1/* 2 * Copyright 2010 Marek Olšák <maraeo@gmail.com> 3 * Copyright 2016 Advanced Micro Devices, Inc. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a 6 * copy of this software and associated documentation files (the "Software"), 7 * to deal in the Software without restriction, including without limitation 8 * on the rights to use, copy, modify, merge, publish, distribute, sub 9 * license, and/or sell copies of the Software, and to permit persons to whom 10 * the Software is furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice (including the next 13 * paragraph) shall be included in all copies or substantial portions of the 14 * Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, 20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 22 * USE OR OTHER DEALINGS IN THE SOFTWARE. */ 23 24/** 25 * Slab allocator for equally sized memory allocations. 26 * 27 * Objects are allocated from "child" pools that are connected to a "parent" 28 * pool. 29 * 30 * Calls to slab_alloc/slab_free for the same child pool must not occur from 31 * multiple threads simultaneously. 32 * 33 * Allocations obtained from one child pool should usually be freed in the 34 * same child pool. Freeing an allocation in a different child pool associated 35 * to the same parent is allowed (and requires no locking by the caller), but 36 * it is discouraged because it implies a performance penalty. 37 * 38 * For convenience and to ease the transition, there is also a set of wrapper 39 * functions around a single parent-child pair. 40 */ 41 42#ifndef SLAB_H 43#define SLAB_H 44 45#include "simple_mtx.h" 46 47#ifdef __cplusplus 48extern "C" { 49#endif 50 51struct slab_element_header; 52struct slab_page_header; 53 54struct slab_parent_pool { 55 simple_mtx_t mutex; 56 unsigned element_size; 57 unsigned num_elements; 58 unsigned item_size; 59}; 60 61struct slab_child_pool { 62 struct slab_parent_pool *parent; 63 64 struct slab_page_header *pages; 65 66 /* Free elements. */ 67 struct slab_element_header *free; 68 69 /* Elements that are owned by this pool but were freed with a different 70 * pool as the argument to slab_free. 71 * 72 * This list is protected by the parent mutex. 73 */ 74 struct slab_element_header *migrated; 75}; 76 77void slab_create_parent(struct slab_parent_pool *parent, 78 unsigned item_size, 79 unsigned num_items); 80void slab_destroy_parent(struct slab_parent_pool *parent); 81void slab_create_child(struct slab_child_pool *pool, 82 struct slab_parent_pool *parent); 83void slab_destroy_child(struct slab_child_pool *pool); 84void *slab_alloc(struct slab_child_pool *pool); 85void *slab_zalloc(struct slab_child_pool *pool); 86void slab_free(struct slab_child_pool *pool, void *ptr); 87 88struct slab_mempool { 89 struct slab_parent_pool parent; 90 struct slab_child_pool child; 91}; 92 93void slab_create(struct slab_mempool *mempool, 94 unsigned item_size, 95 unsigned num_items); 96void slab_destroy(struct slab_mempool *mempool); 97void *slab_alloc_st(struct slab_mempool *mempool); 98void slab_free_st(struct slab_mempool *mempool, void *ptr); 99 100#ifdef __cplusplus 101} 102#endif 103 104#endif 105