Marek Olšák | 761ff40 | 2016-08-27 19:52:31 +0200 | [diff] [blame] | 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. |
Nicolai Hähnle | d8cff81 | 2016-09-27 18:30:18 +0200 | [diff] [blame^] | 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. |
Marek Olšák | 761ff40 | 2016-08-27 19:52:31 +0200 | [diff] [blame] | 40 | */ |
| 41 | |
| 42 | #ifndef SLAB_H |
| 43 | #define SLAB_H |
| 44 | |
| 45 | #include "c11/threads.h" |
| 46 | |
Nicolai Hähnle | d8cff81 | 2016-09-27 18:30:18 +0200 | [diff] [blame^] | 47 | struct slab_element_header; |
| 48 | struct slab_page_header; |
Marek Olšák | 761ff40 | 2016-08-27 19:52:31 +0200 | [diff] [blame] | 49 | |
Nicolai Hähnle | d8cff81 | 2016-09-27 18:30:18 +0200 | [diff] [blame^] | 50 | struct slab_parent_pool { |
Marek Olšák | 761ff40 | 2016-08-27 19:52:31 +0200 | [diff] [blame] | 51 | mtx_t mutex; |
| 52 | unsigned element_size; |
| 53 | unsigned num_elements; |
Nicolai Hähnle | d8cff81 | 2016-09-27 18:30:18 +0200 | [diff] [blame^] | 54 | }; |
| 55 | |
| 56 | struct slab_child_pool { |
| 57 | struct slab_parent_pool *parent; |
| 58 | |
| 59 | struct slab_page_header *pages; |
| 60 | |
| 61 | /* Free elements. */ |
| 62 | struct slab_element_header *free; |
| 63 | |
| 64 | /* Elements that are owned by this pool but were freed with a different |
| 65 | * pool as the argument to slab_free. |
| 66 | * |
| 67 | * This list is protected by the parent mutex. |
| 68 | */ |
| 69 | struct slab_element_header *migrated; |
| 70 | }; |
| 71 | |
| 72 | void slab_create_parent(struct slab_parent_pool *parent, |
| 73 | unsigned item_size, |
| 74 | unsigned num_items); |
| 75 | void slab_destroy_parent(struct slab_parent_pool *parent); |
| 76 | void slab_create_child(struct slab_child_pool *pool, |
| 77 | struct slab_parent_pool *parent); |
| 78 | void slab_destroy_child(struct slab_child_pool *pool); |
| 79 | void *slab_alloc(struct slab_child_pool *pool); |
| 80 | void slab_free(struct slab_child_pool *pool, void *ptr); |
| 81 | |
| 82 | struct slab_mempool { |
| 83 | struct slab_parent_pool parent; |
| 84 | struct slab_child_pool child; |
Marek Olšák | 761ff40 | 2016-08-27 19:52:31 +0200 | [diff] [blame] | 85 | }; |
| 86 | |
| 87 | void slab_create(struct slab_mempool *pool, |
| 88 | unsigned item_size, |
| 89 | unsigned num_items); |
| 90 | void slab_destroy(struct slab_mempool *pool); |
| 91 | void *slab_alloc_st(struct slab_mempool *pool); |
| 92 | void slab_free_st(struct slab_mempool *pool, void *ptr); |
Marek Olšák | 761ff40 | 2016-08-27 19:52:31 +0200 | [diff] [blame] | 93 | |
| 94 | #endif |