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Assert on unknown UST buffer type
[lttng-tools.git] / src / bin / lttng-sessiond / ust-metadata.c
1 /*
2 * ust-metadata.c
3 *
4 * LTTng-UST metadata generation
5 *
6 * Copyright (C) 2010-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License, version 2 only,
10 * as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22 #define _LGPL_SOURCE
23 #include <stdint.h>
24 #include <string.h>
25 #include <stdarg.h>
26 #include <stdio.h>
27 #include <limits.h>
28 #include <unistd.h>
29 #include <inttypes.h>
30 #include <common/common.h>
31
32 #include "ust-registry.h"
33 #include "ust-clock.h"
34 #include "ust-app.h"
35
36 #ifndef max_t
37 #define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
38 #endif
39
40 #define NSEC_PER_SEC 1000000000ULL
41 #define NR_CLOCK_OFFSET_SAMPLES 10
42
43 struct offset_sample {
44 int64_t offset; /* correlation offset */
45 uint64_t measure_delta; /* lower is better */
46 };
47
48 static
49 int _lttng_field_statedump(struct ust_registry_session *session,
50 const struct ustctl_field *fields, size_t nr_fields,
51 size_t *iter_field, size_t nesting);
52
53 static inline
54 int fls(unsigned int x)
55 {
56 int r = 32;
57
58 if (!x)
59 return 0;
60 if (!(x & 0xFFFF0000U)) {
61 x <<= 16;
62 r -= 16;
63 }
64 if (!(x & 0xFF000000U)) {
65 x <<= 8;
66 r -= 8;
67 }
68 if (!(x & 0xF0000000U)) {
69 x <<= 4;
70 r -= 4;
71 }
72 if (!(x & 0xC0000000U)) {
73 x <<= 2;
74 r -= 2;
75 }
76 if (!(x & 0x80000000U)) {
77 x <<= 1;
78 r -= 1;
79 }
80 return r;
81 }
82
83 static inline
84 int get_count_order(unsigned int count)
85 {
86 int order;
87
88 order = fls(count) - 1;
89 if (count & (count - 1))
90 order++;
91 return order;
92 }
93
94 /*
95 * Returns offset where to write in metadata array, or negative error value on error.
96 */
97 static
98 ssize_t metadata_reserve(struct ust_registry_session *session, size_t len)
99 {
100 size_t new_len = session->metadata_len + len;
101 size_t new_alloc_len = new_len;
102 size_t old_alloc_len = session->metadata_alloc_len;
103 ssize_t ret;
104
105 if (new_alloc_len > (UINT32_MAX >> 1))
106 return -EINVAL;
107 if ((old_alloc_len << 1) > (UINT32_MAX >> 1))
108 return -EINVAL;
109
110 if (new_alloc_len > old_alloc_len) {
111 char *newptr;
112
113 new_alloc_len =
114 max_t(size_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
115 newptr = realloc(session->metadata, new_alloc_len);
116 if (!newptr)
117 return -ENOMEM;
118 session->metadata = newptr;
119 /* We zero directly the memory from start of allocation. */
120 memset(&session->metadata[old_alloc_len], 0, new_alloc_len - old_alloc_len);
121 session->metadata_alloc_len = new_alloc_len;
122 }
123 ret = session->metadata_len;
124 session->metadata_len += len;
125 return ret;
126 }
127
128 static
129 int metadata_file_append(struct ust_registry_session *session,
130 const char *str, size_t len)
131 {
132 ssize_t written;
133
134 if (session->metadata_fd < 0) {
135 return 0;
136 }
137 /* Write to metadata file */
138 written = lttng_write(session->metadata_fd, str, len);
139 if (written != len) {
140 return -1;
141 }
142 return 0;
143 }
144
145 /*
146 * We have exclusive access to our metadata buffer (protected by the
147 * ust_lock), so we can do racy operations such as looking for
148 * remaining space left in packet and write, since mutual exclusion
149 * protects us from concurrent writes.
150 */
151 static
152 int lttng_metadata_printf(struct ust_registry_session *session,
153 const char *fmt, ...)
154 {
155 char *str = NULL;
156 size_t len;
157 va_list ap;
158 ssize_t offset;
159 int ret;
160
161 va_start(ap, fmt);
162 ret = vasprintf(&str, fmt, ap);
163 va_end(ap);
164 if (ret < 0)
165 return -ENOMEM;
166
167 len = strlen(str);
168 offset = metadata_reserve(session, len);
169 if (offset < 0) {
170 ret = offset;
171 goto end;
172 }
173 memcpy(&session->metadata[offset], str, len);
174 ret = metadata_file_append(session, str, len);
175 if (ret) {
176 PERROR("Error appending to metadata file");
177 goto end;
178 }
179 DBG3("Append to metadata: \"%s\"", str);
180 ret = 0;
181
182 end:
183 free(str);
184 return ret;
185 }
186
187 static
188 int print_tabs(struct ust_registry_session *session, size_t nesting)
189 {
190 size_t i;
191
192 for (i = 0; i < nesting; i++) {
193 int ret;
194
195 ret = lttng_metadata_printf(session, " ");
196 if (ret) {
197 return ret;
198 }
199 }
200 return 0;
201 }
202
203 static
204 void sanitize_ctf_identifier(char *out, const char *in)
205 {
206 size_t i;
207
208 for (i = 0; i < LTTNG_UST_SYM_NAME_LEN; i++) {
209 switch (in[i]) {
210 case '.':
211 case '$':
212 case ':':
213 out[i] = '_';
214 break;
215 default:
216 out[i] = in[i];
217 }
218 }
219 }
220
221 /* Called with session registry mutex held. */
222 static
223 int ust_metadata_enum_statedump(struct ust_registry_session *session,
224 const char *enum_name,
225 uint64_t enum_id,
226 const struct ustctl_integer_type *container_type,
227 const char *field_name, size_t *iter_field, size_t nesting)
228 {
229 struct ust_registry_enum *reg_enum;
230 const struct ustctl_enum_entry *entries;
231 size_t nr_entries;
232 int ret = 0;
233 size_t i;
234 char identifier[LTTNG_UST_SYM_NAME_LEN];
235
236 rcu_read_lock();
237 reg_enum = ust_registry_lookup_enum_by_id(session, enum_name, enum_id);
238 rcu_read_unlock();
239 /* reg_enum can still be used because session registry mutex is held. */
240 if (!reg_enum) {
241 ret = -ENOENT;
242 goto end;
243 }
244 entries = reg_enum->entries;
245 nr_entries = reg_enum->nr_entries;
246
247 ret = print_tabs(session, nesting);
248 if (ret) {
249 goto end;
250 }
251 ret = lttng_metadata_printf(session,
252 "enum : integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u; } {\n",
253 container_type->size,
254 container_type->alignment,
255 container_type->signedness,
256 (container_type->encoding == ustctl_encode_none)
257 ? "none"
258 : (container_type->encoding == ustctl_encode_UTF8)
259 ? "UTF8"
260 : "ASCII",
261 container_type->base);
262 if (ret) {
263 goto end;
264 }
265 /* Dump all entries */
266 for (i = 0; i < nr_entries; i++) {
267 const struct ustctl_enum_entry *entry = &entries[i];
268 int j, len;
269
270 ret = print_tabs(session, nesting);
271 if (ret) {
272 goto end;
273 }
274 ret = lttng_metadata_printf(session,
275 "\"");
276 if (ret) {
277 goto end;
278 }
279 len = strlen(entry->string);
280 /* Escape the character '"' */
281 for (j = 0; j < len; j++) {
282 char c = entry->string[j];
283
284 switch (c) {
285 case '"':
286 ret = lttng_metadata_printf(session,
287 "\\\"");
288 break;
289 case '\\':
290 ret = lttng_metadata_printf(session,
291 "\\\\");
292 break;
293 default:
294 ret = lttng_metadata_printf(session,
295 "%c", c);
296 break;
297 }
298 if (ret) {
299 goto end;
300 }
301 }
302 ret = lttng_metadata_printf(session,
303 "\" = ");
304 if (ret) {
305 goto end;
306 }
307 if (entry->start == entry->end) {
308 ret = lttng_metadata_printf(session,
309 "%d,\n",
310 entry->start);
311 } else {
312 ret = lttng_metadata_printf(session,
313 "%d ... %d,\n",
314 entry->start, entry->end);
315 }
316 if (ret) {
317 goto end;
318 }
319 }
320 sanitize_ctf_identifier(identifier, field_name);
321 ret = print_tabs(session, nesting);
322 if (ret) {
323 goto end;
324 }
325 ret = lttng_metadata_printf(session, "} _%s;\n",
326 identifier);
327 end:
328 (*iter_field)++;
329 return ret;
330 }
331
332 static
333 int _lttng_variant_statedump(struct ust_registry_session *session,
334 const struct ustctl_field *fields, size_t nr_fields,
335 size_t *iter_field, size_t nesting)
336 {
337 const struct ustctl_field *variant = &fields[*iter_field];
338 uint32_t nr_choices, i;
339 int ret;
340 char identifier[LTTNG_UST_SYM_NAME_LEN];
341
342 if (variant->type.atype != ustctl_atype_variant) {
343 ret = -EINVAL;
344 goto end;
345 }
346 nr_choices = variant->type.u.variant.nr_choices;
347 (*iter_field)++;
348 sanitize_ctf_identifier(identifier, variant->type.u.variant.tag_name);
349 ret = print_tabs(session, nesting);
350 if (ret) {
351 goto end;
352 }
353 ret = lttng_metadata_printf(session,
354 "variant <_%s> {\n",
355 identifier);
356 if (ret) {
357 goto end;
358 }
359
360 for (i = 0; i < nr_choices; i++) {
361 if (*iter_field >= nr_fields) {
362 ret = -EOVERFLOW;
363 goto end;
364 }
365 ret = _lttng_field_statedump(session,
366 fields, nr_fields,
367 iter_field, nesting + 1);
368 if (ret) {
369 goto end;
370 }
371 }
372 sanitize_ctf_identifier(identifier, variant->name);
373 ret = print_tabs(session, nesting);
374 ret = lttng_metadata_printf(session,
375 "} _%s;\n",
376 identifier);
377 if (ret) {
378 goto end;
379 }
380 end:
381 return ret;
382 }
383
384 static
385 int _lttng_field_statedump(struct ust_registry_session *session,
386 const struct ustctl_field *fields, size_t nr_fields,
387 size_t *iter_field, size_t nesting)
388 {
389 int ret = 0;
390 const char *bo_be = " byte_order = be;";
391 const char *bo_le = " byte_order = le;";
392 const char *bo_native = "";
393 const char *bo_reverse;
394 const struct ustctl_field *field;
395
396 if (*iter_field >= nr_fields) {
397 ret = -EOVERFLOW;
398 goto end;
399 }
400 field = &fields[*iter_field];
401
402 if (session->byte_order == BIG_ENDIAN) {
403 bo_reverse = bo_le;
404 } else {
405 bo_reverse = bo_be;
406 }
407
408 switch (field->type.atype) {
409 case ustctl_atype_integer:
410 ret = print_tabs(session, nesting);
411 if (ret) {
412 goto end;
413 }
414 ret = lttng_metadata_printf(session,
415 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
416 field->type.u.basic.integer.size,
417 field->type.u.basic.integer.alignment,
418 field->type.u.basic.integer.signedness,
419 (field->type.u.basic.integer.encoding == ustctl_encode_none)
420 ? "none"
421 : (field->type.u.basic.integer.encoding == ustctl_encode_UTF8)
422 ? "UTF8"
423 : "ASCII",
424 field->type.u.basic.integer.base,
425 field->type.u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
426 field->name);
427 (*iter_field)++;
428 break;
429 case ustctl_atype_enum:
430 ret = ust_metadata_enum_statedump(session,
431 field->type.u.basic.enumeration.name,
432 field->type.u.basic.enumeration.id,
433 &field->type.u.basic.enumeration.container_type,
434 field->name, iter_field, nesting);
435 break;
436 case ustctl_atype_float:
437 ret = print_tabs(session, nesting);
438 if (ret) {
439 goto end;
440 }
441 ret = lttng_metadata_printf(session,
442 "floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
443 field->type.u.basic._float.exp_dig,
444 field->type.u.basic._float.mant_dig,
445 field->type.u.basic._float.alignment,
446 field->type.u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
447 field->name);
448 (*iter_field)++;
449 break;
450 case ustctl_atype_array:
451 {
452 const struct ustctl_basic_type *elem_type;
453
454 ret = print_tabs(session, nesting);
455 if (ret) {
456 goto end;
457 }
458 elem_type = &field->type.u.array.elem_type;
459 ret = lttng_metadata_printf(session,
460 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
461 elem_type->u.basic.integer.size,
462 elem_type->u.basic.integer.alignment,
463 elem_type->u.basic.integer.signedness,
464 (elem_type->u.basic.integer.encoding == ustctl_encode_none)
465 ? "none"
466 : (elem_type->u.basic.integer.encoding == ustctl_encode_UTF8)
467 ? "UTF8"
468 : "ASCII",
469 elem_type->u.basic.integer.base,
470 elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
471 field->name, field->type.u.array.length);
472 (*iter_field)++;
473 break;
474 }
475 case ustctl_atype_sequence:
476 {
477 const struct ustctl_basic_type *elem_type;
478 const struct ustctl_basic_type *length_type;
479
480 elem_type = &field->type.u.sequence.elem_type;
481 length_type = &field->type.u.sequence.length_type;
482 ret = print_tabs(session, nesting);
483 if (ret) {
484 goto end;
485 }
486 ret = lttng_metadata_printf(session,
487 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
488 length_type->u.basic.integer.size,
489 (unsigned int) length_type->u.basic.integer.alignment,
490 length_type->u.basic.integer.signedness,
491 (length_type->u.basic.integer.encoding == ustctl_encode_none)
492 ? "none"
493 : ((length_type->u.basic.integer.encoding == ustctl_encode_UTF8)
494 ? "UTF8"
495 : "ASCII"),
496 length_type->u.basic.integer.base,
497 length_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
498 field->name);
499 if (ret) {
500 goto end;
501 }
502
503 ret = print_tabs(session, nesting);
504 if (ret) {
505 goto end;
506 }
507 ret = lttng_metadata_printf(session,
508 "integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
509 elem_type->u.basic.integer.size,
510 (unsigned int) elem_type->u.basic.integer.alignment,
511 elem_type->u.basic.integer.signedness,
512 (elem_type->u.basic.integer.encoding == ustctl_encode_none)
513 ? "none"
514 : ((elem_type->u.basic.integer.encoding == ustctl_encode_UTF8)
515 ? "UTF8"
516 : "ASCII"),
517 elem_type->u.basic.integer.base,
518 elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
519 field->name,
520 field->name);
521 (*iter_field)++;
522 break;
523 }
524
525 case ustctl_atype_string:
526 /* Default encoding is UTF8 */
527 ret = print_tabs(session, nesting);
528 if (ret) {
529 goto end;
530 }
531 ret = lttng_metadata_printf(session,
532 "string%s _%s;\n",
533 field->type.u.basic.string.encoding == ustctl_encode_ASCII ?
534 " { encoding = ASCII; }" : "",
535 field->name);
536 (*iter_field)++;
537 break;
538 case ustctl_atype_variant:
539 ret = _lttng_variant_statedump(session, fields, nr_fields, iter_field, nesting);
540 if (ret) {
541 goto end;
542 }
543 break;
544 case ustctl_atype_struct:
545 ret = print_tabs(session, nesting);
546 if (ret) {
547 goto end;
548 }
549 ret = lttng_metadata_printf(session,
550 "struct {} _%s;\n",
551 field->name);
552 (*iter_field)++;
553 break;
554 default:
555 ret = -EINVAL;
556 }
557 end:
558 return ret;
559 }
560
561 static
562 int _lttng_context_metadata_statedump(struct ust_registry_session *session,
563 size_t nr_ctx_fields,
564 struct ustctl_field *ctx)
565 {
566 int ret = 0;
567 size_t i = 0;
568
569 if (!ctx)
570 return 0;
571 for (;;) {
572 if (i >= nr_ctx_fields) {
573 break;
574 }
575 ret = _lttng_field_statedump(session, ctx,
576 nr_ctx_fields, &i, 2);
577 if (ret) {
578 break;
579 }
580 }
581 return ret;
582 }
583
584 static
585 int _lttng_fields_metadata_statedump(struct ust_registry_session *session,
586 struct ust_registry_event *event)
587 {
588 int ret = 0;
589 size_t i = 0;
590
591 for (;;) {
592 if (i >= event->nr_fields) {
593 break;
594 }
595 ret = _lttng_field_statedump(session, event->fields,
596 event->nr_fields, &i, 2);
597 if (ret) {
598 break;
599 }
600 }
601 return ret;
602 }
603
604 /*
605 * Should be called with session registry mutex held.
606 */
607 int ust_metadata_event_statedump(struct ust_registry_session *session,
608 struct ust_registry_channel *chan,
609 struct ust_registry_event *event)
610 {
611 int ret = 0;
612
613 /* Don't dump metadata events */
614 if (chan->chan_id == -1U)
615 return 0;
616
617 ret = lttng_metadata_printf(session,
618 "event {\n"
619 " name = \"%s\";\n"
620 " id = %u;\n"
621 " stream_id = %u;\n",
622 event->name,
623 event->id,
624 chan->chan_id);
625 if (ret)
626 goto end;
627
628 ret = lttng_metadata_printf(session,
629 " loglevel = %d;\n",
630 event->loglevel_value);
631 if (ret)
632 goto end;
633
634 if (event->model_emf_uri) {
635 ret = lttng_metadata_printf(session,
636 " model.emf.uri = \"%s\";\n",
637 event->model_emf_uri);
638 if (ret)
639 goto end;
640 }
641
642 ret = lttng_metadata_printf(session,
643 " fields := struct {\n"
644 );
645 if (ret)
646 goto end;
647
648 ret = _lttng_fields_metadata_statedump(session, event);
649 if (ret)
650 goto end;
651
652 ret = lttng_metadata_printf(session,
653 " };\n"
654 "};\n\n");
655 if (ret)
656 goto end;
657 event->metadata_dumped = 1;
658
659 end:
660 return ret;
661 }
662
663 /*
664 * Should be called with session registry mutex held.
665 */
666 int ust_metadata_channel_statedump(struct ust_registry_session *session,
667 struct ust_registry_channel *chan)
668 {
669 int ret = 0;
670
671 /* Don't dump metadata events */
672 if (chan->chan_id == -1U)
673 return 0;
674
675 if (!chan->header_type)
676 return -EINVAL;
677
678 ret = lttng_metadata_printf(session,
679 "stream {\n"
680 " id = %u;\n"
681 " event.header := %s;\n"
682 " packet.context := struct packet_context;\n",
683 chan->chan_id,
684 chan->header_type == USTCTL_CHANNEL_HEADER_COMPACT ?
685 "struct event_header_compact" :
686 "struct event_header_large");
687 if (ret)
688 goto end;
689
690 if (chan->ctx_fields) {
691 ret = lttng_metadata_printf(session,
692 " event.context := struct {\n");
693 if (ret)
694 goto end;
695 }
696 ret = _lttng_context_metadata_statedump(session,
697 chan->nr_ctx_fields,
698 chan->ctx_fields);
699 if (ret)
700 goto end;
701 if (chan->ctx_fields) {
702 ret = lttng_metadata_printf(session,
703 " };\n");
704 if (ret)
705 goto end;
706 }
707
708 ret = lttng_metadata_printf(session,
709 "};\n\n");
710 /* Flag success of metadata dump. */
711 chan->metadata_dumped = 1;
712
713 end:
714 return ret;
715 }
716
717 static
718 int _lttng_stream_packet_context_declare(struct ust_registry_session *session)
719 {
720 return lttng_metadata_printf(session,
721 "struct packet_context {\n"
722 " uint64_clock_monotonic_t timestamp_begin;\n"
723 " uint64_clock_monotonic_t timestamp_end;\n"
724 " uint64_t content_size;\n"
725 " uint64_t packet_size;\n"
726 " uint64_t packet_seq_num;\n"
727 " unsigned long events_discarded;\n"
728 " uint32_t cpu_id;\n"
729 "};\n\n"
730 );
731 }
732
733 /*
734 * Compact header:
735 * id: range: 0 - 30.
736 * id 31 is reserved to indicate an extended header.
737 *
738 * Large header:
739 * id: range: 0 - 65534.
740 * id 65535 is reserved to indicate an extended header.
741 */
742 static
743 int _lttng_event_header_declare(struct ust_registry_session *session)
744 {
745 return lttng_metadata_printf(session,
746 "struct event_header_compact {\n"
747 " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
748 " variant <id> {\n"
749 " struct {\n"
750 " uint27_clock_monotonic_t timestamp;\n"
751 " } compact;\n"
752 " struct {\n"
753 " uint32_t id;\n"
754 " uint64_clock_monotonic_t timestamp;\n"
755 " } extended;\n"
756 " } v;\n"
757 "} align(%u);\n"
758 "\n"
759 "struct event_header_large {\n"
760 " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
761 " variant <id> {\n"
762 " struct {\n"
763 " uint32_clock_monotonic_t timestamp;\n"
764 " } compact;\n"
765 " struct {\n"
766 " uint32_t id;\n"
767 " uint64_clock_monotonic_t timestamp;\n"
768 " } extended;\n"
769 " } v;\n"
770 "} align(%u);\n\n",
771 session->uint32_t_alignment,
772 session->uint16_t_alignment
773 );
774 }
775
776 /*
777 * The offset between monotonic and realtime clock can be negative if
778 * the system sets the REALTIME clock to 0 after boot.
779 */
780 static
781 int measure_single_clock_offset(struct offset_sample *sample)
782 {
783 uint64_t monotonic_avg, monotonic[2], measure_delta, realtime;
784 uint64_t tcf = trace_clock_freq();
785 struct timespec rts = { 0, 0 };
786 int ret;
787
788 monotonic[0] = trace_clock_read64();
789 ret = clock_gettime(CLOCK_REALTIME, &rts);
790 if (ret < 0) {
791 return ret;
792 }
793 monotonic[1] = trace_clock_read64();
794 measure_delta = monotonic[1] - monotonic[0];
795 if (measure_delta > sample->measure_delta) {
796 /*
797 * Discard value if it took longer to read than the best
798 * sample so far.
799 */
800 return 0;
801 }
802 monotonic_avg = (monotonic[0] + monotonic[1]) >> 1;
803 realtime = (uint64_t) rts.tv_sec * tcf;
804 if (tcf == NSEC_PER_SEC) {
805 realtime += rts.tv_nsec;
806 } else {
807 realtime += (uint64_t) rts.tv_nsec * tcf / NSEC_PER_SEC;
808 }
809 sample->offset = (int64_t) realtime - monotonic_avg;
810 sample->measure_delta = measure_delta;
811 return 0;
812 }
813
814 /*
815 * Approximation of NTP time of day to clock monotonic correlation,
816 * taken at start of trace. Keep the measurement that took the less time
817 * to complete, thus removing imprecision caused by preemption.
818 * May return a negative offset.
819 */
820 static
821 int64_t measure_clock_offset(void)
822 {
823 int i;
824 struct offset_sample offset_best_sample = {
825 .offset = 0,
826 .measure_delta = UINT64_MAX,
827 };
828
829 for (i = 0; i < NR_CLOCK_OFFSET_SAMPLES; i++) {
830 if (measure_single_clock_offset(&offset_best_sample)) {
831 return 0;
832 }
833 }
834 return offset_best_sample.offset;
835 }
836
837 /*
838 * Should be called with session registry mutex held.
839 */
840 int ust_metadata_session_statedump(struct ust_registry_session *session,
841 struct ust_app *app,
842 uint32_t major,
843 uint32_t minor)
844 {
845 unsigned char *uuid_c;
846 char uuid_s[UUID_STR_LEN],
847 clock_uuid_s[UUID_STR_LEN];
848 int ret = 0;
849 char hostname[HOST_NAME_MAX];
850
851 assert(session);
852
853 uuid_c = session->uuid;
854
855 snprintf(uuid_s, sizeof(uuid_s),
856 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
857 uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
858 uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
859 uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
860 uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
861
862 /* For crash ABI */
863 ret = lttng_metadata_printf(session,
864 "/* CTF %u.%u */\n\n",
865 CTF_SPEC_MAJOR,
866 CTF_SPEC_MINOR);
867 if (ret) {
868 goto end;
869 }
870
871 ret = lttng_metadata_printf(session,
872 "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
873 "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
874 "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
875 "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
876 "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
877 "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
878 "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
879 "\n"
880 "trace {\n"
881 " major = %u;\n"
882 " minor = %u;\n"
883 " uuid = \"%s\";\n"
884 " byte_order = %s;\n"
885 " packet.header := struct {\n"
886 " uint32_t magic;\n"
887 " uint8_t uuid[16];\n"
888 " uint32_t stream_id;\n"
889 " uint64_t stream_instance_id;\n"
890 " };\n"
891 "};\n\n",
892 session->uint8_t_alignment,
893 session->uint16_t_alignment,
894 session->uint32_t_alignment,
895 session->uint64_t_alignment,
896 session->bits_per_long,
897 session->long_alignment,
898 CTF_SPEC_MAJOR,
899 CTF_SPEC_MINOR,
900 uuid_s,
901 session->byte_order == BIG_ENDIAN ? "be" : "le"
902 );
903 if (ret)
904 goto end;
905
906 /* ignore error, just use empty string if error. */
907 hostname[0] = '\0';
908 ret = gethostname(hostname, sizeof(hostname));
909 if (ret && errno == ENAMETOOLONG)
910 hostname[HOST_NAME_MAX - 1] = '\0';
911 ret = lttng_metadata_printf(session,
912 "env {\n"
913 " hostname = \"%s\";\n"
914 " domain = \"ust\";\n"
915 " tracer_name = \"lttng-ust\";\n"
916 " tracer_major = %u;\n"
917 " tracer_minor = %u;\n",
918 hostname,
919 major,
920 minor
921 );
922 if (ret)
923 goto end;
924
925 /*
926 * If per-application registry, we can output extra information
927 * about the application.
928 */
929 if (app) {
930 ret = lttng_metadata_printf(session,
931 " tracer_patchlevel = %u;\n"
932 " vpid = %d;\n"
933 " procname = \"%s\";\n",
934 app->version.patchlevel,
935 (int) app->pid,
936 app->name
937 );
938 if (ret)
939 goto end;
940 }
941
942 ret = lttng_metadata_printf(session,
943 "};\n\n"
944 );
945 if (ret)
946 goto end;
947
948
949 ret = lttng_metadata_printf(session,
950 "clock {\n"
951 " name = \"%s\";\n",
952 trace_clock_name()
953 );
954 if (ret)
955 goto end;
956
957 if (!trace_clock_uuid(clock_uuid_s)) {
958 ret = lttng_metadata_printf(session,
959 " uuid = \"%s\";\n",
960 clock_uuid_s
961 );
962 if (ret)
963 goto end;
964 }
965
966 ret = lttng_metadata_printf(session,
967 " description = \"%s\";\n"
968 " freq = %" PRIu64 "; /* Frequency, in Hz */\n"
969 " /* clock value offset from Epoch is: offset * (1/freq) */\n"
970 " offset = %" PRId64 ";\n"
971 "};\n\n",
972 trace_clock_description(),
973 trace_clock_freq(),
974 measure_clock_offset()
975 );
976 if (ret)
977 goto end;
978
979 ret = lttng_metadata_printf(session,
980 "typealias integer {\n"
981 " size = 27; align = 1; signed = false;\n"
982 " map = clock.%s.value;\n"
983 "} := uint27_clock_monotonic_t;\n"
984 "\n"
985 "typealias integer {\n"
986 " size = 32; align = %u; signed = false;\n"
987 " map = clock.%s.value;\n"
988 "} := uint32_clock_monotonic_t;\n"
989 "\n"
990 "typealias integer {\n"
991 " size = 64; align = %u; signed = false;\n"
992 " map = clock.%s.value;\n"
993 "} := uint64_clock_monotonic_t;\n\n",
994 trace_clock_name(),
995 session->uint32_t_alignment,
996 trace_clock_name(),
997 session->uint64_t_alignment,
998 trace_clock_name()
999 );
1000 if (ret)
1001 goto end;
1002
1003 ret = _lttng_stream_packet_context_declare(session);
1004 if (ret)
1005 goto end;
1006
1007 ret = _lttng_event_header_declare(session);
1008 if (ret)
1009 goto end;
1010
1011 end:
1012 return ret;
1013 }
LTTng 2.0 tools and control repository
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