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_destroy(struct relay_viewer_stream
*vstream
)
24 free(vstream
->path_name
);
25 free(vstream
->channel_name
);
29 static void viewer_stream_destroy_rcu(struct rcu_head
*head
)
31 struct relay_viewer_stream
*vstream
=
32 caa_container_of(head
, struct relay_viewer_stream
, rcu_node
);
34 viewer_stream_destroy(vstream
);
37 /* Relay stream's lock must be held by the caller. */
38 struct relay_viewer_stream
*viewer_stream_create(struct relay_stream
*stream
,
39 struct lttng_trace_chunk
*trace_chunk
,
40 enum lttng_viewer_seek seek_t
)
42 struct relay_viewer_stream
*vstream
= NULL
;
43 const bool acquired_reference
= lttng_trace_chunk_get(trace_chunk
);
45 ASSERT_LOCKED(stream
->lock
);
46 if (!acquired_reference
) {
50 vstream
= zmalloc(sizeof(*vstream
));
52 PERROR("relay viewer stream zmalloc");
56 vstream
->stream_file
.trace_chunk
= trace_chunk
;
58 vstream
->path_name
= lttng_strndup(stream
->path_name
, LTTNG_VIEWER_PATH_MAX
);
59 if (vstream
->path_name
== NULL
) {
60 PERROR("relay viewer path_name alloc");
63 vstream
->channel_name
= lttng_strndup(stream
->channel_name
,
64 LTTNG_VIEWER_NAME_MAX
);
65 if (vstream
->channel_name
== NULL
) {
66 PERROR("relay viewer channel_name alloc");
70 if (!stream_get(stream
)) {
71 ERR("Cannot get stream");
74 vstream
->stream
= stream
;
76 if (stream
->is_metadata
&& stream
->trace
->viewer_metadata_stream
) {
77 ERR("Cannot attach viewer metadata stream to trace (busy).");
82 case LTTNG_VIEWER_SEEK_BEGINNING
:
84 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
86 if (seq_tail
== -1ULL) {
88 * Tail may not be initialized yet. Nonetheless, we know
89 * we want to send the first index once it becomes
94 vstream
->current_tracefile_id
=
95 tracefile_array_get_file_index_tail(stream
->tfa
);
96 vstream
->index_sent_seqcount
= seq_tail
;
99 case LTTNG_VIEWER_SEEK_LAST
:
100 vstream
->current_tracefile_id
=
101 tracefile_array_get_read_file_index_head(stream
->tfa
);
103 * We seek at the very end of each stream, awaiting for
104 * a future packet to eventually come in.
106 * We don't need to check the head position for -1ULL since the
107 * increment will set it to 0.
109 vstream
->index_sent_seqcount
=
110 tracefile_array_get_seq_head(stream
->tfa
) + 1;
117 * If we never received an index for the current stream, delay
118 * the opening of the index, otherwise open it right now.
120 if (stream
->index_file
== NULL
) {
121 vstream
->index_file
= NULL
;
123 const uint32_t connection_major
= stream
->trace
->session
->major
;
124 const uint32_t connection_minor
= stream
->trace
->session
->minor
;
125 enum lttng_trace_chunk_status chunk_status
;
127 chunk_status
= lttng_index_file_create_from_trace_chunk_read_only(
128 vstream
->stream_file
.trace_chunk
,
130 stream
->channel_name
, stream
->tracefile_size
,
131 vstream
->current_tracefile_id
,
132 lttng_to_index_major(connection_major
,
134 lttng_to_index_minor(connection_major
,
136 true, &vstream
->index_file
);
137 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
138 if (chunk_status
== LTTNG_TRACE_CHUNK_STATUS_NO_FILE
) {
139 vstream
->index_file
= NULL
;
147 * If we never received a data file for the current stream, delay the
148 * opening, otherwise open it right now.
152 char file_path
[LTTNG_PATH_MAX
];
153 enum lttng_trace_chunk_status status
;
155 ret
= utils_stream_file_path(stream
->path_name
,
156 stream
->channel_name
, stream
->tracefile_size
,
157 vstream
->current_tracefile_id
, NULL
, file_path
,
163 status
= lttng_trace_chunk_open_fs_handle(
164 vstream
->stream_file
.trace_chunk
, file_path
,
165 O_RDONLY
, 0, &vstream
->stream_file
.handle
,
167 if (status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
172 if (seek_t
== LTTNG_VIEWER_SEEK_LAST
&& vstream
->index_file
) {
175 lseek_ret
= fs_handle_seek(
176 vstream
->index_file
->file
, 0, SEEK_END
);
181 if (stream
->is_metadata
) {
182 rcu_assign_pointer(stream
->trace
->viewer_metadata_stream
,
186 /* Globally visible after the add unique. */
187 lttng_ht_node_init_u64(&vstream
->stream_n
, stream
->stream_handle
);
188 urcu_ref_init(&vstream
->ref
);
189 lttng_ht_add_unique_u64(viewer_streams_ht
, &vstream
->stream_n
);
195 viewer_stream_destroy(vstream
);
197 if (trace_chunk
&& acquired_reference
) {
198 lttng_trace_chunk_put(trace_chunk
);
203 static void viewer_stream_unpublish(struct relay_viewer_stream
*vstream
)
206 struct lttng_ht_iter iter
;
208 iter
.iter
.node
= &vstream
->stream_n
.node
;
209 ret
= lttng_ht_del(viewer_streams_ht
, &iter
);
213 static void viewer_stream_release(struct urcu_ref
*ref
)
215 struct relay_viewer_stream
*vstream
= caa_container_of(ref
,
216 struct relay_viewer_stream
, ref
);
218 if (vstream
->stream
->is_metadata
) {
219 rcu_assign_pointer(vstream
->stream
->trace
->viewer_metadata_stream
, NULL
);
222 viewer_stream_unpublish(vstream
);
224 if (vstream
->stream_file
.handle
) {
225 fs_handle_close(vstream
->stream_file
.handle
);
226 vstream
->stream_file
.handle
= NULL
;
228 if (vstream
->index_file
) {
229 lttng_index_file_put(vstream
->index_file
);
230 vstream
->index_file
= NULL
;
232 if (vstream
->stream
) {
233 stream_put(vstream
->stream
);
234 vstream
->stream
= NULL
;
236 lttng_trace_chunk_put(vstream
->stream_file
.trace_chunk
);
237 vstream
->stream_file
.trace_chunk
= NULL
;
238 call_rcu(&vstream
->rcu_node
, viewer_stream_destroy_rcu
);
241 /* Must be called with RCU read-side lock held. */
242 bool viewer_stream_get(struct relay_viewer_stream
*vstream
)
244 return urcu_ref_get_unless_zero(&vstream
->ref
);
248 * Get viewer stream by id.
250 * Return viewer stream if found else NULL.
252 struct relay_viewer_stream
*viewer_stream_get_by_id(uint64_t id
)
254 struct lttng_ht_node_u64
*node
;
255 struct lttng_ht_iter iter
;
256 struct relay_viewer_stream
*vstream
= NULL
;
259 lttng_ht_lookup(viewer_streams_ht
, &id
, &iter
);
260 node
= lttng_ht_iter_get_node_u64(&iter
);
262 DBG("Relay viewer stream %" PRIu64
" not found", id
);
265 vstream
= caa_container_of(node
, struct relay_viewer_stream
, stream_n
);
266 if (!viewer_stream_get(vstream
)) {
274 void viewer_stream_put(struct relay_viewer_stream
*vstream
)
277 urcu_ref_put(&vstream
->ref
, viewer_stream_release
);
281 void viewer_stream_close_files(struct relay_viewer_stream
*vstream
)
283 if (vstream
->index_file
) {
284 lttng_index_file_put(vstream
->index_file
);
285 vstream
->index_file
= NULL
;
287 if (vstream
->stream_file
.handle
) {
288 fs_handle_close(vstream
->stream_file
.handle
);
289 vstream
->stream_file
.handle
= NULL
;
293 void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream
*vstream
)
295 const struct relay_stream
*stream
= vstream
->stream
;
298 vstream
->current_tracefile_id
= tracefile_array_get_file_index_tail(stream
->tfa
);
299 seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
300 if (seq_tail
== -1ULL) {
303 vstream
->index_sent_seqcount
= seq_tail
;
307 * Rotate a stream to the next tracefile.
309 * Must be called with the rstream lock held.
310 * Returns 0 on success, 1 on EOF.
312 int viewer_stream_rotate(struct relay_viewer_stream
*vstream
)
316 const struct relay_stream
*stream
= vstream
->stream
;
318 /* Detect the last tracefile to open. */
319 if (stream
->index_received_seqcount
320 == vstream
->index_sent_seqcount
321 && stream
->trace
->session
->connection_closed
) {
326 if (stream
->tracefile_count
== 0) {
327 /* Ignore rotation, there is none to do. */
333 * Try to move to the next file.
335 new_id
= (vstream
->current_tracefile_id
+ 1)
336 % stream
->tracefile_count
;
337 if (tracefile_array_seq_in_file(stream
->tfa
, new_id
,
338 vstream
->index_sent_seqcount
)) {
339 vstream
->current_tracefile_id
= new_id
;
341 uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
344 * This can only be reached on overwrite, which implies there
345 * has been data written at some point, which will have set the
348 assert(seq_tail
!= -1ULL);
350 * We need to resync because we lag behind tail.
352 vstream
->current_tracefile_id
=
353 tracefile_array_get_file_index_tail(stream
->tfa
);
354 vstream
->index_sent_seqcount
= seq_tail
;
356 viewer_stream_close_files(vstream
);
362 void print_viewer_streams(void)
364 struct lttng_ht_iter iter
;
365 struct relay_viewer_stream
*vstream
;
367 if (!viewer_streams_ht
) {
372 cds_lfht_for_each_entry(viewer_streams_ht
->ht
, &iter
.iter
, vstream
,
374 if (!viewer_stream_get(vstream
)) {
377 DBG("vstream %p refcount %ld stream %" PRIu64
" trace %" PRIu64
380 vstream
->ref
.refcount
,
381 vstream
->stream
->stream_handle
,
382 vstream
->stream
->trace
->id
,
383 vstream
->stream
->trace
->session
->id
);
384 viewer_stream_put(vstream
);