399de4f6e6f610ee63da83ed72050213dec8deb7
[lttng-tools.git] / include / lttng-share.h
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@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 as published by the Free
7 * Software Foundation; only version 2 of the License.
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., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #ifndef _LTTNG_SHARE_H
20 #define _LTTNG_SHARE_H
21
22 #include <stdlib.h>
23
24 #include <lttng/lttng.h>
25
26 /* Default channel attributes */
27 #define DEFAULT_CHANNEL_NAME "channel0"
28 #define DEFAULT_CHANNEL_OVERWRITE 0 /* usec */
29 /* DEFAULT_CHANNEL_SUBBUF_SIZE must always be a power of 2 */
30 #define DEFAULT_CHANNEL_SUBBUF_SIZE 4096 /* bytes */
31 /* DEFAULT_CHANNEL_SUBBUF_NUM must always be a power of 2 */
32 #define DEFAULT_CHANNEL_SUBBUF_NUM 8
33 #define DEFAULT_CHANNEL_SWITCH_TIMER 0 /* usec */
34 #define DEFAULT_CHANNEL_READ_TIMER 200 /* usec */
35 #define DEFAULT_CHANNEL_OUTPUT LTTNG_EVENT_MMAP
36
37 #define DEFAULT_METADATA_SUBBUF_SIZE 4096
38 #define DEFAULT_METADATA_SUBBUF_NUM 2
39
40 /* Kernel has different defaults */
41
42 /* DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE must always be a power of 2 */
43 #define DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE 262144 /* bytes */
44 /* DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM must always be a power of 2 */
45 #define DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM 4
46 /* See lttng-kernel.h enum lttng_kernel_output for channel output */
47 #define DEFAULT_KERNEL_CHANNEL_OUTPUT LTTNG_EVENT_SPLICE
48
49 /* User space defaults */
50
51 /* Must be a power of 2 */
52 #define DEFAULT_UST_CHANNEL_SUBBUF_SIZE 4096 /* bytes */
53 /* Must be a power of 2 */
54 #define DEFAULT_UST_CHANNEL_SUBBUF_NUM 4
55 /* See lttng-ust.h enum lttng_ust_output */
56 #define DEFAULT_UST_CHANNEL_OUTPUT LTTNG_UST_MMAP
57
58 /*
59 * Default timeout value for the sem_timedwait() call. Blocking forever is not
60 * wanted so a timeout is used to control the data flow and not freeze the
61 * session daemon.
62 */
63 #define DEFAULT_SEM_WAIT_TIMEOUT 30 /* in seconds */
64
65 /*
66 * Takes a pointer x and transform it so we can use it to access members
67 * without a function call. Here an example:
68 *
69 * #define GET_SIZE(x) LTTNG_REF(x)->size
70 *
71 * struct { int size; } s;
72 *
73 * printf("size : %d\n", GET_SIZE(&s));
74 *
75 * For this example we can't use something like this for compatibility purpose
76 * since this will fail:
77 *
78 * #define GET_SIZE(x) x->size;
79 *
80 * This is mostly use for the compatibility layer of lttng-tools. See
81 * poll/epoll for a good example. Since x can be on the stack or allocated
82 * memory using malloc(), we must use generic accessors for compat in order to
83 * *not* use a function to access members and not the variable name.
84 */
85 #define LTTNG_REF(x) ((typeof(*x) *)(x))
86
87 /*
88 * Memory allocation zeroed
89 */
90 #define zmalloc(x) calloc(1, x)
91
92 #ifndef ARRAY_SIZE
93 #define ARRAY_SIZE(array) (sizeof(array) / (sizeof((array)[0])))
94 #endif
95
96
97 #endif /* _LTTNG_SHARE_H */
This page took 0.031401 seconds and 4 git commands to generate.