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