/* * Copyright 2010 Marek Olšák <maraeo@gmail.com> * Copyright 2016 Advanced Micro Devices, Inc. * * 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. */ /** * Slab allocator for equally sized memory allocations. * * Objects are allocated from "child" pools that are connected to a "parent" * pool. * * Calls to slab_alloc/slab_free for the same child pool must not occur from * multiple threads simultaneously. * * Allocations obtained from one child pool should usually be freed in the * same child pool. Freeing an allocation in a different child pool associated * to the same parent is allowed (and requires no locking by the caller), but * it is discouraged because it implies a performance penalty. * * For convenience and to ease the transition, there is also a set of wrapper * functions around a single parent-child pair. */ #ifndef SLAB_H #define SLAB_H #include "c11/threads.h" struct slab_element_header; struct slab_page_header; struct slab_parent_pool { mtx_t mutex; unsigned element_size; unsigned num_elements; }; struct slab_child_pool { struct slab_parent_pool *parent; struct slab_page_header *pages; /* Free elements. */ struct slab_element_header *free; /* Elements that are owned by this pool but were freed with a different * pool as the argument to slab_free. * * This list is protected by the parent mutex. */ struct slab_element_header *migrated; }; void slab_create_parent(struct slab_parent_pool *parent, unsigned item_size, unsigned num_items); void slab_destroy_parent(struct slab_parent_pool *parent); void slab_create_child(struct slab_child_pool *pool, struct slab_parent_pool *parent); void slab_destroy_child(struct slab_child_pool *pool); void *slab_alloc(struct slab_child_pool *pool); void slab_free(struct slab_child_pool *pool, void *ptr); struct slab_mempool { struct slab_parent_pool parent; struct slab_child_pool child; }; void slab_create(struct slab_mempool *pool, unsigned item_size, unsigned num_items); void slab_destroy(struct slab_mempool *pool); void *slab_alloc_st(struct slab_mempool *pool); void slab_free_st(struct slab_mempool *pool, void *ptr); #endif