622ce85e9f30bbcf01cd15cb1a3abc418813f3de
[lttng-tools.git] / include / lttng / channel.h
1 /*
2 * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
3 *
4 * This library is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU Lesser General Public License, version 2.1 only,
6 * as published by the Free Software Foundation.
7 *
8 * This library is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
11 * for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this library; if not, write to the Free Software Foundation,
15 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17
18 #ifndef LTTNG_CHANNEL_H
19 #define LTTNG_CHANNEL_H
20
21 #include <lttng/domain.h>
22 #include <lttng/event.h>
23 #include <stdint.h>
24
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28
29 /*
30 * Tracer channel attributes. For both kernel and user-space.
31 *
32 * The structures should be initialized to zero before use.
33 */
34 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 12
35 struct lttng_channel_attr {
36 int overwrite; /* 1: overwrite, 0: discard */
37 uint64_t subbuf_size; /* bytes, power of 2 */
38 uint64_t num_subbuf; /* power of 2 */
39 unsigned int switch_timer_interval; /* usec */
40 unsigned int read_timer_interval; /* usec */
41 enum lttng_event_output output; /* splice, mmap */
42 /* LTTng 2.1 padding limit */
43 uint64_t tracefile_size; /* bytes */
44 uint64_t tracefile_count; /* number of tracefiles */
45 /* LTTng 2.3 padding limit */
46 unsigned int live_timer_interval; /* usec */
47 /* LTTng 2.7 padding limit */
48 uint32_t align_to_64;
49 union {
50 uint64_t padding;
51 void *ptr;
52 } extended;
53
54 char padding[LTTNG_CHANNEL_ATTR_PADDING1];
55 };
56
57 /*
58 * Channel information structure. For both kernel and user-space.
59 *
60 * The structures should be initialized to zero before use.
61 */
62 #define LTTNG_CHANNEL_PADDING1 16
63 struct lttng_channel {
64 char name[LTTNG_SYMBOL_NAME_LEN];
65 uint32_t enabled;
66 struct lttng_channel_attr attr;
67
68 char padding[LTTNG_CHANNEL_PADDING1];
69 };
70
71 /*
72 * List the channel(s) of a session.
73 *
74 * The handle CAN NOT be NULL.
75 *
76 * Return the size (number of entries) of the "lttng_channel" array. Caller
77 * must free channels. On error, a negative LTTng error code is returned.
78 */
79 extern int lttng_list_channels(struct lttng_handle *handle,
80 struct lttng_channel **channels);
81
82 /*
83 * Create or enable a channel.
84 *
85 * The chan and handle params can not be NULL.
86 *
87 * Return 0 on success else a negative LTTng error code.
88 */
89 extern int lttng_enable_channel(struct lttng_handle *handle,
90 struct lttng_channel *chan);
91
92 /*
93 * Disable channel.
94 *
95 * Name and handle CAN NOT be NULL.
96 *
97 * Return 0 on success else a negative LTTng error code.
98 */
99 extern int lttng_disable_channel(struct lttng_handle *handle,
100 const char *name);
101
102 /*
103 * Set the default channel attributes for a specific domain and an allocated
104 * lttng_channel_attr pointer.
105 *
106 * If one or both arguments are NULL, nothing happens.
107 */
108 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
109 struct lttng_channel_attr *attr);
110
111 /*
112 * Get the discarded event count of a specific LTTng channel.
113 *
114 * Returns 0 on success, or a negative LTTng error code on error.
115 */
116 extern int lttng_channel_get_discarded_event_count(struct lttng_channel *chan,
117 uint64_t *discarded_events);
118
119 /*
120 * Get the lost packet count of a specific LTTng channel.
121 *
122 * Returns 0 on success, or a negative LTTng error code on error.
123 */
124 extern int lttng_channel_get_lost_packet_count(struct lttng_channel *chan,
125 uint64_t *lost_packets);
126
127 #ifdef __cplusplus
128 }
129 #endif
130
131 #endif /* LTTNG_CHANNEL_H */
This page took 0.045 seconds and 4 git commands to generate.