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 struct lttng_trace_chunk
*viewer_trace_chunk
,
45 enum lttng_viewer_seek seek_t
)
47 struct relay_viewer_stream
*vstream
= NULL
;
48 const bool acquired_reference
= lttng_trace_chunk_get(
51 if (!acquired_reference
) {
55 vstream
= zmalloc(sizeof(*vstream
));
57 PERROR("relay viewer stream zmalloc");
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");
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");
75 if (!stream_get(stream
)) {
76 ERR("Cannot get stream");
79 vstream
->stream
= stream
;
81 pthread_mutex_lock(&stream
->lock
);
83 if (stream
->is_metadata
&& stream
->trace
->viewer_metadata_stream
) {
84 ERR("Cannot attach viewer metadata stream to trace (busy).");
89 case LTTNG_VIEWER_SEEK_BEGINNING
:
91 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
93 if (seq_tail
== -1ULL) {
95 * Tail may not be initialized yet. Nonetheless, we know
96 * we want to send the first index once it becomes
101 vstream
->current_tracefile_id
=
102 tracefile_array_get_file_index_tail(stream
->tfa
);
103 vstream
->index_sent_seqcount
= seq_tail
;
106 case LTTNG_VIEWER_SEEK_LAST
:
107 vstream
->current_tracefile_id
=
108 tracefile_array_get_read_file_index_head(stream
->tfa
);
110 * We seek at the very end of each stream, awaiting for
111 * a future packet to eventually come in.
113 * We don't need to check the head position for -1ULL since the
114 * increment will set it to 0.
116 vstream
->index_sent_seqcount
=
117 tracefile_array_get_seq_head(stream
->tfa
) + 1;
124 * If we never received an index for the current stream, delay
125 * the opening of the index, otherwise open it right now.
127 if (stream
->index_received_seqcount
== 0) {
128 vstream
->index_file
= NULL
;
130 const uint32_t connection_major
= stream
->trace
->session
->major
;
131 const uint32_t connection_minor
= stream
->trace
->session
->minor
;
133 vstream
->index_file
= lttng_index_file_create_from_trace_chunk_read_only(
134 vstream
->stream_file
.trace_chunk
,
136 stream
->channel_name
, stream
->tracefile_size
,
137 vstream
->current_tracefile_id
,
138 lttng_to_index_major(connection_major
,
140 lttng_to_index_minor(connection_major
,
142 if (!vstream
->index_file
) {
147 if (seek_t
== LTTNG_VIEWER_SEEK_LAST
&& vstream
->index_file
) {
150 lseek_ret
= lseek(vstream
->index_file
->fd
, 0, SEEK_END
);
155 if (stream
->is_metadata
) {
156 rcu_assign_pointer(stream
->trace
->viewer_metadata_stream
,
159 pthread_mutex_unlock(&stream
->lock
);
161 /* Globally visible after the add unique. */
162 lttng_ht_node_init_u64(&vstream
->stream_n
, stream
->stream_handle
);
163 urcu_ref_init(&vstream
->ref
);
164 lttng_ht_add_unique_u64(viewer_streams_ht
, &vstream
->stream_n
);
169 pthread_mutex_unlock(&stream
->lock
);
172 viewer_stream_destroy(vstream
);
174 if (viewer_trace_chunk
&& acquired_reference
) {
175 lttng_trace_chunk_put(viewer_trace_chunk
);
180 static void viewer_stream_unpublish(struct relay_viewer_stream
*vstream
)
183 struct lttng_ht_iter iter
;
185 iter
.iter
.node
= &vstream
->stream_n
.node
;
186 ret
= lttng_ht_del(viewer_streams_ht
, &iter
);
190 static void viewer_stream_release(struct urcu_ref
*ref
)
192 struct relay_viewer_stream
*vstream
= caa_container_of(ref
,
193 struct relay_viewer_stream
, ref
);
195 if (vstream
->stream
->is_metadata
) {
196 rcu_assign_pointer(vstream
->stream
->trace
->viewer_metadata_stream
, NULL
);
199 viewer_stream_unpublish(vstream
);
201 if (vstream
->stream_file
.fd
) {
202 stream_fd_put(vstream
->stream_file
.fd
);
203 vstream
->stream_file
.fd
= NULL
;
205 if (vstream
->index_file
) {
206 lttng_index_file_put(vstream
->index_file
);
207 vstream
->index_file
= NULL
;
209 if (vstream
->stream
) {
210 stream_put(vstream
->stream
);
211 vstream
->stream
= NULL
;
213 lttng_trace_chunk_put(vstream
->stream_file
.trace_chunk
);
214 vstream
->stream_file
.trace_chunk
= NULL
;
215 call_rcu(&vstream
->rcu_node
, viewer_stream_destroy_rcu
);
218 /* Must be called with RCU read-side lock held. */
219 bool viewer_stream_get(struct relay_viewer_stream
*vstream
)
221 return urcu_ref_get_unless_zero(&vstream
->ref
);
225 * Get viewer stream by id.
227 * Return viewer stream if found else NULL.
229 struct relay_viewer_stream
*viewer_stream_get_by_id(uint64_t id
)
231 struct lttng_ht_node_u64
*node
;
232 struct lttng_ht_iter iter
;
233 struct relay_viewer_stream
*vstream
= NULL
;
236 lttng_ht_lookup(viewer_streams_ht
, &id
, &iter
);
237 node
= lttng_ht_iter_get_node_u64(&iter
);
239 DBG("Relay viewer stream %" PRIu64
" not found", id
);
242 vstream
= caa_container_of(node
, struct relay_viewer_stream
, stream_n
);
243 if (!viewer_stream_get(vstream
)) {
251 void viewer_stream_put(struct relay_viewer_stream
*vstream
)
254 urcu_ref_put(&vstream
->ref
, viewer_stream_release
);
259 * Rotate a stream to the next tracefile.
261 * Must be called with the rstream lock held.
262 * Returns 0 on success, 1 on EOF, a negative value on error.
264 int viewer_stream_rotate(struct relay_viewer_stream
*vstream
)
268 const struct relay_stream
*stream
= vstream
->stream
;
269 const uint32_t connection_major
= stream
->trace
->session
->major
;
270 const uint32_t connection_minor
= stream
->trace
->session
->minor
;
272 /* Detect the last tracefile to open. */
273 if (stream
->index_received_seqcount
274 == vstream
->index_sent_seqcount
275 && stream
->trace
->session
->connection_closed
) {
280 if (stream
->tracefile_count
== 0) {
281 /* Ignore rotation, there is none to do. */
287 * Try to move to the next file.
289 new_id
= (vstream
->current_tracefile_id
+ 1)
290 % stream
->tracefile_count
;
291 if (tracefile_array_seq_in_file(stream
->tfa
, new_id
,
292 vstream
->index_sent_seqcount
)) {
293 vstream
->current_tracefile_id
= new_id
;
295 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
298 * This can only be reached on overwrite, which implies there
299 * has been data written at some point, which will have set the
302 assert(seq_tail
!= -1ULL);
304 * We need to resync because we lag behind tail.
306 vstream
->current_tracefile_id
=
307 tracefile_array_get_file_index_tail(stream
->tfa
);
308 vstream
->index_sent_seqcount
= seq_tail
;
311 if (vstream
->index_file
) {
312 lttng_index_file_put(vstream
->index_file
);
313 vstream
->index_file
= NULL
;
315 if (vstream
->stream_file
.fd
) {
316 stream_fd_put(vstream
->stream_file
.fd
);
317 vstream
->stream_file
.fd
= NULL
;
319 vstream
->index_file
=
320 lttng_index_file_create_from_trace_chunk_read_only(
321 vstream
->stream_file
.trace_chunk
,
323 stream
->channel_name
,
324 stream
->tracefile_size
,
325 vstream
->current_tracefile_id
,
326 lttng_to_index_major(connection_major
,
328 lttng_to_index_minor(connection_major
,
330 if (!vstream
->index_file
) {
340 void print_viewer_streams(void)
342 struct lttng_ht_iter iter
;
343 struct relay_viewer_stream
*vstream
;
345 if (!viewer_streams_ht
) {
350 cds_lfht_for_each_entry(viewer_streams_ht
->ht
, &iter
.iter
, vstream
,
352 if (!viewer_stream_get(vstream
)) {
355 DBG("vstream %p refcount %ld stream %" PRIu64
" trace %" PRIu64
358 vstream
->ref
.refcount
,
359 vstream
->stream
->stream_handle
,
360 vstream
->stream
->trace
->id
,
361 vstream
->stream
->trace
->session
->id
);
362 viewer_stream_put(vstream
);