Fix: split index and data file rotation logic
[lttng-tools.git] / src / bin / lttng-relayd / stream.h
1 #ifndef _STREAM_H
2 #define _STREAM_H
3
4 /*
5 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
6 * David Goulet <dgoulet@efficios.com>
7 * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License, version 2 only, as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * more details.
17 *
18 * You should have received a copy of the GNU General Public License along with
19 * this program; if not, write to the Free Software Foundation, Inc., 51
20 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 */
22
23 #include <limits.h>
24 #include <inttypes.h>
25 #include <pthread.h>
26 #include <urcu/list.h>
27
28 #include <common/hashtable/hashtable.h>
29
30 #include "session.h"
31 #include "stream-fd.h"
32 #include "tracefile-array.h"
33
34 struct relay_stream_chunk_id {
35 bool is_set;
36 uint64_t value;
37 };
38
39 /*
40 * Represents a stream in the relay
41 */
42 struct relay_stream {
43 uint64_t stream_handle;
44
45 struct urcu_ref ref;
46 /* Back reference to trace. Protected by refcount on trace object. */
47 struct ctf_trace *trace;
48
49 /*
50 * To protect from concurrent read/update. The viewer stream
51 * lock nests inside the stream lock. The stream lock nests
52 * inside the ctf_trace lock.
53 */
54 pthread_mutex_t lock;
55 /* previous data sequence number written to disk. */
56 uint64_t prev_data_seq;
57 /* previous index sequence number written to disk. */
58 uint64_t prev_index_seq;
59 /* seq num to encounter before closing. */
60 uint64_t last_net_seq_num;
61
62 /* FD on which to write the stream data. */
63 struct stream_fd *stream_fd;
64 /* index file on which to write the index data. */
65 struct lttng_index_file *index_file;
66
67 char *path_name;
68 /*
69 * prev_path_name is only used for session rotation support.
70 * It is essentially used to work around the fact that index
71 * files are always created from the 'data' connection.
72 *
73 * Hence, it is possible to receive a ROTATE_STREAM command
74 * which affects the stream's path_name before the creation of
75 * an index file. In this situation, the index file of the
76 * 'previous' chunk would be created in the new destination folder.
77 *
78 * It would then be unlinked when the actual index of the new chunk
79 * is created.
80 */
81 char *prev_path_name;
82 char *channel_name;
83
84 /* On-disk circular buffer of tracefiles. */
85 uint64_t tracefile_size;
86 uint64_t tracefile_size_current;
87 uint64_t tracefile_count;
88
89 /*
90 * Position in the tracefile where we have the full index also on disk.
91 */
92 uint64_t pos_after_last_complete_data_index;
93
94 /*
95 * Counts the number of received indexes. The "tag" associated
96 * with an index is taken before incrementing this seqcount.
97 * Therefore, the sequence tag associated with the last index
98 * received is always index_received_seqcount - 1.
99 */
100 uint64_t index_received_seqcount;
101
102 /*
103 * Tracefile array is an index of the stream trace files,
104 * indexed by position. It allows keeping track of the oldest
105 * available indexes when overwriting trace files in tracefile
106 * rotation.
107 */
108 struct tracefile_array *tfa;
109
110 bool closed; /* Stream is closed. */
111 bool close_requested; /* Close command has been received. */
112
113 /*
114 * Counts number of indexes in indexes_ht. Redundant info.
115 * Protected by stream lock.
116 */
117 int indexes_in_flight;
118 struct lttng_ht *indexes_ht;
119
120 /*
121 * If the stream is inactive, this field is updated with the
122 * live beacon timestamp end, when it is active, this
123 * field == -1ULL.
124 */
125 uint64_t beacon_ts_end;
126
127 /* CTF stream ID, -1ULL when unset (first packet not received yet). */
128 uint64_t ctf_stream_id;
129
130 /* Indicate if the stream was initialized for a data pending command. */
131 bool data_pending_check_done;
132
133 /* Is this stream a metadata stream ? */
134 int32_t is_metadata;
135 /* Amount of metadata received (bytes). */
136 uint64_t metadata_received;
137
138 /*
139 * Member of the stream list in struct ctf_trace.
140 * Updates are protected by the stream_list_lock.
141 * Traversals are protected by RCU.
142 */
143 struct cds_list_head stream_node;
144 /*
145 * Temporary list belonging to the connection until all streams
146 * are received for that connection.
147 * Member of the stream recv list in the connection.
148 * Updates are protected by the stream_recv_list_lock.
149 * Traversals are protected by RCU.
150 */
151 bool in_recv_list;
152 struct cds_list_head recv_node;
153 bool published; /* Protected by session lock. */
154 /*
155 * Node of stream within global stream hash table.
156 */
157 struct lttng_ht_node_u64 node;
158 bool in_stream_ht; /* is stream in stream hash table. */
159 struct rcu_head rcu_node; /* For call_rcu teardown. */
160 /*
161 * When we have written the data and index corresponding to this
162 * seq_num, rotate the tracefile (session rotation). The path_name is
163 * already up-to-date.
164 * This is set to -1ULL when no rotation is pending.
165 *
166 * Always access with stream lock held.
167 */
168 uint64_t rotate_at_seq_num;
169 /*
170 * When rotate_at_seq_num != -1ULL, meaning that a rotation is ongoing,
171 * data_rotated and index_rotated respectively indicate if the stream's
172 * data and index have been rotated. A rotation is considered completed
173 * when both rotations have occurred.
174 */
175 bool data_rotated;
176 bool index_rotated;
177 /*
178 * This is the id of the chunk where we are writing to if no rotation is
179 * pending (rotate_at_seq_num == -1ULL). If a rotation is pending, this
180 * is the chunk_id we will have after the rotation. It must be updated
181 * atomically with rotate_at_seq_num.
182 *
183 * Always access with stream lock held.
184 *
185 * This attribute is not set if the stream is created by a pre-2.11
186 * consumer.
187 */
188 struct relay_stream_chunk_id current_chunk_id;
189 };
190
191 struct relay_stream *stream_create(struct ctf_trace *trace,
192 uint64_t stream_handle, char *path_name,
193 char *channel_name, uint64_t tracefile_size,
194 uint64_t tracefile_count, const struct relay_stream_chunk_id *chunk_id);
195
196 struct relay_stream *stream_get_by_id(uint64_t stream_id);
197 bool stream_get(struct relay_stream *stream);
198 void stream_put(struct relay_stream *stream);
199 void try_stream_close(struct relay_stream *stream);
200 void stream_publish(struct relay_stream *stream);
201 void print_relay_streams(void);
202
203 #endif /* _STREAM_H */
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