1 #ifndef _LINUX_RING_BUFFER_BACKEND_TYPES_H
2 #define _LINUX_RING_BUFFER_BACKEND_TYPES_H
5 * linux/ringbuffer/backend_types.h
7 * Copyright (C) 2008-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 * Ring buffer backend (types).
11 * Dual LGPL v2.1/GPL v2 license.
16 struct lib_ring_buffer_backend_pages
{
17 unsigned long mmap_offset
; /* offset of the subbuffer in mmap */
18 union v_atomic records_commit
; /* current records committed count */
19 union v_atomic records_unread
; /* records to read */
20 unsigned long data_size
; /* Amount of data to read from subbuf */
21 DECLARE_SHMP(char, p
); /* Backing memory map */
24 struct lib_ring_buffer_backend_subbuffer
{
25 /* Identifier for subbuf backend pages. Exchanged atomically. */
26 unsigned long id
; /* backend subbuffer identifier */
30 * Forward declaration of frontend-specific channel and ring_buffer.
33 struct lib_ring_buffer
;
35 struct lib_ring_buffer_backend
{
36 /* Array of ring_buffer_backend_subbuffer for writer */
37 DECLARE_SHMP(struct lib_ring_buffer_backend_subbuffer
, buf_wsb
);
38 /* ring_buffer_backend_subbuffer for reader */
39 struct lib_ring_buffer_backend_subbuffer buf_rsb
;
41 * Pointer array of backend pages, for whole buffer.
42 * Indexed by ring_buffer_backend_subbuffer identifier (id) index.
44 DECLARE_SHMP(struct lib_ring_buffer_backend_pages
*, array
);
45 DECLARE_SHMP(char, memory_map
); /* memory mapping */
47 DECLARE_SHMP(struct channel
, chan
); /* Associated channel */
48 int cpu
; /* This buffer's cpu. -1 if global. */
49 union v_atomic records_read
; /* Number of records read */
50 unsigned int allocated
:1; /* Bool: is buffer allocated ? */
53 struct channel_backend
{
54 unsigned long buf_size
; /* Size of the buffer */
55 unsigned long subbuf_size
; /* Sub-buffer size */
56 unsigned int subbuf_size_order
; /* Order of sub-buffer size */
57 unsigned int num_subbuf_order
; /*
58 * Order of number of sub-buffers/buffer
61 unsigned int buf_size_order
; /* Order of buffer size */
62 int extra_reader_sb
:1; /* Bool: has extra reader subbuffer */
63 DECLARE_SHMP(struct lib_ring_buffer
, buf
); /* Channel per-cpu buffers */
64 unsigned long num_subbuf
; /* Number of sub-buffers for writer */
65 u64 start_tsc
; /* Channel creation TSC value */
66 void *priv
; /* Client-specific information */
67 const struct lib_ring_buffer_config
*config
; /* Ring buffer configuration */
68 char name
[NAME_MAX
]; /* Channel name */
71 #endif /* _LINUX_RING_BUFFER_BACKEND_TYPES_H */