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 "lttng-relayd.hpp"
12 #include "viewer-stream.hpp"
14 #include <common/common.hpp>
15 #include <common/compat/string.hpp>
16 #include <common/index/index.hpp>
17 #include <common/urcu.hpp>
18 #include <common/utils.hpp>
23 #include <sys/types.h>
25 static void viewer_stream_release_composite_objects(struct relay_viewer_stream
*vstream
)
27 if (vstream
->stream_file
.handle
) {
28 fs_handle_close(vstream
->stream_file
.handle
);
29 vstream
->stream_file
.handle
= nullptr;
31 if (vstream
->index_file
) {
32 lttng_index_file_put(vstream
->index_file
);
33 vstream
->index_file
= nullptr;
35 if (vstream
->stream
) {
36 stream_put(vstream
->stream
);
37 vstream
->stream
= nullptr;
39 lttng_trace_chunk_put(vstream
->stream_file
.trace_chunk
);
40 vstream
->stream_file
.trace_chunk
= nullptr;
43 static void viewer_stream_destroy(struct relay_viewer_stream
*vstream
)
45 free(vstream
->path_name
);
46 free(vstream
->channel_name
);
50 static void viewer_stream_destroy_rcu(struct rcu_head
*head
)
52 struct relay_viewer_stream
*vstream
=
53 lttng::utils::container_of(head
, &relay_viewer_stream::rcu_node
);
55 viewer_stream_destroy(vstream
);
58 /* Relay stream's lock must be held by the caller. */
59 struct relay_viewer_stream
*viewer_stream_create(struct relay_stream
*stream
,
60 struct lttng_trace_chunk
*trace_chunk
,
61 enum lttng_viewer_seek seek_t
)
63 struct relay_viewer_stream
*vstream
= nullptr;
65 ASSERT_LOCKED(stream
->lock
);
67 vstream
= zmalloc
<relay_viewer_stream
>();
69 PERROR("relay viewer stream zmalloc");
73 const bool acquired_reference
= lttng_trace_chunk_get(trace_chunk
);
75 LTTNG_ASSERT(acquired_reference
);
78 vstream
->stream_file
.trace_chunk
= trace_chunk
;
79 vstream
->path_name
= lttng_strndup(stream
->path_name
, LTTNG_VIEWER_PATH_MAX
);
80 if (vstream
->path_name
== nullptr) {
81 PERROR("relay viewer path_name alloc");
84 vstream
->channel_name
= lttng_strndup(stream
->channel_name
, LTTNG_VIEWER_NAME_MAX
);
85 if (vstream
->channel_name
== nullptr) {
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
= tracefile_array_get_file_index_tail(stream
->tfa
);
115 vstream
->index_sent_seqcount
= seq_tail
;
118 case LTTNG_VIEWER_SEEK_LAST
:
119 vstream
->current_tracefile_id
=
120 tracefile_array_get_read_file_index_head(stream
->tfa
);
122 * We seek at the very end of each stream, awaiting for
123 * a future packet to eventually come in.
125 * We don't need to check the head position for -1ULL since the
126 * increment will set it to 0.
128 vstream
->index_sent_seqcount
= tracefile_array_get_seq_head(stream
->tfa
) + 1;
135 * If we never received an index for the current stream, delay
136 * the opening of the index, otherwise open it right now.
138 if (stream
->index_file
== nullptr) {
139 vstream
->index_file
= nullptr;
140 } else if (vstream
->stream_file
.trace_chunk
) {
141 const uint32_t connection_major
= stream
->trace
->session
->major
;
142 const uint32_t connection_minor
= stream
->trace
->session
->minor
;
143 enum lttng_trace_chunk_status chunk_status
;
145 chunk_status
= lttng_index_file_create_from_trace_chunk_read_only(
146 vstream
->stream_file
.trace_chunk
,
148 stream
->channel_name
,
149 stream
->tracefile_size
,
150 vstream
->current_tracefile_id
,
151 lttng_to_index_major(connection_major
, connection_minor
),
152 lttng_to_index_minor(connection_major
, connection_minor
),
154 &vstream
->index_file
);
155 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
156 if (chunk_status
== LTTNG_TRACE_CHUNK_STATUS_NO_FILE
) {
157 vstream
->index_file
= nullptr;
165 * If we never received a data file for the current stream, delay the
166 * opening, otherwise open it right now.
168 if (stream
->file
&& vstream
->stream_file
.trace_chunk
) {
170 char file_path
[LTTNG_PATH_MAX
];
171 enum lttng_trace_chunk_status status
;
173 ret
= utils_stream_file_path(stream
->path_name
,
174 stream
->channel_name
,
175 stream
->tracefile_size
,
176 vstream
->current_tracefile_id
,
184 status
= lttng_trace_chunk_open_fs_handle(vstream
->stream_file
.trace_chunk
,
188 &vstream
->stream_file
.handle
,
190 if (status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
195 if (seek_t
== LTTNG_VIEWER_SEEK_LAST
&& vstream
->index_file
) {
198 lseek_ret
= fs_handle_seek(vstream
->index_file
->file
, 0, SEEK_END
);
203 if (stream
->is_metadata
) {
204 rcu_assign_pointer(stream
->trace
->viewer_metadata_stream
, vstream
);
207 vstream
->last_seen_rotation_count
= stream
->completed_rotation_count
;
209 /* Globally visible after the add unique. */
210 lttng_ht_node_init_u64(&vstream
->stream_n
, stream
->stream_handle
);
211 urcu_ref_init(&vstream
->ref
);
212 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 auto *vstream
= lttng::utils::container_of(ref
, &relay_viewer_stream::ref
);
238 if (vstream
->stream
->is_metadata
) {
239 rcu_assign_pointer(vstream
->stream
->trace
->viewer_metadata_stream
, NULL
);
241 viewer_stream_unpublish(vstream
);
242 viewer_stream_release_composite_objects(vstream
);
243 call_rcu(&vstream
->rcu_node
, viewer_stream_destroy_rcu
);
246 /* Must be called with RCU read-side lock held. */
247 bool viewer_stream_get(struct relay_viewer_stream
*vstream
)
249 return urcu_ref_get_unless_zero(&vstream
->ref
);
253 * Get viewer stream by id.
255 * Return viewer stream if found else NULL.
257 struct relay_viewer_stream
*viewer_stream_get_by_id(uint64_t id
)
259 struct lttng_ht_node_u64
*node
;
260 struct lttng_ht_iter iter
;
261 struct relay_viewer_stream
*vstream
= nullptr;
263 const lttng::urcu::read_lock_guard read_lock
;
264 lttng_ht_lookup(viewer_streams_ht
, &id
, &iter
);
265 node
= lttng_ht_iter_get_node
<lttng_ht_node_u64
>(&iter
);
267 DBG("Relay viewer stream %" PRIu64
" not found", id
);
270 vstream
= lttng::utils::container_of(node
, &relay_viewer_stream::stream_n
);
271 if (!viewer_stream_get(vstream
)) {
278 void viewer_stream_put(struct relay_viewer_stream
*vstream
)
280 const lttng::urcu::read_lock_guard read_lock
;
281 urcu_ref_put(&vstream
->ref
, viewer_stream_release
);
284 void viewer_stream_close_files(struct relay_viewer_stream
*vstream
)
286 if (vstream
->index_file
) {
287 lttng_index_file_put(vstream
->index_file
);
288 vstream
->index_file
= nullptr;
290 if (vstream
->stream_file
.handle
) {
291 fs_handle_close(vstream
->stream_file
.handle
);
292 vstream
->stream_file
.handle
= nullptr;
296 void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream
*vstream
)
298 const struct relay_stream
*stream
= vstream
->stream
;
301 vstream
->current_tracefile_id
= tracefile_array_get_file_index_tail(stream
->tfa
);
302 seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
303 if (seq_tail
== -1ULL) {
308 * Move the index sent seqcount forward if it was lagging behind
309 * the new tail of the tracefile array. If the current
310 * index_sent_seqcount is already further than the tracefile
311 * array tail position, keep its current position.
313 vstream
->index_sent_seqcount
= std::max(seq_tail
, vstream
->index_sent_seqcount
);
317 * Rotate a stream to the next tracefile.
319 * Must be called with the rstream lock held.
320 * Returns 0 on success, 1 on EOF.
322 int viewer_stream_rotate(struct relay_viewer_stream
*vstream
)
326 const struct relay_stream
*stream
= vstream
->stream
;
328 /* Detect the last tracefile to open. */
329 if (stream
->index_received_seqcount
== vstream
->index_sent_seqcount
&&
330 stream
->trace
->session
->connection_closed
) {
335 if (stream
->tracefile_count
== 0) {
336 /* Ignore rotation, there is none to do. */
342 * Try to move to the next file.
344 new_id
= (vstream
->current_tracefile_id
+ 1) % stream
->tracefile_count
;
345 if (tracefile_array_seq_in_file(stream
->tfa
, new_id
, vstream
->index_sent_seqcount
)) {
346 vstream
->current_tracefile_id
= new_id
;
348 const uint64_t seq_tail
= tracefile_array_get_seq_tail(stream
->tfa
);
351 * This can only be reached on overwrite, which implies there
352 * has been data written at some point, which will have set the
355 LTTNG_ASSERT(seq_tail
!= -1ULL);
357 * We need to resync because we lag behind tail.
359 vstream
->current_tracefile_id
= tracefile_array_get_file_index_tail(stream
->tfa
);
360 vstream
->index_sent_seqcount
= seq_tail
;
362 viewer_stream_close_files(vstream
);
368 void print_viewer_streams()
370 if (!viewer_streams_ht
) {
375 lttng::urcu::lfht_iteration_adapter
<relay_viewer_stream
,
376 decltype(relay_viewer_stream::stream_n
),
377 &relay_viewer_stream::stream_n
>(
378 *viewer_streams_ht
->ht
)) {
379 if (!viewer_stream_get(vstream
)) {
383 DBG("vstream %p refcount %ld stream %" PRIu64
" trace %" PRIu64
" session %" PRIu64
,
385 vstream
->ref
.refcount
,
386 vstream
->stream
->stream_handle
,
387 vstream
->stream
->trace
->id
,
388 vstream
->stream
->trace
->session
->id
);
389 viewer_stream_put(vstream
);