2 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
4 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
11 #include <common/common.h>
12 #include <common/index/index.h>
13 #include <common/compat/string.h>
14 #include <common/utils.h>
15 #include <sys/types.h>
19 #include "lttng-relayd.h"
20 #include "viewer-stream.h"
22 static void viewer_stream_release_composite_objects(struct relay_viewer_stream
*vstream
)
24 if (vstream
->stream_file
.handle
) {
25 fs_handle_close(vstream
->stream_file
.handle
);
26 vstream
->stream_file
.handle
= NULL
;
28 if (vstream
->index_file
) {
29 lttng_index_file_put(vstream
->index_file
);
30 vstream
->index_file
= NULL
;
32 if (vstream
->stream
) {
33 stream_put(vstream
->stream
);
34 vstream
->stream
= NULL
;
36 lttng_trace_chunk_put(vstream
->stream_file
.trace_chunk
);
37 vstream
->stream_file
.trace_chunk
= NULL
;
40 static void viewer_stream_destroy(struct relay_viewer_stream
*vstream
)
42 free(vstream
->path_name
);
43 free(vstream
->channel_name
);
47 static void viewer_stream_destroy_rcu(struct rcu_head
*head
)
49 struct relay_viewer_stream
*vstream
=
50 caa_container_of(head
, struct relay_viewer_stream
, rcu_node
);
52 viewer_stream_destroy(vstream
);
55 /* Relay stream's lock must be held by the caller. */
56 struct relay_viewer_stream
*viewer_stream_create(struct relay_stream
*stream
,
57 struct lttng_trace_chunk
*trace_chunk
,
58 enum lttng_viewer_seek seek_t
)
60 struct relay_viewer_stream
*vstream
= NULL
;
62 ASSERT_LOCKED(stream
->lock
);
64 vstream
= zmalloc(sizeof(*vstream
));
66 PERROR("relay viewer stream zmalloc");
71 const bool acquired_reference
= lttng_trace_chunk_get(
74 assert(acquired_reference
);
77 vstream
->stream_file
.trace_chunk
= trace_chunk
;
78 vstream
->path_name
= lttng_strndup(stream
->path_name
, LTTNG_VIEWER_PATH_MAX
);
79 if (vstream
->path_name
== NULL
) {
80 PERROR("relay viewer path_name alloc");
83 vstream
->channel_name
= lttng_strndup(stream
->channel_name
,
84 LTTNG_VIEWER_NAME_MAX
);
85 if (vstream
->channel_name
== NULL
) {
86 PERROR("relay viewer channel_name alloc");
90 if (!stream_get(stream
)) {
91 ERR("Cannot get stream");
94 vstream
->stream
= stream
;
96 if (stream
->is_metadata
&& stream
->trace
->viewer_metadata_stream
) {
97 ERR("Cannot attach viewer metadata stream to trace (busy).");
102 case LTTNG_VIEWER_SEEK_BEGINNING
:
104 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
106 if (seq_tail
== -1ULL) {
108 * Tail may not be initialized yet. Nonetheless, we know
109 * we want to send the first index once it becomes
114 vstream
->current_tracefile_id
=
115 tracefile_array_get_file_index_tail(stream
->tfa
);
116 vstream
->index_sent_seqcount
= seq_tail
;
119 case LTTNG_VIEWER_SEEK_LAST
:
120 vstream
->current_tracefile_id
=
121 tracefile_array_get_read_file_index_head(stream
->tfa
);
123 * We seek at the very end of each stream, awaiting for
124 * a future packet to eventually come in.
126 * We don't need to check the head position for -1ULL since the
127 * increment will set it to 0.
129 vstream
->index_sent_seqcount
=
130 tracefile_array_get_seq_head(stream
->tfa
) + 1;
137 * If we never received an index for the current stream, delay
138 * the opening of the index, otherwise open it right now.
140 if (stream
->index_file
== NULL
) {
141 vstream
->index_file
= NULL
;
143 const uint32_t connection_major
= stream
->trace
->session
->major
;
144 const uint32_t connection_minor
= stream
->trace
->session
->minor
;
145 enum lttng_trace_chunk_status chunk_status
;
147 chunk_status
= lttng_index_file_create_from_trace_chunk_read_only(
148 vstream
->stream_file
.trace_chunk
,
150 stream
->channel_name
, stream
->tracefile_size
,
151 vstream
->current_tracefile_id
,
152 lttng_to_index_major(connection_major
,
154 lttng_to_index_minor(connection_major
,
156 true, &vstream
->index_file
);
157 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
158 if (chunk_status
== LTTNG_TRACE_CHUNK_STATUS_NO_FILE
) {
159 vstream
->index_file
= NULL
;
167 * If we never received a data file for the current stream, delay the
168 * opening, otherwise open it right now.
172 char file_path
[LTTNG_PATH_MAX
];
173 enum lttng_trace_chunk_status status
;
175 ret
= utils_stream_file_path(stream
->path_name
,
176 stream
->channel_name
, stream
->tracefile_size
,
177 vstream
->current_tracefile_id
, NULL
, file_path
,
183 status
= lttng_trace_chunk_open_fs_handle(
184 vstream
->stream_file
.trace_chunk
, file_path
,
185 O_RDONLY
, 0, &vstream
->stream_file
.handle
,
187 if (status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
192 if (seek_t
== LTTNG_VIEWER_SEEK_LAST
&& vstream
->index_file
) {
195 lseek_ret
= fs_handle_seek(
196 vstream
->index_file
->file
, 0, SEEK_END
);
201 if (stream
->is_metadata
) {
202 rcu_assign_pointer(stream
->trace
->viewer_metadata_stream
,
206 vstream
->last_seen_rotation_count
= stream
->completed_rotation_count
;
208 /* Globally visible after the add unique. */
209 lttng_ht_node_init_u64(&vstream
->stream_n
, stream
->stream_handle
);
210 urcu_ref_init(&vstream
->ref
);
211 lttng_ht_add_unique_u64(viewer_streams_ht
, &vstream
->stream_n
);
217 /* Not using `put` since vstream is assumed to be published. */
218 viewer_stream_release_composite_objects(vstream
);
219 viewer_stream_destroy(vstream
);
224 static void viewer_stream_unpublish(struct relay_viewer_stream
*vstream
)
227 struct lttng_ht_iter iter
;
229 iter
.iter
.node
= &vstream
->stream_n
.node
;
230 ret
= lttng_ht_del(viewer_streams_ht
, &iter
);
234 static void viewer_stream_release(struct urcu_ref
*ref
)
236 struct relay_viewer_stream
*vstream
= caa_container_of(ref
,
237 struct relay_viewer_stream
, ref
);
239 if (vstream
->stream
->is_metadata
) {
240 rcu_assign_pointer(vstream
->stream
->trace
->viewer_metadata_stream
, NULL
);
242 viewer_stream_unpublish(vstream
);
243 viewer_stream_release_composite_objects(vstream
);
244 call_rcu(&vstream
->rcu_node
, viewer_stream_destroy_rcu
);
247 /* Must be called with RCU read-side lock held. */
248 bool viewer_stream_get(struct relay_viewer_stream
*vstream
)
250 return urcu_ref_get_unless_zero(&vstream
->ref
);
254 * Get viewer stream by id.
256 * Return viewer stream if found else NULL.
258 struct relay_viewer_stream
*viewer_stream_get_by_id(uint64_t id
)
260 struct lttng_ht_node_u64
*node
;
261 struct lttng_ht_iter iter
;
262 struct relay_viewer_stream
*vstream
= NULL
;
265 lttng_ht_lookup(viewer_streams_ht
, &id
, &iter
);
266 node
= lttng_ht_iter_get_node_u64(&iter
);
268 DBG("Relay viewer stream %" PRIu64
" not found", id
);
271 vstream
= caa_container_of(node
, struct relay_viewer_stream
, stream_n
);
272 if (!viewer_stream_get(vstream
)) {
280 void viewer_stream_put(struct relay_viewer_stream
*vstream
)
283 urcu_ref_put(&vstream
->ref
, viewer_stream_release
);
287 void viewer_stream_close_files(struct relay_viewer_stream
*vstream
)
289 if (vstream
->index_file
) {
290 lttng_index_file_put(vstream
->index_file
);
291 vstream
->index_file
= NULL
;
293 if (vstream
->stream_file
.handle
) {
294 fs_handle_close(vstream
->stream_file
.handle
);
295 vstream
->stream_file
.handle
= NULL
;
299 void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream
*vstream
)
301 const struct relay_stream
*stream
= vstream
->stream
;
304 vstream
->current_tracefile_id
= tracefile_array_get_file_index_tail(stream
->tfa
);
305 seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
306 if (seq_tail
== -1ULL) {
311 * Move the index sent seqcount forward if it was lagging behind
312 * the new tail of the tracefile array. If the current
313 * index_sent_seqcount is already further than the tracefile
314 * array tail position, keep its current position.
316 vstream
->index_sent_seqcount
= seq_tail
> vstream
->index_sent_seqcount
?
317 seq_tail
: vstream
->index_sent_seqcount
;
321 * Rotate a stream to the next tracefile.
323 * Must be called with the rstream lock held.
324 * Returns 0 on success, 1 on EOF.
326 int viewer_stream_rotate(struct relay_viewer_stream
*vstream
)
330 const struct relay_stream
*stream
= vstream
->stream
;
332 /* Detect the last tracefile to open. */
333 if (stream
->index_received_seqcount
334 == vstream
->index_sent_seqcount
335 && stream
->trace
->session
->connection_closed
) {
340 if (stream
->tracefile_count
== 0) {
341 /* Ignore rotation, there is none to do. */
347 * Try to move to the next file.
349 new_id
= (vstream
->current_tracefile_id
+ 1)
350 % stream
->tracefile_count
;
351 if (tracefile_array_seq_in_file(stream
->tfa
, new_id
,
352 vstream
->index_sent_seqcount
)) {
353 vstream
->current_tracefile_id
= new_id
;
355 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
358 * This can only be reached on overwrite, which implies there
359 * has been data written at some point, which will have set the
362 assert(seq_tail
!= -1ULL);
364 * We need to resync because we lag behind tail.
366 vstream
->current_tracefile_id
=
367 tracefile_array_get_file_index_tail(stream
->tfa
);
368 vstream
->index_sent_seqcount
= seq_tail
;
370 viewer_stream_close_files(vstream
);
376 void print_viewer_streams(void)
378 struct lttng_ht_iter iter
;
379 struct relay_viewer_stream
*vstream
;
381 if (!viewer_streams_ht
) {
386 cds_lfht_for_each_entry(viewer_streams_ht
->ht
, &iter
.iter
, vstream
,
388 if (!viewer_stream_get(vstream
)) {
391 DBG("vstream %p refcount %ld stream %" PRIu64
" trace %" PRIu64
394 vstream
->ref
.refcount
,
395 vstream
->stream
->stream_handle
,
396 vstream
->stream
->trace
->id
,
397 vstream
->stream
->trace
->session
->id
);
398 viewer_stream_put(vstream
);