2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
4 * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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.
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
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.
21 #include <common/common.h>
22 #include <common/index/index.h>
23 #include <common/compat/string.h>
25 #include "lttng-relayd.h"
26 #include "viewer-stream.h"
28 static void viewer_stream_destroy(struct relay_viewer_stream
*vstream
)
30 free(vstream
->path_name
);
31 free(vstream
->channel_name
);
35 static void viewer_stream_destroy_rcu(struct rcu_head
*head
)
37 struct relay_viewer_stream
*vstream
=
38 caa_container_of(head
, struct relay_viewer_stream
, rcu_node
);
40 viewer_stream_destroy(vstream
);
43 struct relay_viewer_stream
*viewer_stream_create(struct relay_stream
*stream
,
44 enum lttng_viewer_seek seek_t
)
46 struct relay_viewer_stream
*vstream
;
48 vstream
= zmalloc(sizeof(*vstream
));
50 PERROR("relay viewer stream zmalloc");
54 vstream
->path_name
= lttng_strndup(stream
->path_name
, LTTNG_VIEWER_PATH_MAX
);
55 if (vstream
->path_name
== NULL
) {
56 PERROR("relay viewer path_name alloc");
59 vstream
->channel_name
= lttng_strndup(stream
->channel_name
,
60 LTTNG_VIEWER_NAME_MAX
);
61 if (vstream
->channel_name
== NULL
) {
62 PERROR("relay viewer channel_name alloc");
66 if (!stream_get(stream
)) {
67 ERR("Cannot get stream");
70 vstream
->stream
= stream
;
72 pthread_mutex_lock(&stream
->lock
);
74 if (stream
->is_metadata
&& stream
->trace
->viewer_metadata_stream
) {
75 ERR("Cannot attach viewer metadata stream to trace (busy).");
80 case LTTNG_VIEWER_SEEK_BEGINNING
:
82 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
84 if (seq_tail
== -1ULL) {
86 * Tail may not be initialized yet. Nonetheless, we know
87 * we want to send the first index once it becomes
92 vstream
->current_tracefile_id
=
93 tracefile_array_get_file_index_tail(stream
->tfa
);
94 vstream
->index_sent_seqcount
= seq_tail
;
97 case LTTNG_VIEWER_SEEK_LAST
:
98 vstream
->current_tracefile_id
=
99 tracefile_array_get_file_index_head(stream
->tfa
);
101 * We seek at the very end of each stream, awaiting for
102 * a future packet to eventually come in.
104 * We don't need to check the head position for -1ULL since the
105 * increment will set it to 0.
107 vstream
->index_sent_seqcount
=
108 tracefile_array_get_seq_head(stream
->tfa
) + 1;
115 * If we never received an index for the current stream, delay
116 * the opening of the index, otherwise open it right now.
118 if (stream
->index_received_seqcount
== 0) {
119 vstream
->index_fd
= NULL
;
123 read_fd
= index_open(vstream
->path_name
, vstream
->channel_name
,
124 stream
->tracefile_count
,
125 vstream
->current_tracefile_id
);
129 vstream
->index_fd
= stream_fd_create(read_fd
);
130 if (!vstream
->index_fd
) {
131 if (close(read_fd
)) {
138 if (seek_t
== LTTNG_VIEWER_SEEK_LAST
&& vstream
->index_fd
) {
141 lseek_ret
= lseek(vstream
->index_fd
->fd
, 0, SEEK_END
);
146 if (stream
->is_metadata
) {
147 rcu_assign_pointer(stream
->trace
->viewer_metadata_stream
,
150 pthread_mutex_unlock(&stream
->lock
);
152 /* Globally visible after the add unique. */
153 lttng_ht_node_init_u64(&vstream
->stream_n
, stream
->stream_handle
);
154 lttng_ht_add_unique_u64(viewer_streams_ht
, &vstream
->stream_n
);
156 pthread_mutex_init(&vstream
->reflock
, NULL
);
157 urcu_ref_init(&vstream
->ref
);
162 pthread_mutex_unlock(&stream
->lock
);
165 viewer_stream_destroy(vstream
);
170 static void viewer_stream_unpublish(struct relay_viewer_stream
*vstream
)
173 struct lttng_ht_iter iter
;
175 iter
.iter
.node
= &vstream
->stream_n
.node
;
176 ret
= lttng_ht_del(viewer_streams_ht
, &iter
);
180 static void viewer_stream_release(struct urcu_ref
*ref
)
182 struct relay_viewer_stream
*vstream
= caa_container_of(ref
,
183 struct relay_viewer_stream
, ref
);
185 if (vstream
->stream
->is_metadata
) {
186 rcu_assign_pointer(vstream
->stream
->trace
->viewer_metadata_stream
, NULL
);
189 viewer_stream_unpublish(vstream
);
191 if (vstream
->stream_fd
) {
192 stream_fd_put(vstream
->stream_fd
);
193 vstream
->stream_fd
= NULL
;
195 if (vstream
->index_fd
) {
196 stream_fd_put(vstream
->index_fd
);
197 vstream
->index_fd
= NULL
;
199 if (vstream
->stream
) {
200 stream_put(vstream
->stream
);
201 vstream
->stream
= NULL
;
203 call_rcu(&vstream
->rcu_node
, viewer_stream_destroy_rcu
);
206 /* Must be called with RCU read-side lock held. */
207 bool viewer_stream_get(struct relay_viewer_stream
*vstream
)
209 bool has_ref
= false;
211 pthread_mutex_lock(&vstream
->reflock
);
212 if (vstream
->ref
.refcount
!= 0) {
214 urcu_ref_get(&vstream
->ref
);
216 pthread_mutex_unlock(&vstream
->reflock
);
222 * Get viewer stream by id.
224 * Return viewer stream if found else NULL.
226 struct relay_viewer_stream
*viewer_stream_get_by_id(uint64_t id
)
228 struct lttng_ht_node_u64
*node
;
229 struct lttng_ht_iter iter
;
230 struct relay_viewer_stream
*vstream
= NULL
;
233 lttng_ht_lookup(viewer_streams_ht
, &id
, &iter
);
234 node
= lttng_ht_iter_get_node_u64(&iter
);
236 DBG("Relay viewer stream %" PRIu64
" not found", id
);
239 vstream
= caa_container_of(node
, struct relay_viewer_stream
, stream_n
);
240 if (!viewer_stream_get(vstream
)) {
248 void viewer_stream_put(struct relay_viewer_stream
*vstream
)
251 pthread_mutex_lock(&vstream
->reflock
);
252 urcu_ref_put(&vstream
->ref
, viewer_stream_release
);
253 pthread_mutex_unlock(&vstream
->reflock
);
258 * Rotate a stream to the next tracefile.
260 * Must be called with the rstream lock held.
261 * Returns 0 on success, 1 on EOF, a negative value on error.
263 int viewer_stream_rotate(struct relay_viewer_stream
*vstream
)
266 struct relay_stream
*stream
= vstream
->stream
;
269 /* Detect the last tracefile to open. */
270 if (stream
->index_received_seqcount
271 == vstream
->index_sent_seqcount
272 && stream
->trace
->session
->connection_closed
) {
277 if (stream
->tracefile_count
== 0) {
278 /* Ignore rotation, there is none to do. */
284 * Try to move to the next file.
286 new_id
= (vstream
->current_tracefile_id
+ 1)
287 % stream
->tracefile_count
;
288 if (tracefile_array_seq_in_file(stream
->tfa
, new_id
,
289 vstream
->index_sent_seqcount
)) {
290 vstream
->current_tracefile_id
= new_id
;
292 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
295 * This can only be reached on overwrite, which implies there
296 * has been data written at some point, which will have set the
299 assert(seq_tail
!= -1ULL);
301 * We need to resync because we lag behind tail.
303 vstream
->current_tracefile_id
=
304 tracefile_array_get_file_index_tail(stream
->tfa
);
305 vstream
->index_sent_seqcount
= seq_tail
;
308 if (vstream
->index_fd
) {
309 stream_fd_put(vstream
->index_fd
);
310 vstream
->index_fd
= NULL
;
312 if (vstream
->stream_fd
) {
313 stream_fd_put(vstream
->stream_fd
);
314 vstream
->stream_fd
= NULL
;
317 ret
= index_open(vstream
->path_name
, vstream
->channel_name
,
318 stream
->tracefile_count
,
319 vstream
->current_tracefile_id
);
323 vstream
->index_fd
= stream_fd_create(ret
);
324 if (vstream
->index_fd
) {
336 void print_viewer_streams(void)
338 struct lttng_ht_iter iter
;
339 struct relay_viewer_stream
*vstream
;
341 if (!viewer_streams_ht
) {
346 cds_lfht_for_each_entry(viewer_streams_ht
->ht
, &iter
.iter
, vstream
,
348 if (!viewer_stream_get(vstream
)) {
351 DBG("vstream %p refcount %ld stream %" PRIu64
" trace %" PRIu64
354 vstream
->ref
.refcount
,
355 vstream
->stream
->stream_handle
,
356 vstream
->stream
->trace
->id
,
357 vstream
->stream
->trace
->session
->id
);
358 viewer_stream_put(vstream
);