forked from KolibriOS/kolibrios
88 lines
2.9 KiB
C
88 lines
2.9 KiB
C
|
/*
|
||
|
|
* Copyright 2010 Marek Olšák <maraeo@gmail.com>
|
||
|
|
*
|
||
|
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
||
|
|
* copy of this software and associated documentation files (the "Software"),
|
||
|
|
* to deal in the Software without restriction, including without limitation
|
||
|
|
* on the rights to use, copy, modify, merge, publish, distribute, sub
|
||
|
|
* license, and/or sell copies of the Software, and to permit persons to whom
|
||
|
|
* the Software is furnished to do so, subject to the following conditions:
|
||
|
|
*
|
||
|
|
* The above copyright notice and this permission notice (including the next
|
||
|
|
* paragraph) shall be included in all copies or substantial portions of the
|
||
|
|
* Software.
|
||
|
|
*
|
||
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
|
||
|
|
* THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
|
||
|
|
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
|
||
|
|
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
|
||
|
|
* USE OR OTHER DEALINGS IN THE SOFTWARE. */
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @file
|
||
|
|
* Simple slab allocator for equally sized memory allocations.
|
||
|
|
* util_slab_alloc and util_slab_free have time complexity in O(1).
|
||
|
|
*
|
||
|
|
* Good for allocations which have very low lifetime and are allocated
|
||
|
|
* and freed very often. Use a profiler first to know if it's worth using it!
|
||
|
|
*
|
||
|
|
* Candidates: transfer_map
|
||
|
|
*
|
||
|
|
* @author Marek Olšák
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef U_SLAB_H
|
||
|
|
#define U_SLAB_H
|
||
|
|
|
||
|
|
#include "os/os_thread.h"
|
||
|
|
|
||
|
|
enum util_slab_threading {
|
||
|
|
UTIL_SLAB_SINGLETHREADED = FALSE,
|
||
|
|
UTIL_SLAB_MULTITHREADED = TRUE
|
||
|
|
};
|
||
|
|
|
||
|
|
/* The page is an array of blocks (allocations). */
|
||
|
|
struct util_slab_page {
|
||
|
|
/* The header (linked-list pointers). */
|
||
|
|
struct util_slab_page *prev, *next;
|
||
|
|
|
||
|
|
/* Memory after the last member is dedicated to the page itself.
|
||
|
|
* The allocated size is always larger than this structure. */
|
||
|
|
};
|
||
|
|
|
||
|
|
struct util_slab_mempool {
|
||
|
|
/* Public members. */
|
||
|
|
void *(*alloc)(struct util_slab_mempool *pool);
|
||
|
|
void (*free)(struct util_slab_mempool *pool, void *ptr);
|
||
|
|
|
||
|
|
/* Private members. */
|
||
|
|
struct util_slab_block *first_free;
|
||
|
|
|
||
|
|
struct util_slab_page list;
|
||
|
|
|
||
|
|
unsigned block_size;
|
||
|
|
unsigned page_size;
|
||
|
|
unsigned num_blocks;
|
||
|
|
unsigned num_pages;
|
||
|
|
enum util_slab_threading threading;
|
||
|
|
|
||
|
|
pipe_mutex mutex;
|
||
|
|
};
|
||
|
|
|
||
|
|
void util_slab_create(struct util_slab_mempool *pool,
|
||
|
|
unsigned item_size,
|
||
|
|
unsigned num_blocks,
|
||
|
|
enum util_slab_threading threading);
|
||
|
|
|
||
|
|
void util_slab_destroy(struct util_slab_mempool *pool);
|
||
|
|
|
||
|
|
void util_slab_set_thread_safety(struct util_slab_mempool *pool,
|
||
|
|
enum util_slab_threading threading);
|
||
|
|
|
||
|
|
#define util_slab_alloc(pool) (pool)->alloc(pool)
|
||
|
|
#define util_slab_free(pool, ptr) (pool)->free(pool, ptr)
|
||
|
|
|
||
|
|
#endif
|