summaryrefslogtreecommitdiffstats
path: root/libglusterfs/src/iobuf.h
blob: fc8ff623ad4e9d3c773898ec8791a43798d7dd9e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/*
   Copyright (c) 2010 Gluster, Inc. <http://www.gluster.com>
   This file is part of GlusterFS.

   GlusterFS is free software; you can redistribute it and/or modify
   it under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation; either version 3 of the License,
   or (at your option) any later version.

   GlusterFS is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program.  If not, see
   <http://www.gnu.org/licenses/>.
*/

#ifndef _IOBUF_H_
#define _IOBUF_H_

#include "list.h"
#include "common-utils.h"
#include <pthread.h>
#include <sys/mman.h>
#include <sys/uio.h>

/* Lets try to define the new anonymous mapping
 * flag, in case the system is still using the
 * now deprecated MAP_ANON flag.
 *
 * Also, this should ideally be in a centralized/common
 * header which can be used by other source files also.
 */
#ifndef MAP_ANONYMOUS
#define MAP_ANONYMOUS MAP_ANON
#endif

/* one allocatable unit for the consumers of the IOBUF API */
/* each unit hosts @page_size bytes of memory */
struct iobuf;

/* one region of memory MMAPed from the operating system */
/* each region MMAPs @arena_size bytes of memory */
/* each arena hosts @arena_size / @page_size IOBUFs */
struct iobuf_arena;

/* expandable and contractable pool of memory, internally broken into arenas */
struct iobuf_pool;


struct iobuf {
        union {
                struct list_head      list;
                struct {
                        struct iobuf *next;
                        struct iobuf *prev;
                };
        };
        struct iobuf_arena  *iobuf_arena;

        gf_lock_t            lock; /* for ->ptr and ->ref */
        int                  ref;  /* 0 == passive, >0 == active */

        void                *ptr;  /* usable memory region by the consumer */
};


struct iobuf_arena {
        union {
                struct list_head            list;
                struct {
                        struct iobuf_arena *next;
                        struct iobuf_arena *prev;
                };
        };
        struct iobuf_pool  *iobuf_pool;

        void               *mem_base;
        struct iobuf       *iobufs;     /* allocated iobufs list */

        int                 active_cnt;
        struct iobuf        active;     /* head node iobuf
                                           (unused by itself) */
        int                 passive_cnt;
        struct iobuf        passive;    /* head node iobuf
                                           (unused by itself) */
};


struct iobuf_pool {
        pthread_mutex_t     mutex;
        size_t              page_size;  /* size of all iobufs in this pool */
        size_t              arena_size; /* size of memory region in arena */

        int                 arena_cnt;
        struct iobuf_arena  arenas;     /* head node arena
                                           (unused by itself) */
        struct iobuf_arena  filled;     /* arenas without  free iobufs */
        struct iobuf_arena  purge;      /* arenas which can be purged */
};




struct iobuf_pool *iobuf_pool_new (size_t arena_size, size_t page_size);
void iobuf_pool_destroy (struct iobuf_pool *iobuf_pool);
struct iobuf *iobuf_get (struct iobuf_pool *iobuf_pool);
void iobuf_unref (struct iobuf *iobuf);
struct iobuf *iobuf_ref (struct iobuf *iobuf);
void iobuf_pool_destroy (struct iobuf_pool *iobuf_pool);
void iobuf_to_iovec(struct iobuf *iob, struct iovec *iov);

#define iobuf_ptr(iob) ((iob)->ptr)
#define iobpool_pagesize(iobpool) ((iobpool)->page_size)
#define iobuf_pagesize(iob) (iobpool_pagesize((iob)->iobuf_arena->iobuf_pool))


struct iobref {
        gf_lock_t          lock;
        int                ref;
        struct iobuf      *iobrefs[8];
};

struct iobref *iobref_new ();
struct iobref *iobref_ref (struct iobref *iobref);
void iobref_unref (struct iobref *iobref);
int iobref_add (struct iobref *iobref, struct iobuf *iobuf);
int iobref_merge (struct iobref *to, struct iobref *from);


size_t iobuf_size (struct iobuf *iobuf);
size_t iobref_size (struct iobref *iobref);
void   iobuf_stats_dump (struct iobuf_pool *iobuf_pool);

#endif /* !_IOBUF_H_ */