Preliminary work for full UST support
[lttng-tools.git] / ltt-sessiond / trace-ust.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; only version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307, USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include <lttngerr.h>
25 #include <lttng-share.h>
26
27 #include "hashtable.h"
28 #include "trace-ust.h"
29
30 /*
31 * Find the channel in the hashtable.
32 */
33 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct cds_lfht *ht,
34 char *name)
35 {
36 struct cds_lfht_node *node;
37 struct cds_lfht_iter iter;
38
39 rcu_read_lock();
40 node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
41 if (node == NULL) {
42 rcu_read_unlock();
43 goto error;
44 }
45 rcu_read_unlock();
46
47 DBG2("Trace UST channel %s found by name", name);
48
49 return caa_container_of(node, struct ltt_ust_channel, node);
50
51 error:
52 DBG2("Trace UST channel %s not found by name", name);
53 return NULL;
54 }
55
56 /*
57 * Find the event in the hashtable.
58 */
59 struct ltt_ust_event *trace_ust_find_event_by_name(struct cds_lfht *ht,
60 char *name)
61 {
62 struct cds_lfht_node *node;
63 struct cds_lfht_iter iter;
64
65 rcu_read_lock();
66 node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
67 if (node == NULL) {
68 rcu_read_unlock();
69 goto error;
70 }
71 rcu_read_unlock();
72
73 DBG2("Found UST event by name %s", name);
74
75 return caa_container_of(node, struct ltt_ust_event, node);
76
77 error:
78 return NULL;
79 }
80
81 /*
82 * Allocate and initialize a ust session data structure.
83 *
84 * Return pointer to structure or NULL.
85 */
86 struct ltt_ust_session *trace_ust_create_session(char *path, unsigned int uid,
87 struct lttng_domain *domain)
88 {
89 int ret;
90 struct ltt_ust_session *lus;
91
92 /* Allocate a new ltt ust session */
93 lus = malloc(sizeof(struct ltt_ust_session));
94 if (lus == NULL) {
95 perror("create ust session malloc");
96 goto error;
97 }
98
99 /* Init data structure */
100 lus->consumer_fds_sent = 0;
101 lus->uid = uid;
102
103 /* Alloc UST domain hash tables */
104 lus->domain_pid = hashtable_new(0);
105 lus->domain_exec = hashtable_new_str(0);
106
107 /* Alloc UST global domain channels' HT */
108 lus->domain_global.channels = hashtable_new_str(0);
109
110 /* Set session path */
111 ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
112 if (ret < 0) {
113 PERROR("snprintf kernel traces path");
114 goto error;
115 }
116
117 DBG2("UST trace session create successful");
118
119 return lus;
120
121 error:
122 return NULL;
123 }
124
125 /*
126 * Allocate and initialize a ust channel data structure.
127 *
128 * Return pointer to structure or NULL.
129 */
130 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
131 char *path)
132 {
133 int ret;
134 struct ltt_ust_channel *luc;
135
136 luc = malloc(sizeof(struct ltt_ust_channel));
137 if (luc == NULL) {
138 perror("ltt_ust_channel malloc");
139 goto error;
140 }
141
142 /* Copy UST channel attributes */
143 luc->attr.overwrite = chan->attr.overwrite;
144 luc->attr.subbuf_size = chan->attr.subbuf_size;
145 luc->attr.num_subbuf = chan->attr.num_subbuf;
146 luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
147 luc->attr.read_timer_interval = chan->attr.read_timer_interval;
148 luc->attr.output = chan->attr.output;
149
150 /* Translate to UST output enum */
151 switch (luc->attr.output) {
152 default:
153 luc->attr.output = LTTNG_UST_MMAP;
154 break;
155 }
156
157 /* Copy channel name */
158 strncpy(luc->name, chan->name, sizeof(&luc->name));
159 luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
160
161 /* Init node */
162 hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
163 /* Alloc hash tables */
164 luc->events = hashtable_new_str(0);
165 luc->ctx = hashtable_new_str(0);
166
167 /* Set trace output path */
168 ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
169 if (ret < 0) {
170 perror("asprintf ust create channel");
171 goto error;
172 }
173
174 DBG2("Trace UST channel %s created", luc->name);
175
176 return luc;
177
178 error:
179 return NULL;
180 }
181
182 /*
183 * Allocate and initialize a ust event. Set name and event type.
184 *
185 * Return pointer to structure or NULL.
186 */
187 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
188 {
189 struct ltt_ust_event *lue;
190
191 lue = malloc(sizeof(struct ltt_ust_event));
192 if (lue == NULL) {
193 PERROR("ust event malloc");
194 goto error;
195 }
196
197 switch (ev->type) {
198 case LTTNG_EVENT_PROBE:
199 lue->attr.instrumentation = LTTNG_UST_PROBE;
200 break;
201 case LTTNG_EVENT_FUNCTION:
202 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
203 break;
204 case LTTNG_EVENT_FUNCTION_ENTRY:
205 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
206 break;
207 case LTTNG_EVENT_TRACEPOINT:
208 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
209 break;
210 default:
211 ERR("Unknown ust instrumentation type (%d)", ev->type);
212 goto error;
213 }
214
215 /* Copy event name */
216 strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
217 lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
218
219 /* Init node */
220 hashtable_node_init(&lue->node, (void *) lue->attr.name,
221 strlen(lue->attr.name));
222 /* Alloc context hash tables */
223 lue->ctx = hashtable_new_str(5);
224
225 return lue;
226
227 error:
228 return NULL;
229 }
230
231 /*
232 * Allocate and initialize a ust metadata.
233 *
234 * Return pointer to structure or NULL.
235 */
236 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
237 {
238 int ret;
239 struct ltt_ust_metadata *lum;
240
241 lum = malloc(sizeof(struct ltt_ust_metadata));
242 if (lum == NULL) {
243 perror("ust metadata malloc");
244 goto error;
245 }
246
247 /* Set default attributes */
248 lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
249 lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
250 lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
251 lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
252 lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
253 lum->attr.output = DEFAULT_UST_CHANNEL_OUTPUT;
254
255 lum->handle = -1;
256 /* Set metadata trace path */
257 ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
258 if (ret < 0) {
259 perror("asprintf ust metadata");
260 goto error;
261 }
262
263 return lum;
264
265 error:
266 return NULL;
267 }
268
269 /*
270 * RCU safe free context structure.
271 */
272 static void destroy_context_rcu(struct rcu_head *head)
273 {
274 struct cds_lfht_node *node =
275 caa_container_of(head, struct cds_lfht_node, head);
276 struct ltt_ust_context *ctx =
277 caa_container_of(node, struct ltt_ust_context, node);
278
279 free(ctx);
280 }
281
282 /*
283 * Cleanup UST context hash table.
284 */
285 static void destroy_context(struct cds_lfht *ht)
286 {
287 int ret;
288 struct cds_lfht_node *node;
289 struct cds_lfht_iter iter;
290
291 hashtable_get_first(ht, &iter);
292 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
293 ret = hashtable_del(ht, &iter);
294 if (!ret) {
295 call_rcu(&node->head, destroy_context_rcu);
296 }
297 hashtable_get_next(ht, &iter);
298 }
299 }
300
301 /*
302 * Cleanup ust event structure.
303 */
304 void trace_ust_destroy_event(struct ltt_ust_event *event)
305 {
306 DBG2("Trace destroy UST event %s", event->attr.name);
307 destroy_context(event->ctx);
308 free(event);
309 }
310
311 /*
312 * URCU intermediate call to complete destroy event.
313 */
314 static void destroy_event_rcu(struct rcu_head *head)
315 {
316 struct cds_lfht_node *node =
317 caa_container_of(head, struct cds_lfht_node, head);
318 struct ltt_ust_event *event =
319 caa_container_of(node, struct ltt_ust_event, node);
320
321 trace_ust_destroy_event(event);
322 }
323
324 /*
325 * Cleanup ust channel structure.
326 */
327 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
328 {
329 int ret;
330 struct cds_lfht_node *node;
331 struct cds_lfht_iter iter;
332
333 DBG2("Trace destroy UST channel %s", channel->name);
334
335 rcu_read_lock();
336
337 hashtable_get_first(channel->events, &iter);
338 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
339 ret = hashtable_del(channel->events, &iter);
340 if (!ret) {
341 call_rcu(&node->head, destroy_event_rcu);
342 }
343 hashtable_get_next(channel->events, &iter);
344 }
345
346 free(channel->events);
347 destroy_context(channel->ctx);
348 free(channel);
349
350 rcu_read_unlock();
351 }
352
353 /*
354 * URCU intermediate call to complete destroy channel.
355 */
356 static void destroy_channel_rcu(struct rcu_head *head)
357 {
358 struct cds_lfht_node *node =
359 caa_container_of(head, struct cds_lfht_node, head);
360 struct ltt_ust_channel *channel =
361 caa_container_of(node, struct ltt_ust_channel, node);
362
363 trace_ust_destroy_channel(channel);
364 }
365
366 /*
367 * Cleanup ust metadata structure.
368 */
369 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
370 {
371 DBG2("Trace UST destroy metadata %d", metadata->handle);
372
373 free(metadata);
374 }
375
376 /*
377 * Iterate over a hash table containing channels and cleanup safely.
378 */
379 static void destroy_channels(struct cds_lfht *channels)
380 {
381 int ret;
382 struct cds_lfht_node *node;
383 struct cds_lfht_iter iter;
384
385 hashtable_get_first(channels, &iter);
386 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
387 ret = hashtable_del(channels, &iter);
388 if (!ret) {
389 call_rcu(&node->head, destroy_channel_rcu);
390 }
391 hashtable_get_next(channels, &iter);
392 }
393 }
394
395 /*
396 * Cleanup UST pid domain.
397 */
398 static void destroy_domain_pid(struct cds_lfht *ht)
399 {
400 int ret;
401 struct cds_lfht_node *node;
402 struct cds_lfht_iter iter;
403 struct ltt_ust_domain_pid *d;
404
405 hashtable_get_first(ht, &iter);
406 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
407 ret = hashtable_del(ht , &iter);
408 if (!ret) {
409 d = caa_container_of(node, struct ltt_ust_domain_pid, node);
410 destroy_channels(d->channels);
411 }
412 hashtable_get_next(ht, &iter);
413 }
414 }
415
416 /*
417 * Cleanup UST exec name domain.
418 */
419 static void destroy_domain_exec(struct cds_lfht *ht)
420 {
421 int ret;
422 struct cds_lfht_node *node;
423 struct cds_lfht_iter iter;
424 struct ltt_ust_domain_exec *d;
425
426 hashtable_get_first(ht, &iter);
427 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
428 ret = hashtable_del(ht , &iter);
429 if (!ret) {
430 d = caa_container_of(node, struct ltt_ust_domain_exec, node);
431 destroy_channels(d->channels);
432 }
433 hashtable_get_next(ht, &iter);
434 }
435 }
436
437 /*
438 * Cleanup UST global domain.
439 */
440 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
441 {
442 destroy_channels(dom->channels);
443 }
444
445 /*
446 * Cleanup ust session structure
447 */
448 void trace_ust_destroy_session(struct ltt_ust_session *session)
449 {
450 /* Extra safety */
451 if (session == NULL) {
452 return;
453 }
454
455 rcu_read_lock();
456
457 DBG2("Trace UST destroy session %d", session->uid);
458
459 //if (session->metadata != NULL) {
460 // trace_ust_destroy_metadata(session->metadata);
461 //}
462
463 /* Cleaning up UST domain */
464 destroy_domain_global(&session->domain_global);
465 destroy_domain_pid(session->domain_pid);
466 destroy_domain_exec(session->domain_exec);
467
468 free(session);
469
470 rcu_read_unlock();
471 }
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