/* * 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