Commit | Line | Data |
---|---|---|
8020ceb5 MD |
1 | /* |
2 | * ltt-events.c | |
3 | * | |
4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * Holds LTTng per-session event registry. | |
7 | * | |
8 | * Dual LGPL v2.1/GPL v2 license. | |
9 | */ | |
10 | ||
b5234c06 MD |
11 | #define _GNU_SOURCE |
12 | #include <stdio.h> | |
13 | #include <urcu/list.h> | |
14 | #include <pthread.h> | |
15 | #include <urcu-bp.h> | |
16 | #include <urcu/compiler.h> | |
17 | #include <urcu/uatomic.h> | |
18 | #include <uuid/uuid.h> | |
19 | #include <ust/tracepoint.h> | |
20 | #include <errno.h> | |
21 | #include "usterr_signal_safe.h" | |
22 | #include "ust/core.h" | |
8020ceb5 MD |
23 | #include "ltt-events.h" |
24 | #include "ltt-tracer.h" | |
b5234c06 | 25 | #include "ust/wait.h" |
8020ceb5 | 26 | |
b5234c06 MD |
27 | static CDS_LIST_HEAD(sessions); |
28 | static CDS_LIST_HEAD(ltt_transport_list); | |
8020ceb5 | 29 | static DEFINE_MUTEX(sessions_mutex); |
8020ceb5 MD |
30 | |
31 | static void _ltt_event_destroy(struct ltt_event *event); | |
32 | static void _ltt_channel_destroy(struct ltt_channel *chan); | |
33 | static int _ltt_event_unregister(struct ltt_event *event); | |
34 | static | |
35 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
36 | struct ltt_channel *chan, | |
37 | struct ltt_event *event); | |
38 | static | |
39 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
40 | ||
8020ceb5 MD |
41 | void synchronize_trace(void) |
42 | { | |
8020ceb5 | 43 | synchronize_rcu(); |
8020ceb5 MD |
44 | } |
45 | ||
46 | struct ltt_session *ltt_session_create(void) | |
47 | { | |
48 | struct ltt_session *session; | |
49 | ||
b5234c06 MD |
50 | pthread_mutex_lock(&sessions_mutex); |
51 | session = zmalloc(sizeof(struct ltt_session)); | |
8020ceb5 MD |
52 | if (!session) |
53 | return NULL; | |
b5234c06 MD |
54 | CDS_INIT_LIST_HEAD(&session->chan); |
55 | CDS_INIT_LIST_HEAD(&session->events); | |
56 | uuid_generate(session->uuid); | |
57 | cds_list_add(&session->list, &sessions); | |
58 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
59 | return session; |
60 | } | |
61 | ||
62 | void ltt_session_destroy(struct ltt_session *session) | |
63 | { | |
64 | struct ltt_channel *chan, *tmpchan; | |
65 | struct ltt_event *event, *tmpevent; | |
66 | int ret; | |
67 | ||
b5234c06 MD |
68 | pthread_mutex_lock(&sessions_mutex); |
69 | CMM_ACCESS_ONCE(session->active) = 0; | |
70 | cds_list_for_each_entry(event, &session->events, list) { | |
8020ceb5 MD |
71 | ret = _ltt_event_unregister(event); |
72 | WARN_ON(ret); | |
73 | } | |
74 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
b5234c06 | 75 | cds_list_for_each_entry_safe(event, tmpevent, &session->events, list) |
8020ceb5 | 76 | _ltt_event_destroy(event); |
b5234c06 | 77 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list) |
8020ceb5 | 78 | _ltt_channel_destroy(chan); |
b5234c06 MD |
79 | cds_list_del(&session->list); |
80 | pthread_mutex_unlock(&sessions_mutex); | |
81 | free(session); | |
8020ceb5 MD |
82 | } |
83 | ||
976fe9ea | 84 | int ltt_session_enable(struct ltt_session *session) |
8020ceb5 MD |
85 | { |
86 | int ret = 0; | |
87 | struct ltt_channel *chan; | |
88 | ||
b5234c06 | 89 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
90 | if (session->active) { |
91 | ret = -EBUSY; | |
92 | goto end; | |
93 | } | |
94 | ||
95 | /* | |
96 | * Snapshot the number of events per channel to know the type of header | |
97 | * we need to use. | |
98 | */ | |
b5234c06 | 99 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
100 | if (chan->header_type) |
101 | continue; /* don't change it if session stop/restart */ | |
102 | if (chan->free_event_id < 31) | |
103 | chan->header_type = 1; /* compact */ | |
104 | else | |
105 | chan->header_type = 2; /* large */ | |
106 | } | |
107 | ||
b5234c06 MD |
108 | CMM_ACCESS_ONCE(session->active) = 1; |
109 | CMM_ACCESS_ONCE(session->been_active) = 1; | |
8020ceb5 | 110 | ret = _ltt_session_metadata_statedump(session); |
4b4de73e | 111 | if (ret) |
b5234c06 | 112 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 113 | end: |
b5234c06 | 114 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
115 | return ret; |
116 | } | |
117 | ||
976fe9ea | 118 | int ltt_session_disable(struct ltt_session *session) |
8020ceb5 MD |
119 | { |
120 | int ret = 0; | |
121 | ||
b5234c06 | 122 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
123 | if (!session->active) { |
124 | ret = -EBUSY; | |
125 | goto end; | |
126 | } | |
b5234c06 | 127 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 128 | end: |
b5234c06 | 129 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
130 | return ret; |
131 | } | |
132 | ||
976fe9ea MD |
133 | int ltt_channel_enable(struct ltt_channel *channel) |
134 | { | |
135 | int old; | |
136 | ||
9beb36ba MD |
137 | if (channel == channel->session->metadata) |
138 | return -EPERM; | |
b5234c06 | 139 | old = uatomic_xchg(&channel->enabled, 1); |
976fe9ea MD |
140 | if (old) |
141 | return -EEXIST; | |
142 | return 0; | |
143 | } | |
144 | ||
145 | int ltt_channel_disable(struct ltt_channel *channel) | |
146 | { | |
147 | int old; | |
148 | ||
9beb36ba MD |
149 | if (channel == channel->session->metadata) |
150 | return -EPERM; | |
b5234c06 | 151 | old = uatomic_xchg(&channel->enabled, 0); |
976fe9ea MD |
152 | if (!old) |
153 | return -EEXIST; | |
154 | return 0; | |
155 | } | |
156 | ||
157 | int ltt_event_enable(struct ltt_event *event) | |
158 | { | |
159 | int old; | |
160 | ||
9beb36ba MD |
161 | if (event->chan == event->chan->session->metadata) |
162 | return -EPERM; | |
b5234c06 | 163 | old = uatomic_xchg(&event->enabled, 1); |
976fe9ea MD |
164 | if (old) |
165 | return -EEXIST; | |
166 | return 0; | |
167 | } | |
168 | ||
169 | int ltt_event_disable(struct ltt_event *event) | |
170 | { | |
171 | int old; | |
172 | ||
9beb36ba MD |
173 | if (event->chan == event->chan->session->metadata) |
174 | return -EPERM; | |
b5234c06 | 175 | old = uatomic_xchg(&event->enabled, 0); |
976fe9ea MD |
176 | if (!old) |
177 | return -EEXIST; | |
178 | return 0; | |
179 | } | |
180 | ||
8020ceb5 MD |
181 | static struct ltt_transport *ltt_transport_find(const char *name) |
182 | { | |
183 | struct ltt_transport *transport; | |
184 | ||
b5234c06 | 185 | cds_list_for_each_entry(transport, <t_transport_list, node) { |
8020ceb5 MD |
186 | if (!strcmp(transport->name, name)) |
187 | return transport; | |
188 | } | |
189 | return NULL; | |
190 | } | |
191 | ||
192 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, | |
193 | const char *transport_name, | |
194 | void *buf_addr, | |
195 | size_t subbuf_size, size_t num_subbuf, | |
196 | unsigned int switch_timer_interval, | |
b5234c06 MD |
197 | unsigned int read_timer_interval, |
198 | int *shmid) | |
8020ceb5 MD |
199 | { |
200 | struct ltt_channel *chan; | |
201 | struct ltt_transport *transport; | |
202 | ||
b5234c06 | 203 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
204 | if (session->been_active) |
205 | goto active; /* Refuse to add channel to active session */ | |
206 | transport = ltt_transport_find(transport_name); | |
207 | if (!transport) { | |
b5234c06 | 208 | DBG("LTTng transport %s not found\n", |
8020ceb5 MD |
209 | transport_name); |
210 | goto notransport; | |
211 | } | |
b5234c06 | 212 | chan = zmalloc(sizeof(struct ltt_channel)); |
8020ceb5 MD |
213 | if (!chan) |
214 | goto nomem; | |
215 | chan->session = session; | |
216 | chan->id = session->free_chan_id++; | |
217 | /* | |
218 | * Note: the channel creation op already writes into the packet | |
219 | * headers. Therefore the "chan" information used as input | |
220 | * should be already accessible. | |
221 | */ | |
222 | chan->chan = transport->ops.channel_create("[lttng]", chan, buf_addr, | |
223 | subbuf_size, num_subbuf, switch_timer_interval, | |
b5234c06 | 224 | read_timer_interval, shmid); |
8020ceb5 MD |
225 | if (!chan->chan) |
226 | goto create_error; | |
976fe9ea | 227 | chan->enabled = 1; |
8020ceb5 | 228 | chan->ops = &transport->ops; |
b5234c06 MD |
229 | cds_list_add(&chan->list, &session->chan); |
230 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
231 | return chan; |
232 | ||
233 | create_error: | |
b5234c06 | 234 | free(chan); |
8020ceb5 MD |
235 | nomem: |
236 | notransport: | |
237 | active: | |
b5234c06 | 238 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
239 | return NULL; |
240 | } | |
241 | ||
242 | /* | |
243 | * Only used internally at session destruction. | |
244 | */ | |
245 | static | |
246 | void _ltt_channel_destroy(struct ltt_channel *chan) | |
247 | { | |
248 | chan->ops->channel_destroy(chan->chan); | |
b5234c06 | 249 | cds_list_del(&chan->list); |
8020ceb5 | 250 | lttng_destroy_context(chan->ctx); |
b5234c06 | 251 | free(chan); |
8020ceb5 MD |
252 | } |
253 | ||
254 | /* | |
255 | * Supports event creation while tracing session is active. | |
256 | */ | |
257 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, | |
b5234c06 | 258 | struct lttng_ust_event *event_param, |
8020ceb5 MD |
259 | void *filter) |
260 | { | |
261 | struct ltt_event *event; | |
262 | int ret; | |
263 | ||
b5234c06 | 264 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
265 | if (chan->free_event_id == -1UL) |
266 | goto full; | |
267 | /* | |
268 | * This is O(n^2) (for each event, the loop is called at event | |
269 | * creation). Might require a hash if we have lots of events. | |
270 | */ | |
b5234c06 | 271 | cds_list_for_each_entry(event, &chan->session->events, list) |
8020ceb5 MD |
272 | if (!strcmp(event->desc->name, event_param->name)) |
273 | goto exist; | |
b5234c06 | 274 | event = zmalloc(sizeof(struct ltt_event)); |
8020ceb5 MD |
275 | if (!event) |
276 | goto cache_error; | |
277 | event->chan = chan; | |
278 | event->filter = filter; | |
279 | event->id = chan->free_event_id++; | |
976fe9ea | 280 | event->enabled = 1; |
8020ceb5 MD |
281 | event->instrumentation = event_param->instrumentation; |
282 | /* Populate ltt_event structure before tracepoint registration. */ | |
b5234c06 | 283 | cmm_smp_wmb(); |
8020ceb5 | 284 | switch (event_param->instrumentation) { |
b5234c06 | 285 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 MD |
286 | event->desc = ltt_event_get(event_param->name); |
287 | if (!event->desc) | |
288 | goto register_error; | |
b5234c06 | 289 | ret = __tracepoint_probe_register(event_param->name, |
8020ceb5 MD |
290 | event->desc->probe_callback, |
291 | event); | |
292 | if (ret) | |
293 | goto register_error; | |
294 | break; | |
8020ceb5 MD |
295 | default: |
296 | WARN_ON_ONCE(1); | |
297 | } | |
298 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); | |
299 | if (ret) | |
300 | goto statedump_error; | |
b5234c06 MD |
301 | cds_list_add(&event->list, &chan->session->events); |
302 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
303 | return event; |
304 | ||
305 | statedump_error: | |
b5234c06 | 306 | WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name, |
8020ceb5 MD |
307 | event->desc->probe_callback, |
308 | event)); | |
309 | ltt_event_put(event->desc); | |
310 | register_error: | |
b5234c06 | 311 | free(event); |
8020ceb5 MD |
312 | cache_error: |
313 | exist: | |
314 | full: | |
b5234c06 | 315 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
316 | return NULL; |
317 | } | |
318 | ||
319 | /* | |
320 | * Only used internally at session destruction. | |
321 | */ | |
322 | int _ltt_event_unregister(struct ltt_event *event) | |
323 | { | |
324 | int ret = -EINVAL; | |
325 | ||
326 | switch (event->instrumentation) { | |
b5234c06 MD |
327 | case LTTNG_UST_TRACEPOINT: |
328 | ret = __tracepoint_probe_unregister(event->desc->name, | |
8020ceb5 MD |
329 | event->desc->probe_callback, |
330 | event); | |
331 | if (ret) | |
332 | return ret; | |
333 | break; | |
8020ceb5 MD |
334 | default: |
335 | WARN_ON_ONCE(1); | |
336 | } | |
337 | return ret; | |
338 | } | |
339 | ||
340 | /* | |
341 | * Only used internally at session destruction. | |
342 | */ | |
343 | static | |
344 | void _ltt_event_destroy(struct ltt_event *event) | |
345 | { | |
346 | switch (event->instrumentation) { | |
b5234c06 | 347 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 MD |
348 | ltt_event_put(event->desc); |
349 | break; | |
8020ceb5 MD |
350 | default: |
351 | WARN_ON_ONCE(1); | |
352 | } | |
b5234c06 | 353 | cds_list_del(&event->list); |
8020ceb5 | 354 | lttng_destroy_context(event->ctx); |
b5234c06 | 355 | free(event); |
8020ceb5 MD |
356 | } |
357 | ||
358 | /* | |
359 | * We have exclusive access to our metadata buffer (protected by the | |
360 | * sessions_mutex), so we can do racy operations such as looking for | |
361 | * remaining space left in packet and write, since mutual exclusion | |
362 | * protects us from concurrent writes. | |
363 | */ | |
364 | int lttng_metadata_printf(struct ltt_session *session, | |
365 | const char *fmt, ...) | |
366 | { | |
367 | struct lib_ring_buffer_ctx ctx; | |
368 | struct ltt_channel *chan = session->metadata; | |
b5234c06 | 369 | char *str = NULL; |
8020ceb5 MD |
370 | int ret = 0, waitret; |
371 | size_t len, reserve_len, pos; | |
372 | va_list ap; | |
373 | ||
b5234c06 | 374 | WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active)); |
8020ceb5 MD |
375 | |
376 | va_start(ap, fmt); | |
b5234c06 | 377 | ret = vasprintf(&str, fmt, ap); |
8020ceb5 | 378 | va_end(ap); |
b5234c06 | 379 | if (ret < 0) |
8020ceb5 MD |
380 | return -ENOMEM; |
381 | ||
382 | len = strlen(str); | |
383 | pos = 0; | |
384 | ||
385 | for (pos = 0; pos < len; pos += reserve_len) { | |
386 | reserve_len = min_t(size_t, | |
387 | chan->ops->packet_avail_size(chan->chan), | |
388 | len - pos); | |
389 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
390 | sizeof(char), -1); | |
391 | /* | |
392 | * We don't care about metadata buffer's records lost | |
393 | * count, because we always retry here. Report error if | |
394 | * we need to bail out after timeout or being | |
395 | * interrupted. | |
396 | */ | |
b5234c06 | 397 | waitret = wait_cond_interruptible_timeout( |
8020ceb5 MD |
398 | ({ |
399 | ret = chan->ops->event_reserve(&ctx, 0); | |
400 | ret != -ENOBUFS || !ret; | |
401 | }), | |
b5234c06 MD |
402 | LTTNG_METADATA_TIMEOUT_MSEC); |
403 | if (!waitret || waitret == -EINTR || ret) { | |
404 | DBG("LTTng: Failure to write metadata to buffers (%s)\n", | |
405 | waitret == -EINTR ? "interrupted" : | |
8020ceb5 | 406 | (ret == -ENOBUFS ? "timeout" : "I/O error")); |
b5234c06 | 407 | if (waitret == -EINTR) |
8020ceb5 MD |
408 | ret = waitret; |
409 | goto end; | |
410 | } | |
411 | chan->ops->event_write(&ctx, &str[pos], reserve_len); | |
412 | chan->ops->event_commit(&ctx); | |
413 | } | |
414 | end: | |
b5234c06 | 415 | free(str); |
8020ceb5 MD |
416 | return ret; |
417 | } | |
418 | ||
419 | static | |
420 | int _ltt_field_statedump(struct ltt_session *session, | |
421 | const struct lttng_event_field *field) | |
422 | { | |
423 | int ret = 0; | |
424 | ||
425 | switch (field->type.atype) { | |
426 | case atype_integer: | |
427 | ret = lttng_metadata_printf(session, | |
428 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n", | |
429 | field->type.u.basic.integer.size, | |
430 | field->type.u.basic.integer.alignment, | |
431 | field->type.u.basic.integer.signedness, | |
432 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
433 | ? "none" | |
434 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
435 | ? "UTF8" | |
436 | : "ASCII", | |
437 | field->type.u.basic.integer.base, | |
403c40b4 MD |
438 | #ifdef __BIG_ENDIAN |
439 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
440 | #else | |
441 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
442 | #endif | |
443 | field->name); | |
444 | break; | |
445 | case atype_float: | |
446 | ret = lttng_metadata_printf(session, | |
447 | " floating_point { exp_dig = %u; mant_dig = %u; align = %u; } %s;\n", | |
448 | field->type.u.basic._float.exp_dig, | |
449 | field->type.u.basic._float.mant_dig, | |
450 | field->type.u.basic._float.alignment, | |
451 | #ifdef __BIG_ENDIAN | |
8020ceb5 MD |
452 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
453 | #else | |
454 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
455 | #endif | |
456 | field->name); | |
457 | break; | |
458 | case atype_enum: | |
459 | ret = lttng_metadata_printf(session, | |
460 | " %s %s;\n", | |
461 | field->type.u.basic.enumeration.name, | |
462 | field->name); | |
463 | break; | |
464 | case atype_array: | |
465 | { | |
466 | const struct lttng_basic_type *elem_type; | |
467 | ||
468 | elem_type = &field->type.u.array.elem_type; | |
469 | ret = lttng_metadata_printf(session, | |
470 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n", | |
471 | elem_type->u.basic.integer.size, | |
472 | elem_type->u.basic.integer.alignment, | |
473 | elem_type->u.basic.integer.signedness, | |
474 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
475 | ? "none" | |
476 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
477 | ? "UTF8" | |
478 | : "ASCII", | |
479 | elem_type->u.basic.integer.base, | |
403c40b4 | 480 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
481 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
482 | #else | |
483 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
484 | #endif | |
485 | field->name, field->type.u.array.length); | |
486 | break; | |
487 | } | |
488 | case atype_sequence: | |
489 | { | |
490 | const struct lttng_basic_type *elem_type; | |
491 | const struct lttng_basic_type *length_type; | |
492 | ||
493 | elem_type = &field->type.u.sequence.elem_type; | |
494 | length_type = &field->type.u.sequence.length_type; | |
495 | ret = lttng_metadata_printf(session, | |
496 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
497 | length_type->u.basic.integer.size, | |
498 | (unsigned int) length_type->u.basic.integer.alignment, | |
499 | length_type->u.basic.integer.signedness, | |
500 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
501 | ? "none" | |
502 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
503 | ? "UTF8" | |
504 | : "ASCII"), | |
505 | length_type->u.basic.integer.base, | |
403c40b4 | 506 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
507 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
508 | #else | |
509 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
510 | #endif | |
511 | field->name); | |
512 | if (ret) | |
513 | return ret; | |
514 | ||
515 | ret = lttng_metadata_printf(session, | |
516 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n", | |
517 | elem_type->u.basic.integer.size, | |
518 | (unsigned int) elem_type->u.basic.integer.alignment, | |
519 | elem_type->u.basic.integer.signedness, | |
520 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
521 | ? "none" | |
522 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
523 | ? "UTF8" | |
524 | : "ASCII"), | |
525 | elem_type->u.basic.integer.base, | |
403c40b4 | 526 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
527 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
528 | #else | |
529 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
530 | #endif | |
531 | field->name, | |
532 | field->name); | |
533 | break; | |
534 | } | |
535 | ||
536 | case atype_string: | |
537 | /* Default encoding is UTF8 */ | |
538 | ret = lttng_metadata_printf(session, | |
539 | " string%s %s;\n", | |
540 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
541 | " { encoding = ASCII; }" : "", | |
542 | field->name); | |
543 | break; | |
544 | default: | |
545 | WARN_ON_ONCE(1); | |
546 | return -EINVAL; | |
547 | } | |
548 | return ret; | |
549 | } | |
550 | ||
551 | static | |
552 | int _ltt_context_metadata_statedump(struct ltt_session *session, | |
553 | struct lttng_ctx *ctx) | |
554 | { | |
555 | int ret = 0; | |
556 | int i; | |
557 | ||
558 | if (!ctx) | |
559 | return 0; | |
560 | for (i = 0; i < ctx->nr_fields; i++) { | |
561 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
562 | ||
563 | ret = _ltt_field_statedump(session, &field->event_field); | |
564 | if (ret) | |
565 | return ret; | |
566 | } | |
567 | return ret; | |
568 | } | |
569 | ||
570 | static | |
571 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
572 | struct ltt_event *event) | |
573 | { | |
574 | const struct lttng_event_desc *desc = event->desc; | |
575 | int ret = 0; | |
576 | int i; | |
577 | ||
578 | for (i = 0; i < desc->nr_fields; i++) { | |
579 | const struct lttng_event_field *field = &desc->fields[i]; | |
580 | ||
581 | ret = _ltt_field_statedump(session, field); | |
582 | if (ret) | |
583 | return ret; | |
584 | } | |
585 | return ret; | |
586 | } | |
587 | ||
588 | static | |
589 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
590 | struct ltt_channel *chan, | |
591 | struct ltt_event *event) | |
592 | { | |
593 | int ret = 0; | |
594 | ||
b5234c06 | 595 | if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
596 | return 0; |
597 | if (chan == session->metadata) | |
598 | return 0; | |
599 | ||
600 | ret = lttng_metadata_printf(session, | |
601 | "event {\n" | |
602 | " name = %s;\n" | |
603 | " id = %u;\n" | |
604 | " stream_id = %u;\n", | |
605 | event->desc->name, | |
606 | event->id, | |
607 | event->chan->id); | |
608 | if (ret) | |
609 | goto end; | |
610 | ||
611 | if (event->ctx) { | |
612 | ret = lttng_metadata_printf(session, | |
613 | " context := struct {\n"); | |
614 | if (ret) | |
615 | goto end; | |
616 | } | |
617 | ret = _ltt_context_metadata_statedump(session, event->ctx); | |
618 | if (ret) | |
619 | goto end; | |
620 | if (event->ctx) { | |
621 | ret = lttng_metadata_printf(session, | |
622 | " };\n"); | |
623 | if (ret) | |
624 | goto end; | |
625 | } | |
626 | ||
627 | ret = lttng_metadata_printf(session, | |
628 | " fields := struct {\n" | |
629 | ); | |
630 | if (ret) | |
631 | goto end; | |
632 | ||
633 | ret = _ltt_fields_metadata_statedump(session, event); | |
634 | if (ret) | |
635 | goto end; | |
636 | ||
637 | /* | |
638 | * LTTng space reservation can only reserve multiples of the | |
639 | * byte size. | |
640 | */ | |
641 | ret = lttng_metadata_printf(session, | |
642 | " };\n" | |
643 | "};\n\n"); | |
644 | if (ret) | |
645 | goto end; | |
646 | ||
647 | event->metadata_dumped = 1; | |
648 | end: | |
649 | return ret; | |
650 | ||
651 | } | |
652 | ||
653 | static | |
654 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
655 | struct ltt_channel *chan) | |
656 | { | |
657 | int ret = 0; | |
658 | ||
b5234c06 | 659 | if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
660 | return 0; |
661 | if (chan == session->metadata) | |
662 | return 0; | |
663 | ||
664 | WARN_ON_ONCE(!chan->header_type); | |
665 | ret = lttng_metadata_printf(session, | |
666 | "stream {\n" | |
667 | " id = %u;\n" | |
668 | " event.header := %s;\n" | |
669 | " packet.context := struct packet_context;\n", | |
670 | chan->id, | |
671 | chan->header_type == 1 ? "struct event_header_compact" : | |
672 | "struct event_header_large"); | |
673 | if (ret) | |
674 | goto end; | |
675 | ||
676 | if (chan->ctx) { | |
677 | ret = lttng_metadata_printf(session, | |
678 | " event.context := struct {\n"); | |
679 | if (ret) | |
680 | goto end; | |
681 | } | |
682 | ret = _ltt_context_metadata_statedump(session, chan->ctx); | |
683 | if (ret) | |
684 | goto end; | |
685 | if (chan->ctx) { | |
686 | ret = lttng_metadata_printf(session, | |
687 | " };\n"); | |
688 | if (ret) | |
689 | goto end; | |
690 | } | |
691 | ||
692 | ret = lttng_metadata_printf(session, | |
693 | "};\n\n"); | |
694 | ||
695 | chan->metadata_dumped = 1; | |
696 | end: | |
697 | return ret; | |
698 | } | |
699 | ||
700 | static | |
701 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
702 | { | |
703 | return lttng_metadata_printf(session, | |
704 | "struct packet_context {\n" | |
705 | " uint64_t timestamp_begin;\n" | |
706 | " uint64_t timestamp_end;\n" | |
707 | " uint32_t events_discarded;\n" | |
708 | " uint32_t content_size;\n" | |
709 | " uint32_t packet_size;\n" | |
710 | " uint32_t cpu_id;\n" | |
711 | "};\n\n" | |
712 | ); | |
713 | } | |
714 | ||
715 | /* | |
716 | * Compact header: | |
717 | * id: range: 0 - 30. | |
718 | * id 31 is reserved to indicate an extended header. | |
719 | * | |
720 | * Large header: | |
721 | * id: range: 0 - 65534. | |
722 | * id 65535 is reserved to indicate an extended header. | |
723 | */ | |
724 | static | |
725 | int _ltt_event_header_declare(struct ltt_session *session) | |
726 | { | |
727 | return lttng_metadata_printf(session, | |
728 | "struct event_header_compact {\n" | |
729 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
730 | " variant <id> {\n" | |
731 | " struct {\n" | |
732 | " uint27_t timestamp;\n" | |
733 | " } compact;\n" | |
734 | " struct {\n" | |
735 | " uint32_t id;\n" | |
736 | " uint64_t timestamp;\n" | |
737 | " } extended;\n" | |
738 | " } v;\n" | |
739 | "} align(%u);\n" | |
740 | "\n" | |
741 | "struct event_header_large {\n" | |
742 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
743 | " variant <id> {\n" | |
744 | " struct {\n" | |
745 | " uint32_t timestamp;\n" | |
746 | " } compact;\n" | |
747 | " struct {\n" | |
748 | " uint32_t id;\n" | |
749 | " uint64_t timestamp;\n" | |
750 | " } extended;\n" | |
751 | " } v;\n" | |
752 | "} align(%u);\n\n", | |
753 | ltt_alignof(uint32_t) * CHAR_BIT, | |
754 | ltt_alignof(uint16_t) * CHAR_BIT | |
755 | ); | |
756 | } | |
757 | ||
758 | /* | |
759 | * Output metadata into this session's metadata buffers. | |
760 | */ | |
761 | static | |
762 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
763 | { | |
b5234c06 MD |
764 | unsigned char *uuid_c = session->uuid; |
765 | char uuid_s[37]; | |
8020ceb5 MD |
766 | struct ltt_channel *chan; |
767 | struct ltt_event *event; | |
768 | int ret = 0; | |
769 | ||
b5234c06 | 770 | if (!CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
771 | return 0; |
772 | if (session->metadata_dumped) | |
773 | goto skip_session; | |
774 | if (!session->metadata) { | |
b5234c06 | 775 | DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
8020ceb5 MD |
776 | return -EPERM; |
777 | } | |
778 | ||
779 | snprintf(uuid_s, sizeof(uuid_s), | |
780 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", | |
781 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
782 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
783 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
784 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
785 | ||
786 | ret = lttng_metadata_printf(session, | |
787 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" | |
788 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
789 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
790 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
791 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
792 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
793 | "\n" | |
794 | "trace {\n" | |
795 | " major = %u;\n" | |
796 | " minor = %u;\n" | |
797 | " uuid = \"%s\";\n" | |
798 | " byte_order = %s;\n" | |
799 | " packet.header := struct {\n" | |
800 | " uint32_t magic;\n" | |
801 | " uint8_t uuid[16];\n" | |
802 | " uint32_t stream_id;\n" | |
803 | " };\n" | |
804 | "};\n\n", | |
805 | ltt_alignof(uint8_t) * CHAR_BIT, | |
806 | ltt_alignof(uint16_t) * CHAR_BIT, | |
807 | ltt_alignof(uint32_t) * CHAR_BIT, | |
808 | ltt_alignof(uint64_t) * CHAR_BIT, | |
809 | CTF_VERSION_MAJOR, | |
810 | CTF_VERSION_MINOR, | |
811 | uuid_s, | |
403c40b4 | 812 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
813 | "be" |
814 | #else | |
815 | "le" | |
816 | #endif | |
817 | ); | |
818 | if (ret) | |
819 | goto end; | |
820 | ||
821 | ret = _ltt_stream_packet_context_declare(session); | |
822 | if (ret) | |
823 | goto end; | |
824 | ||
825 | ret = _ltt_event_header_declare(session); | |
826 | if (ret) | |
827 | goto end; | |
828 | ||
829 | skip_session: | |
b5234c06 | 830 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
831 | ret = _ltt_channel_metadata_statedump(session, chan); |
832 | if (ret) | |
833 | goto end; | |
834 | } | |
835 | ||
b5234c06 | 836 | cds_list_for_each_entry(event, &session->events, list) { |
8020ceb5 MD |
837 | ret = _ltt_event_metadata_statedump(session, event->chan, event); |
838 | if (ret) | |
839 | goto end; | |
840 | } | |
841 | session->metadata_dumped = 1; | |
842 | end: | |
843 | return ret; | |
844 | } | |
845 | ||
846 | /** | |
847 | * ltt_transport_register - LTT transport registration | |
848 | * @transport: transport structure | |
849 | * | |
850 | * Registers a transport which can be used as output to extract the data out of | |
b5234c06 | 851 | * LTTng. |
8020ceb5 MD |
852 | */ |
853 | void ltt_transport_register(struct ltt_transport *transport) | |
854 | { | |
b5234c06 MD |
855 | pthread_mutex_lock(&sessions_mutex); |
856 | cds_list_add_tail(&transport->node, <t_transport_list); | |
857 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 | 858 | } |
8020ceb5 MD |
859 | |
860 | /** | |
861 | * ltt_transport_unregister - LTT transport unregistration | |
862 | * @transport: transport structure | |
863 | */ | |
864 | void ltt_transport_unregister(struct ltt_transport *transport) | |
865 | { | |
b5234c06 MD |
866 | pthread_mutex_lock(&sessions_mutex); |
867 | cds_list_del(&transport->node); | |
868 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
869 | } |
870 | ||
b5234c06 MD |
871 | static |
872 | void __attribute__((destructor)) ltt_events_exit(void) | |
8020ceb5 MD |
873 | { |
874 | struct ltt_session *session, *tmpsession; | |
875 | ||
b5234c06 | 876 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, list) |
8020ceb5 | 877 | ltt_session_destroy(session); |
8020ceb5 | 878 | } |