Add important DEBUG statement
[lttng-tools.git] / lttng-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 lus->start_trace = 0;
103
104 /* Alloc UST domain hash tables */
105 lus->domain_pid = hashtable_new(0);
106 lus->domain_exec = hashtable_new_str(0);
107
108 /* Alloc UST global domain channels' HT */
109 lus->domain_global.channels = hashtable_new_str(0);
110
111 /* Set session path */
112 ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
113 if (ret < 0) {
114 PERROR("snprintf kernel traces path");
115 goto error_free_session;
116 }
117
118 DBG2("UST trace session create successful");
119
120 return lus;
121
122 error_free_session:
123 free(lus);
124 error:
125 return NULL;
126 }
127
128 /*
129 * Allocate and initialize a ust channel data structure.
130 *
131 * Return pointer to structure or NULL.
132 */
133 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
134 char *path)
135 {
136 int ret;
137 struct ltt_ust_channel *luc;
138
139 luc = malloc(sizeof(struct ltt_ust_channel));
140 if (luc == NULL) {
141 perror("ltt_ust_channel malloc");
142 goto error;
143 }
144
145 /* Copy UST channel attributes */
146 luc->attr.overwrite = chan->attr.overwrite;
147 luc->attr.subbuf_size = chan->attr.subbuf_size;
148 luc->attr.num_subbuf = chan->attr.num_subbuf;
149 luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
150 luc->attr.read_timer_interval = chan->attr.read_timer_interval;
151 luc->attr.output = chan->attr.output;
152
153 /* Translate to UST output enum */
154 switch (luc->attr.output) {
155 default:
156 luc->attr.output = LTTNG_UST_MMAP;
157 break;
158 }
159
160 /* Copy channel name */
161 strncpy(luc->name, chan->name, sizeof(&luc->name));
162 luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
163
164 /* Init node */
165 hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
166 /* Alloc hash tables */
167 luc->events = hashtable_new_str(0);
168 luc->ctx = hashtable_new_str(0);
169
170 /* Set trace output path */
171 ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
172 if (ret < 0) {
173 perror("asprintf ust create channel");
174 goto error_free_channel;
175 }
176
177 DBG2("Trace UST channel %s created", luc->name);
178
179 return luc;
180
181 error_free_channel:
182 free(luc);
183 error:
184 return NULL;
185 }
186
187 /*
188 * Allocate and initialize a ust event. Set name and event type.
189 *
190 * Return pointer to structure or NULL.
191 */
192 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
193 {
194 struct ltt_ust_event *lue;
195
196 lue = malloc(sizeof(struct ltt_ust_event));
197 if (lue == NULL) {
198 PERROR("ust event malloc");
199 goto error;
200 }
201
202 switch (ev->type) {
203 case LTTNG_EVENT_PROBE:
204 lue->attr.instrumentation = LTTNG_UST_PROBE;
205 break;
206 case LTTNG_EVENT_FUNCTION:
207 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
208 break;
209 case LTTNG_EVENT_FUNCTION_ENTRY:
210 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
211 break;
212 case LTTNG_EVENT_TRACEPOINT:
213 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
214 break;
215 default:
216 ERR("Unknown ust instrumentation type (%d)", ev->type);
217 goto error_free_event;
218 }
219
220 /* Copy event name */
221 strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
222 lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
223
224 /* Init node */
225 hashtable_node_init(&lue->node, (void *) lue->attr.name,
226 strlen(lue->attr.name));
227 /* Alloc context hash tables */
228 lue->ctx = hashtable_new_str(0);
229
230 return lue;
231
232 error_free_event:
233 free(lue);
234 error:
235 return NULL;
236 }
237
238 /*
239 * Allocate and initialize a ust metadata.
240 *
241 * Return pointer to structure or NULL.
242 */
243 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
244 {
245 int ret;
246 struct ltt_ust_metadata *lum;
247
248 lum = zmalloc(sizeof(struct ltt_ust_metadata));
249 if (lum == NULL) {
250 perror("ust metadata malloc");
251 goto error;
252 }
253
254 /* Set default attributes */
255 lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
256 lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
257 lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
258 lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
259 lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
260 lum->attr.output = LTTNG_UST_MMAP;
261
262 lum->handle = -1;
263 /* Set metadata trace path */
264 ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
265 if (ret < 0) {
266 perror("asprintf ust metadata");
267 goto error_free_metadata;
268 }
269
270 return lum;
271
272 error_free_metadata:
273 free(lum);
274 error:
275 return NULL;
276 }
277
278 /*
279 * RCU safe free context structure.
280 */
281 static void destroy_context_rcu(struct rcu_head *head)
282 {
283 struct cds_lfht_node *node =
284 caa_container_of(head, struct cds_lfht_node, head);
285 struct ltt_ust_context *ctx =
286 caa_container_of(node, struct ltt_ust_context, node);
287
288 free(ctx);
289 }
290
291 /*
292 * Cleanup UST context hash table.
293 */
294 static void destroy_context(struct cds_lfht *ht)
295 {
296 int ret;
297 struct cds_lfht_node *node;
298 struct cds_lfht_iter iter;
299
300 cds_lfht_for_each(ht, &iter, node) {
301 ret = hashtable_del(ht, &iter);
302 if (!ret) {
303 call_rcu(&node->head, destroy_context_rcu);
304 }
305 }
306
307 hashtable_destroy(ht);
308 }
309
310 /*
311 * Cleanup ust event structure.
312 */
313 void trace_ust_destroy_event(struct ltt_ust_event *event)
314 {
315 DBG2("Trace destroy UST event %s", event->attr.name);
316 destroy_context(event->ctx);
317
318 free(event);
319 }
320
321 /*
322 * URCU intermediate call to complete destroy event.
323 */
324 static void destroy_event_rcu(struct rcu_head *head)
325 {
326 struct cds_lfht_node *node =
327 caa_container_of(head, struct cds_lfht_node, head);
328 struct ltt_ust_event *event =
329 caa_container_of(node, struct ltt_ust_event, node);
330
331 trace_ust_destroy_event(event);
332 }
333
334 static void destroy_event(struct cds_lfht *ht)
335 {
336 int ret;
337 struct cds_lfht_node *node;
338 struct cds_lfht_iter iter;
339
340 cds_lfht_for_each(ht, &iter, node) {
341 ret = hashtable_del(ht, &iter);
342 if (!ret) {
343 call_rcu(&node->head, destroy_event_rcu);
344 }
345 }
346
347 hashtable_destroy(ht);
348 }
349
350 /*
351 * Cleanup ust channel structure.
352 */
353 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
354 {
355 int ret;
356 struct cds_lfht_node *node;
357 struct cds_lfht_iter iter;
358
359 DBG2("Trace destroy UST channel %s", channel->name);
360
361 rcu_read_lock();
362
363 cds_lfht_for_each(channel->events, &iter, node) {
364 ret = hashtable_del(channel->events, &iter);
365 if (!ret) {
366 destroy_event(channel->events);
367 }
368 }
369
370 destroy_context(channel->ctx);
371 free(channel);
372
373 rcu_read_unlock();
374 }
375
376 /*
377 * URCU intermediate call to complete destroy channel.
378 */
379 static void destroy_channel_rcu(struct rcu_head *head)
380 {
381 struct cds_lfht_node *node =
382 caa_container_of(head, struct cds_lfht_node, head);
383 struct ltt_ust_channel *channel =
384 caa_container_of(node, struct ltt_ust_channel, node);
385
386 trace_ust_destroy_channel(channel);
387 }
388
389 /*
390 * Cleanup ust metadata structure.
391 */
392 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
393 {
394 DBG2("Trace UST destroy metadata %d", metadata->handle);
395
396 free(metadata);
397 }
398
399 /*
400 * Iterate over a hash table containing channels and cleanup safely.
401 */
402 static void destroy_channels(struct cds_lfht *channels)
403 {
404 int ret;
405 struct cds_lfht_node *node;
406 struct cds_lfht_iter iter;
407
408 cds_lfht_for_each(channels, &iter, node) {
409 ret = hashtable_del(channels, &iter);
410 if (!ret) {
411 call_rcu(&node->head, destroy_channel_rcu);
412 }
413 }
414
415 hashtable_destroy(channels);
416 }
417
418 /*
419 * Cleanup UST pid domain.
420 */
421 static void destroy_domain_pid(struct cds_lfht *ht)
422 {
423 int ret;
424 struct cds_lfht_iter iter;
425 struct ltt_ust_domain_pid *dpid;
426
427 cds_lfht_for_each_entry(ht, &iter, dpid, node) {
428 ret = hashtable_del(ht , &iter);
429 if (!ret) {
430 destroy_channels(dpid->channels);
431 }
432 }
433
434 hashtable_destroy(ht);
435 }
436
437 /*
438 * Cleanup UST exec name domain.
439 */
440 static void destroy_domain_exec(struct cds_lfht *ht)
441 {
442 int ret;
443 struct cds_lfht_iter iter;
444 struct ltt_ust_domain_exec *dexec;
445
446 cds_lfht_for_each_entry(ht, &iter, dexec, node) {
447 ret = hashtable_del(ht , &iter);
448 if (!ret) {
449 destroy_channels(dexec->channels);
450 }
451 }
452
453 hashtable_destroy(ht);
454 }
455
456 /*
457 * Cleanup UST global domain.
458 */
459 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
460 {
461 destroy_channels(dom->channels);
462 }
463
464 /*
465 * Cleanup ust session structure
466 */
467 void trace_ust_destroy_session(struct ltt_ust_session *session)
468 {
469 /* Extra protection */
470 if (session == NULL) {
471 return;
472 }
473
474 rcu_read_lock();
475
476 DBG2("Trace UST destroy session %d", session->uid);
477
478 /* Cleaning up UST domain */
479 destroy_domain_global(&session->domain_global);
480 destroy_domain_pid(session->domain_pid);
481 destroy_domain_exec(session->domain_exec);
482
483 free(session);
484
485 rcu_read_unlock();
486 }
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