Live timer set up
[lttng-tools.git] / src / bin / lttng-sessiond / channel.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
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <inttypes.h>
20 #include <string.h>
21 #include <unistd.h>
22
23 #include <common/common.h>
24 #include <common/defaults.h>
25 #include <common/sessiond-comm/sessiond-comm.h>
26
27 #include "channel.h"
28 #include "lttng-sessiond.h"
29 #include "kernel.h"
30 #include "ust-ctl.h"
31 #include "utils.h"
32 #include "ust-app.h"
33
34 /*
35 * Return allocated channel attributes.
36 */
37 struct lttng_channel *channel_new_default_attr(int dom,
38 enum lttng_buffer_type type)
39 {
40 struct lttng_channel *chan;
41
42 chan = zmalloc(sizeof(struct lttng_channel));
43 if (chan == NULL) {
44 PERROR("zmalloc channel init");
45 goto error_alloc;
46 }
47
48 if (snprintf(chan->name, sizeof(chan->name), "%s",
49 DEFAULT_CHANNEL_NAME) < 0) {
50 PERROR("snprintf default channel name");
51 goto error;
52 }
53
54 /* Same for all domains. */
55 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
56 chan->attr.tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE;
57 chan->attr.tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT;
58
59 switch (dom) {
60 case LTTNG_DOMAIN_KERNEL:
61 assert(type == LTTNG_BUFFER_GLOBAL);
62 chan->attr.subbuf_size =
63 default_get_kernel_channel_subbuf_size();
64 chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
65 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
66 chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
67 chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
68 chan->attr.live_timer_interval = DEFAULT_KERNEL_CHANNEL_LIVE_TIMER;
69 break;
70 case LTTNG_DOMAIN_UST:
71 switch (type) {
72 case LTTNG_BUFFER_PER_UID:
73 chan->attr.subbuf_size = default_get_ust_uid_channel_subbuf_size();
74 chan->attr.num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM;
75 chan->attr.output = DEFAULT_UST_UID_CHANNEL_OUTPUT;
76 chan->attr.switch_timer_interval =
77 DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
78 chan->attr.read_timer_interval =
79 DEFAULT_UST_UID_CHANNEL_READ_TIMER;
80 chan->attr.live_timer_interval =
81 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER;
82 break;
83 case LTTNG_BUFFER_PER_PID:
84 default:
85 chan->attr.subbuf_size = default_get_ust_pid_channel_subbuf_size();
86 chan->attr.num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM;
87 chan->attr.output = DEFAULT_UST_PID_CHANNEL_OUTPUT;
88 chan->attr.switch_timer_interval =
89 DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
90 chan->attr.read_timer_interval =
91 DEFAULT_UST_PID_CHANNEL_READ_TIMER;
92 chan->attr.live_timer_interval =
93 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER;
94 break;
95 }
96 break;
97 default:
98 goto error; /* Not implemented */
99 }
100
101 return chan;
102
103 error:
104 free(chan);
105 error_alloc:
106 return NULL;
107 }
108
109 /*
110 * Disable kernel channel of the kernel session.
111 */
112 int channel_kernel_disable(struct ltt_kernel_session *ksession,
113 char *channel_name)
114 {
115 int ret;
116 struct ltt_kernel_channel *kchan;
117
118 assert(ksession);
119 assert(channel_name);
120
121 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
122 if (kchan == NULL) {
123 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
124 goto error;
125 }
126
127 /* Only if channel is enabled disable it. */
128 if (kchan->enabled == 1) {
129 ret = kernel_disable_channel(kchan);
130 if (ret < 0 && ret != -EEXIST) {
131 ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL;
132 goto error;
133 }
134 }
135
136 ret = LTTNG_OK;
137
138 error:
139 return ret;
140 }
141
142 /*
143 * Enable kernel channel of the kernel session.
144 */
145 int channel_kernel_enable(struct ltt_kernel_session *ksession,
146 struct ltt_kernel_channel *kchan)
147 {
148 int ret;
149
150 assert(ksession);
151 assert(kchan);
152
153 if (kchan->enabled == 0) {
154 ret = kernel_enable_channel(kchan);
155 if (ret < 0) {
156 ret = LTTNG_ERR_KERN_CHAN_ENABLE_FAIL;
157 goto error;
158 }
159 } else {
160 ret = LTTNG_ERR_KERN_CHAN_EXIST;
161 goto error;
162 }
163
164 ret = LTTNG_OK;
165
166 error:
167 return ret;
168 }
169
170 /*
171 * Create kernel channel of the kernel session and notify kernel thread.
172 */
173 int channel_kernel_create(struct ltt_kernel_session *ksession,
174 struct lttng_channel *attr, int kernel_pipe)
175 {
176 int ret;
177 struct lttng_channel *defattr = NULL;
178
179 assert(ksession);
180
181 /* Creating channel attributes if needed */
182 if (attr == NULL) {
183 defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
184 LTTNG_BUFFER_GLOBAL);
185 if (defattr == NULL) {
186 ret = LTTNG_ERR_FATAL;
187 goto error;
188 }
189 attr = defattr;
190 }
191
192 if (ksession->snapshot_mode) {
193 /* Force channel attribute for snapshot mode. */
194 attr->attr.overwrite = 1;
195 attr->attr.output = LTTNG_EVENT_MMAP;
196 }
197
198 /* Channel not found, creating it */
199 ret = kernel_create_channel(ksession, attr);
200 if (ret < 0) {
201 ret = LTTNG_ERR_KERN_CHAN_FAIL;
202 goto error;
203 }
204
205 /* Notify kernel thread that there is a new channel */
206 ret = notify_thread_pipe(kernel_pipe);
207 if (ret < 0) {
208 ret = LTTNG_ERR_FATAL;
209 goto error;
210 }
211
212 ret = LTTNG_OK;
213 error:
214 free(defattr);
215 return ret;
216 }
217
218 /*
219 * Enable UST channel for session and domain.
220 */
221 int channel_ust_enable(struct ltt_ust_session *usess,
222 struct ltt_ust_channel *uchan)
223 {
224 int ret = LTTNG_OK;
225
226 assert(usess);
227 assert(uchan);
228
229 /* If already enabled, everything is OK */
230 if (uchan->enabled) {
231 DBG3("Channel %s already enabled. Skipping", uchan->name);
232 ret = LTTNG_ERR_UST_CHAN_EXIST;
233 goto end;
234 }
235
236 DBG2("Channel %s being enabled in UST domain", uchan->name);
237
238 /*
239 * Enable channel for UST global domain on all applications. Ignore return
240 * value here since whatever error we got, it means that the channel was
241 * not created on one or many registered applications and we can not report
242 * this to the user yet. However, at this stage, the channel was
243 * successfully created on the session daemon side so the enable-channel
244 * command is a success.
245 */
246 (void) ust_app_enable_channel_glb(usess, uchan);
247
248 uchan->enabled = 1;
249 DBG2("Channel %s enabled successfully", uchan->name);
250
251 end:
252 return ret;
253 }
254
255 /*
256 * Create UST channel for session and domain.
257 */
258 int channel_ust_create(struct ltt_ust_session *usess,
259 struct lttng_channel *attr, enum lttng_buffer_type type)
260 {
261 int ret = LTTNG_OK;
262 struct ltt_ust_channel *uchan = NULL;
263 struct lttng_channel *defattr = NULL;
264
265 assert(usess);
266
267 /* Creating channel attributes if needed */
268 if (attr == NULL) {
269 defattr = channel_new_default_attr(LTTNG_DOMAIN_UST, type);
270 if (defattr == NULL) {
271 ret = LTTNG_ERR_FATAL;
272 goto error;
273 }
274 attr = defattr;
275 }
276
277 if (usess->snapshot_mode) {
278 /* Force channel attribute for snapshot mode. */
279 attr->attr.overwrite = 1;
280 attr->attr.output = LTTNG_EVENT_MMAP;
281 }
282
283 /*
284 * Validate UST buffer size and number of buffers: must both be power of 2
285 * and nonzero. We validate right here for UST, because applications will
286 * not report the error to the user (unlike kernel tracing).
287 */
288 if (!attr->attr.subbuf_size ||
289 (attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
290 ret = LTTNG_ERR_INVALID;
291 goto error;
292 }
293
294 /*
295 * Invalid subbuffer size if it's lower then the page size.
296 */
297 if (attr->attr.subbuf_size < page_size) {
298 ret = LTTNG_ERR_INVALID;
299 goto error;
300 }
301
302 if (!attr->attr.num_subbuf ||
303 (attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
304 ret = LTTNG_ERR_INVALID;
305 goto error;
306 }
307
308 if (attr->attr.output != LTTNG_EVENT_MMAP) {
309 ret = LTTNG_ERR_NOT_SUPPORTED;
310 goto error;
311 }
312
313 /*
314 * The tracefile_size should not be < to the subbuf_size, otherwise
315 * we won't be able to write the packets on disk
316 */
317 if ((attr->attr.tracefile_size > 0) &&
318 (attr->attr.tracefile_size < attr->attr.subbuf_size)) {
319 ret = LTTNG_ERR_INVALID;
320 goto error;
321 }
322
323 /* Validate buffer type. */
324 switch (type) {
325 case LTTNG_BUFFER_PER_PID:
326 break;
327 case LTTNG_BUFFER_PER_UID:
328 break;
329 default:
330 ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED;
331 goto error;
332 }
333
334 /* Create UST channel */
335 uchan = trace_ust_create_channel(attr);
336 if (uchan == NULL) {
337 ret = LTTNG_ERR_FATAL;
338 goto error;
339 }
340 uchan->enabled = 1;
341 if (trace_ust_is_max_id(usess->used_channel_id)) {
342 ret = LTTNG_ERR_UST_CHAN_FAIL;
343 goto error;
344 }
345 uchan->id = trace_ust_get_next_chan_id(usess);
346
347 DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64,
348 uchan->name, type, uchan->id);
349
350 /* Flag session buffer type. */
351 if (!usess->buffer_type_changed) {
352 usess->buffer_type = type;
353 usess->buffer_type_changed = 1;
354 } else if (usess->buffer_type != type) {
355 /* Buffer type was already set. Refuse to create channel. */
356 ret = LTTNG_ERR_BUFFER_TYPE_MISMATCH;
357 goto error_free_chan;
358 }
359
360 /* Enable channel for global domain */
361 ret = ust_app_create_channel_glb(usess, uchan);
362 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
363 ret = LTTNG_ERR_UST_CHAN_FAIL;
364 goto error_free_chan;
365 }
366
367 /* Adding the channel to the channel hash table. */
368 rcu_read_lock();
369 lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node);
370 rcu_read_unlock();
371
372 DBG2("Channel %s created successfully", uchan->name);
373
374 free(defattr);
375 return LTTNG_OK;
376
377 error_free_chan:
378 /*
379 * No need to remove the channel from the hash table because at this point
380 * it was not added hence the direct call and no call_rcu().
381 */
382 trace_ust_destroy_channel(uchan);
383 error:
384 free(defattr);
385 return ret;
386 }
387
388 /*
389 * Disable UST channel for session and domain.
390 */
391 int channel_ust_disable(struct ltt_ust_session *usess,
392 struct ltt_ust_channel *uchan)
393 {
394 int ret = LTTNG_OK;
395
396 assert(usess);
397 assert(uchan);
398
399 /* Already disabled */
400 if (uchan->enabled == 0) {
401 DBG2("Channel UST %s already disabled", uchan->name);
402 goto end;
403 }
404
405 DBG2("Channel %s being disabled in UST global domain", uchan->name);
406 /* Disable channel for global domain */
407 ret = ust_app_disable_channel_glb(usess, uchan);
408 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
409 ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL;
410 goto error;
411 }
412
413 uchan->enabled = 0;
414
415 DBG2("Channel %s disabled successfully", uchan->name);
416
417 return LTTNG_OK;
418
419 end:
420 error:
421 return ret;
422 }
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