 520  * Negative values indicate an error.
 521  */
 522 int mi_lttng_events_open(struct mi_writer *writer);
 523
 524 /*
 525  * Machine interface for printing an event.
 526  * The trace event type currently supported are:
 527  *  TRACEPOINT,
 528  *  PROBE,
 529  *  FUNCTION,
 530  *  FUNCTION_ENTRY,
 531  *  SYSCALL
 532  *
 533  * writer An instance of a mi writer.
 534  * event single trace event.
 535  * is_open Defines whether or not the session element shall be closed.
 536  *         This should be used carefully and the client
 537  *         must close the event element.
 538  *         Use case: nested additional information
 539  * domain Event's domain
 540  *
 541  * Returns zero if the element's value could be written.
 542  * Negative values indicate an error.
 543  */
 544 int mi_lttng_event(struct mi_writer *writer, struct lttng_event *event,
 545                 int is_open, enum lttng_domain_type domain);
 546
 547 /*
 548  * Machine interface for struct lttng_event_field.
 549  *
 550  * writer An instance of a mi writer.
 551  * field An event_field instance.
 552  *
 553  * Returns zero if the element's value could be written.
 554  * Negative values indicate an error.
 555  */
 556 int mi_lttng_event_field(struct mi_writer *writer,
 557                 struct lttng_event_field *field);
 558
 559 /*
 560  * Machine interface: open a event_fields element.
 561  *
 562  * writer An instance of a machine interface writer.
 563  *
 564  * Returns zero if the element have be written.
 565  * Negative values indicate an error.
 566  */
 567 int mi_lttng_event_fields_open(struct mi_writer *writer);
 568
 569 /*
 570  * Machine interface: open a trackers element.
 571  *
 572  * writer An instance of a machine interface writer.
 573  *
 574  * Returns zero if the element's value could be written.
 575  * Negative values indicate an error.
 576  */
 577 int mi_lttng_trackers_open(struct mi_writer *writer);
 578
 579 /*
 580  * Machine interface: open a pid_tracker element.
 581  *
 582  * writer An instance of a machine interface writer.
 583  *
 584  * Returns zero if the element's value could be written.
 585  * Negative values indicate an error.
 586  *
 587  * Note: A targets element is also opened for each tracker definition
 588  */
 589 int mi_lttng_pid_tracker_open(struct mi_writer *writer);
 590
 591 /*
 592  * Machine interface: open a PIDs element.
 593  *
 594  * writer An instance of a machine interface writer.
 595  *
 596  * Returns zero if the element's value could be written.
 597  * Negative values indicate an error.
 598  */
 599 int mi_lttng_pids_open(struct mi_writer *writer);
 600
 601 /*
 602  * Machine interface: open a processes element.
 603  *
 604  * writer An instance of a machine interface writer.
 605  *
 606  * Returns zero if the element's value could be written.
 607  * Negative values indicate an error.
 608  */
 609 int mi_lttng_processes_open(struct mi_writer *writer);
 610
 611 /*
 612  * Machine interface of a Process.
 613  *
 614  * writer An instance of a machine interface writer.
 615  * pid A PID.
 616  *
 617  * is_open Defines whether or not the session element shall be closed.
 618  *         This should be used carefully and the client
 619  *         must close the pid element.
 620  *         Use case: nested addition information on a domain
 621  *                  ex: channel event.
 622  *
 623  * Returns zero if the element's value could be written.
 624  * Negative values indicate an error.
 625  */
 626 int mi_lttng_process(struct mi_writer *writer, pid_t pid , const char *name,
 627                 int is_open);
 628
 629 /*
 630  * TODO: move pid of lttng list -u to process semantic on mi api bump
 631  * Machine interface of a Process.
 632  *
 633  * writer An instance of a machine interface writer.
 634  * pid A PID.
 635  *
 636  * is_open Defines whether or not the session element shall be closed.
 637  *         This should be used carefully and the client
 638  *         must close the pid element.
 639  *         Use case: nested addition information on a domain
 640  *                  ex: channel event.
 641  *
 642  * Returns zero if the element's value could be written.
 643  * Negative values indicate an error.
 644  */
 645 int mi_lttng_pid(struct mi_writer *writer, pid_t pid , const char *name,
 646                 int is_open);
 647 /*
 648  * Machine interface: open a targets element.
 649  *
 650  * writer An instance of a machine interface writer.
 651  *
 652  * Returns zero if the element's value could be written.
 653  * Negative values indicate an error.
 654  */
 655 int mi_lttng_targets_open(struct mi_writer *writer);
 656
 657 /*
 658  * Machine interface for track/untrack a pid_target
 659  *
 660  * writer An instance of a machine interface writer.
 661  *
 662  * Returns zero if the element's value could be written.
 663  * Negative values indicate an error.
 664  */
 665 int mi_lttng_pid_target(struct mi_writer *writer, pid_t pid, int is_open);
 666
 667 /*
 668  * Machine interface of a context.
 669  *
 670  * writer An instance of a machine interface writer
 671  *
 672  * context An instance of a lttng_event_context
 673  *
 674  * is_open Define if we close the context element
 675  *         This should be used carefully and the client
 676  *         need to close the context element.
 677  * Returns zero if the element's value could be written.
 678  * Negative values indicate an error.
 679  */
 680 int mi_lttng_context(struct mi_writer *writer,
 681                 struct lttng_event_context *context, int is_open);
 682
 683 /*
 684  * Machine interface of a perf_counter_context.
 685  *
 686  * writer An instance of a machine interface writer
 687  *
 688  * contest An instance of a lttng_event_perf_counter_ctx
 689  *
 690  * Returns zero if the element's value could be written.
 691  * Negative values indicate an error.
 692  */
 693 int mi_lttng_perf_counter_context(struct mi_writer *writer,
 694                 struct lttng_event_perf_counter_ctx  *perf_context);
 695
 696 /*
 697  * Machine interface of the snapshot list_output.
 698  * It specifies the session for which we are listing snapshots,
 699  * and it opens a snapshots element to list a sequence
 700  * of snapshots.
 701  *
 702  * writer An instance of a machine interface writer.
 703  *
 704  * session_name: Snapshot output for session "session_name".
 705  *
 706  * Note: The client has to close the session and the snapshots elements after
 707  * having listed every lttng_snapshot_output.
 708  *
 709  * Returns zero if the element's value could be written.
 710  * Negative values indicate an error.
 711  */
 712 int mi_lttng_snapshot_output_session_name(struct mi_writer *writer,
 713                 const char *session_name);
 714
 715 /*
 716  * Machine interface of the snapshot output.
 717  * The machine interface serializes the following attributes:
 718  * - id: ID of the snapshot output.
 719  * - name: Name of the output.
 720  * - data_url : Destination of the output.
 721  * - ctrl_url: Destination of the output.
 722  * - max_size: total size of all stream combined.
 723  *
 724  * writer An instance of a machine interface writer.
 725  *
 726  * output: A list of snapshot_output.
 727  *
 728  * Returns zero if the element's value could be written.
 729  * Negative values indicate an error.
 730  */
 731 int mi_lttng_snapshot_list_output(struct mi_writer *writer,
 732                 struct lttng_snapshot_output *output);
 733
 734 /*
 735  * Machine interface of the output of the command snapshot del output
 736  * when deleting a snapshot either by id or by name.
 737  * If the snapshot was found and successfully deleted using its id,
 738  * it return the id of the snapshot and the current session name on which it
 739  * was attached.
 740  *
 741  * Otherwise, it do the same process with the name of the snapshot, if the
 742  * snapshot output id is undefined.
 743  *
 744  * writer An instance of a machine interface writer.
 745  *
 746  * id: ID of the snapshot output.
 747  *
 748  * name: Name of the snapshot.
 749  *
 750  * current_session_name: Session to which the snapshot belongs.
 751  *
 752  * Returns zero if the element's value could be written.
 753  * Negative values indicate an error.
 754  */
 755 int mi_lttng_snapshot_del_output(struct mi_writer *writer, int id,
 756                 const char *name, const char *current_session_name);
 757
 758 /*
 759  * Machine interface of the output of the command snapshot add output
 760  * when adding a snapshot from a user URL.
 761  *
 762  * If the snapshot was successfully added, the machine interface lists
 763  * these information:
 764  * - id: ID of the newly add snapshot output.
 765  * - current_session_name: Name of the session to which the output was added.
 766  * - ctrl_url: Destination of the output.
 767  * - max_size: total size of all stream combined.
 768  *
 769  * writer An instance of a machine interface writer.
 770  *
 771  * current_session_name: Session to which the snapshot belongs.
 772  *
 773  * n_ptr:
 774  *
 775  * output: iterator over a lttng_snapshot_output_list which contain
 776  * the snapshot output informations.
 777  *
 778  * Returns zero if the element's value could be written.
 779  * Negative values indicate an error.
 780  */
 781 int mi_lttng_snapshot_add_output(struct mi_writer *writer,
 782                 const char *current_session_name, const char *n_ptr,
 783                 struct lttng_snapshot_output *output);
 784
 785 /*
 786  * Machine interface of the output of the command snapshot
 787  * record  from a URL (if given).
 788  *
 789  * If the snapshot is successfully recorded from a url, the machine interface
 790  * output the following information:
 791  * - url: Destination of the output stored in the snapshot.
 792  *
 793  * Otherwise, the machine interface output the data and ctrl url received
 794  * from the command-line.
 795  *
 796  * writer An instance of a machine interface writer.
 797  *
 798  * current_session_name: Snapshot record for session "current_session_name".
 799  *
 800  * ctrl_url, data_url: Destination of the output receive from the command-line.
 801  *
 802  * Returns zero if the element's value could be written.
 803  * Negative values indicate an error.
 804  */
 805 int mi_lttng_snapshot_record(struct mi_writer *writer,
 806                 const char *current_session_name, const char *url,
 807                 const char *cmdline_ctrl_url, const char *cmdline_data_url);
 808
 809 #endif /* _MI_LTTNG_H */