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2f8f53af DG |
1 | /* |
2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> | |
3 | * David Goulet <dgoulet@efficios.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License, version 2 only, as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along with | |
15 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
16 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
17 | */ | |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <common/common.h> | |
21 | #include <common/index/index.h> | |
22 | ||
23 | #include "lttng-relayd.h" | |
24 | #include "viewer-stream.h" | |
25 | ||
26 | static void free_stream(struct relay_viewer_stream *stream) | |
27 | { | |
28 | assert(stream); | |
29 | ||
30 | free(stream->path_name); | |
31 | free(stream->channel_name); | |
32 | free(stream); | |
33 | } | |
34 | ||
35 | static void deferred_free_viewer_stream(struct rcu_head *head) | |
36 | { | |
37 | struct relay_viewer_stream *stream = | |
38 | caa_container_of(head, struct relay_viewer_stream, rcu_node); | |
39 | ||
40 | free_stream(stream); | |
41 | } | |
42 | ||
43 | struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream, | |
44 | enum lttng_viewer_seek seek_t) | |
45 | { | |
46 | struct relay_viewer_stream *vstream; | |
47 | ||
48 | assert(stream); | |
49 | ||
50 | vstream = zmalloc(sizeof(*vstream)); | |
51 | if (!vstream) { | |
52 | PERROR("relay viewer stream zmalloc"); | |
53 | goto error; | |
54 | } | |
55 | ||
56 | vstream->session_id = stream->session->id; | |
57 | vstream->stream_handle = stream->stream_handle; | |
58 | vstream->path_name = strndup(stream->path_name, LTTNG_VIEWER_PATH_MAX); | |
59 | vstream->channel_name = strndup(stream->channel_name, | |
60 | LTTNG_VIEWER_NAME_MAX); | |
61 | vstream->tracefile_count = stream->tracefile_count; | |
62 | vstream->metadata_flag = stream->metadata_flag; | |
63 | vstream->tracefile_count_last = -1ULL; | |
64 | ||
65 | switch (seek_t) { | |
66 | case VIEWER_SEEK_BEGINNING: | |
67 | vstream->tracefile_count_current = stream->oldest_tracefile_id; | |
68 | break; | |
69 | case VIEWER_SEEK_LAST: | |
70 | vstream->tracefile_count_current = stream->tracefile_count_current; | |
71 | break; | |
72 | default: | |
73 | assert(0); | |
74 | goto error; | |
75 | } | |
76 | ||
77 | vstream->ctf_trace = stream->ctf_trace; | |
78 | if (vstream->metadata_flag) { | |
79 | vstream->ctf_trace->viewer_metadata_stream = vstream; | |
80 | } | |
81 | uatomic_inc(&vstream->ctf_trace->refcount); | |
82 | ||
83 | /* Globally visible after the add unique. */ | |
84 | lttng_ht_node_init_u64(&vstream->stream_n, stream->stream_handle); | |
85 | lttng_ht_add_unique_u64(viewer_streams_ht, &vstream->stream_n); | |
86 | ||
87 | vstream->index_read_fd = -1; | |
88 | vstream->read_fd = -1; | |
89 | ||
90 | /* | |
91 | * This is to avoid a race between the initialization of this object and | |
92 | * the close of the given stream. If the stream is unable to find this | |
93 | * viewer stream when closing, this copy will at least take the latest | |
94 | * value. We also need that for the seek_last. | |
95 | */ | |
96 | vstream->total_index_received = stream->total_index_received; | |
97 | ||
98 | /* | |
99 | * If we never received an index for the current stream, delay the opening | |
100 | * of the index, otherwise open it right now. | |
101 | */ | |
102 | if (vstream->tracefile_count_current == stream->tracefile_count_current | |
103 | && vstream->total_index_received == 0) { | |
104 | vstream->index_read_fd = -1; | |
105 | } else { | |
106 | int read_fd; | |
107 | ||
108 | read_fd = index_open(vstream->path_name, vstream->channel_name, | |
109 | vstream->tracefile_count, vstream->tracefile_count_current); | |
110 | if (read_fd < 0) { | |
111 | goto error; | |
112 | } | |
113 | vstream->index_read_fd = read_fd; | |
114 | } | |
115 | ||
116 | if (seek_t == VIEWER_SEEK_LAST && vstream->index_read_fd >= 0) { | |
117 | off_t lseek_ret; | |
118 | ||
119 | lseek_ret = lseek(vstream->index_read_fd, | |
120 | vstream->total_index_received * sizeof(struct ctf_packet_index), | |
121 | SEEK_CUR); | |
122 | if (lseek_ret < 0) { | |
123 | goto error; | |
124 | } | |
125 | vstream->last_sent_index = vstream->total_index_received; | |
126 | } | |
127 | ||
128 | return vstream; | |
129 | ||
130 | error: | |
131 | if (vstream) { | |
132 | free_stream(vstream); | |
133 | } | |
134 | return NULL; | |
135 | } | |
136 | ||
137 | void viewer_stream_delete(struct relay_viewer_stream *stream) | |
138 | { | |
139 | int ret; | |
140 | struct lttng_ht_iter iter; | |
141 | ||
142 | iter.iter.node = &stream->stream_n.node; | |
143 | ret = lttng_ht_del(viewer_streams_ht, &iter); | |
144 | assert(!ret); | |
145 | } | |
146 | ||
147 | void viewer_stream_destroy(struct relay_viewer_stream *stream) | |
148 | { | |
149 | int ret; | |
150 | unsigned long ret_ref; | |
151 | ||
152 | assert(stream); | |
153 | ret_ref = uatomic_add_return(&stream->ctf_trace->refcount, -1); | |
154 | assert(ret_ref >= 0); | |
155 | ||
156 | if (stream->read_fd >= 0) { | |
157 | ret = close(stream->read_fd); | |
158 | if (ret < 0) { | |
159 | PERROR("close read_fd"); | |
160 | } | |
161 | } | |
162 | if (stream->index_read_fd >= 0) { | |
163 | ret = close(stream->index_read_fd); | |
164 | if (ret < 0) { | |
165 | PERROR("close index_read_fd"); | |
166 | } | |
167 | } | |
168 | ||
169 | /* | |
170 | * If the only stream left in the HT is the metadata stream, | |
171 | * we need to remove it because we won't detect a EOF for this | |
172 | * stream. | |
173 | */ | |
174 | if (ret_ref == 1 && stream->ctf_trace->viewer_metadata_stream) { | |
175 | viewer_stream_delete(stream->ctf_trace->viewer_metadata_stream); | |
176 | viewer_stream_destroy(stream->ctf_trace->viewer_metadata_stream); | |
177 | stream->ctf_trace->metadata_stream = NULL; | |
178 | DBG("Freeing ctf_trace %" PRIu64, stream->ctf_trace->id); | |
179 | /* | |
180 | * The streaming-side is already closed and we can't receive a new | |
181 | * stream concurrently at this point (since the session is being | |
182 | * destroyed), so when we detect the refcount equals 0, we are the | |
183 | * only owners of the ctf_trace and we can free it ourself. | |
184 | */ | |
185 | free(stream->ctf_trace); | |
186 | } | |
187 | ||
188 | call_rcu(&stream->rcu_node, deferred_free_viewer_stream); | |
189 | } | |
190 | ||
191 | /* | |
192 | * Find viewer stream by id. RCU read side lock MUST be acquired. | |
193 | * | |
194 | * Return stream if found else NULL. | |
195 | */ | |
196 | struct relay_viewer_stream *viewer_stream_find_by_id(uint64_t id) | |
197 | { | |
198 | struct lttng_ht_node_u64 *node; | |
199 | struct lttng_ht_iter iter; | |
200 | struct relay_viewer_stream *stream = NULL; | |
201 | ||
202 | lttng_ht_lookup(viewer_streams_ht, &id, &iter); | |
203 | node = lttng_ht_iter_get_node_u64(&iter); | |
204 | if (!node) { | |
205 | DBG("Relay viewer stream %" PRIu64 " not found", id); | |
206 | goto end; | |
207 | } | |
208 | stream = caa_container_of(node, struct relay_viewer_stream, stream_n); | |
209 | ||
210 | end: | |
211 | return stream; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Rotate a stream to the next tracefile. | |
216 | * | |
217 | * Returns 0 on success, 1 on EOF, a negative value on error. | |
218 | */ | |
219 | int viewer_stream_rotate(struct relay_viewer_stream *vstream, | |
220 | struct relay_stream *stream) | |
221 | { | |
222 | int ret; | |
223 | uint64_t tracefile_id; | |
224 | ||
225 | assert(vstream); | |
226 | ||
227 | tracefile_id = (vstream->tracefile_count_current + 1) % | |
228 | vstream->tracefile_count; | |
229 | ||
230 | /* Detect the last tracefile to open. */ | |
231 | if (vstream->tracefile_count_last != -1ULL && | |
232 | vstream->tracefile_count_last == | |
233 | vstream->tracefile_count_current) { | |
234 | ret = 1; | |
235 | goto end; | |
236 | } | |
237 | ||
238 | /* | |
239 | * If the stream on the streaming side still exists, lock to execute | |
240 | * rotation in order to avoid races between a modification on the index | |
241 | * values. | |
242 | */ | |
243 | if (stream) { | |
244 | pthread_mutex_lock(&stream->viewer_stream_rotation_lock); | |
245 | } | |
246 | ||
247 | /* | |
248 | * The writer and the reader are not working in the same tracefile, we can | |
249 | * read up to EOF, we don't care about the total_index_received. | |
250 | */ | |
251 | if (!stream || (stream->tracefile_count_current != tracefile_id)) { | |
252 | vstream->close_write_flag = 1; | |
253 | } else { | |
254 | /* | |
255 | * We are opening a file that is still open in write, make sure we | |
256 | * limit our reading to the number of indexes received. | |
257 | */ | |
258 | vstream->close_write_flag = 0; | |
259 | if (stream) { | |
260 | vstream->total_index_received = stream->total_index_received; | |
261 | } | |
262 | } | |
263 | vstream->tracefile_count_current = tracefile_id; | |
264 | ||
265 | ret = close(vstream->index_read_fd); | |
266 | if (ret < 0) { | |
267 | PERROR("close index file %d", vstream->index_read_fd); | |
268 | } | |
269 | vstream->index_read_fd = -1; | |
270 | ||
271 | ret = close(vstream->read_fd); | |
272 | if (ret < 0) { | |
273 | PERROR("close tracefile %d", vstream->read_fd); | |
274 | } | |
275 | vstream->read_fd = -1; | |
276 | ||
277 | pthread_mutex_lock(&vstream->overwrite_lock); | |
278 | vstream->abort_flag = 0; | |
279 | pthread_mutex_unlock(&vstream->overwrite_lock); | |
280 | ||
281 | if (stream) { | |
282 | pthread_mutex_unlock(&stream->viewer_stream_rotation_lock); | |
283 | } | |
284 | ||
285 | ret = index_open(vstream->path_name, vstream->channel_name, | |
286 | vstream->tracefile_count, vstream->tracefile_count_current); | |
287 | if (ret < 0) { | |
288 | goto error; | |
289 | } | |
290 | vstream->index_read_fd = ret; | |
291 | ||
292 | ret = 0; | |
293 | ||
294 | end: | |
295 | error: | |
296 | return ret; | |
297 | } |