trace2/tr2_tgt_event.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "json-writer.h"
   4 #include "run-command.h"
   5 #include "version.h"
   6 #include "trace2/tr2_dst.h"
   7 #include "trace2/tr2_tbuf.h"
   8 #include "trace2/tr2_sid.h"
   9 #include "trace2/tr2_sysenv.h"
  10 #include "trace2/tr2_tgt.h"
  11 #include "trace2/tr2_tls.h"
  12
  13 static struct tr2_dst tr2dst_event = { TR2_SYSENV_EVENT, 0, 0, 0, 0 };
  14
  15 /*
  16  * The version number of the JSON data generated by the EVENT target in this
  17  * source file. The version should be incremented if new event types are added,
  18  * if existing fields are removed, or if there are significant changes in
  19  * interpretation of existing events or fields. Smaller changes, such as adding
  20  * a new field to an existing event, do not require an increment to the EVENT
  21  * format version.
  22  */
  23 #define TR2_EVENT_VERSION "3"
  24
  25 /*
  26  * Region nesting limit for messages written to the event target.
  27  *
  28  * The "region_enter" and "region_leave" messages (especially recursive
  29  * messages such as those produced while diving the worktree or index)
  30  * are primarily intended for the performance target during debugging.
  31  *
  32  * Some of the outer-most messages, however, may be of interest to the
  33  * event target.  Use the TR2_SYSENV_EVENT_NESTING setting to increase
  34  * region details in the event target.
  35  */
  36 static int tr2env_event_max_nesting_levels = 2;
  37
  38 /*
  39  * Use the TR2_SYSENV_EVENT_BRIEF to omit the <time>, <file>, and
  40  * <line> fields from most events.
  41  */
  42 static int tr2env_event_be_brief;
  43
  44 static int fn_init(void)
  45 {
  46         int want = tr2_dst_trace_want(&tr2dst_event);
  47         int max_nesting;
  48         int want_brief;
  49         const char *nesting;
  50         const char *brief;
  51
  52         if (!want)
  53                 return want;
  54
  55         nesting = tr2_sysenv_get(TR2_SYSENV_EVENT_NESTING);
  56         if (nesting && *nesting && ((max_nesting = atoi(nesting)) > 0))
  57                 tr2env_event_max_nesting_levels = max_nesting;
  58
  59         brief = tr2_sysenv_get(TR2_SYSENV_EVENT_BRIEF);
  60         if (brief && *brief &&
  61             ((want_brief = git_parse_maybe_bool(brief)) != -1))
  62                 tr2env_event_be_brief = want_brief;
  63
  64         return want;
  65 }
  66
  67 static void fn_term(void)
  68 {
  69         tr2_dst_trace_disable(&tr2dst_event);
  70 }
  71
  72 /*
  73  * Append common key-value pairs to the currently open JSON object.
  74  *     "event:"<event_name>"
  75  *      "sid":"<sid>"
  76  *   "thread":"<thread_name>"
  77  *     "time":"<time>"
  78  *     "file":"<filename>"
  79  *     "line":<line_number>
  80  *     "repo":<repo_id>
  81  */
  82 static void event_fmt_prepare(const char *event_name, const char *file,
  83                               int line, const struct repository *repo,
  84                               struct json_writer *jw)
  85 {
  86         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
  87         struct tr2_tbuf tb_now;
  88
  89         jw_object_string(jw, "event", event_name);
  90         jw_object_string(jw, "sid", tr2_sid_get());
  91         jw_object_string(jw, "thread", ctx->thread_name.buf);
  92
  93         /*
  94          * In brief mode, only emit <time> on these 2 event types.
  95          */
  96         if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
  97             !strcmp(event_name, "atexit")) {
  98                 tr2_tbuf_utc_datetime_extended(&tb_now);
  99                 jw_object_string(jw, "time", tb_now.buf);
 100         }
 101
 102         if (!tr2env_event_be_brief && file && *file) {
 103                 jw_object_string(jw, "file", file);
 104                 jw_object_intmax(jw, "line", line);
 105         }
 106
 107         if (repo)
 108                 jw_object_intmax(jw, "repo", repo->trace2_repo_id);
 109 }
 110
 111 static void fn_too_many_files_fl(const char *file, int line)
 112 {
 113         const char *event_name = "too_many_files";
 114         struct json_writer jw = JSON_WRITER_INIT;
 115
 116         jw_object_begin(&jw, 0);
 117         event_fmt_prepare(event_name, file, line, NULL, &jw);
 118         jw_end(&jw);
 119
 120         tr2_dst_write_line(&tr2dst_event, &jw.json);
 121         jw_release(&jw);
 122 }
 123
 124 static void fn_version_fl(const char *file, int line)
 125 {
 126         const char *event_name = "version";
 127         struct json_writer jw = JSON_WRITER_INIT;
 128
 129         jw_object_begin(&jw, 0);
 130         event_fmt_prepare(event_name, file, line, NULL, &jw);
 131         jw_object_string(&jw, "evt", TR2_EVENT_VERSION);
 132         jw_object_string(&jw, "exe", git_version_string);
 133         jw_end(&jw);
 134
 135         tr2_dst_write_line(&tr2dst_event, &jw.json);
 136         jw_release(&jw);
 137
 138         if (tr2dst_event.too_many_files)
 139                 fn_too_many_files_fl(file, line);
 140 }
 141
 142 static void fn_start_fl(const char *file, int line,
 143                         uint64_t us_elapsed_absolute, const char **argv)
 144 {
 145         const char *event_name = "start";
 146         struct json_writer jw = JSON_WRITER_INIT;
 147         double t_abs = (double)us_elapsed_absolute / 1000000.0;
 148
 149         jw_object_begin(&jw, 0);
 150         event_fmt_prepare(event_name, file, line, NULL, &jw);
 151         jw_object_double(&jw, "t_abs", 6, t_abs);
 152         jw_object_inline_begin_array(&jw, "argv");
 153         jw_array_argv(&jw, argv);
 154         jw_end(&jw);
 155         jw_end(&jw);
 156
 157         tr2_dst_write_line(&tr2dst_event, &jw.json);
 158         jw_release(&jw);
 159 }
 160
 161 static void fn_exit_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 162                        int code)
 163 {
 164         const char *event_name = "exit";
 165         struct json_writer jw = JSON_WRITER_INIT;
 166         double t_abs = (double)us_elapsed_absolute / 1000000.0;
 167
 168         jw_object_begin(&jw, 0);
 169         event_fmt_prepare(event_name, file, line, NULL, &jw);
 170         jw_object_double(&jw, "t_abs", 6, t_abs);
 171         jw_object_intmax(&jw, "code", code);
 172         jw_end(&jw);
 173
 174         tr2_dst_write_line(&tr2dst_event, &jw.json);
 175         jw_release(&jw);
 176 }
 177
 178 static void fn_signal(uint64_t us_elapsed_absolute, int signo)
 179 {
 180         const char *event_name = "signal";
 181         struct json_writer jw = JSON_WRITER_INIT;
 182         double t_abs = (double)us_elapsed_absolute / 1000000.0;
 183
 184         jw_object_begin(&jw, 0);
 185         event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw);
 186         jw_object_double(&jw, "t_abs", 6, t_abs);
 187         jw_object_intmax(&jw, "signo", signo);
 188         jw_end(&jw);
 189
 190         tr2_dst_write_line(&tr2dst_event, &jw.json);
 191         jw_release(&jw);
 192 }
 193
 194 static void fn_atexit(uint64_t us_elapsed_absolute, int code)
 195 {
 196         const char *event_name = "atexit";
 197         struct json_writer jw = JSON_WRITER_INIT;
 198         double t_abs = (double)us_elapsed_absolute / 1000000.0;
 199
 200         jw_object_begin(&jw, 0);
 201         event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw);
 202         jw_object_double(&jw, "t_abs", 6, t_abs);
 203         jw_object_intmax(&jw, "code", code);
 204         jw_end(&jw);
 205
 206         tr2_dst_write_line(&tr2dst_event, &jw.json);
 207         jw_release(&jw);
 208 }
 209
 210 static void maybe_add_string_va(struct json_writer *jw, const char *field_name,
 211                                 const char *fmt, va_list ap)
 212 {
 213         if (fmt && *fmt) {
 214                 va_list copy_ap;
 215                 struct strbuf buf = STRBUF_INIT;
 216
 217                 va_copy(copy_ap, ap);
 218                 strbuf_vaddf(&buf, fmt, copy_ap);
 219                 va_end(copy_ap);
 220
 221                 jw_object_string(jw, field_name, buf.buf);
 222                 strbuf_release(&buf);
 223                 return;
 224         }
 225 }
 226
 227 static void fn_error_va_fl(const char *file, int line, const char *fmt,
 228                            va_list ap)
 229 {
 230         const char *event_name = "error";
 231         struct json_writer jw = JSON_WRITER_INIT;
 232
 233         jw_object_begin(&jw, 0);
 234         event_fmt_prepare(event_name, file, line, NULL, &jw);
 235         maybe_add_string_va(&jw, "msg", fmt, ap);
 236         /*
 237          * Also emit the format string as a field in case
 238          * post-processors want to aggregate common error
 239          * messages by type without argument fields (such
 240          * as pathnames or branch names) cluttering it up.
 241          */
 242         if (fmt && *fmt)
 243                 jw_object_string(&jw, "fmt", fmt);
 244         jw_end(&jw);
 245
 246         tr2_dst_write_line(&tr2dst_event, &jw.json);
 247         jw_release(&jw);
 248 }
 249
 250 static void fn_command_path_fl(const char *file, int line, const char *pathname)
 251 {
 252         const char *event_name = "cmd_path";
 253         struct json_writer jw = JSON_WRITER_INIT;
 254
 255         jw_object_begin(&jw, 0);
 256         event_fmt_prepare(event_name, file, line, NULL, &jw);
 257         jw_object_string(&jw, "path", pathname);
 258         jw_end(&jw);
 259
 260         tr2_dst_write_line(&tr2dst_event, &jw.json);
 261         jw_release(&jw);
 262 }
 263
 264 static void fn_command_ancestry_fl(const char *file, int line, const char **parent_names)
 265 {
 266         const char *event_name = "cmd_ancestry";
 267         const char *parent_name = NULL;
 268         struct json_writer jw = JSON_WRITER_INIT;
 269
 270         jw_object_begin(&jw, 0);
 271         event_fmt_prepare(event_name, file, line, NULL, &jw);
 272         jw_object_inline_begin_array(&jw, "ancestry");
 273
 274         while ((parent_name = *parent_names++))
 275                 jw_array_string(&jw, parent_name);
 276
 277         jw_end(&jw); /* 'ancestry' array */
 278         jw_end(&jw); /* event object */
 279
 280         tr2_dst_write_line(&tr2dst_event, &jw.json);
 281         jw_release(&jw);
 282 }
 283
 284 static void fn_command_name_fl(const char *file, int line, const char *name,
 285                                const char *hierarchy)
 286 {
 287         const char *event_name = "cmd_name";
 288         struct json_writer jw = JSON_WRITER_INIT;
 289
 290         jw_object_begin(&jw, 0);
 291         event_fmt_prepare(event_name, file, line, NULL, &jw);
 292         jw_object_string(&jw, "name", name);
 293         if (hierarchy && *hierarchy)
 294                 jw_object_string(&jw, "hierarchy", hierarchy);
 295         jw_end(&jw);
 296
 297         tr2_dst_write_line(&tr2dst_event, &jw.json);
 298         jw_release(&jw);
 299 }
 300
 301 static void fn_command_mode_fl(const char *file, int line, const char *mode)
 302 {
 303         const char *event_name = "cmd_mode";
 304         struct json_writer jw = JSON_WRITER_INIT;
 305
 306         jw_object_begin(&jw, 0);
 307         event_fmt_prepare(event_name, file, line, NULL, &jw);
 308         jw_object_string(&jw, "name", mode);
 309         jw_end(&jw);
 310
 311         tr2_dst_write_line(&tr2dst_event, &jw.json);
 312         jw_release(&jw);
 313 }
 314
 315 static void fn_alias_fl(const char *file, int line, const char *alias,
 316                         const char **argv)
 317 {
 318         const char *event_name = "alias";
 319         struct json_writer jw = JSON_WRITER_INIT;
 320
 321         jw_object_begin(&jw, 0);
 322         event_fmt_prepare(event_name, file, line, NULL, &jw);
 323         jw_object_string(&jw, "alias", alias);
 324         jw_object_inline_begin_array(&jw, "argv");
 325         jw_array_argv(&jw, argv);
 326         jw_end(&jw);
 327         jw_end(&jw);
 328
 329         tr2_dst_write_line(&tr2dst_event, &jw.json);
 330         jw_release(&jw);
 331 }
 332
 333 static void fn_child_start_fl(const char *file, int line,
 334                               uint64_t us_elapsed_absolute,
 335                               const struct child_process *cmd)
 336 {
 337         const char *event_name = "child_start";
 338         struct json_writer jw = JSON_WRITER_INIT;
 339
 340         jw_object_begin(&jw, 0);
 341         event_fmt_prepare(event_name, file, line, NULL, &jw);
 342         jw_object_intmax(&jw, "child_id", cmd->trace2_child_id);
 343         if (cmd->trace2_hook_name) {
 344                 jw_object_string(&jw, "child_class", "hook");
 345                 jw_object_string(&jw, "hook_name", cmd->trace2_hook_name);
 346         } else {
 347                 const char *child_class =
 348                         cmd->trace2_child_class ? cmd->trace2_child_class : "?";
 349                 jw_object_string(&jw, "child_class", child_class);
 350         }
 351         if (cmd->dir)
 352                 jw_object_string(&jw, "cd", cmd->dir);
 353         jw_object_bool(&jw, "use_shell", cmd->use_shell);
 354         jw_object_inline_begin_array(&jw, "argv");
 355         if (cmd->git_cmd)
 356                 jw_array_string(&jw, "git");
 357         jw_array_argv(&jw, cmd->args.v);
 358         jw_end(&jw);
 359         jw_end(&jw);
 360
 361         tr2_dst_write_line(&tr2dst_event, &jw.json);
 362         jw_release(&jw);
 363 }
 364
 365 static void fn_child_exit_fl(const char *file, int line,
 366                              uint64_t us_elapsed_absolute, int cid, int pid,
 367                              int code, uint64_t us_elapsed_child)
 368 {
 369         const char *event_name = "child_exit";
 370         struct json_writer jw = JSON_WRITER_INIT;
 371         double t_rel = (double)us_elapsed_child / 1000000.0;
 372
 373         jw_object_begin(&jw, 0);
 374         event_fmt_prepare(event_name, file, line, NULL, &jw);
 375         jw_object_intmax(&jw, "child_id", cid);
 376         jw_object_intmax(&jw, "pid", pid);
 377         jw_object_intmax(&jw, "code", code);
 378         jw_object_double(&jw, "t_rel", 6, t_rel);
 379         jw_end(&jw);
 380
 381         tr2_dst_write_line(&tr2dst_event, &jw.json);
 382
 383         jw_release(&jw);
 384 }
 385
 386 static void fn_child_ready_fl(const char *file, int line,
 387                               uint64_t us_elapsed_absolute, int cid, int pid,
 388                               const char *ready, uint64_t us_elapsed_child)
 389 {
 390         const char *event_name = "child_ready";
 391         struct json_writer jw = JSON_WRITER_INIT;
 392         double t_rel = (double)us_elapsed_child / 1000000.0;
 393
 394         jw_object_begin(&jw, 0);
 395         event_fmt_prepare(event_name, file, line, NULL, &jw);
 396         jw_object_intmax(&jw, "child_id", cid);
 397         jw_object_intmax(&jw, "pid", pid);
 398         jw_object_string(&jw, "ready", ready);
 399         jw_object_double(&jw, "t_rel", 6, t_rel);
 400         jw_end(&jw);
 401
 402         tr2_dst_write_line(&tr2dst_event, &jw.json);
 403
 404         jw_release(&jw);
 405 }
 406
 407 static void fn_thread_start_fl(const char *file, int line,
 408                                uint64_t us_elapsed_absolute)
 409 {
 410         const char *event_name = "thread_start";
 411         struct json_writer jw = JSON_WRITER_INIT;
 412
 413         jw_object_begin(&jw, 0);
 414         event_fmt_prepare(event_name, file, line, NULL, &jw);
 415         jw_end(&jw);
 416
 417         tr2_dst_write_line(&tr2dst_event, &jw.json);
 418         jw_release(&jw);
 419 }
 420
 421 static void fn_thread_exit_fl(const char *file, int line,
 422                               uint64_t us_elapsed_absolute,
 423                               uint64_t us_elapsed_thread)
 424 {
 425         const char *event_name = "thread_exit";
 426         struct json_writer jw = JSON_WRITER_INIT;
 427         double t_rel = (double)us_elapsed_thread / 1000000.0;
 428
 429         jw_object_begin(&jw, 0);
 430         event_fmt_prepare(event_name, file, line, NULL, &jw);
 431         jw_object_double(&jw, "t_rel", 6, t_rel);
 432         jw_end(&jw);
 433
 434         tr2_dst_write_line(&tr2dst_event, &jw.json);
 435         jw_release(&jw);
 436 }
 437
 438 static void fn_exec_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 439                        int exec_id, const char *exe, const char **argv)
 440 {
 441         const char *event_name = "exec";
 442         struct json_writer jw = JSON_WRITER_INIT;
 443
 444         jw_object_begin(&jw, 0);
 445         event_fmt_prepare(event_name, file, line, NULL, &jw);
 446         jw_object_intmax(&jw, "exec_id", exec_id);
 447         if (exe)
 448                 jw_object_string(&jw, "exe", exe);
 449         jw_object_inline_begin_array(&jw, "argv");
 450         jw_array_argv(&jw, argv);
 451         jw_end(&jw);
 452         jw_end(&jw);
 453
 454         tr2_dst_write_line(&tr2dst_event, &jw.json);
 455         jw_release(&jw);
 456 }
 457
 458 static void fn_exec_result_fl(const char *file, int line,
 459                               uint64_t us_elapsed_absolute, int exec_id,
 460                               int code)
 461 {
 462         const char *event_name = "exec_result";
 463         struct json_writer jw = JSON_WRITER_INIT;
 464
 465         jw_object_begin(&jw, 0);
 466         event_fmt_prepare(event_name, file, line, NULL, &jw);
 467         jw_object_intmax(&jw, "exec_id", exec_id);
 468         jw_object_intmax(&jw, "code", code);
 469         jw_end(&jw);
 470
 471         tr2_dst_write_line(&tr2dst_event, &jw.json);
 472         jw_release(&jw);
 473 }
 474
 475 static void fn_param_fl(const char *file, int line, const char *param,
 476                         const char *value)
 477 {
 478         const char *event_name = "def_param";
 479         struct json_writer jw = JSON_WRITER_INIT;
 480
 481         jw_object_begin(&jw, 0);
 482         event_fmt_prepare(event_name, file, line, NULL, &jw);
 483         jw_object_string(&jw, "param", param);
 484         jw_object_string(&jw, "value", value);
 485         jw_end(&jw);
 486
 487         tr2_dst_write_line(&tr2dst_event, &jw.json);
 488         jw_release(&jw);
 489 }
 490
 491 static void fn_repo_fl(const char *file, int line,
 492                        const struct repository *repo)
 493 {
 494         const char *event_name = "def_repo";
 495         struct json_writer jw = JSON_WRITER_INIT;
 496
 497         jw_object_begin(&jw, 0);
 498         event_fmt_prepare(event_name, file, line, repo, &jw);
 499         jw_object_string(&jw, "worktree", repo->worktree);
 500         jw_end(&jw);
 501
 502         tr2_dst_write_line(&tr2dst_event, &jw.json);
 503         jw_release(&jw);
 504 }
 505
 506 static void fn_region_enter_printf_va_fl(const char *file, int line,
 507                                          uint64_t us_elapsed_absolute,
 508                                          const char *category,
 509                                          const char *label,
 510                                          const struct repository *repo,
 511                                          const char *fmt, va_list ap)
 512 {
 513         const char *event_name = "region_enter";
 514         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
 515         if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 516                 struct json_writer jw = JSON_WRITER_INIT;
 517
 518                 jw_object_begin(&jw, 0);
 519                 event_fmt_prepare(event_name, file, line, repo, &jw);
 520                 jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
 521                 if (category)
 522                         jw_object_string(&jw, "category", category);
 523                 if (label)
 524                         jw_object_string(&jw, "label", label);
 525                 maybe_add_string_va(&jw, "msg", fmt, ap);
 526                 jw_end(&jw);
 527
 528                 tr2_dst_write_line(&tr2dst_event, &jw.json);
 529                 jw_release(&jw);
 530         }
 531 }
 532
 533 static void fn_region_leave_printf_va_fl(
 534         const char *file, int line, uint64_t us_elapsed_absolute,
 535         uint64_t us_elapsed_region, const char *category, const char *label,
 536         const struct repository *repo, const char *fmt, va_list ap)
 537 {
 538         const char *event_name = "region_leave";
 539         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
 540         if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 541                 struct json_writer jw = JSON_WRITER_INIT;
 542                 double t_rel = (double)us_elapsed_region / 1000000.0;
 543
 544                 jw_object_begin(&jw, 0);
 545                 event_fmt_prepare(event_name, file, line, repo, &jw);
 546                 jw_object_double(&jw, "t_rel", 6, t_rel);
 547                 jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
 548                 if (category)
 549                         jw_object_string(&jw, "category", category);
 550                 if (label)
 551                         jw_object_string(&jw, "label", label);
 552                 maybe_add_string_va(&jw, "msg", fmt, ap);
 553                 jw_end(&jw);
 554
 555                 tr2_dst_write_line(&tr2dst_event, &jw.json);
 556                 jw_release(&jw);
 557         }
 558 }
 559
 560 static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
 561                        uint64_t us_elapsed_region, const char *category,
 562                        const struct repository *repo, const char *key,
 563                        const char *value)
 564 {
 565         const char *event_name = "data";
 566         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
 567         if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 568                 struct json_writer jw = JSON_WRITER_INIT;
 569                 double t_abs = (double)us_elapsed_absolute / 1000000.0;
 570                 double t_rel = (double)us_elapsed_region / 1000000.0;
 571
 572                 jw_object_begin(&jw, 0);
 573                 event_fmt_prepare(event_name, file, line, repo, &jw);
 574                 jw_object_double(&jw, "t_abs", 6, t_abs);
 575                 jw_object_double(&jw, "t_rel", 6, t_rel);
 576                 jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
 577                 jw_object_string(&jw, "category", category);
 578                 jw_object_string(&jw, "key", key);
 579                 jw_object_string(&jw, "value", value);
 580                 jw_end(&jw);
 581
 582                 tr2_dst_write_line(&tr2dst_event, &jw.json);
 583                 jw_release(&jw);
 584         }
 585 }
 586
 587 static void fn_data_json_fl(const char *file, int line,
 588                             uint64_t us_elapsed_absolute,
 589                             uint64_t us_elapsed_region, const char *category,
 590                             const struct repository *repo, const char *key,
 591                             const struct json_writer *value)
 592 {
 593         const char *event_name = "data_json";
 594         struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
 595         if (ctx->nr_open_regions <= tr2env_event_max_nesting_levels) {
 596                 struct json_writer jw = JSON_WRITER_INIT;
 597                 double t_abs = (double)us_elapsed_absolute / 1000000.0;
 598                 double t_rel = (double)us_elapsed_region / 1000000.0;
 599
 600                 jw_object_begin(&jw, 0);
 601                 event_fmt_prepare(event_name, file, line, repo, &jw);
 602                 jw_object_double(&jw, "t_abs", 6, t_abs);
 603                 jw_object_double(&jw, "t_rel", 6, t_rel);
 604                 jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
 605                 jw_object_string(&jw, "category", category);
 606                 jw_object_string(&jw, "key", key);
 607                 jw_object_sub_jw(&jw, "value", value);
 608                 jw_end(&jw);
 609
 610                 tr2_dst_write_line(&tr2dst_event, &jw.json);
 611                 jw_release(&jw);
 612         }
 613 }
 614
 615 struct tr2_tgt tr2_tgt_event = {
 616         &tr2dst_event,
 617
 618         fn_init,
 619         fn_term,
 620
 621         fn_version_fl,
 622         fn_start_fl,
 623         fn_exit_fl,
 624         fn_signal,
 625         fn_atexit,
 626         fn_error_va_fl,
 627         fn_command_path_fl,
 628         fn_command_ancestry_fl,
 629         fn_command_name_fl,
 630         fn_command_mode_fl,
 631         fn_alias_fl,
 632         fn_child_start_fl,
 633         fn_child_exit_fl,
 634         fn_child_ready_fl,
 635         fn_thread_start_fl,
 636         fn_thread_exit_fl,
 637         fn_exec_fl,
 638         fn_exec_result_fl,
 639         fn_param_fl,
 640         fn_repo_fl,
 641         fn_region_enter_printf_va_fl,
 642         fn_region_leave_printf_va_fl,
 643         fn_data_fl,
 644         fn_data_json_fl,
 645         NULL, /* printf */
 646 };