relayd: close viewer stream trace chunk earlier on release
[lttng-tools.git] / src / bin / lttng-relayd / viewer-stream.c
1 /*
2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
4 * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <common/common.h>
22 #include <common/index/index.h>
23 #include <common/compat/string.h>
24
25 #include "lttng-relayd.h"
26 #include "viewer-stream.h"
27
28 static void viewer_stream_destroy(struct relay_viewer_stream *vstream)
29 {
30 free(vstream->path_name);
31 free(vstream->channel_name);
32 free(vstream);
33 }
34
35 static void viewer_stream_destroy_rcu(struct rcu_head *head)
36 {
37 struct relay_viewer_stream *vstream =
38 caa_container_of(head, struct relay_viewer_stream, rcu_node);
39
40 viewer_stream_destroy(vstream);
41 }
42
43 struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
44 struct lttng_trace_chunk *viewer_trace_chunk,
45 enum lttng_viewer_seek seek_t)
46 {
47 struct relay_viewer_stream *vstream = NULL;
48 const bool acquired_reference = lttng_trace_chunk_get(
49 viewer_trace_chunk);
50
51 if (!acquired_reference) {
52 goto error;
53 }
54
55 vstream = zmalloc(sizeof(*vstream));
56 if (!vstream) {
57 PERROR("relay viewer stream zmalloc");
58 goto error;
59 }
60
61 vstream->stream_file.trace_chunk = viewer_trace_chunk;
62 viewer_trace_chunk = NULL;
63 vstream->path_name = lttng_strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX);
64 if (vstream->path_name == NULL) {
65 PERROR("relay viewer path_name alloc");
66 goto error;
67 }
68 vstream->channel_name = lttng_strndup(stream->channel_name,
69 LTTNG_VIEWER_NAME_MAX);
70 if (vstream->channel_name == NULL) {
71 PERROR("relay viewer channel_name alloc");
72 goto error;
73 }
74
75 if (!stream_get(stream)) {
76 ERR("Cannot get stream");
77 goto error;
78 }
79 vstream->stream = stream;
80
81 pthread_mutex_lock(&stream->lock);
82
83 if (stream->is_metadata && stream->trace->viewer_metadata_stream) {
84 ERR("Cannot attach viewer metadata stream to trace (busy).");
85 goto error_unlock;
86 }
87
88 switch (seek_t) {
89 case LTTNG_VIEWER_SEEK_BEGINNING:
90 {
91 uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
92
93 if (seq_tail == -1ULL) {
94 /*
95 * Tail may not be initialized yet. Nonetheless, we know
96 * we want to send the first index once it becomes
97 * available.
98 */
99 seq_tail = 0;
100 }
101 vstream->current_tracefile_id =
102 tracefile_array_get_file_index_tail(stream->tfa);
103 vstream->index_sent_seqcount = seq_tail;
104 break;
105 }
106 case LTTNG_VIEWER_SEEK_LAST:
107 vstream->current_tracefile_id =
108 tracefile_array_get_read_file_index_head(stream->tfa);
109 /*
110 * We seek at the very end of each stream, awaiting for
111 * a future packet to eventually come in.
112 *
113 * We don't need to check the head position for -1ULL since the
114 * increment will set it to 0.
115 */
116 vstream->index_sent_seqcount =
117 tracefile_array_get_seq_head(stream->tfa) + 1;
118 break;
119 default:
120 goto error_unlock;
121 }
122
123 /*
124 * If we never received an index for the current stream, delay
125 * the opening of the index, otherwise open it right now.
126 */
127 if (stream->index_received_seqcount == 0) {
128 vstream->index_file = NULL;
129 } else {
130 const uint32_t connection_major = stream->trace->session->major;
131 const uint32_t connection_minor = stream->trace->session->minor;
132
133 vstream->index_file = lttng_index_file_create_from_trace_chunk_read_only(
134 vstream->stream_file.trace_chunk,
135 stream->path_name,
136 stream->channel_name, stream->tracefile_size,
137 vstream->current_tracefile_id,
138 lttng_to_index_major(connection_major,
139 connection_minor),
140 lttng_to_index_minor(connection_major,
141 connection_minor));
142 if (!vstream->index_file) {
143 goto error_unlock;
144 }
145 }
146
147 if (seek_t == LTTNG_VIEWER_SEEK_LAST && vstream->index_file) {
148 off_t lseek_ret;
149
150 lseek_ret = lseek(vstream->index_file->fd, 0, SEEK_END);
151 if (lseek_ret < 0) {
152 goto error_unlock;
153 }
154 }
155 if (stream->is_metadata) {
156 rcu_assign_pointer(stream->trace->viewer_metadata_stream,
157 vstream);
158 }
159 pthread_mutex_unlock(&stream->lock);
160
161 /* Globally visible after the add unique. */
162 lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle);
163 lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n);
164
165 urcu_ref_init(&vstream->ref);
166
167 return vstream;
168
169 error_unlock:
170 pthread_mutex_unlock(&stream->lock);
171 error:
172 if (vstream) {
173 viewer_stream_destroy(vstream);
174 }
175 if (viewer_trace_chunk && acquired_reference) {
176 lttng_trace_chunk_put(viewer_trace_chunk);
177 }
178 return NULL;
179 }
180
181 static void viewer_stream_unpublish(struct relay_viewer_stream *vstream)
182 {
183 int ret;
184 struct lttng_ht_iter iter;
185
186 iter.iter.node = &vstream->stream_n.node;
187 ret = lttng_ht_del(viewer_streams_ht, &iter);
188 assert(!ret);
189 }
190
191 static void viewer_stream_release(struct urcu_ref *ref)
192 {
193 struct relay_viewer_stream *vstream = caa_container_of(ref,
194 struct relay_viewer_stream, ref);
195
196 if (vstream->stream->is_metadata) {
197 rcu_assign_pointer(vstream->stream->trace->viewer_metadata_stream, NULL);
198 }
199
200 viewer_stream_unpublish(vstream);
201
202 if (vstream->stream_file.fd) {
203 stream_fd_put(vstream->stream_file.fd);
204 vstream->stream_file.fd = NULL;
205 }
206 if (vstream->index_file) {
207 lttng_index_file_put(vstream->index_file);
208 vstream->index_file = NULL;
209 }
210 if (vstream->stream) {
211 stream_put(vstream->stream);
212 vstream->stream = NULL;
213 }
214 lttng_trace_chunk_put(vstream->stream_file.trace_chunk);
215 vstream->stream_file.trace_chunk = NULL;
216 call_rcu(&vstream->rcu_node, viewer_stream_destroy_rcu);
217 }
218
219 /* Must be called with RCU read-side lock held. */
220 bool viewer_stream_get(struct relay_viewer_stream *vstream)
221 {
222 return urcu_ref_get_unless_zero(&vstream->ref);
223 }
224
225 /*
226 * Get viewer stream by id.
227 *
228 * Return viewer stream if found else NULL.
229 */
230 struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id)
231 {
232 struct lttng_ht_node_u64 *node;
233 struct lttng_ht_iter iter;
234 struct relay_viewer_stream *vstream = NULL;
235
236 rcu_read_lock();
237 lttng_ht_lookup(viewer_streams_ht, &id, &iter);
238 node = lttng_ht_iter_get_node_u64(&iter);
239 if (!node) {
240 DBG("Relay viewer stream %" PRIu64 " not found", id);
241 goto end;
242 }
243 vstream = caa_container_of(node, struct relay_viewer_stream, stream_n);
244 if (!viewer_stream_get(vstream)) {
245 vstream = NULL;
246 }
247 end:
248 rcu_read_unlock();
249 return vstream;
250 }
251
252 void viewer_stream_put(struct relay_viewer_stream *vstream)
253 {
254 rcu_read_lock();
255 urcu_ref_put(&vstream->ref, viewer_stream_release);
256 rcu_read_unlock();
257 }
258
259 /*
260 * Rotate a stream to the next tracefile.
261 *
262 * Must be called with the rstream lock held.
263 * Returns 0 on success, 1 on EOF, a negative value on error.
264 */
265 int viewer_stream_rotate(struct relay_viewer_stream *vstream)
266 {
267 int ret;
268 uint64_t new_id;
269 const struct relay_stream *stream = vstream->stream;
270 const uint32_t connection_major = stream->trace->session->major;
271 const uint32_t connection_minor = stream->trace->session->minor;
272
273 /* Detect the last tracefile to open. */
274 if (stream->index_received_seqcount
275 == vstream->index_sent_seqcount
276 && stream->trace->session->connection_closed) {
277 ret = 1;
278 goto end;
279 }
280
281 if (stream->tracefile_count == 0) {
282 /* Ignore rotation, there is none to do. */
283 ret = 0;
284 goto end;
285 }
286
287 /*
288 * Try to move to the next file.
289 */
290 new_id = (vstream->current_tracefile_id + 1)
291 % stream->tracefile_count;
292 if (tracefile_array_seq_in_file(stream->tfa, new_id,
293 vstream->index_sent_seqcount)) {
294 vstream->current_tracefile_id = new_id;
295 } else {
296 uint64_t seq_tail = tracefile_array_get_seq_tail(stream->tfa);
297
298 /*
299 * This can only be reached on overwrite, which implies there
300 * has been data written at some point, which will have set the
301 * tail.
302 */
303 assert(seq_tail != -1ULL);
304 /*
305 * We need to resync because we lag behind tail.
306 */
307 vstream->current_tracefile_id =
308 tracefile_array_get_file_index_tail(stream->tfa);
309 vstream->index_sent_seqcount = seq_tail;
310 }
311
312 if (vstream->index_file) {
313 lttng_index_file_put(vstream->index_file);
314 vstream->index_file = NULL;
315 }
316 if (vstream->stream_file.fd) {
317 stream_fd_put(vstream->stream_file.fd);
318 vstream->stream_file.fd = NULL;
319 }
320 vstream->index_file =
321 lttng_index_file_create_from_trace_chunk_read_only(
322 vstream->stream_file.trace_chunk,
323 stream->path_name,
324 stream->channel_name,
325 stream->tracefile_size,
326 vstream->current_tracefile_id,
327 lttng_to_index_major(connection_major,
328 connection_minor),
329 lttng_to_index_minor(connection_major,
330 connection_minor));
331 if (!vstream->index_file) {
332 ret = -1;
333 goto end;
334 } else {
335 ret = 0;
336 }
337 end:
338 return ret;
339 }
340
341 void print_viewer_streams(void)
342 {
343 struct lttng_ht_iter iter;
344 struct relay_viewer_stream *vstream;
345
346 if (!viewer_streams_ht) {
347 return;
348 }
349
350 rcu_read_lock();
351 cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter, vstream,
352 stream_n.node) {
353 if (!viewer_stream_get(vstream)) {
354 continue;
355 }
356 DBG("vstream %p refcount %ld stream %" PRIu64 " trace %" PRIu64
357 " session %" PRIu64,
358 vstream,
359 vstream->ref.refcount,
360 vstream->stream->stream_handle,
361 vstream->stream->trace->id,
362 vstream->stream->trace->session->id);
363 viewer_stream_put(vstream);
364 }
365 rcu_read_unlock();
366 }
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