bb5b7a365aaae214a10bd3757e34f1074ce4e81f
[lttng-tools.git] / src / bin / lttng-relayd / lttng-relayd.h
1 /*
2 * Copyright (C) 2012 - 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
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as 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
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #ifndef LTTNG_RELAYD_H
20 #define LTTNG_RELAYD_H
21
22 #define _LGPL_SOURCE
23 #include <limits.h>
24 #include <urcu.h>
25 #include <urcu/wfqueue.h>
26
27 #include <common/hashtable/hashtable.h>
28 #include <common/index/ctf-index.h>
29
30 #include "ctf-trace.h"
31
32 /*
33 * Queue used to enqueue relay requests
34 */
35 struct relay_cmd_queue {
36 struct cds_wfq_queue queue;
37 int32_t futex;
38 };
39
40 enum connection_type {
41 RELAY_DATA = 1,
42 RELAY_CONTROL = 2,
43 RELAY_VIEWER_COMMAND = 3,
44 RELAY_VIEWER_NOTIFICATION = 4,
45 };
46
47 /*
48 * Represents a session for the relay point of view
49 */
50 struct relay_session {
51 /*
52 * This session id is used to identify a set of stream to a tracing session
53 * but also make sure we have a unique session id associated with a session
54 * daemon which can provide multiple data source.
55 */
56 uint64_t id;
57 struct lttcomm_sock *sock;
58 char session_name[NAME_MAX];
59 char hostname[HOST_NAME_MAX];
60 uint32_t live_timer;
61 struct lttng_ht_node_ulong session_n;
62 struct rcu_head rcu_node;
63 uint32_t viewer_attached;
64 uint32_t stream_count;
65 /* Tell if this session is for a snapshot or not. */
66 unsigned int snapshot:1;
67
68 /*
69 * Indicate version protocol for this session. This is especially useful
70 * for the data thread that has no idea which version it operates on since
71 * linking control/data sockets is non trivial.
72 */
73 uint64_t minor;
74 uint64_t major;
75 };
76
77 /*
78 * Represents a stream in the relay
79 */
80 struct relay_stream {
81 uint64_t stream_handle;
82 uint64_t prev_seq; /* previous data sequence number encountered */
83 struct lttng_ht_node_ulong stream_n;
84 struct relay_session *session;
85 struct rcu_head rcu_node;
86 int fd;
87 /* FD on which to write the index data. */
88 int index_fd;
89 /* FD on which to read the index data for the viewer. */
90 int read_index_fd;
91
92 char *path_name;
93 char *channel_name;
94 /* on-disk circular buffer of tracefiles */
95 uint64_t tracefile_size;
96 uint64_t tracefile_size_current;
97 uint64_t tracefile_count;
98 uint64_t tracefile_count_current;
99 /* To inform the viewer up to where it can go back in time. */
100 uint64_t oldest_tracefile_id;
101
102 uint64_t total_index_received;
103 struct relay_viewer_stream *viewer_stream;
104 uint64_t last_net_seq_num;
105
106 /*
107 * This node is added to the *control* connection hash table and the
108 * pointer is copied in here so we can access it when deleting this object.
109 * When deleting this, the ctf trace ht MUST NOT be destroyed. This happens
110 * at connection deletion.
111 */
112 struct lttng_ht_node_str ctf_trace_node;
113 struct lttng_ht *ctf_traces_ht;
114
115 /*
116 * To protect from concurrent read/update between the
117 * streaming-side and the viewer-side.
118 * This lock must be held, we reading/updating the
119 * ctf_trace pointer.
120 */
121 pthread_mutex_t lock;
122
123 struct ctf_trace *ctf_trace;
124 /*
125 * If the stream is inactive, this field is updated with the live beacon
126 * timestamp end, when it is active, this field == -1ULL.
127 */
128 uint64_t beacon_ts_end;
129 /*
130 * To protect the update of the close_write_flag and the checks of
131 * the tracefile_count_current.
132 * It is taken before checking whenever we need to know if the
133 * writer and reader are working in the same tracefile.
134 */
135 pthread_mutex_t viewer_stream_rotation_lock;
136
137 /* Information telling us when to close the stream */
138 unsigned int close_flag:1;
139 /* Indicate if the stream was initialized for a data pending command. */
140 unsigned int data_pending_check_done:1;
141 unsigned int metadata_flag:1;
142 /*
143 * To detect when we start overwriting old data, it is used to
144 * update the oldest_tracefile_id.
145 */
146 unsigned int tracefile_overwrite:1;
147 };
148
149 /*
150 * Shadow copy of the relay_stream structure for the viewer side. The only
151 * fields updated by the writer (streaming side) after allocation are :
152 * total_index_received and close_flag. Everything else is updated by the
153 * reader (viewer side).
154 */
155 struct relay_viewer_stream {
156 uint64_t stream_handle;
157 uint64_t session_id;
158 int read_fd;
159 int index_read_fd;
160 char *path_name;
161 char *channel_name;
162 uint64_t last_sent_index;
163 uint64_t total_index_received;
164 uint64_t tracefile_count;
165 uint64_t tracefile_count_current;
166 /* Stop after reading this tracefile. */
167 uint64_t tracefile_count_last;
168 struct lttng_ht_node_u64 stream_n;
169 struct rcu_head rcu_node;
170 struct ctf_trace *ctf_trace;
171 /*
172 * This lock blocks only when the writer is about to start overwriting
173 * a file currently read by the reader.
174 *
175 * This is nested INSIDE the viewer_stream_rotation_lock.
176 */
177 pthread_mutex_t overwrite_lock;
178 /* Information telling us if the stream is a metadata stream. */
179 unsigned int metadata_flag:1;
180 /*
181 * Information telling us that the stream is closed in write, so
182 * we don't expect new indexes and we can read up to EOF.
183 */
184 unsigned int close_write_flag:1;
185 /*
186 * If the streaming side closes a FD in use in the viewer side,
187 * it sets this flag to inform that it is a normal error.
188 */
189 unsigned int abort_flag:1;
190 };
191
192 /*
193 * Internal structure to map a socket with the corresponding session.
194 * A hashtable indexed on the socket FD is used for the lookups.
195 */
196 struct relay_command {
197 struct lttcomm_sock *sock;
198 struct relay_session *session;
199 struct cds_wfq_node node;
200 struct lttng_ht_node_ulong sock_n;
201 struct rcu_head rcu_node;
202 enum connection_type type;
203 unsigned int version_check_done:1;
204 /* protocol version to use for this session */
205 uint32_t major;
206 uint32_t minor;
207 struct lttng_ht *ctf_traces_ht; /* indexed by path name */
208 uint64_t session_id;
209 };
210
211 struct relay_local_data {
212 struct lttng_ht *sessions_ht;
213 };
214
215 extern char *opt_output_path;
216
217 extern struct lttng_ht *relay_streams_ht;
218 extern struct lttng_ht *viewer_streams_ht;
219 extern struct lttng_ht *indexes_ht;
220
221 extern const char *tracing_group_name;
222
223 extern const char * const config_section_name;
224
225 struct relay_stream *relay_stream_find_by_id(uint64_t stream_id);
226
227 #endif /* LTTNG_RELAYD_H */
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