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  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #ifndef _MI_LTTNG_H
  20 #define _MI_LTTNG_H
  21
  22 #include <stdint.h>
  23
  24 #include <common/error.h>
  25 #include <common/macros.h>
  26 #include <common/config/session-config.h>
  27 #include <lttng/lttng.h>
  28
  29 /* Don't want to reference snapshot-internal.h here */
  30 struct lttng_snapshot_output;
  31
  32 /* Instance of a machine interface writer. */
  33 struct mi_writer {
  34         struct config_writer *writer;
  35         enum lttng_mi_output_type type;
  36 };
  37
  38 /*
  39  * Version information for the machine interface.
  40  */
  41 struct mi_lttng_version {
  42         char version[LTTNG_NAME_MAX]; /* Version number of package */
  43         uint32_t version_major; /* LTTng-Tools major version number */
  44         uint32_t version_minor; /* LTTng-Tools minor version number */
  45         uint32_t version_patchlevel; /* LTTng-Tools patchlevel version number */
  46         char version_commit[LTTNG_NAME_MAX]; /* Commit hash of the current version */
  47         char version_name[LTTNG_NAME_MAX];
  48         char package_url[LTTNG_NAME_MAX]; /* Define to the home page for this package. */
  49 };
  50
  51 /* Strings related to command */
  52 extern const char * const mi_lttng_element_command;
  53 extern const char * const mi_lttng_element_command_action;
  54 extern const char * const mi_lttng_element_command_add_context;
  55 extern const char * const mi_lttng_element_command_calibrate;
  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_name;
  65 extern const char * const mi_lttng_element_command_output;
  66 extern const char * const mi_lttng_element_command_save;
  67 extern const char * const mi_lttng_element_command_set_session;
  68 extern const char * const mi_lttng_element_command_snapshot;
  69 extern const char * const mi_lttng_element_command_snapshot_add;
  70 extern const char * const mi_lttng_element_command_snapshot_del;
  71 extern const char * const mi_lttng_element_command_snapshot_list;
  72 extern const char * const mi_lttng_element_command_snapshot_record;
  73 extern const char * const mi_lttng_element_command_start;
  74 extern const char * const mi_lttng_element_command_stop;
  75 extern const char * const mi_lttng_element_command_success;
  76 extern const char * const mi_lttng_element_command_track;
  77 extern const char * const mi_lttng_element_command_untrack;
  78 extern const char * const mi_lttng_element_command_version;
  79
  80 /* Strings related to version command */
  81 extern const char * const mi_lttng_element_version;
  82 extern const char * const mi_lttng_element_version_commit;
  83 extern const char * const mi_lttng_element_version_description;
  84 extern const char * const mi_lttng_element_version_license;
  85 extern const char * const mi_lttng_element_version_major;
  86 extern const char * const mi_lttng_element_version_minor;
  87 extern const char * const mi_lttng_element_version_patch_level;
  88 extern const char * const mi_lttng_element_version_str;
  89 extern const char * const mi_lttng_element_version_web;
  90
  91 /* String related to a lttng_event_field */
  92 extern const char * const mi_lttng_element_event_field;
  93 extern const char * const mi_lttng_element_event_fields;
  94
  95 /* String related to lttng_event_context */
  96 extern const char * const mi_lttng_context_type_perf_counter;
  97 extern const char * const mi_lttng_context_type_perf_cpu_counter;
  98 extern const char * const mi_lttng_context_type_perf_thread_counter;
  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
 112 /* General element of mi_lttng */
 113 extern const char * const mi_lttng_element_empty;
 114 extern const char * const mi_lttng_element_id;
 115 extern const char * const mi_lttng_element_nowrite;
 116 extern const char * const mi_lttng_element_success;
 117 extern const char * const mi_lttng_element_type_enum;
 118 extern const char * const mi_lttng_element_type_float;
 119 extern const char * const mi_lttng_element_type_integer;
 120 extern const char * const mi_lttng_element_type_other;
 121 extern const char * const mi_lttng_element_type_string;
 122
 123 /* String related to loglevel */
 124 extern const char * const mi_lttng_loglevel_str_alert;
 125 extern const char * const mi_lttng_loglevel_str_crit;
 126 extern const char * const mi_lttng_loglevel_str_debug;
 127 extern const char * const mi_lttng_loglevel_str_debug_function;
 128 extern const char * const mi_lttng_loglevel_str_debug_line;
 129 extern const char * const mi_lttng_loglevel_str_debug_module;
 130 extern const char * const mi_lttng_loglevel_str_debug_process;
 131 extern const char * const mi_lttng_loglevel_str_debug_program;
 132 extern const char * const mi_lttng_loglevel_str_debug_system;
 133 extern const char * const mi_lttng_loglevel_str_debug_unit;
 134 extern const char * const mi_lttng_loglevel_str_emerg;
 135 extern const char * const mi_lttng_loglevel_str_err;
 136 extern const char * const mi_lttng_loglevel_str_info;
 137 extern const char * const mi_lttng_loglevel_str_notice;
 138 extern const char * const mi_lttng_loglevel_str_unknown;
 139 extern const char * const mi_lttng_loglevel_str_warning;
 140
 141 /* String related to loglevel JUL */
 142 extern const char * const mi_lttng_loglevel_str_jul_all;
 143 extern const char * const mi_lttng_loglevel_str_jul_config;
 144 extern const char * const mi_lttng_loglevel_str_jul_fine;
 145 extern const char * const mi_lttng_loglevel_str_jul_finer;
 146 extern const char * const mi_lttng_loglevel_str_jul_finest;
 147 extern const char * const mi_lttng_loglevel_str_jul_info;
 148 extern const char * const mi_lttng_loglevel_str_jul_off;
 149 extern const char * const mi_lttng_loglevel_str_jul_severe;
 150 extern const char * const mi_lttng_loglevel_str_jul_warning;
 151
 152 /* String related to loglevel Log4j */
 153 extern const char * const mi_lttng_loglevel_str_log4j_off;
 154 extern const char * const mi_lttng_loglevel_str_log4j_fatal;
 155 extern const char * const mi_lttng_loglevel_str_log4j_error;
 156 extern const char * const mi_lttng_loglevel_str_log4j_warn;
 157 extern const char * const mi_lttng_loglevel_str_log4j_info;
 158 extern const char * const mi_lttng_loglevel_str_log4j_debug;
 159 extern const char * const mi_lttng_loglevel_str_log4j_trace;
 160 extern const char * const mi_lttng_loglevel_str_log4j_all;
 161
 162 /* String related to loglevel Python */
 163 extern const char * const mi_lttng_loglevel_str_python_critical;
 164 extern const char * const mi_lttng_loglevel_str_python_error;
 165 extern const char * const mi_lttng_loglevel_str_python_warning;
 166 extern const char * const mi_lttng_loglevel_str_python_info;
 167 extern const char * const mi_lttng_loglevel_str_python_debug;
 168 extern const char * const mi_lttng_loglevel_str_python_notset;
 169
 170 /* String related to loglevel type */
 171 extern const char * const mi_lttng_loglevel_type_all;
 172 extern const char * const mi_lttng_loglevel_type_range;
 173 extern const char * const mi_lttng_loglevel_type_single;
 174 extern const char * const mi_lttng_loglevel_type_unknown;
 175
 176 /* Sting related to lttng_calibrate */
 177 extern const char * const mi_lttng_element_calibrate;
 178 extern const char * const mi_lttng_element_calibrate_function;
 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 /* Utility string function  */
 189 const char *mi_lttng_loglevel_string(int value, enum lttng_domain_type domain);
 190 const char *mi_lttng_logleveltype_string(enum lttng_loglevel_type value);
 191 const char *mi_lttng_eventfieldtype_string(enum lttng_event_field_type value);
 192 const char *mi_lttng_domaintype_string(enum lttng_domain_type value);
 193 const char *mi_lttng_buffertype_string(enum lttng_buffer_type value);
 194 const char *mi_lttng_calibratetype_string(enum lttng_calibrate_type val);
 195
 196 /* String related to track/untrack command */
 197 const char * const mi_lttng_element_track_untrack_all_wildcard;
 198
 199 /*
 200  * Create an instance of a machine interface writer.
 201  *
 202  * fd_output File to which the XML content must be written. The file will be
 203  * closed once the mi_writer has been destroyed.
 204  *
 205  * Returns an instance of a machine interface writer on success, NULL on
 206  * error.
 207  */
 208 struct mi_writer *mi_lttng_writer_create(int fd_output, int mi_output_type);
 209
 210 /*
 211  * Destroy an instance of a machine interface writer.
 212  *
 213  * writer An instance of a machine interface writer.
 214  *
 215  * Returns zero if the XML document could be closed cleanly. Negative values
 216  * indicate an error.
 217  */
 218 int mi_lttng_writer_destroy(struct mi_writer *writer);
 219
 220 /*
 221  * Open a command tag and add it's name node.
 222  *
 223  * writer An instance of a machine interface writer.
 224  * command The command name.
 225  *
 226  * Returns zero if the XML document could be closed cleanly.
 227  * Negative values indicate an error.
 228  */
 229 int mi_lttng_writer_command_open(struct mi_writer *writer, const char *command);
 230
 231 /*
 232  * Close a command tag.
 233  *
 234  * writer An instance of a machine interface writer.
 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_close(struct mi_writer *writer);
 240
 241 /*
 242  * Open an element tag.
 243  *
 244  * writer An instance of a machine interface writer.
 245  * element_name Element tag name.
 246  *
 247  * Returns zero if the XML document could be closed cleanly.
 248  * Negative values indicate an error.
 249  */
 250 int mi_lttng_writer_open_element(struct mi_writer *writer,
 251                 const char *element_name);
 252
 253 /*
 254  * Close the current element tag.
 255  *
 256  * writer An instance of a machine interface writer.
 257  *
 258  * Returns zero if the XML document could be closed cleanly.
 259  * Negative values indicate an error.
 260  */
 261 int mi_lttng_writer_close_element(struct mi_writer *writer);
 262
 263 /*
 264  * Close multiple element.
 265  *
 266  * writer An instance of a machine interface writer.
 267  * nb_element Number of elements.
 268  *
 269  * Returns zero if the XML document could be closed cleanly.
 270  * Negative values indicate an error.
 271  */
 272 int mi_lttng_close_multi_element(struct mi_writer *writer,
 273                 unsigned int nb_element);
 274
 275 /*
 276  * Write an element of type unsigned int.
 277  *
 278  * writer An instance of a machine interface writer.
 279  * element_name Element name.
 280  * value Unsigned int value of the element
 281  *
 282  * Returns zero if the element's value could be written.
 283  * Negative values indicate an error.
 284  */
 285 int mi_lttng_writer_write_element_unsigned_int(struct mi_writer *writer,
 286                 const char *element_name, uint64_t value);
 287
 288 /*
 289  * Write an element of type signed int.
 290  *
 291  * writer An instance of a machine interface writer.
 292  * element_name Element name.
 293  * value Signed int value of the element.
 294  *
 295  * Returns zero if the element's value could be written.
 296  * Negative values indicate an error.
 297  */
 298 int mi_lttng_writer_write_element_signed_int(struct mi_writer *writer,
 299                 const char *element_name, int64_t value);
 300
 301 /*
 302  * Write an element of type boolean.
 303  *
 304  * writer An instance of a machine interface writer.
 305  * element_name Element name.
 306  * value Boolean value of the element.
 307  *
 308  * Returns zero if the element's value could be written.
 309  * Negative values indicate an error.
 310  */
 311 int mi_lttng_writer_write_element_bool(struct mi_writer *writer,
 312                 const char *element_name, int value);
 313
 314 /*
 315  * Write an element of type string.
 316  *
 317  * writer An instance of a machine interface writer.
 318  * element_name Element name.
 319  * value String value of the element.
 320  *
 321  * Returns zero if the element's value could be written.
 322  * Negative values indicate an error.
 323  */
 324 int mi_lttng_writer_write_element_string(struct mi_writer *writer,
 325                 const char *element_name, const char *value);
 326
 327 /*
 328  * Machine interface of struct version.
 329  *
 330  * writer An instance of a machine interface writer.
 331  * version Version struct.
 332  * lttng_description String value of the version description.
 333  * lttng_license String value of the version license.
 334  *
 335  * Returns zero if the element's value could be written.
 336  * Negative values indicate an error.
 337  */
 338 int mi_lttng_version(struct mi_writer *writer, struct mi_lttng_version *version,
 339                 const char *lttng_description, const char *lttng_license);
 340
 341 /*
 342  * Machine interface: open a sessions element.
 343  *
 344  * writer An instance of a machine interface writer.
 345  *
 346  * Returns zero if the element's value could be written.
 347  * Negative values indicate an error.
 348  */
 349 int mi_lttng_sessions_open(struct mi_writer *writer);
 350
 351 /*
 352  * Machine interface of struct session.
 353  *
 354  * writer An instance of a machine interface writer.
 355  * session An instance of a session.
 356  * is_open Defines whether or not the session element shall be closed.
 357  *         This should be used carefully and the client
 358  *         must close the session element.
 359  *         Use case: nested additional information on a session
 360  *                  ex: domain,channel event.
 361  *
 362  * Returns zero if the element's value could be written.
 363  * Negative values indicate an error.
 364  */
 365 int mi_lttng_session(struct mi_writer *writer,
 366                 struct lttng_session *session, int is_open);
 367
 368 /*
 369  * Machine interface: open a domains element.
 370  *
 371  * writer An instance of a machine interface writer.
 372  *
 373  * Returns zero if the element's value could be written.
 374  * Negative values indicate an error.
 375  */
 376 int mi_lttng_domains_open(struct mi_writer *writer);
 377
 378 /*
 379  * Machine interface of struct domain.
 380  *
 381  * writer An instance of a machine interface writer.
 382  * domain An instance of a domain.
 383  *
 384  * is_open Defines whether or not the session element shall be closed.
 385  *         This should be used carefully and the client
 386  *         must close the domain element.
 387  *         Use case: nested addition information on a domain
 388  *                  ex: channel event.
 389  *
 390  * Returns zero if the element's value could be written.
 391  * Negative values indicate an error.
 392  */
 393 int mi_lttng_domain(struct mi_writer *writer,
 394                 struct lttng_domain *domain, int is_open);
 395
 396 /*
 397  * Machine interface: open a channels element.
 398  *
 399  * writer An instance of a machine interface writer.
 400  *
 401  * Returns zero if the element's value could be written.
 402  * Negative values indicate an error.
 403  */
 404 int mi_lttng_channels_open(struct mi_writer *writer);
 405
 406 /*
 407  * Machine interface of struct channel.
 408  *
 409  * writer An instance of a machine interface writer.
 410  * channel An instance of a channel.
 411  *
 412  * is_open Defines whether or not the session element shall be closed.
 413  *         This should be used carefully and the client
 414  *         must close the channel element.
 415  *         Use case: nested addition information on a channel.
 416  *                  ex: channel event.
 417  *
 418  * Returns zero if the element's value could be written.
 419  * Negative values indicate an error.
 420  */
 421 int mi_lttng_channel(struct mi_writer *writer,
 422                 struct lttng_channel *channel, int is_open);
 423
 424 /*
 425  * Machine interface of struct channel_attr.
 426  *
 427  * writer An instance of a machine interface writer.
 428  * attr An instance of a channel_attr struct.
 429  *
 430  * Returns zero if the element's value could be written.
 431  * Negative values indicate an error.
 432  */
 433 int mi_lttng_channel_attr(struct mi_writer *writer,
 434                 struct lttng_channel_attr *attr);
 435
 436 /*
 437 * Machine interface for event common attributes.
 438 *
 439 * writer An instance of a mi writer.
 440 * event single trace event.
 441 *
 442 * The common attribute are:
 443 * - mi event element
 444 * - event name
 445 * - event type
 446 * - enabled tag
 447 * - event filter
 448 *
 449 * Returns zero if the element's value could be written.
 450 * Negative values indicate an error.
 451 */
 452 int mi_lttng_event_common_attributes(struct mi_writer *writer,
 453                 struct lttng_event *event);
 454
 455 /*
 456  * Machine interface for kernel tracepoint event with a loglevel.
 457  *
 458  * writer An instance of a mi writer.
 459  * event single trace event.
 460  * domain Event's domain
 461  *
 462  * Returns zero if the element's value could be written.
 463  * Negative values indicate an error.
 464  */
 465 int mi_lttng_event_tracepoint_loglevel(struct mi_writer *writer,
 466                 struct lttng_event *event, enum lttng_domain_type domain);
 467
 468 /*
 469  * Machine interface for kernel tracepoint event with no loglevel.
 470  *
 471  * writer An instance of a mi writer.
 472  * event single trace event.
 473  *
 474  * Returns zero if the element's value could be written.
 475  * Negative values indicate an error.
 476  */
 477 int mi_lttng_event_tracepoint_no_loglevel(struct mi_writer *writer,
 478                 struct lttng_event *event);
 479
 480 /*
 481  * Machine interface for kernel function and probe event.
 482  *
 483  * writer An instance of a mi writer.
 484  * event single trace event.
 485  *
 486  * Returns zero if the element's value could be written.
 487  * Negative values indicate an error.
 488  */
 489 int mi_lttng_event_function_probe(struct mi_writer *writer,
 490                 struct lttng_event *event);
 491
 492 /*
 493  * Machine interface for kernel function entry event.
 494  *
 495  * writer An instance of a mi writer.
 496  * event single trace event.
 497  *
 498  * Returns zero if the element's value could be written.
 499  * Negative values indicate an error.
 500  */
 501 int mi_lttng_event_function_entry(struct mi_writer *writer,
 502                 struct lttng_event *event);
 503
 504 /*
 505  * Machine interface: open an events element.
 506  *
 507  * writer An instance of a machine interface writer.
 508  *
 509  * Returns zero if the element's value could be written.
 510  * Negative values indicate an error.
 511  */
 512 int mi_lttng_events_open(struct mi_writer *writer);
 513
 514 /*
 515  * Machine interface for printing an event.
 516  * The trace event type currently supported are:
 517  *  TRACEPOINT,
 518  *  PROBE,
 519  *  FUNCTION,
 520  *  FUNCTION_ENTRY,
 521  *  SYSCALL
 522  *
 523  * writer An instance of a mi writer.
 524  * event single trace event.
 525  * is_open Defines whether or not the session element shall be closed.
 526  *         This should be used carefully and the client
 527  *         must close the event element.
 528  *         Use case: nested additional information
 529  * domain Event's domain
 530  *
 531  * Returns zero if the element's value could be written.
 532  * Negative values indicate an error.
 533  */
 534 int mi_lttng_event(struct mi_writer *writer, struct lttng_event *event,
 535                 int is_open, enum lttng_domain_type domain);
 536
 537 /*
 538  * Machine interface for struct lttng_event_field.
 539  *
 540  * writer An instance of a mi writer.
 541  * field An event_field instance.
 542  *
 543  * Returns zero if the element's value could be written.
 544  * Negative values indicate an error.
 545  */
 546 int mi_lttng_event_field(struct mi_writer *writer,
 547                 struct lttng_event_field *field);
 548
 549 /*
 550  * Machine interface: open a event_fields element.
 551  *
 552  * writer An instance of a machine interface writer.
 553  *
 554  * Returns zero if the element have be written.
 555  * Negative values indicate an error.
 556  */
 557 int mi_lttng_event_fields_open(struct mi_writer *writer);
 558
 559 /*
 560  * Machine interface: open a trackers element.
 561  *
 562  * writer An instance of a machine interface writer.
 563  *
 564  * Returns zero if the element's value could be written.
 565  * Negative values indicate an error.
 566  */
 567 int mi_lttng_trackers_open(struct mi_writer *writer);
 568
 569 /*
 570  * Machine interface: open a pid_tracker 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  * Note: A targets element is also opened for each tracker definition
 578  */
 579 int mi_lttng_pid_tracker_open(struct mi_writer *writer);
 580
 581 /*
 582  * Machine interface: open a PIDs element.
 583  *
 584  * writer An instance of a machine interface writer.
 585  *
 586  * Returns zero if the element's value could be written.
 587  * Negative values indicate an error.
 588  */
 589 int mi_lttng_pids_open(struct mi_writer *writer);
 590
 591 /*
 592  * Machine interface: open a processes 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_processes_open(struct mi_writer *writer);
 600
 601 /*
 602  * Machine interface of a Process.
 603  *
 604  * writer An instance of a machine interface writer.
 605  * pid A PID.
 606  *
 607  * is_open Defines whether or not the session element shall be closed.
 608  *         This should be used carefully and the client
 609  *         must close the pid element.
 610  *         Use case: nested addition information on a domain
 611  *                  ex: channel event.
 612  *
 613  * Returns zero if the element's value could be written.
 614  * Negative values indicate an error.
 615  */
 616 int mi_lttng_process(struct mi_writer *writer, pid_t pid , const char *name,
 617                 int is_open);
 618
 619 /*
 620  * TODO: move pid of lttng list -u to process semantic on mi api bump
 621  * Machine interface of a Process.
 622  *
 623  * writer An instance of a machine interface writer.
 624  * pid A PID.
 625  *
 626  * is_open Defines whether or not the session element shall be closed.
 627  *         This should be used carefully and the client
 628  *         must close the pid element.
 629  *         Use case: nested addition information on a domain
 630  *                  ex: channel event.
 631  *
 632  * Returns zero if the element's value could be written.
 633  * Negative values indicate an error.
 634  */
 635 int mi_lttng_pid(struct mi_writer *writer, pid_t pid , const char *name,
 636                 int is_open);
 637 /*
 638  * Machine interface: open a targets element.
 639  *
 640  * writer An instance of a machine interface writer.
 641  *
 642  * Returns zero if the element's value could be written.
 643  * Negative values indicate an error.
 644  */
 645 int mi_lttng_targets_open(struct mi_writer *writer);
 646
 647 /*
 648  * Machine interface for track/untrack a pid_target
 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_pid_target(struct mi_writer *writer, pid_t pid, int is_open);
 656
 657 /*
 658  * Machine interface for struct lttng_calibrate.
 659  *
 660  * writer An instance of a machine interface writer.
 661  *
 662  * calibrate A lttng_calibrate instance.
 663  *
 664  * Returns zero if the element's value could be written.
 665  * Negative values indicate an error.
 666  */
 667 int mi_lttng_calibrate(struct mi_writer *writer,
 668                 struct lttng_calibrate *calibrate);
 669
 670 /*
 671  * Machine interface of a context.
 672  *
 673  * writer An instance of a machine interface writer
 674  *
 675  * context An instance of a lttng_event_context
 676  *
 677  * is_open Define if we close the context element
 678  *         This should be used carefully and the client
 679  *         need to close the context element.
 680  * Returns zero if the element's value could be written.
 681  * Negative values indicate an error.
 682  */
 683 int mi_lttng_context(struct mi_writer *writer,
 684                 struct lttng_event_context *context, int is_open);
 685
 686 /*
 687  * Machine interface of a perf_counter_context.
 688  *
 689  * writer An instance of a machine interface writer
 690  *
 691  * contest An instance of a lttng_event_perf_counter_ctx
 692  *
 693  * Returns zero if the element's value could be written.
 694  * Negative values indicate an error.
 695  */
 696 int mi_lttng_perf_counter_context(struct mi_writer *writer,
 697                 struct lttng_event_perf_counter_ctx  *perf_context);
 698
 699 /*
 700  * Machine interface of the snapshot list_output.
 701  * It specifies the session for which we are listing snapshots,
 702  * and it opens a snapshots element to list a sequence
 703  * of snapshots.
 704  *
 705  * writer An instance of a machine interface writer.
 706  *
 707  * session_name: Snapshot output for session "session_name".
 708  *
 709  * Note: The client has to close the session and the snapshots elements after
 710  * having listed every lttng_snapshot_output.
 711  *
 712  * Returns zero if the element's value could be written.
 713  * Negative values indicate an error.
 714  */
 715 int mi_lttng_snapshot_output_session_name(struct mi_writer *writer,
 716                 const char *session_name);
 717
 718 /*
 719  * Machine interface of the snapshot output.
 720  * The machine interface serializes the following attributes:
 721  * - id: ID of the snapshot output.
 722  * - name: Name of the output.
 723  * - data_url : Destination of the output.
 724  * - ctrl_url: Destination of the output.
 725  * - max_size: total size of all stream combined.
 726  *
 727  * writer An instance of a machine interface writer.
 728  *
 729  * output: A list of snapshot_output.
 730  *
 731  * Returns zero if the element's value could be written.
 732  * Negative values indicate an error.
 733  */
 734 int mi_lttng_snapshot_list_output(struct mi_writer *writer,
 735                 struct lttng_snapshot_output *output);
 736
 737 /*
 738  * Machine interface of the output of the command snapshot del output
 739  * when deleting a snapshot either by id or by name.
 740  * If the snapshot was found and successfully deleted using its id,
 741  * it return the id of the snapshot and the current session name on which it
 742  * was attached.
 743  *
 744  * Otherwise, it do the same process with the name of the snapshot, if the
 745  * snapshot output id is undefined.
 746  *
 747  * writer An instance of a machine interface writer.
 748  *
 749  * id: ID of the snapshot output.
 750  *
 751  * name: Name of the snapshot.
 752  *
 753  * current_session_name: Session to which the snapshot belongs.
 754  *
 755  * Returns zero if the element's value could be written.
 756  * Negative values indicate an error.
 757  */
 758 int mi_lttng_snapshot_del_output(struct mi_writer *writer, int id,
 759                 const char *name, const char *current_session_name);
 760
 761 /*
 762  * Machine interface of the output of the command snapshot add output
 763  * when adding a snapshot from a user URL.
 764  *
 765  * If the snapshot was successfully added, the machine interface lists
 766  * these information:
 767  * - id: ID of the newly add snapshot output.
 768  * - current_session_name: Name of the session to which the output was added.
 769  * - ctrl_url: Destination of the output.
 770  * - max_size: total size of all stream combined.
 771  *
 772  * writer An instance of a machine interface writer.
 773  *
 774  * current_session_name: Session to which the snapshot belongs.
 775  *
 776  * n_ptr:
 777  *
 778  * output: iterator over a lttng_snapshot_output_list which contain
 779  * the snapshot output informations.
 780  *
 781  * Returns zero if the element's value could be written.
 782  * Negative values indicate an error.
 783  */
 784 int mi_lttng_snapshot_add_output(struct mi_writer *writer,
 785                 const char *current_session_name, const char *n_ptr,
 786                 struct lttng_snapshot_output *output);
 787
 788 /*
 789  * Machine interface of the output of the command snapshot
 790  * record  from a URL (if given).
 791  *
 792  * If the snapshot is successfully recorded from a url, the machine interface
 793  * output the following information:
 794  * - url: Destination of the output stored in the snapshot.
 795  *
 796  * Otherwise, the machine interface output the data and ctrl url received
 797  * from the command-line.
 798  *
 799  * writer An instance of a machine interface writer.
 800  *
 801  * current_session_name: Snapshot record for session "current_session_name".
 802  *
 803  * ctrl_url, data_url: Destination of the output receive from the command-line.
 804  *
 805  * Returns zero if the element's value could be written.
 806  * Negative values indicate an error.
 807  */
 808 int mi_lttng_snapshot_record(struct mi_writer *writer,
 809                 const char *current_session_name, const char *url,
 810                 const char *cmdline_ctrl_url, const char *cmdline_data_url);
 811
 812 #endif /* _MI_LTTNG_H */