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> | |
f4681817 MD |
21 | #include <sys/shm.h> |
22 | #include <sys/ipc.h> | |
23 | #include <ust/lttng-events.h> | |
1dbfff0c | 24 | #include <ust/usterr-signal-safe.h> |
b5234c06 | 25 | #include "ust/core.h" |
8020ceb5 | 26 | #include "ltt-tracer.h" |
b5234c06 | 27 | #include "ust/wait.h" |
8d8a24c8 | 28 | #include "../libringbuffer/shm.h" |
8020ceb5 | 29 | |
b5234c06 MD |
30 | static CDS_LIST_HEAD(sessions); |
31 | static CDS_LIST_HEAD(ltt_transport_list); | |
8020ceb5 | 32 | static DEFINE_MUTEX(sessions_mutex); |
8020ceb5 MD |
33 | |
34 | static void _ltt_event_destroy(struct ltt_event *event); | |
35 | static void _ltt_channel_destroy(struct ltt_channel *chan); | |
36 | static int _ltt_event_unregister(struct ltt_event *event); | |
37 | static | |
38 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
39 | struct ltt_channel *chan, | |
40 | struct ltt_event *event); | |
41 | static | |
42 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
43 | ||
8020ceb5 MD |
44 | void synchronize_trace(void) |
45 | { | |
8020ceb5 | 46 | synchronize_rcu(); |
8020ceb5 MD |
47 | } |
48 | ||
49 | struct ltt_session *ltt_session_create(void) | |
50 | { | |
51 | struct ltt_session *session; | |
52 | ||
b5234c06 MD |
53 | pthread_mutex_lock(&sessions_mutex); |
54 | session = zmalloc(sizeof(struct ltt_session)); | |
8020ceb5 MD |
55 | if (!session) |
56 | return NULL; | |
b5234c06 MD |
57 | CDS_INIT_LIST_HEAD(&session->chan); |
58 | CDS_INIT_LIST_HEAD(&session->events); | |
59 | uuid_generate(session->uuid); | |
60 | cds_list_add(&session->list, &sessions); | |
61 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
62 | return session; |
63 | } | |
64 | ||
65 | void ltt_session_destroy(struct ltt_session *session) | |
66 | { | |
67 | struct ltt_channel *chan, *tmpchan; | |
68 | struct ltt_event *event, *tmpevent; | |
69 | int ret; | |
70 | ||
b5234c06 MD |
71 | pthread_mutex_lock(&sessions_mutex); |
72 | CMM_ACCESS_ONCE(session->active) = 0; | |
73 | cds_list_for_each_entry(event, &session->events, list) { | |
8020ceb5 MD |
74 | ret = _ltt_event_unregister(event); |
75 | WARN_ON(ret); | |
76 | } | |
77 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
b5234c06 | 78 | cds_list_for_each_entry_safe(event, tmpevent, &session->events, list) |
8020ceb5 | 79 | _ltt_event_destroy(event); |
b5234c06 | 80 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list) |
8020ceb5 | 81 | _ltt_channel_destroy(chan); |
b5234c06 MD |
82 | cds_list_del(&session->list); |
83 | pthread_mutex_unlock(&sessions_mutex); | |
84 | free(session); | |
8020ceb5 MD |
85 | } |
86 | ||
976fe9ea | 87 | int ltt_session_enable(struct ltt_session *session) |
8020ceb5 MD |
88 | { |
89 | int ret = 0; | |
90 | struct ltt_channel *chan; | |
91 | ||
b5234c06 | 92 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
93 | if (session->active) { |
94 | ret = -EBUSY; | |
95 | goto end; | |
96 | } | |
97 | ||
98 | /* | |
99 | * Snapshot the number of events per channel to know the type of header | |
100 | * we need to use. | |
101 | */ | |
b5234c06 | 102 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
103 | if (chan->header_type) |
104 | continue; /* don't change it if session stop/restart */ | |
105 | if (chan->free_event_id < 31) | |
106 | chan->header_type = 1; /* compact */ | |
107 | else | |
108 | chan->header_type = 2; /* large */ | |
109 | } | |
110 | ||
b5234c06 MD |
111 | CMM_ACCESS_ONCE(session->active) = 1; |
112 | CMM_ACCESS_ONCE(session->been_active) = 1; | |
8020ceb5 | 113 | ret = _ltt_session_metadata_statedump(session); |
4b4de73e | 114 | if (ret) |
b5234c06 | 115 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 116 | end: |
b5234c06 | 117 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
118 | return ret; |
119 | } | |
120 | ||
976fe9ea | 121 | int ltt_session_disable(struct ltt_session *session) |
8020ceb5 MD |
122 | { |
123 | int ret = 0; | |
124 | ||
b5234c06 | 125 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
126 | if (!session->active) { |
127 | ret = -EBUSY; | |
128 | goto end; | |
129 | } | |
b5234c06 | 130 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 131 | end: |
b5234c06 | 132 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
133 | return ret; |
134 | } | |
135 | ||
976fe9ea MD |
136 | int ltt_channel_enable(struct ltt_channel *channel) |
137 | { | |
138 | int old; | |
139 | ||
9beb36ba MD |
140 | if (channel == channel->session->metadata) |
141 | return -EPERM; | |
b5234c06 | 142 | old = uatomic_xchg(&channel->enabled, 1); |
976fe9ea MD |
143 | if (old) |
144 | return -EEXIST; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | int ltt_channel_disable(struct ltt_channel *channel) | |
149 | { | |
150 | int old; | |
151 | ||
9beb36ba MD |
152 | if (channel == channel->session->metadata) |
153 | return -EPERM; | |
b5234c06 | 154 | old = uatomic_xchg(&channel->enabled, 0); |
976fe9ea MD |
155 | if (!old) |
156 | return -EEXIST; | |
157 | return 0; | |
158 | } | |
159 | ||
160 | int ltt_event_enable(struct ltt_event *event) | |
161 | { | |
162 | int old; | |
163 | ||
9beb36ba MD |
164 | if (event->chan == event->chan->session->metadata) |
165 | return -EPERM; | |
b5234c06 | 166 | old = uatomic_xchg(&event->enabled, 1); |
976fe9ea MD |
167 | if (old) |
168 | return -EEXIST; | |
169 | return 0; | |
170 | } | |
171 | ||
172 | int ltt_event_disable(struct ltt_event *event) | |
173 | { | |
174 | int old; | |
175 | ||
9beb36ba MD |
176 | if (event->chan == event->chan->session->metadata) |
177 | return -EPERM; | |
b5234c06 | 178 | old = uatomic_xchg(&event->enabled, 0); |
976fe9ea MD |
179 | if (!old) |
180 | return -EEXIST; | |
181 | return 0; | |
182 | } | |
183 | ||
8020ceb5 MD |
184 | static struct ltt_transport *ltt_transport_find(const char *name) |
185 | { | |
186 | struct ltt_transport *transport; | |
187 | ||
b5234c06 | 188 | cds_list_for_each_entry(transport, <t_transport_list, node) { |
8020ceb5 MD |
189 | if (!strcmp(transport->name, name)) |
190 | return transport; | |
191 | } | |
192 | return NULL; | |
193 | } | |
194 | ||
195 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, | |
196 | const char *transport_name, | |
197 | void *buf_addr, | |
198 | size_t subbuf_size, size_t num_subbuf, | |
199 | unsigned int switch_timer_interval, | |
f4681817 | 200 | unsigned int read_timer_interval) |
8020ceb5 MD |
201 | { |
202 | struct ltt_channel *chan; | |
203 | struct ltt_transport *transport; | |
204 | ||
b5234c06 | 205 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
206 | if (session->been_active) |
207 | goto active; /* Refuse to add channel to active session */ | |
208 | transport = ltt_transport_find(transport_name); | |
209 | if (!transport) { | |
b5234c06 | 210 | DBG("LTTng transport %s not found\n", |
8020ceb5 MD |
211 | transport_name); |
212 | goto notransport; | |
213 | } | |
b5234c06 | 214 | chan = zmalloc(sizeof(struct ltt_channel)); |
8020ceb5 MD |
215 | if (!chan) |
216 | goto nomem; | |
217 | chan->session = session; | |
218 | chan->id = session->free_chan_id++; | |
219 | /* | |
220 | * Note: the channel creation op already writes into the packet | |
221 | * headers. Therefore the "chan" information used as input | |
222 | * should be already accessible. | |
223 | */ | |
1d498196 | 224 | transport->ops.channel_create("[lttng]", chan, buf_addr, |
8020ceb5 | 225 | subbuf_size, num_subbuf, switch_timer_interval, |
8d8a24c8 | 226 | read_timer_interval); |
8020ceb5 MD |
227 | if (!chan->chan) |
228 | goto create_error; | |
976fe9ea | 229 | chan->enabled = 1; |
8020ceb5 | 230 | chan->ops = &transport->ops; |
b5234c06 MD |
231 | cds_list_add(&chan->list, &session->chan); |
232 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
233 | return chan; |
234 | ||
235 | create_error: | |
b5234c06 | 236 | free(chan); |
8020ceb5 MD |
237 | nomem: |
238 | notransport: | |
239 | active: | |
b5234c06 | 240 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
241 | return NULL; |
242 | } | |
243 | ||
244 | /* | |
245 | * Only used internally at session destruction. | |
246 | */ | |
247 | static | |
248 | void _ltt_channel_destroy(struct ltt_channel *chan) | |
249 | { | |
1d498196 | 250 | chan->ops->channel_destroy(chan); |
b5234c06 | 251 | cds_list_del(&chan->list); |
8020ceb5 | 252 | lttng_destroy_context(chan->ctx); |
b5234c06 | 253 | free(chan); |
8020ceb5 MD |
254 | } |
255 | ||
256 | /* | |
257 | * Supports event creation while tracing session is active. | |
258 | */ | |
259 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, | |
b5234c06 | 260 | struct lttng_ust_event *event_param, |
8020ceb5 MD |
261 | void *filter) |
262 | { | |
263 | struct ltt_event *event; | |
264 | int ret; | |
265 | ||
b5234c06 | 266 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
267 | if (chan->free_event_id == -1UL) |
268 | goto full; | |
269 | /* | |
270 | * This is O(n^2) (for each event, the loop is called at event | |
271 | * creation). Might require a hash if we have lots of events. | |
272 | */ | |
b5234c06 | 273 | cds_list_for_each_entry(event, &chan->session->events, list) |
8020ceb5 MD |
274 | if (!strcmp(event->desc->name, event_param->name)) |
275 | goto exist; | |
b5234c06 | 276 | event = zmalloc(sizeof(struct ltt_event)); |
8020ceb5 MD |
277 | if (!event) |
278 | goto cache_error; | |
279 | event->chan = chan; | |
280 | event->filter = filter; | |
281 | event->id = chan->free_event_id++; | |
976fe9ea | 282 | event->enabled = 1; |
8020ceb5 MD |
283 | event->instrumentation = event_param->instrumentation; |
284 | /* Populate ltt_event structure before tracepoint registration. */ | |
b5234c06 | 285 | cmm_smp_wmb(); |
8020ceb5 | 286 | switch (event_param->instrumentation) { |
b5234c06 | 287 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 MD |
288 | event->desc = ltt_event_get(event_param->name); |
289 | if (!event->desc) | |
290 | goto register_error; | |
b5234c06 | 291 | ret = __tracepoint_probe_register(event_param->name, |
8020ceb5 MD |
292 | event->desc->probe_callback, |
293 | event); | |
294 | if (ret) | |
295 | goto register_error; | |
296 | break; | |
8020ceb5 MD |
297 | default: |
298 | WARN_ON_ONCE(1); | |
299 | } | |
300 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); | |
301 | if (ret) | |
302 | goto statedump_error; | |
b5234c06 MD |
303 | cds_list_add(&event->list, &chan->session->events); |
304 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
305 | return event; |
306 | ||
307 | statedump_error: | |
b5234c06 | 308 | WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name, |
8020ceb5 MD |
309 | event->desc->probe_callback, |
310 | event)); | |
311 | ltt_event_put(event->desc); | |
312 | register_error: | |
b5234c06 | 313 | free(event); |
8020ceb5 MD |
314 | cache_error: |
315 | exist: | |
316 | full: | |
b5234c06 | 317 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
318 | return NULL; |
319 | } | |
320 | ||
321 | /* | |
322 | * Only used internally at session destruction. | |
323 | */ | |
324 | int _ltt_event_unregister(struct ltt_event *event) | |
325 | { | |
326 | int ret = -EINVAL; | |
327 | ||
328 | switch (event->instrumentation) { | |
b5234c06 MD |
329 | case LTTNG_UST_TRACEPOINT: |
330 | ret = __tracepoint_probe_unregister(event->desc->name, | |
8020ceb5 MD |
331 | event->desc->probe_callback, |
332 | event); | |
333 | if (ret) | |
334 | return ret; | |
335 | break; | |
8020ceb5 MD |
336 | default: |
337 | WARN_ON_ONCE(1); | |
338 | } | |
339 | return ret; | |
340 | } | |
341 | ||
342 | /* | |
343 | * Only used internally at session destruction. | |
344 | */ | |
345 | static | |
346 | void _ltt_event_destroy(struct ltt_event *event) | |
347 | { | |
348 | switch (event->instrumentation) { | |
b5234c06 | 349 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 MD |
350 | ltt_event_put(event->desc); |
351 | break; | |
8020ceb5 MD |
352 | default: |
353 | WARN_ON_ONCE(1); | |
354 | } | |
b5234c06 | 355 | cds_list_del(&event->list); |
8020ceb5 | 356 | lttng_destroy_context(event->ctx); |
b5234c06 | 357 | free(event); |
8020ceb5 MD |
358 | } |
359 | ||
360 | /* | |
361 | * We have exclusive access to our metadata buffer (protected by the | |
362 | * sessions_mutex), so we can do racy operations such as looking for | |
363 | * remaining space left in packet and write, since mutual exclusion | |
364 | * protects us from concurrent writes. | |
365 | */ | |
366 | int lttng_metadata_printf(struct ltt_session *session, | |
367 | const char *fmt, ...) | |
368 | { | |
369 | struct lib_ring_buffer_ctx ctx; | |
370 | struct ltt_channel *chan = session->metadata; | |
b5234c06 | 371 | char *str = NULL; |
8020ceb5 MD |
372 | int ret = 0, waitret; |
373 | size_t len, reserve_len, pos; | |
374 | va_list ap; | |
375 | ||
b5234c06 | 376 | WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active)); |
8020ceb5 MD |
377 | |
378 | va_start(ap, fmt); | |
b5234c06 | 379 | ret = vasprintf(&str, fmt, ap); |
8020ceb5 | 380 | va_end(ap); |
b5234c06 | 381 | if (ret < 0) |
8020ceb5 MD |
382 | return -ENOMEM; |
383 | ||
384 | len = strlen(str); | |
385 | pos = 0; | |
386 | ||
387 | for (pos = 0; pos < len; pos += reserve_len) { | |
388 | reserve_len = min_t(size_t, | |
1d498196 | 389 | chan->ops->packet_avail_size(chan->chan, chan->handle), |
8020ceb5 MD |
390 | len - pos); |
391 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
1d498196 | 392 | sizeof(char), -1, chan->handle); |
8020ceb5 MD |
393 | /* |
394 | * We don't care about metadata buffer's records lost | |
395 | * count, because we always retry here. Report error if | |
396 | * we need to bail out after timeout or being | |
397 | * interrupted. | |
398 | */ | |
b5234c06 | 399 | waitret = wait_cond_interruptible_timeout( |
8020ceb5 MD |
400 | ({ |
401 | ret = chan->ops->event_reserve(&ctx, 0); | |
402 | ret != -ENOBUFS || !ret; | |
403 | }), | |
b5234c06 MD |
404 | LTTNG_METADATA_TIMEOUT_MSEC); |
405 | if (!waitret || waitret == -EINTR || ret) { | |
406 | DBG("LTTng: Failure to write metadata to buffers (%s)\n", | |
407 | waitret == -EINTR ? "interrupted" : | |
8020ceb5 | 408 | (ret == -ENOBUFS ? "timeout" : "I/O error")); |
b5234c06 | 409 | if (waitret == -EINTR) |
8020ceb5 MD |
410 | ret = waitret; |
411 | goto end; | |
412 | } | |
413 | chan->ops->event_write(&ctx, &str[pos], reserve_len); | |
414 | chan->ops->event_commit(&ctx); | |
415 | } | |
416 | end: | |
b5234c06 | 417 | free(str); |
8020ceb5 MD |
418 | return ret; |
419 | } | |
420 | ||
421 | static | |
422 | int _ltt_field_statedump(struct ltt_session *session, | |
423 | const struct lttng_event_field *field) | |
424 | { | |
425 | int ret = 0; | |
426 | ||
427 | switch (field->type.atype) { | |
428 | case atype_integer: | |
429 | ret = lttng_metadata_printf(session, | |
430 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n", | |
431 | field->type.u.basic.integer.size, | |
432 | field->type.u.basic.integer.alignment, | |
433 | field->type.u.basic.integer.signedness, | |
434 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
435 | ? "none" | |
436 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
437 | ? "UTF8" | |
438 | : "ASCII", | |
439 | field->type.u.basic.integer.base, | |
403c40b4 MD |
440 | #ifdef __BIG_ENDIAN |
441 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
442 | #else | |
443 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
444 | #endif | |
445 | field->name); | |
446 | break; | |
447 | case atype_float: | |
448 | ret = lttng_metadata_printf(session, | |
449 | " floating_point { exp_dig = %u; mant_dig = %u; align = %u; } %s;\n", | |
450 | field->type.u.basic._float.exp_dig, | |
451 | field->type.u.basic._float.mant_dig, | |
452 | field->type.u.basic._float.alignment, | |
453 | #ifdef __BIG_ENDIAN | |
8020ceb5 MD |
454 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
455 | #else | |
456 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
457 | #endif | |
458 | field->name); | |
459 | break; | |
460 | case atype_enum: | |
461 | ret = lttng_metadata_printf(session, | |
462 | " %s %s;\n", | |
463 | field->type.u.basic.enumeration.name, | |
464 | field->name); | |
465 | break; | |
466 | case atype_array: | |
467 | { | |
468 | const struct lttng_basic_type *elem_type; | |
469 | ||
470 | elem_type = &field->type.u.array.elem_type; | |
471 | ret = lttng_metadata_printf(session, | |
472 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n", | |
473 | elem_type->u.basic.integer.size, | |
474 | elem_type->u.basic.integer.alignment, | |
475 | elem_type->u.basic.integer.signedness, | |
476 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
477 | ? "none" | |
478 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
479 | ? "UTF8" | |
480 | : "ASCII", | |
481 | elem_type->u.basic.integer.base, | |
403c40b4 | 482 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
483 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
484 | #else | |
485 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
486 | #endif | |
487 | field->name, field->type.u.array.length); | |
488 | break; | |
489 | } | |
490 | case atype_sequence: | |
491 | { | |
492 | const struct lttng_basic_type *elem_type; | |
493 | const struct lttng_basic_type *length_type; | |
494 | ||
495 | elem_type = &field->type.u.sequence.elem_type; | |
496 | length_type = &field->type.u.sequence.length_type; | |
497 | ret = lttng_metadata_printf(session, | |
498 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
499 | length_type->u.basic.integer.size, | |
500 | (unsigned int) length_type->u.basic.integer.alignment, | |
501 | length_type->u.basic.integer.signedness, | |
502 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
503 | ? "none" | |
504 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
505 | ? "UTF8" | |
506 | : "ASCII"), | |
507 | length_type->u.basic.integer.base, | |
403c40b4 | 508 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
509 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
510 | #else | |
511 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
512 | #endif | |
513 | field->name); | |
514 | if (ret) | |
515 | return ret; | |
516 | ||
517 | ret = lttng_metadata_printf(session, | |
518 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n", | |
519 | elem_type->u.basic.integer.size, | |
520 | (unsigned int) elem_type->u.basic.integer.alignment, | |
521 | elem_type->u.basic.integer.signedness, | |
522 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
523 | ? "none" | |
524 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
525 | ? "UTF8" | |
526 | : "ASCII"), | |
527 | elem_type->u.basic.integer.base, | |
403c40b4 | 528 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
529 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
530 | #else | |
531 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
532 | #endif | |
533 | field->name, | |
534 | field->name); | |
535 | break; | |
536 | } | |
537 | ||
538 | case atype_string: | |
539 | /* Default encoding is UTF8 */ | |
540 | ret = lttng_metadata_printf(session, | |
541 | " string%s %s;\n", | |
542 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
543 | " { encoding = ASCII; }" : "", | |
544 | field->name); | |
545 | break; | |
546 | default: | |
547 | WARN_ON_ONCE(1); | |
548 | return -EINVAL; | |
549 | } | |
550 | return ret; | |
551 | } | |
552 | ||
553 | static | |
554 | int _ltt_context_metadata_statedump(struct ltt_session *session, | |
555 | struct lttng_ctx *ctx) | |
556 | { | |
557 | int ret = 0; | |
558 | int i; | |
559 | ||
560 | if (!ctx) | |
561 | return 0; | |
562 | for (i = 0; i < ctx->nr_fields; i++) { | |
563 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
564 | ||
565 | ret = _ltt_field_statedump(session, &field->event_field); | |
566 | if (ret) | |
567 | return ret; | |
568 | } | |
569 | return ret; | |
570 | } | |
571 | ||
572 | static | |
573 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
574 | struct ltt_event *event) | |
575 | { | |
576 | const struct lttng_event_desc *desc = event->desc; | |
577 | int ret = 0; | |
578 | int i; | |
579 | ||
580 | for (i = 0; i < desc->nr_fields; i++) { | |
581 | const struct lttng_event_field *field = &desc->fields[i]; | |
582 | ||
583 | ret = _ltt_field_statedump(session, field); | |
584 | if (ret) | |
585 | return ret; | |
586 | } | |
587 | return ret; | |
588 | } | |
589 | ||
590 | static | |
591 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
592 | struct ltt_channel *chan, | |
593 | struct ltt_event *event) | |
594 | { | |
595 | int ret = 0; | |
596 | ||
b5234c06 | 597 | if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
598 | return 0; |
599 | if (chan == session->metadata) | |
600 | return 0; | |
601 | ||
602 | ret = lttng_metadata_printf(session, | |
603 | "event {\n" | |
604 | " name = %s;\n" | |
605 | " id = %u;\n" | |
606 | " stream_id = %u;\n", | |
607 | event->desc->name, | |
608 | event->id, | |
609 | event->chan->id); | |
610 | if (ret) | |
611 | goto end; | |
612 | ||
613 | if (event->ctx) { | |
614 | ret = lttng_metadata_printf(session, | |
615 | " context := struct {\n"); | |
616 | if (ret) | |
617 | goto end; | |
618 | } | |
619 | ret = _ltt_context_metadata_statedump(session, event->ctx); | |
620 | if (ret) | |
621 | goto end; | |
622 | if (event->ctx) { | |
623 | ret = lttng_metadata_printf(session, | |
624 | " };\n"); | |
625 | if (ret) | |
626 | goto end; | |
627 | } | |
628 | ||
629 | ret = lttng_metadata_printf(session, | |
630 | " fields := struct {\n" | |
631 | ); | |
632 | if (ret) | |
633 | goto end; | |
634 | ||
635 | ret = _ltt_fields_metadata_statedump(session, event); | |
636 | if (ret) | |
637 | goto end; | |
638 | ||
639 | /* | |
640 | * LTTng space reservation can only reserve multiples of the | |
641 | * byte size. | |
642 | */ | |
643 | ret = lttng_metadata_printf(session, | |
644 | " };\n" | |
645 | "};\n\n"); | |
646 | if (ret) | |
647 | goto end; | |
648 | ||
649 | event->metadata_dumped = 1; | |
650 | end: | |
651 | return ret; | |
652 | ||
653 | } | |
654 | ||
655 | static | |
656 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
657 | struct ltt_channel *chan) | |
658 | { | |
659 | int ret = 0; | |
660 | ||
b5234c06 | 661 | if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
662 | return 0; |
663 | if (chan == session->metadata) | |
664 | return 0; | |
665 | ||
666 | WARN_ON_ONCE(!chan->header_type); | |
667 | ret = lttng_metadata_printf(session, | |
668 | "stream {\n" | |
669 | " id = %u;\n" | |
670 | " event.header := %s;\n" | |
671 | " packet.context := struct packet_context;\n", | |
672 | chan->id, | |
673 | chan->header_type == 1 ? "struct event_header_compact" : | |
674 | "struct event_header_large"); | |
675 | if (ret) | |
676 | goto end; | |
677 | ||
678 | if (chan->ctx) { | |
679 | ret = lttng_metadata_printf(session, | |
680 | " event.context := struct {\n"); | |
681 | if (ret) | |
682 | goto end; | |
683 | } | |
684 | ret = _ltt_context_metadata_statedump(session, chan->ctx); | |
685 | if (ret) | |
686 | goto end; | |
687 | if (chan->ctx) { | |
688 | ret = lttng_metadata_printf(session, | |
689 | " };\n"); | |
690 | if (ret) | |
691 | goto end; | |
692 | } | |
693 | ||
694 | ret = lttng_metadata_printf(session, | |
695 | "};\n\n"); | |
696 | ||
697 | chan->metadata_dumped = 1; | |
698 | end: | |
699 | return ret; | |
700 | } | |
701 | ||
702 | static | |
703 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
704 | { | |
705 | return lttng_metadata_printf(session, | |
706 | "struct packet_context {\n" | |
707 | " uint64_t timestamp_begin;\n" | |
708 | " uint64_t timestamp_end;\n" | |
709 | " uint32_t events_discarded;\n" | |
710 | " uint32_t content_size;\n" | |
711 | " uint32_t packet_size;\n" | |
712 | " uint32_t cpu_id;\n" | |
713 | "};\n\n" | |
714 | ); | |
715 | } | |
716 | ||
717 | /* | |
718 | * Compact header: | |
719 | * id: range: 0 - 30. | |
720 | * id 31 is reserved to indicate an extended header. | |
721 | * | |
722 | * Large header: | |
723 | * id: range: 0 - 65534. | |
724 | * id 65535 is reserved to indicate an extended header. | |
725 | */ | |
726 | static | |
727 | int _ltt_event_header_declare(struct ltt_session *session) | |
728 | { | |
729 | return lttng_metadata_printf(session, | |
730 | "struct event_header_compact {\n" | |
731 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
732 | " variant <id> {\n" | |
733 | " struct {\n" | |
734 | " uint27_t timestamp;\n" | |
735 | " } compact;\n" | |
736 | " struct {\n" | |
737 | " uint32_t id;\n" | |
738 | " uint64_t timestamp;\n" | |
739 | " } extended;\n" | |
740 | " } v;\n" | |
741 | "} align(%u);\n" | |
742 | "\n" | |
743 | "struct event_header_large {\n" | |
744 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
745 | " variant <id> {\n" | |
746 | " struct {\n" | |
747 | " uint32_t timestamp;\n" | |
748 | " } compact;\n" | |
749 | " struct {\n" | |
750 | " uint32_t id;\n" | |
751 | " uint64_t timestamp;\n" | |
752 | " } extended;\n" | |
753 | " } v;\n" | |
754 | "} align(%u);\n\n", | |
1dbfff0c MD |
755 | lttng_alignof(uint32_t) * CHAR_BIT, |
756 | lttng_alignof(uint16_t) * CHAR_BIT | |
8020ceb5 MD |
757 | ); |
758 | } | |
759 | ||
760 | /* | |
761 | * Output metadata into this session's metadata buffers. | |
762 | */ | |
763 | static | |
764 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
765 | { | |
b5234c06 MD |
766 | unsigned char *uuid_c = session->uuid; |
767 | char uuid_s[37]; | |
8020ceb5 MD |
768 | struct ltt_channel *chan; |
769 | struct ltt_event *event; | |
770 | int ret = 0; | |
771 | ||
b5234c06 | 772 | if (!CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
773 | return 0; |
774 | if (session->metadata_dumped) | |
775 | goto skip_session; | |
776 | if (!session->metadata) { | |
b5234c06 | 777 | DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
8020ceb5 MD |
778 | return -EPERM; |
779 | } | |
780 | ||
781 | snprintf(uuid_s, sizeof(uuid_s), | |
782 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", | |
783 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
784 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
785 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
786 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
787 | ||
788 | ret = lttng_metadata_printf(session, | |
789 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" | |
790 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
791 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
792 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
793 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
794 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
795 | "\n" | |
796 | "trace {\n" | |
797 | " major = %u;\n" | |
798 | " minor = %u;\n" | |
799 | " uuid = \"%s\";\n" | |
800 | " byte_order = %s;\n" | |
801 | " packet.header := struct {\n" | |
802 | " uint32_t magic;\n" | |
803 | " uint8_t uuid[16];\n" | |
804 | " uint32_t stream_id;\n" | |
805 | " };\n" | |
806 | "};\n\n", | |
1dbfff0c MD |
807 | lttng_alignof(uint8_t) * CHAR_BIT, |
808 | lttng_alignof(uint16_t) * CHAR_BIT, | |
809 | lttng_alignof(uint32_t) * CHAR_BIT, | |
810 | lttng_alignof(uint64_t) * CHAR_BIT, | |
8020ceb5 MD |
811 | CTF_VERSION_MAJOR, |
812 | CTF_VERSION_MINOR, | |
813 | uuid_s, | |
403c40b4 | 814 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
815 | "be" |
816 | #else | |
817 | "le" | |
818 | #endif | |
819 | ); | |
820 | if (ret) | |
821 | goto end; | |
822 | ||
823 | ret = _ltt_stream_packet_context_declare(session); | |
824 | if (ret) | |
825 | goto end; | |
826 | ||
827 | ret = _ltt_event_header_declare(session); | |
828 | if (ret) | |
829 | goto end; | |
830 | ||
831 | skip_session: | |
b5234c06 | 832 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
833 | ret = _ltt_channel_metadata_statedump(session, chan); |
834 | if (ret) | |
835 | goto end; | |
836 | } | |
837 | ||
b5234c06 | 838 | cds_list_for_each_entry(event, &session->events, list) { |
8020ceb5 MD |
839 | ret = _ltt_event_metadata_statedump(session, event->chan, event); |
840 | if (ret) | |
841 | goto end; | |
842 | } | |
843 | session->metadata_dumped = 1; | |
844 | end: | |
845 | return ret; | |
846 | } | |
847 | ||
848 | /** | |
849 | * ltt_transport_register - LTT transport registration | |
850 | * @transport: transport structure | |
851 | * | |
852 | * Registers a transport which can be used as output to extract the data out of | |
b5234c06 | 853 | * LTTng. |
8020ceb5 MD |
854 | */ |
855 | void ltt_transport_register(struct ltt_transport *transport) | |
856 | { | |
b5234c06 MD |
857 | pthread_mutex_lock(&sessions_mutex); |
858 | cds_list_add_tail(&transport->node, <t_transport_list); | |
859 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 | 860 | } |
8020ceb5 MD |
861 | |
862 | /** | |
863 | * ltt_transport_unregister - LTT transport unregistration | |
864 | * @transport: transport structure | |
865 | */ | |
866 | void ltt_transport_unregister(struct ltt_transport *transport) | |
867 | { | |
b5234c06 MD |
868 | pthread_mutex_lock(&sessions_mutex); |
869 | cds_list_del(&transport->node); | |
870 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
871 | } |
872 | ||
b5234c06 MD |
873 | static |
874 | void __attribute__((destructor)) ltt_events_exit(void) | |
8020ceb5 MD |
875 | { |
876 | struct ltt_session *session, *tmpsession; | |
877 | ||
b5234c06 | 878 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, list) |
8020ceb5 | 879 | ltt_session_destroy(session); |
8020ceb5 | 880 | } |