1 #ifndef _LTTNG_RING_BUFFER_BACKEND_TYPES_H
2 #define _LTTNG_RING_BUFFER_BACKEND_TYPES_H
5 * linux/ringbuffer/backend_types.h
7 * Ring buffer backend (types).
9 * Copyright (C) 2008-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; only
14 * version 2.1 of the License.
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this library; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #include "shm_internal.h"
30 #define RB_BACKEND_PAGES_PADDING 16
31 struct lttng_ust_lib_ring_buffer_backend_pages
{
32 unsigned long mmap_offset
; /* offset of the subbuffer in mmap */
33 union v_atomic records_commit
; /* current records committed count */
34 union v_atomic records_unread
; /* records to read */
35 unsigned long data_size
; /* Amount of data to read from subbuf */
36 DECLARE_SHMP(char, p
); /* Backing memory map */
37 char padding
[RB_BACKEND_PAGES_PADDING
];
40 struct lttng_ust_lib_ring_buffer_backend_subbuffer
{
41 /* Identifier for subbuf backend pages. Exchanged atomically. */
42 unsigned long id
; /* backend subbuffer identifier */
46 * Forward declaration of frontend-specific channel and ring_buffer.
49 struct lttng_ust_lib_ring_buffer
;
51 struct lttng_ust_lib_ring_buffer_backend_pages_shmp
{
52 DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages
, shmp
);
55 #define RB_BACKEND_RING_BUFFER_PADDING 64
56 struct lttng_ust_lib_ring_buffer_backend
{
57 /* Array of ring_buffer_backend_subbuffer for writer */
58 DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_subbuffer
, buf_wsb
);
59 /* ring_buffer_backend_subbuffer for reader */
60 struct lttng_ust_lib_ring_buffer_backend_subbuffer buf_rsb
;
62 * Pointer array of backend pages, for whole buffer.
63 * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
65 DECLARE_SHMP(struct lttng_ust_lib_ring_buffer_backend_pages_shmp
, array
);
66 DECLARE_SHMP(char, memory_map
); /* memory mapping */
68 DECLARE_SHMP(struct channel
, chan
); /* Associated channel */
69 int cpu
; /* This buffer's cpu. -1 if global. */
70 union v_atomic records_read
; /* Number of records read */
71 unsigned int allocated
:1; /* is buffer allocated ? */
72 char padding
[RB_BACKEND_RING_BUFFER_PADDING
];
75 struct lttng_ust_lib_ring_buffer_shmp
{
76 DECLARE_SHMP(struct lttng_ust_lib_ring_buffer
, shmp
); /* Channel per-cpu buffers */
79 #define RB_BACKEND_CHANNEL_PADDING 64
80 struct channel_backend
{
81 unsigned long buf_size
; /* Size of the buffer */
82 unsigned long subbuf_size
; /* Sub-buffer size */
83 unsigned int subbuf_size_order
; /* Order of sub-buffer size */
84 unsigned int num_subbuf_order
; /*
85 * Order of number of sub-buffers/buffer
88 unsigned int buf_size_order
; /* Order of buffer size */
89 unsigned int extra_reader_sb
:1; /* has extra reader subbuffer ? */
90 unsigned long num_subbuf
; /* Number of sub-buffers for writer */
91 uint64_t start_tsc
; /* Channel creation TSC value */
92 DECLARE_SHMP(void *, priv_data
);/* Client-specific information */
93 struct lttng_ust_lib_ring_buffer_config config
; /* Ring buffer configuration */
94 char name
[NAME_MAX
]; /* Channel name */
95 char padding
[RB_BACKEND_CHANNEL_PADDING
];
96 struct lttng_ust_lib_ring_buffer_shmp buf
[];
99 #endif /* _LTTNG_RING_BUFFER_BACKEND_TYPES_H */