2 * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
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.
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
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
18 #ifndef LTTNG_CHANNEL_H
19 #define LTTNG_CHANNEL_H
21 #include <lttng/domain.h>
22 #include <lttng/event.h>
30 * Tracer channel attributes. For both kernel and user-space.
32 * The structures should be initialized to zero before use.
34 #define LTTNG_CHANNEL_ATTR_PADDING1 LTTNG_SYMBOL_NAME_LEN + 12
35 struct lttng_channel_attr
{
36 int overwrite
; /* -1: session default, 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 */
54 char padding
[LTTNG_CHANNEL_ATTR_PADDING1
];
58 * Channel information structure. For both kernel and user-space.
60 * The structures should be initialized to zero before use.
62 #define LTTNG_CHANNEL_PADDING1 16
63 struct lttng_channel
{
64 char name
[LTTNG_SYMBOL_NAME_LEN
];
66 struct lttng_channel_attr attr
;
68 char padding
[LTTNG_CHANNEL_PADDING1
];
72 * List the channel(s) of a session.
74 * The handle CAN NOT be NULL.
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.
79 extern int lttng_list_channels(struct lttng_handle
*handle
,
80 struct lttng_channel
**channels
);
83 * Create or enable a channel.
85 * The chan and handle params can not be NULL.
87 * Return 0 on success else a negative LTTng error code.
89 extern int lttng_enable_channel(struct lttng_handle
*handle
,
90 struct lttng_channel
*chan
);
95 * Name and handle CAN NOT be NULL.
97 * Return 0 on success else a negative LTTng error code.
99 extern int lttng_disable_channel(struct lttng_handle
*handle
,
103 * Set the default channel attributes for a specific domain and an allocated
104 * lttng_channel_attr pointer.
106 * If one or both arguments are NULL, nothing happens.
108 extern void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
109 struct lttng_channel_attr
*attr
);
112 * Get the discarded event count of a specific LTTng channel.
114 * Returns 0 on success, or a negative LTTng error code on error.
116 extern int lttng_channel_get_discarded_event_count(struct lttng_channel
*chan
,
117 uint64_t *discarded_events
);
120 * Get the lost packet count of a specific LTTng channel.
122 * Returns 0 on success, or a negative LTTng error code on error.
124 extern int lttng_channel_get_lost_packet_count(struct lttng_channel
*chan
,
125 uint64_t *lost_packets
);
131 #endif /* LTTNG_CHANNEL_H */