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/*
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 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
General Public License for more details.
You should have received a copy of the GNU 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>
#define GF_VARIABLE_IOBUF_COUNT 32
/* 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;
};
};
size_t page_size; /* size of all iobufs in this arena */
size_t arena_size; /* this is equal to
(iobuf_pool->arena_size / page_size)
* page_size */
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 arena_size; /* size of memory region in
arena */
size_t default_page_size; /* default size of iobuf */
int arena_cnt;
struct list_head arenas[GF_VARIABLE_IOBUF_COUNT];
/* array of arenas. Each element of
the array is a list of arenas
holding iobufs of particular
page_size
*/
struct list_head filled[GF_VARIABLE_IOBUF_COUNT];
/*
array of arenas without free iobufs
*/
struct list_head purge[GF_VARIABLE_IOBUF_COUNT];
/*
array of of 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_default_pagesize(iobpool) ((iobpool)->default_page_size)
#define iobuf_pagesize(iob) (iob->iobuf_arena->page_size)
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);
struct iobuf *
iobuf_get2 (struct iobuf_pool *iobuf_pool, size_t page_size);
#endif /* !_IOBUF_H_ */
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